Nenad Bursac, PhD

• Professor of Biomedical Engineering
• Associate Professor in Medicine
• Professor in Cell Biology
• Member of the Duke Cancer Institute
• Co-Director of the Regeneration Next Initiative

https://medicine.duke.edu/faculty/nenad-bursac-phd

Tahmaz L treatment bipolar disorder buy secnidazole 1 gr amex, Ozgok Y ombrello glass treatment purchase secnidazole 1 gr with amex, Zor M medicine rocks state park cheap secnidazole 1gr buy line, et al: Laparoscopy-assisted tubeless percutaneous nephrolithotomy in previously operated ectopic pelvic kidney with fragmented J­J stent symptoms whooping cough buy 500mg secnidazole fast delivery, Urol Res 37:257­260 treatment quad tendonitis buy secnidazole 1gr low cost, 2009. Tanriverdi O, Boylu U, Kendirci M, et al: the learning curve in the training of percutaneous nephrolithotomy, Eur Urol 52:206­211, 2007. Tefekli A, Altunrende F, Tepeler K, et al: Tubeless percutaneous nephrolithotomy in selected patients: a prospective randomized comparison, Int Urol Nephrol 39:57­63, 2007. Tepeler A, Armaan A, Akman T, et al: Impact of percutaneous renal access technique on outcomes of percutaneous nephrolithotomy, J Endourol 26:828­833, 2012. Traxer O: Management of injury to the bowel during percutaneous stone removal, J Endourol 23:1777­1780, 2009. Turillazzi E, Pomara C, Bisceglia R, et al: Vascular air embolism complicating percutaneous nephrolithotomy: medical malpractice or fatal unforeseeable complication Rivera M, Viers B, Cockerill P, et al: Pre- and postoperative predictors of infection-related complications in patients undergoing percutaneous nephrolithotomy, J Endourol 30:982­986, 2016. Rusnak B, Castañeda-Zúñiga W, Kotula F, et al: An improved dilator system for percutaneous nephrostomies, Radiology 144:174, 1982. Safak M, Gogus C, Soygur T: Nephrostomy tract dilation using a balloon dilator in percutaneous renal surgery: experience with 95 cases and comparison with the fascial dilator system, Urol Int 71:382­384, 2003. Seitz C, Desai M, Häcker A, et al: Incidence, prevention, and management of complications following percutaneous nephrolitholapaxy, Eur Urol 61:146­158, 2012. Seldinger S-I: Catheter replacement of the needle in percutaneous arteriography; a new technique, Acta Radiol 39:368­376, 1953. Seyrek M, Binbay M, Yuruk E, et al: Perioperative prophylaxis for percutaneous nephrolithotomy: randomized study concerning the drug and dosage, J Endourol 26:1431­1436, 2012. Sharifiaghdas F, Tabibi A, Nouralizadeh A, et al: Our experience with totally ultrasonography-guided percutaneous nephrolithotomy in children, J Endourol 2015. Shen P, Liu Y, Wang J: Nephrostomy tube-free versus nephrostomy tube for renal drainage after percutaneous nephrolithotomy: a systematic review and meta-analysis, Urol Int 88:298­306, 2012. Siev M, Motamedinia P, Leavitt D, et al: Does peak inspiratory pressure increase in the prone position Verrier C, Bessede T, Hajj P, et al: Decrease in and management of urolithiasis after kidney transplantation, J Urol 187:1651­1655, 2012. Wang J, Zhang C, Tan D, et al: the effect of local anesthetic infiltration around nephrostomy tract on postoperative pain control after percutaneous nephrolithotomy: a systematic review and meta-analysis, Urol Int 97:125­133, 2016. Wang J, Zhang C, Tan G, et al: the use of adjunctive hemostatic agents in tubeless percutaneous nephrolithotomy: a meta-analysis, Urolithiasis 42:509­517, 2014. Wezel F, Mamoulakis C, Rioja J, et al: Two contemporary series of percutaneous tract dilation for percutaneous nephrolithotomy, J Endourol 23:1655­1661, 2009. Wu W, Zhao Z, Zhu H, et al: Safety and efficacy of minimally invasive percutaneous nephrolithotomy in treatment of calculi in horseshoe kidneys, J Endourol 28:926­929, 2014. Xiao B, Hu W, Zhang X, et al: Ultrasound-guided mini-percutaneous nephrolithotomy in patients aged less than 3 years: the largest reported singlecenter experience in China, Urolithiasis 44:179­183, 2016. Yakoubi R, Lemdani M, Monga M, et al: Is there a role for alpha-blockers in ureteral stent related symptoms Zeng G, Zhao Z, Wan S, et al: Failure of initial renal arterial embolization for severe post-percutaneous nephrolithotomy hemorrhage: a multicenter study of risk factors, J Urol 190:2133­2138, 2013. Zhong Q, Zheng C, Mo J, et al: Total tubeless versus standard percutaneous nephrolithotomy: a meta-analysis, J Endourol 27:420­426, 2013. Zhou L, Cai X, Li H, et al: Effects of alpha-blockers, antimuscarinics, or combination therapy in relieving ureteral stent-related symptoms: a metaanalysis, J Endourol 29:650­656, 2015. Irrigation fluid should be normal saline routinely or a solution free from electrolytes such as glycine or mannitol when monopolar electrocautery is required. Using bipolar electrocautery permits the use of normal saline for transurethral surgical procedures, avoiding the potential complications of these other solutions. Sterile water should be avoided because of the small risk for absorption, electrolyte disturbance, and hemolysis. A high-intensity xenon or halogen external light source delivers white light through a fiber-optic cable and endoscope to the field of view. Modern light source units feature light-level detection and automatic light-output adjustment to provide constant illumination. First introduced into urologic practice in 2007, narrow-band imaging utilizes only blue (415 nm) and green (540 nm) wavelengths to image the urothelium (Bryan et al. These wavelengths are strongly absorbed by hemoglobin, enhancing the visibility of urothelial capillaries, small papillary lesions, and carcinoma in-situ. A meta-analysis of 8 studies including 1022 patients found that narrowband imaging improves detection accuracy of noninvasive lesions, including carcinoma in situ (Zheng et al. These findings were supported by a more recent randomized multicenter study, which found narrow-band imaging to be superior to white-light cystoscopy for detecting non­muscle-invasive bladder cancer (Ye et al. Video-endoscopic units have several advantages including better visualization, which enhances patient safety and surgical training; decreased risk for bodily fluid exposure; and improved surgeon ergonomics. Traditional video-endoscopic systems consist of a light source, endoscope camera, image processor/recorder, and monitor. In the traditional system, a series of glass rods or fiber-optic bundles transmits the endoscopic image to the eyepiece. The development of endoscopic tools and techniques has transformed many areas of medical and surgical care-perhaps none more than urology. Bladder outlet obstruction, urothelial tumors, ureteral obstruction, and nephrolithiasis are just a few of the urologic conditions revolutionized by endoscopic procedures. This article will highlight significant events in the history of modern endoscope development, then describe contemporary videoendoscopic equipment. We will then explain in detail the indications, patient preparation, and techniques of cystourethroscopy and ureteropyeloscopy. Little progress was made until 1806, when Philipp Bozzini developed the first "modern" endoscope (Engel, 2003). The Lichtleiter or "Light Conductor" used angled mirrors to conduct candlelight from a sharkskin-covered box into the body through aluminum tubing. In 1853, the French urologist Antonin Jean Desormeaux introduced a smaller profile endoscope with improved mirrors that utilized a kerosene lamp for illumination (Shah, 2002). He excised a urethral papilloma through this instrument, and he became the first individual to perform a therapeutic endoscopic procedure. In 1877, Max Nitze moved the source of illumination (water-cooled electric platinum filament) to the end of the instrument and utilized a series of optical lenses placed at precise distances along the length of a hollow, air-filled scope to conduct and magnify the image (Herr, 2006). Few design improvements occurred-save development of the Amici prism in 1906, which allowed 90-degree offset images to maintain correct orientation-until 1966, when Harold Hopkins developed his rod-lens system (Gow, 1998). By abandoning hollowchamber optical relay lenses for a series of glass rods with only short gaps of air between them, Hopkins was able to improve light transmission and decrease scope size. In 1854, John Tyndall demonstrated that light could travel through a curved stream of water by internal reflection (Whewell et al. This finding led to drawing molten glass into flexible, small-diameter fibers for light transmission. The development of fiber optics made possible the creation of flexible endoscopes. In 1964, Marshall reported the first application of flexible ureteroscopy (Marshall, 1964). However, the utility of flexible ureteroscopes was severely limited until the addition of a working channel and active tip deflection in the early 1980s (Bagley et al. Although still widely used, fiber-optic endoscopes are fragile and have limited optical resolution. Compared with rod-lens and fiber-optic bundle systems, digital sensor technology offers improved image resolution and durability without the need for a separate light cable and camera (Quayle et al. Routinely performed in both the office and operating room, cystourethroscopy provides direct visualization of the urethra and bladder. Most are for diagnostic purposes, but transurethral therapeutic procedures may also be performed. A frequent reason for cystourethroscopy is the evaluation of microscopic or gross hematuria. Videoendoscopic unit consisting of a fixed tower, monitor, light source, image processor, video-recording device, and printer. Urothelial carcinoma surveillance is another routine indication for cystourethroscopy. Upper tract surveillance may be accomplished by selective ureteral catheterization with retrograde pyelography, upper-tract washes for cytology, and brush biopsies for histologic evaluation. Cystoscopy may be used in the assessment of lower urinary tract complaints such as recurrent infections, voiding dysfunction, and chronic pelvic pain. In select cases, urethral strictures, bladder stones, and foreign bodies may be treated in the office. Ureteral stents can also be placed or exchanged in clinic with fluoroscopic assistance. Equipment Cystourethroscopes are available in a variety of sizes and come in both rigid and flexible models. Devised by French instrument designer Joseph-FrédéricBenoît Charrière (1803 to 1876), a 1-Fr device has a circumference of 1 3 of a millimeter (Osborn and Baron, 2006). Rigid cystoscopes utilize the Hopkins rod-lens optical system, which provides improved optical clarity compared with the fiber-optic bundles used in flexible endoscopes (Lyon et al. Rigid cystourethroscopes have larger working channels than flexible scopes, resulting in increased irrigation flow and the ability to use a greater variety of working instruments. In contrast, the smaller size of flexible cystourethroscopes improves patient comfort, making them ideal for office-based procedures. Endoscope passage does not require the patient to be in the frog-leg or lithotomy position. Their active tip deflection makes it easier to thoroughly inspect the bladder and negotiate an elevated bladder neck or median lobe of the prostate. A 70- or 120-degree lens may be required to thoroughly inspect the anterior and inferolateral walls, dome, and neck of the bladder. Smaller sheaths (15 and 17 Fr) are ideal for diagnostic cystoscopy, with larger models being used for therapeutic procedures requiring improved irrigant flow and larger working channels. Each sheath has an associated obturator that blunts the distal end of the sheath for passage into the bladder without visual assistance. Flexible Cystourethroscopes Flexible cystourethroscopes range between 16 and 17 Fr. Models differ with regard to tip deflection, direction of view, field of view, working channel size, illumination, and optics (Table 13. Most models have an "inline" eyepiece lens and produce a field of view of approximately 120 degrees. Tip deflection ranges between 120 and 210 degrees and is either intuitive (same direction as lever deflection) or counterintuitive (opposite direction of lever deflection). They are now available in high-definition (1920 × 1080 pixels) and standard-definition (720 × 480 pixels) models. Compared with the fiber-optic and standard-definition models, the high-definition scope had a significantly higher resolution and depth of field. Color representation was only slightly better, and there was no difference in contrast evaluation among the three models. Illumination was significantly better in the fiber-optic model compared with both digital cystoscopes. A randomized study of 1022 flexible cystoscopy cases compared optics, performance, and durability of fiber-optic and standarddefinition digital scopes (Okhunov et al. There was a trend toward improved mean surgeon optical ranking in favor of the digital scopes (p = 0. Data from an independent endoscope repair company found that flexible cystoscopes require less than one repair every 2 years (Canales et al. Unlike flexible ureteroscopes, flexible cystourethroscopes are robust, likely making the optical mechanism a lesser determinant of scope durability. Patient Preparation Informed consent must be obtained before performing any cystoscopic procedure. A urinalysis and urine culture, if indicated, should be completed before cystoscopy. All urinary tract infections must be treated given the risk for bacteremia and sepsis after lower urinary tract manipulation. Rigid cystourethroscope set consisting of sheath, obturator, bridges, and lenses (from top to bottom). Neither organization recommends antimicrobial prophylaxis for routine diagnostic cystoscopy in the absence of patient-related risk factors (Table 13. This recommendation is largely based on a meta-analysis of 32 randomized controlled trials evaluating antimicrobial prophylaxis before transurethral resection of the prostate, which showed a decrease in bacteriuria, bacteremia, symptomatic urinary tract infection, and high-grade fever (Berry and Barratt, 2002). The numbers on the side of the sheath indicate the maximum working channel size when a dual bridge is used (4 Fr for both lumens) or when a single bridge is employed (5 Fr). Alternative agents include an aminoglycoside with or without ampicillin, a first- or second-generation cephalosporin, or amoxicillin/clavulanate. However, the Best Practice Policy has not been updated since 2012, and there are increasing concerns about the rising incidence of fluoroquinolone resistance (Marino Sabo and Stern, 2014). Most commercially available agents contain iodophors or chlorhexidine gluconate in either an aqueous or alcohol-based solution. Both chlorhexidine gluconate and alcohol-based solutions can damage mucous membranes and therefore are not recommended on the genitalia. Aqueous-based iodophor-containing products such as Betadine are safe on all skin surfaces regardless of patient age. After application of an antiseptic agent, lubricating gel is instilled into the urethra of patients undergoing flexible cystourethroscopy. A meta-analysis of four randomized trials involving 411 patients found that patients receiving lidocaine gel were 1. However, only one of the four trials showed a statistical benefit to lidocaine gel, which is consistent with a larger metaanalysis involving 817 patients from 9 randomized trials that showed no difference in procedure tolerance (Patel et al. Other techniques have been employed to improve patient comfort during flexible cystourethroscopy.

Direct examination of the urethra medicines360 buy line secnidazole, bladder treatment zona order secnidazole 1 gr overnight delivery, and prostatic urethra in male patients can be performed for diagnostic and screening purposes symptoms tracker generic secnidazole 1gr with visa, and in some cases treatments can be administered treatment lymphoma 500 mg secnidazole order free shipping. The most common reasons office cystourethroscopy is performed is for diagnosis of lower urinary tract malignancy treatment abbreviation buy secnidazole without a prescription, urinary obstruction, or in some cases to assist with insertion of a urethral catheter. For patients with a urinary diversion such as an ileal conduit, office looposcopy can be performed to assess for pathology within the ilial conduit. This is performed with a flexible cystoscope and is generally well tolerated with only a mild amount of patient discomfort if there is significant pressure and reflux into the upper tracts. These are useful tests to obtain some basic information of the voiding status of the patient. Uroflowmetry is performed in the office with the patient voiding either in a standing or seated position. In general, a peak or maximum flow rate (Qmax), mean flow rate, voided volume is obtained along with a voiding curve/pattern. Radiologic Imaging During the evaluation of the urologic patient, information obtained with the history and findings on physical examination may prompt the need for radiologic testing. Although the details on the principles of imaging studies are covered in depth in later chapters, basic imaging that may be ordered for specific findings are briefly reviewed in the following section. The principles on these more complex imaging studies will be covered later in this text, but the basic indications for ordering them in patients are when conditions of the upper tracts and bladder are suspected. Ultimately, patient symptoms may be used to decide if more complex imaging is warranted. Ultrasonography Most urologists should be familiar with the indications for ordering ultrasonography of the kidneys, bladder, and prostate. In fact, more and more urologists are performing basic renal ultrasonography in the office setting. Renal ultrasonography is ordered to obtain information on the size and shape of the kidneys, the presence or absence of hydronephrosis, anatomic abnormalities such as cysts and masses, echogenicity, and vasculature. Patients with a history of stones or symptoms of flank pain may benefit from renal ultrasonography to assess for possible obstruction. Renal ultrasonography is not sufficient as a stand-alone imaging study for the workup of hematuria, and other cross-sectional abdominal imaging should be considered for this diagnosis. Urologists rarely order ultrasonography of the bladder as a diagnostic study, but the bladder is often assessed during abdominal and renal ultrasonography. Large masses, large stones, and volume can be assessed by basic ultrasonography of the bladder, but limited information is provided by formal ultrasonography of the bladder. It should be noted that ultrasonography of the ureters is very difficult and should not be used as a method to diagnose conditions of the ureter such as stones or malignancy, although routine ultrasonography may be used to detect severe hydroureter. Ultrasonography of the prostate is ordered and obtained most often in conjunction with prostate biopsy. More detailed analysis on the technology and indications for its use in the diagnosis of prostate cancer will be covered later in this text. Information on the seminal vesicles and ejaculatory duct patency may be acquired for the assessment of ejaculatory and fertility disorders. The presence of full seminal vesicles along with a dilated ejaculatory duct may help the urologist to decide of additional testing or treatment is indicated. There are numerous diagnostic modalities within the urologic armamentarium, and a fundamental understanding of when to order these tests is critical when evaluating the urologic patient. The history and physical examination along with a properly collected urinalysis will help develop a differential diagnosis and direct which additional laboratory testing, office procedures, and imaging should be ordered. Csako G: False-positive results for ketone with the drug mesna and other free-sulfhydryl compounds, Clin Chem 33(2 Pt 1):289­292, 1987. Gulleroglu K, Gulleroglu B, Baskin E: Nutcracker syndrome, World J Nephrol 3(4):277­281, 2014. Kincaid-Smith P: Haematuria and exercise-related haematuria, Br Med J 285(4):1595­1597, 1982. Steiner H, Bergmeister M, Verdorfer I, et al: Early results of bladder-cancer screening in a high-risk population of heavy smokers, Brit J Urol 102(3): 291­296, 2008. For diagnostic x-rays the conversion factor is 1, so the absorbed dose is the same as the equivalent dose. When the amount of radiation energy absorbed by patients during therapeutic radiation is discussed, the dose is given in gray. When exposure to patients or medical personnel resulting from diagnostic ionizing radiation procedures is discussed, the dose is given in sieverts. The distribution of energy absorption in the human body is different based on the body part being imaged and a variety of other factors. The most important risk of radiation exposure from diagnostic imaging is the development of cancer. The effective dose is a quantity used to denote the radiation risk (expressed in sieverts) to a population of patients from an imaging study. Exposure to the eyes and gonads has a more significant biologic impact than exposure to the extremities, so recommended exposure limits vary according to the body part. An effective radiation dose of as little as 10 mSv may result in the development of a malignancy in 1 of 1000 individuals exposed (National Research Council of the National Academies, 2006). Because many urologic conditions cannot be assessed by physical examination, conventional radiography has long been critical to the diagnosis of conditions of the adrenals, kidneys, ureters, and bladder. With so many different imaging options available, it is important for the urologist to be familiar with different options and their correct implementation. In this article we discuss the indications for imaging in urology, with an emphasis on the underlying physical principles of the imaging modalities. The strengths and limitations of each modality and the techniques necessary to maximize image quality and minimize the risks and harms to urologic patients are discussed. Conventional radiography includes abdominal plain radiography, intravenous excretory urography, retrograde pyelography, loopography, retrograde urethrography, and cystography. Urologists frequently perform and interpret conventional radiography examinations, including fluoroscopic examinations, in the office and operating room environments. Relative Radiation Levels the assessment of biologic risk from radiation exposure is complex. Another often-overlooked source of significant radiation exposure is seen in the use of fluoroscopy. Fluoroscopy for 1 minute results in a radiation dose to the skin equivalent to 10 times that of a single radiograph of the same anatomic area (Geise and Morin, 2000). Physics Urologists should be familiar with the physics of conventional radiography and fluoroscopy, as well as the implications and dangers of radiation exposure to the patient and the operator. The underlying physical principles of conventional radiography involve emitting a stream of photons from an x-ray source. These photons travel through the air and strike tissue, imparting energy to that tissue. Certain patient populations such as those with recurrent renal calculus disease or those with a urologic malignancy may be at increased risk of developing cancer because of repeated exposures to ionizing radiation. Attempts should be made to limit axial imaging studies to the anatomic area of interest and to substitute imaging studies not requiring ionizing radiation when feasible. The cumulative dose of radiation to medical personnel (including physicians) may increase relatively rapidly in circumstances in which fluoroscopy is used. Reduction in radiation exposure to medical personnel is achieved by three major mechanisms: (1) limiting the time of exposure; (2) maximizing distance from the radiation source; and (3) shielding. The resultant charge per unit mass of air is referred to as the radiation exposure. Absorbed dose is the energy absorbed from the radiation exposure and is measured in units called gray (Gy). Because different types of radiation have different types of interaction with tissue, a conversion factor is applied to better express the amount of energy absorbed by a given tissue. Maintaining the maximum practical distance from an active radiation source significantly decreases exposure to medical personnel. Positioning the image intensifier as close to the patient as feasible substantially reduces scatter radiation. Standard aprons, thyroid shields, radiation-resistant eye protection, and leaded gloves provide significant shielding for medical personnel and should be worn by all personnel involved in the use of fluoroscopy. A practice of routinely collimating to the minimum required visual fluoroscopy field results in significant reductions in radiation exposure when compared with a usual approach to collimation. This may have important implications for decreasing the risk of malignancy in patients and operators. Many different types of contrast media have been used to enhance medical imaging and thus improve diagnostic and therapeutic decisions made by urologists. However, like all other pharmaceuticals, there are inherent risks associated with the use of contrast media. The x-ray source located beneath the table reduces the radiation exposure to the urologist. Locating the image intensifier as close to the patient as feasible reduces scatter radiation. Radiation dose during fluoroscopy is directly proportional to the time of exposure and to the number of exposures. The exposure time during fluoroscopy should be minimized by using short bursts of fluoroscopy and using the "last image hold" feature of the fluoroscopy unit. Cardiac arrest may occur from allergic-like as well as physiologic adverse reactions Allergic-Like Diffuse edema/facial edema/ shortness of breath Diffuse erythema and hypotension Laryngeal edema with hypoxia Wheezing/bronchospasm with hypoxia Anaphylactic shock/ hypotension/tachycardia Physiologic Vasovagal reaction resists treatment Arrhythmia Seizures Hypertensive emergency Physiologic Protracted nausea/emesis Hypertension Chest pain Vasovagal responds to treatment Physiologic Limited nausea/emesis Transient flushing/warm/ chills Headache/dizziness/ anxiety/altered taste Mild hypertension Vasovagal but resolves spontaneously imaging study as well as alternative imaging modalities that could provide the same information without the need for radiation or contrast exposure. Given that an antigenantibody response is rarely identified, allergic-like contrast medium reactions are classified as "anaphylactoid," "allergic-like," or "idiosyncratic" (Brockow, 2005; Bush and Swanson, 1991; Cohan and Dunnick, 1987; Dunnick and Cohan, 1994). Their reactions are often dose and concentration dependent (Bush and Swanson, 1991; Cohan and Dunnick, 1987; Dunnick and Cohan, 1994; Lieberman and Seigle, 1999). These reactions can be related to anxiety and have been known to occur when obtaining consent for the imaging procedure, during venous cannulation, or during administration of contrast medium. Treatment of Contrast Reactions Severe contrast reactions are rare but may require immediate treatment. In the case of severe reactions the patient will need emergency care and attention to respiratory and cardiovascular systems. To reduce the chance of significant morbidity and mortality, a plan and protocol must be in place with trained staff who are trained to recognize, assess, and treat contrast reactions. If necessary, administer chlorpheniramine 4 to 10 mg orally, intravenously, or intramuscularly and diazepam 5 mg for anxiety. For bronchospasm, oxygen 6 to 10 L/min should be administered and a -agonist inhaler used at 2 puffs (90 mcg/puff) for a total of 180 mcg; this can be repeated up to three times. For bronchospasm, oxygen 6 to 10 L/ min should be administered and a -agonist inhaler used at 2 puffs (90 mcg/puff) for a total of 180 mcg; this can be repeated up to three times. Epinephrine can be added to moderate or severe bronchospasm (see the following for epinephrine dosing). The patient usually requires emergency care, involving particular attention to the respiratory and cardiovascular systems. If bronchospasm is severe and not responsive to inhalers, or if an upper airway edema (including laryngospasm) is present, epinephrine should be used promptly. Rapid administration of epinephrine is the treatment of choice for severe contrast reactions. Epinephrine must be administered with care to patients who have cardiac disease or those who are taking beta-blockers because the unopposed alpha effects of epinephrine in these patients may cause severe hypertension or angina. Careful monitoring of patient vital signs is paramount; the presence of both hypotension and tachycardia indicates a higher likelihood of anaphylactic reaction. Bradycardia is a sign of vasovagal reaction and therefore the use of beta-blockers is to be avoided. Hypotension resulting from an anaphylactic reaction can be treated with intravenous iso-osmolar fluids. Prednisone: 50 mg by mouth at 13 hours, 7 hours, and 1 hour before contrast media injection Plus diphenhydramine (Benadryl) 50 mg intravenously, intramuscularly, or by mouth 1 hour before contrast medium injection 2. Methylprednisolone (Medrol): 32 mg by mouth 12 hours and 2 hours before contrast media injection Plus diphenhydramine (Benadryl): 50 mg intravenously, intramuscularly, or by mouth 1 hour before contrast medium injection From American College of Radiology Manual on Contrast Media, version 9, 2013. Premedication There is no known premedication strategy that will eliminate the risk of a severe adverse reaction to contrast media. The regimens suggested in the literature include the use of corticosteroids, antihistamines, H1 and H2 antagonists, and ephedrine. Several premedication regimens have been proposed to reduce the frequency and/or severity of reactions to contrast media. It has been demonstrated that the use of nonionic contrast media combined with a premedication strategy including corticosteroids results in a reduction in reaction rates compared to other protocols for patients who have experienced a prior contrast media­induced reaction. A randomized trial of premedication for average-risk patients before high-osmolality iodinated contrast medium showed a reduction in mild, intermediate, and severe reactions (Lasser et al. Because severe reactions are rare events, it is difficult to design a study that would be adequately powered to measure a difference. It is estimated that the number of patients needed to premedicate to prevent one reaction in high-risk patients was 69 for avoidance of any reaction, and 569 patients to prevent a severe reaction (Mervak et al. It is estimated that the number needed to treat to prevent a lethal reaction in high-risk patients would be approximately 50,000 patients (Davenport et al. There are no published studies addressing the use of premedication strategies before oral contrast or gadolinium-based intravenous contrast medium in high-risk patients. The current premedication recommendations in these patients are extrapolated from patients receiving intravascular iodinated contrast media. The risks to patients for premedication with corticosteroids are small and include leukocytosis, asymptomatic hyperglycemia, and possible infection risk (Davenport et al. Oral administration of steroids seems preferable to intravascular administration, with prednisone and methylprednisolone being equally effective. If the patient is unable to take oral medication, 200 mg of hydrocortisone intravenously may be substituted for oral prednisone. One consistent finding is that steroids should be given at least 6 hours before the injection of contrast media regardless of the route of steroid administration.

Generic secnidazole 500 mg amex. Black Mold Symptoms & 16 Natural Remedies.

Lezrek M administering medications 7th edition ebook 1 gr secnidazole order with visa, Bazine K medications via g tube order secnidazole online from canada, Ammani A symptoms upper respiratory infection order cheapest secnidazole and secnidazole, et al: Needle renal displacement technique for the percutaneous approach to the superior calix silicium hair treatment purchase secnidazole 1gr with amex, J Endourol 25:1723­1726 medications during labor purchase secnidazole without prescription, 2011. Li H, Chen Y, Liu C, et al: Construction of a three-dimensional model of renal stones: comprehensive planning for percutaneous nephrolithotomy and assistance in surgery, World J Urol 31:1587­1592, 2013a. Li K, Liu C, Zhang X, et al: Risk factors for septic shock after mini-percutaneous nephrolithotripsy with holmium laser, Urology 81:1173­1176, 2013b. Mouracade P, Spie R, Lang H, et al: Tubeless percutaneous nephrolithotomy: what about replacing the double-J stent with a ureteral catheter Okeke Z, Andonian S, Srinivasan A, et al: Cryotherapy of the nephrostomy tract: a novel technique to decrease the risk of hemorrhage after tubeless percutaneous renal surgery, J Endourol 23:417­420, 2009. Ozkan D, Akkaya T, Karakoyunlu N, et al: Effect of ultrasound-guided intercostal nerve block on postoperative pain after percutaneous nephrolithotomy, Anaesthesist 1-6:2013. Pauer W, Lugmayr H: Metallic wallstents: a new therapy for extrinsic ureteral obstruction, J Urol 148:281­284, 1992. Purkait B, Goel A: Factors affecting outcomes of percutaneous nephrolithotomy in horseshoe kidneys, Urology 85:1523­1524, 2015. Radecka E, Brehmer M, Holmgren K, et al: Complications associated with percutaneous nephrolithotripsy: supra- versus subcostal access. Ray K, Rattan S, Yohannes T: Urinothorax: unexpected cause of a pleural effusion, Mayo Clin Proc 78:1433­1434, 2003. Rehman J, Chughtai B, Schulsinger D, et al: A percutaneous subcostal approach for intercostal stones, J Endourol 22:497­502, 2008. Reinberg Y, Ferral H, Gonzalez R, et al: Intraureteral metallic self-expanding endoprosthesis (Wallstent) in the treatment of difficult ureteral strictures, J Urol 151:1619­1622, 1994. Ricciardi S, Sallustio P, Troisi R: Life-threatening biliary complications after percutaneous nephro-lithotomy: a case report, Acta Chir Belg 107:336­337, 2007. Spann A, Poteet J, Hyatt D, et al: Safe and effective obtainment of access for percutaneous nephrolithotomy by urologists: the Louisiana State University experience, J Endourol 25:1421­1425, 2011. Srivastava A, Gupta P, Chaturvedi S, et al: Percutaneous nephrolithotomy in ectopically located kidneys and in patients with musculoskeletal deformities, Urol Int 85:37­41, 2010. Tabibi A, Akhavizadegan H, Nouri-Mahdavi K, et al: Percutaneous nephrolithotomy with and without retrograde pyelography: a randomized clinical trial, Int Braz J Urol 33:19­24, 2007. For most men, the least comfortable portion of the procedure is during scope passage through the membranous urethra (Taghizadeh et al. In an attempt to improve tolerance, a randomized trial was performed to evaluate the effectiveness of increased hydrostatic pressure of the irrigation solution (Gunendran et al. Manual compression of the irrigation bag during passage of the scope through the membranous urethra was compared with gravity irrigation alone in 151 men undergoing flexible cystourethroscopy. One hundred male patients undergoing flexible cystourethroscopy were randomized; one-half of the subjects were allowed to watch the procedure on a video monitor, and the remaining patients were not (Patel et al. Men who viewed the procedure had significantly less pain on a 100-mm visual analog pain scale (14 vs. These findings were confirmed by another randomized study of 76 male patients (Soomro et al. In contrast, a randomized study on 100 women undergoing office-based cystoscopy with a 17-Fr rigid scope found no difference in procedural pain (Patel et al. Seventy men undergoing flexible cystoscopy were randomized to either no music or classical music played during the procedure (Yeo et al. Patients listening to classical music had significantly less pain, higher satisfaction, lower postprocedure pulse rates, and lower systolic blood pressures. Technique Before inserting the cystourethroscope, the external genitalia is inspected for cutaneous lesions and anatomic abnormalities. Dilation should be performed to at least 2 Fr wider than the intended endoscope size. The scope will often need to be directed anteriorly as it is advanced into the bladder. Flexible cystourethroscopes can often be inserted into the bladder like a Foley catheter with active deflection being used as needed. In morbidly obese patients, it is often easier to lay the scope down, retract the pannus with the nondominant hand, and direct the tip of the flexible scope into the urethra like a Foley catheter. Once in the mid-penile urethra, the scope is placed in the dominant hand and advanced as usual. The penis should be angled 45 to 90 degrees relative to the abdominal wall while passing the scope through the anterior urethra. Once beyond the membranous urethra, the cystoscope is directed anteriorly to enter the bladder. With flexible cystoscopes, this is accomplished by active upward deflection, and with rigid cystoscopes by dropping the distal end of the scope toward the operative table. The lower urinary tract is systematically evaluated under maximal irrigation as the scope is advanced. The periurethral glands of Littre should be noted as they drain into the urethra dorsally. Patients, in particular young men, should be encouraged to relax as much as possible as the scope is advanced through the membranous urethra. Once in the prostatic urethra, the verumontanum and utricle are identified posteriorly. The length of the posterior urethra is measured, and the size of the prostatic lobes are evaluated. The remainder of the bladder is inspected for stones, trabeculation, cellules, diverticula, erythematous patches, and papillary and sessile lesions. Visualization of the lateral walls is accomplished by rotating the cystoscope while keeping the camera orientation fixed. The dome, anterior and posterolateral walls are inspected with a 70- or 120-degree lens. After completing the procedure, the bladder is emptied, and the endoscope is withdrawn. If a Foley catheter is to be placed after the cystoscopy, it is best to leave the bladder at least partially full before removing the cystoscope. Special Circumstances Suprapubic Cystostomy the indications for cystoscopy in patients with suprapubic cystostomy tubes are the same as those without chronic indwelling catheters. However, these individuals are at increased risk for infection, bladder calculi, and bladder cancer (El Masri et al. There is no level-one data showing that use of surveillance cystoscopy improves survival in patients with long-term indwelling catheters. As a result, controversy exists regarding the utility of surveillance cystoscopy in patients with neurogenic bladder and long-term indwelling catheters (Vince and Klausner, 2017). However, many patients with long-term suprapubic tubes suffer from urethral stricture disease, making the suprapubic tract the only feasible route to the bladder. Every effort should be made to avoid endoscopy through a suprapubic tract until it has had time to mature, which usually takes several weeks from the time of creation. There will be occasions when endoscopy through an immature suprapubic tract is required. When needed, it is helpful to place a wire through the suprapubic tube before removal. This safety wire helps maintain access to the bladder and can serve to guide placement of the endoscope. This technique is also helpful in morbidly obese patients with long, often tortuous tracts. Ureteral access is often challenging during rigid cystoscopy through the cystostomy tract because of the acute angle required to cannulate the ureteral orifice. Alternatively, patients with low-grade urethral strictures may be able to accommodate transurethral passage of a semirigid ureteroscope facilitating standard ureteral access. Lastly, the ureteral orifices may be difficult to identify because of edema caused by the chronic suprapubic tube. Administering intravenous indigo carmine or methylene blue early in the procedure may help visualize the ureteral orifices. However, patients with comorbidities making percutaneous treatment prohibitively dangerous have been successfully managed with ureteroscopy. Two studies have reported stone-free rates of 91% and 93% for ureteroscopic treatment of patients with stones larger than 2 cm (Grasso et al. Continent Urinary Diversions There are two general classes of continent urinary diversions after cystectomy. Orthotopic urinary diversions are anastomosed to the urethra and rely on the striated urinary sphincter to maintain continence. Continent cutaneous reservoirs utilize a catheterizable channel spanning from the diversion to the anterior abdominal wall. The catheterizable channel may be composed of the appendix (Mitrofanoff), tapered/imbricated terminal ileum and ileocecal valve, or an intussuscepted nipple valve. Before undertaking any endoscopic procedure involving a continent urinary diversion, it is imperative to obtain the operative note. Transurethral access to orthotopic diversions is often straightforward and can be accomplished using a rigid cystoscope. If a urethral anastomotic contracture is noted and the patient is not suffering from outlet obstruction, then it is advisable to use the smallest scope possible rather than dilate or incise the stricture to prevent worsening urinary incontinence. Diagnostic endoscopy of continent cutaneous reservoirs is best accomplished using a flexible cystoscope through the catheterizable channel. Preoperative computed tomography or intraoperative ultrasound should be used to minimize the risk for bowel injury during percutaneous access. Once within the diversion, visualization is often challenging because of mucus, mucosal folds, bowel peristalsis, and, if present, tortuous afferent limb. Too little irrigation will make mucosal folds more prominent and impair visualization, but overdistention will prevent access to the afferent limb and will often result in troublesome retroflexion of flexible cystoscopes. Once again, ancillary techniques such as using angled catheters and indigo carmine or methylene blue may be required. Despite yielding only a small amount of material for evaluation, ureteroscopic biopsy has been shown to accurately predict final pathologic grade in approximately 90% of patients (Rojas et al. Diagnostic ureteroscopy has not been shown to negatively impact long-term or disease-specific survival in patients undergoing extirpative therapy (Ishikawa et al. However, a recent study reported an increased risk for intravesical recurrence, highlighting the need for long-term bladder surveillance (Yoo et al. In the past, urologists reserved endoscopic treatment of upper tract urothelial tumors for compelling indications such as solitary kidney, renal insufficiency, bilateral upper tract urothelial cell carcinoma, or significant medical comorbidities. However, with improvements in instrumentation and technique, endoscopic treatment of low-grade disease has been reported to be a reasonable option without compromising survival (Cutress et al. Larger tumors can be challenging to fully ablate in one session, prompting reports of percutaneous nephroscopy with electroresection (Cutress et al. Nevertheless, when feasible, ureteroscopy is preferable because it avoids the small, but reported risk for seeding the percutaneous tract and retroperitoneum with tumor (Sengupta and Harewood, 1998; Sharma et al. There are two situations in which ureteroscopic endopyelotomy may not be the preferred approach. Patients with concomitant renal calculi should be treated percutaneously to allow simultaneous stone removal and endopyelotomy. It may be best to limit ureteroscopic endopyelotomy to those patients with a documented absence of crossing vessels and to treat those with crossing vessels using laparoscopic ureteropyeloplasty. Patients with ureteral strictures can also be managed from a ureteroscopic approach. Endoureterotomy is less successful in patients with ureteral strictures longer than 1. Ureteroscopic incision of short ureteral strictures in otherwise healthy ureters is a reasonably successful treatment option (Emiliani and Breda, 2015). Semirigid ureteroscope with an offset eyepiece, which has a straight working channel permitting passage of rigid instruments. Other Indications for Ureteroscopy Diagnostic ureteroscopy can be performed for persistent, unexplained positive cytology, filling defects noted on excretory urography, and recurrent urinary tract infections localized to a single renal unit. With the miniaturization of flexible ureteroscopes, the safety of flexible ureteroscopy has increased significantly. Rather than relying on ureteropyelography alone, we can now safely and easily perform diagnostic ureteroscopy. Ureteroscopy has also been used for removal of foreign bodies including suture, proximally migrated ureteral stents, balloon catheters, and other fractured working instruments. Benign essential hematuria can be diagnosed and treated with flexible ureteroscopy. This condition is defined as unilateral gross hematuria for which there is no radiographically defined cause (Bagley et al. These patients frequently have had studies including excretory urography, renal sonography, arteriography, or a combination of these. Flexible ureteroscopic inspection of the involved kidney usually results in diagnosis and successful treatment. The most common finding in patients with benign essential hematuria is a small hemangioma, which can often be fulgurated. Other endoscopic findings in patients with benign essential hematuria include small venous ruptures, papillary tumors, varices, and calculi (Dooley and Pietrow, 2004). Although larger rod lens rigid ureteroscopes are still available in some operating rooms, the smaller-diameter fiber-optic ureteroscopes are less traumatic, require ureteral dilation less often, and are equally capable. Semirigid ureteroscopes are smaller in diameter because of the incorporation of fiber optics into their construction. Each fiber is coated with a cladding; an additional layer of glass with a different refractive index.

Depending on the indication for the study medicine neurontin secnidazole 500 mg order with mastercard, it is useful to dilute the contrast material (to 50% or less) with sterile fluid medicine 54 543 secnidazole 500 mg order. This prevents subtle filling defects in the collecting system or ureter from being obscured treatments yeast infections pregnant secnidazole 500mg buy otc. Care should be taken to evacuate air bubbles from the syringe and catheter before injection symptoms whooping cough generic 1gr secnidazole with amex. After air is expelled from the catheter into the bladder medications causing pancreatitis buy secnidazole with amex, the ureteral orifice is intubated. More or less contrast may be required depending on the size of the patient and the capaciousness of the collecting system. Limited use of fluoroscopy while injecting helps prevent overdistension of the collecting system and reduces the risk of extravasation of contrast. Historically, when a retrograde pyelogram consisted of a series of radiographs taken at intervals, it was important to document various stages of filling and emptying of the ureter and collecting systems. Because of peristalsis the entire ureter will often not be seen on any given static exposure or view. With current equipment, including tables that incorporate fluoroscopy, it is possible to evaluate the ureter during peristalsis in real time, thus reducing the need for static image documentation. Elucidation of filling defects and deformities of the ureters or intrarenal collecting systems 4. Opacification or distention of collecting system to facilitate percutaneous access 5. In the evaluation of traumatic or iatrogenic injury to the ureter or collecting system Limitations Retrograde pyelography may be difficult in cases in which the bladder is involved with diffuse inflammation or neoplastic changes, especially when bleeding is present. Identification of the ureteral orifices may be facilitated by the intravenous injection of indigotindisulfonate sodium or methylene blue in such cases. Changes associated with bladder outlet obstruction may result in angulation of the intramural ureters. Attempts to cannulate the ureteral orifice may result in trauma to the ureteral orifice and extravasation of contrast material into the bladder wall. The potential for damage to the intramural ureter must be weighed against the potential information to be obtained by the retrograde pyelogram. A filling defect in the left distal ureter (arrow) is a low-grade transitional cell carcinoma. The ureter demonstrates dilation, elongation, and tortuosity, the hallmarks of chronic obstruction. Complications Backflow occurs during retrograde pyelography when contrast is injected under pressure and escapes the collecting system. Pyelovenous backflow is seen when contrast enters the venous system, resulting in visualization of the renal vein. Although backflow does not usually cause measurable clinical harm, the potential implications of backflow include (1) introduction of bacteria from infected urine into the vascular system and (2) the absorption of contrast media, which could result in adverse reactions in susceptible patients. It has been demonstrated that the risk of significant urinary tract infection is only about 10% and the risk of sepsis is low when antibiotic prophylaxis therapy is administered before endoscopic procedures (including retrograde pyelography) (Christiano et al. Although contrast reactions are rare with retrograde pyelography, they have been reported (Johenning, 1980; Weese et al. In patients with documented severe contrast allergy, prophylactic pretreatment may be appropriate. In those patients considered at risk, care should be taken to inject under low pressures to minimize the probability of backflow and absorption of the contrast into the vasculature system. The balloon on such a catheter can then be inflated to 5 to 10 cc with sterile water. By gently introducing contrast through the catheter, the loop can be distended, usually producing bilateral reflux into the upper tracts. Evaluation of infection, hematuria, renal insufficiency, or pain after urinary diversion 2. Retrograde urethrography may be particularly beneficial in demonstrating the total length of a urethral stricture, which cannot be negotiated by cystoscopy. Retrograde urethrography also demonstrates the anatomy of the urethra distal to a stricture, which may not be assessable by voiding cystourethrography. Retrograde urethrography may be performed in the office or in the operating room before performing visual internal urethrotomy or formal urethroplasty. Historically the term "loopogram" has been associated with ileal conduit diversion but may be used in reference to any bowel segment serving as a urinary conduit. When imaging patients with a continent diversion involving a reservoir or neobladder, "pouch-o-gram" would be more accurately descriptive. Because an ileal conduit urinary diversion usually has freely refluxing ureterointestinal anastomoses, the ureters and upper collecting systems may be visualized. In other forms of diversion, the ureterointestinal anastomoses may be purposely nonrefluxing. When the patient has compromised renal function or is allergic to iodinated contrast material, loopogram can be performed with a low risk of systemic absorption (Hudson et al. The patient usually is positioned slightly obliquely to allow evaluation of the full length of urethra. A small catheter may be inserted into the fossa navicularis with the balloon inflated to 2 cc with sterile water. Evaluation of traumatic gross hematuria Technique the patient is positioned supine. Loopogram in a patient with epispadius/exstrophy and ileal conduit urinary diversion. After contrast administration via a catheter placed in the ileal conduit, free reflux of both ureterointestinal anastomoses is demonstrated (B). Normal retrograde urethrogram demonstrating (A) the balloon technique for retrograde urethrography, (B) Brodney clamp (arrowhead) technique; note the bulbar urethral stricture (arrow), and (C) normal structures of the male urethra. The shape and contour of the bladder may give information about neurogenic dysfunction or bladder outlet obstruction. A plain radiograph is performed to evaluate for stones and residual contrast and to confirm position and technique. The bladder is filled under gravity with 200 to 400 cc of contrast depending on bladder size and patient comfort. Adequate filling is important to demonstrate intravesical pathology or bladder rupture. Oblique films should be obtained because posterior diverticula or fistulae may be obscured by the full bladder. The study provides valuable information regarding the posterior urethra in pediatric patients. Evaluation of intravesical pathology of bladder diverticula of inguinal hernia involving the bladder of colovesical or vesicovaginal fistulae of bladder or anastomotic integrity after surgical of blunt or penetrating trauma to the bladder Technique the study may be performed with the patient supine or in a semiupright position using a table capable of bringing the patient into the full upright position. In children, a 5- to 8-Fr feeding tube is used to fill the bladder to the appropriate volume. Patient comfort should be taken into account when determining the appropriate volume. A voiding cystourethrogram performed for the evaluation of recurrent urinary tract infection in this female patient. Bladder filling in patients with spinal cord injuries higher than T6 may precipitate autonomic dysreflexia (Barbaric, 1976; Fleischman and Shah, 1977; Linsenmeyer et al. It is very sensitive to changes that induce focal or global changes in kidney function. Because neither gadolinium or iodinated intravenous contrast agents are used, scintigraphy does not damage the kidney, has no lingering toxicity, results in minimal absorbed radiation, and is free from allergic reactions. Compared with other diagnostic imaging studies such as retrograde pyelogram, renal scintigraphy is noninvasive, has minimal risk and minimal discomfort, and allows determination of the function of the kidney. Once the agent is intravenously injected, gamma scintillation cameras measure radiation emitted from the radioisotope and digital Indications 1. Evaluation of the urethra in males and females Limitations this study requires bladder filling using a catheter. This may be traumatic in children and difficult in some patients with anatomic abnormalities of the urethra or bladder neck. Therefore it is most useful for identifying cortical defects or ectopic or abhorrent kidneys. The tracer is well suited for evaluation of renal function and diuretic scintigraphy. The initial phase is the flow phase, in which 2-second images are gathered for 2 minutes and then 1-second images for 60 seconds. The flow phase shows renal uptake, background clearance, and abnormal vascular lesions, which may indicate arteriovenous malformations, tumors, or active bleeding. In the second phase, the renal phase, time to peak uptake is typically between 2 and 4 minutes. The renal phase is the most sensitive indicator of renal dysfunction; 1-minute images are taken for 30 minutes. In the final phase, the excretory phase, 1-minute images are taken for 30 minutes. The T1/2 is the time it takes for collecting system activity to decrease by 50% from that at the time of diuretic administration. This is highly technician dependent because the diuretic must be given when the collecting system is displaying maximum activity. Transit time through the collecting system in less than 10 minutes is consistent with a normal, nonobstructed collecting system. T1/2 of 10 to 20 minutes shows mild to moderate delay and may be a mechanical obstruction. The level of obstruction usually can be determined as can abnormalities such as ureteral duplication (Ell and Gambhir, 2004). The diuretic renal scan is another imaging study in which communication with the interpreting physician is vital for correct performance of the test as well as appropriate interpretation. For example, there are times when patients with unilateral or bilateral ureteral stents are sent for diuretic scintigraphy to determine differential renal function. If a bladder catheter is not placed and is open to drainage during the diuretic renal scan, the radiopharmaceutical excreted from the healthy kidney may wash up into or back flow via the ureteral stent into the stented kidney, giving the false-positive appearance to have more function than is physiologically present. Dynamic function images demonstrate good uptake of tracer by both kidneys and prompt visualization of the collecting systems. Printout of quantitative data shows the differential renal function to be 47% on the left, 53% on the right. The T12 is 5 min on the left and 7 min on the right, consistent with both kidneys being unobstructed. Gallbladder activity, in particular, can cause false-positive interpretation when it overlies activity in the renal collecting system or is inappropriately included in the area of interrogation. Liver activity is variable and tends to be more pronounced in children and patients with renal insufficiency. This false-positive test may lead to inappropriately reconstructing a kidney that has little or insufficient function. Nuclear Medicine in Urologic Oncology Whole-Body Bone Scan Conventional radionuclide imaging in urologic malignancy has long been the standard for detecting bone metastasis. The whole-body bone scan, or skeletal scintigraphy, is the most sensitive method for detecting bone metastasis (Narayan et al. In patients with diffuse metastatic bone involvement, the bone scan can be mistaken for normal because there is uniformly increased uptake in the bony structures (Kim et al. This patient presented with a right-sided seminoma with bulky right-sided retroperitoneal lymph nodes. Tomography is an imaging method that produces 3D images of internal structures by recording the passage of x-rays as they pass through different body tissues. A collimated x-ray beam is generated on one side of the patient and the amount of transmitted radiation is measured by a detector placed on the opposite side of the x-ray beam. These measurements are then repeated systematically while a series of exposures from different projections is made as the x-ray beam rotates around the patient. The result is production of a 3D image of internal structures in the human body by recording the passage of different energy waves through various internal structures. Data collected by the detectors are reconstructed by computerized algorithms to result in a viewable tomographic display. There are several different imaging variables that are adjusted to allow adequate, detailed image resolution, while minimizing the time on the scanner and limiting exposure to radiation. The variable application of pitch, beam collimation, detector size, and tube voltage are used by the radiologist and imaging technologist for ideal image requisition. A detailed description of each of these variables is beyond the scope of this chapter. The helical raw images are processed using interpolation algorithms to visualize the internal structures as sagittal, coronal, or axial reconstructed images. These 3D images offer improved preoperative planning, appreciation of proximity to adjacent organs, and the ability to define vasculature and improve communication with patients who can now easily see their particular pathology and better appreciate the challenges faced by their surgeon. It also has been used for fluid aspiration, drain placement, catheter placement, percutaneous cryoablation, and radiofrequency ablation of renal tumors. It is indicated in the workup of hematuria, kidney stones, renal masses, renal colic, and urothelial tumors. The thin slices offered by the 16-slice detector offer much greater detail of internal structures. The upper pole of the right and left kidneys is indicated with rk and lk, respectively. The main renal veins are indicated with solid arrows, and the right main renal artery is indicated with an open arrow. The left main renal vein is indicated with a solid straight arrow, and the left main renal artery is indicated with an open arrow.

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