Current patterns of imaging utilization lead to frequent serendipitous discovery of renal lesions. Today, the majority of solid renal masses that are ultimately proved to be renal cell carcinomas were incidental findings on imaging studies performed for non-urinary tract symptoms. While earlier discovery has led to treatment of smaller and earlier-stage malignancies, the percentage of benign lesions discovered has also increased. A strategy for characterization of solid masses in adults based on the lesion's growth pattern, the "ball" versus the "bean," is presented. Common and uncommon renal masses, in concert with clinical and other imaging clues, are reviewed within the context of a renal ball or bean.

OBJECTIVE. The objective of our study was to evaluate the success rate for radiofrequency ablation of renal tumors and to determine the risk of serious complications.CONCLUSION. No serious complications occurred after 27 CT-guided radiofrequency ablation sessions in 22 patients. In total, no residual tumor was detected on follow-up contrast-enhanced CT or MRI 1-35 months (mean, 7 months) after final tumor ablation in 20 (91%) of 22 patients. Two patients with residual viable tumor deferred further treatment. Complete tumor ablation was achieved after a single treatment session in 83% of patients, and in 8% of patients after subsequent ablation sessions. Size was the major determinant for achieving tumor eradication with a single session of ablation, with all 11 tumors 3 cm or smaller being completely ablated after one session. Tumor location, histology, and the presence of renal disease did not correlate with treatment success. Contrast-enhanced CT performed immediately after ablation is reliable to exclude residual viable tumor. CT-guided radiofrequency ablation of renal tumors is safe and has a high rate of success in the treatment of small renal tumors, with no evidence of recurrence at midterm follow-up of treated patients.

The language of radiology is rich with descriptions of imaging findings, often metaphorical, which have found common usage in the day-to-day practice of genitourinary radiology. These "classic signs" give us confidence in our diagnosis. Some of the signs have become so familiar to us that they are referred to as an "Aunt Minnie." When the sign is invoked, or an Aunt Minnie is recognized, it often brings an impression of the image to mind, and it may have specific diagnostic and pathologic implications. The article uses classic signs accumulated from the literature to review a variety of pathologic conditions in the urinary tract.

BACKGROUNDThe purpose of this study was to review the trend of using chest computed tomography (CT) and aortography in evaluating patients with blunt thoracic trauma.METHODSA total of 85 patients who had blunt aortic injury diagnosed by chest CT, aortography, or both were included in this study.RESULTSAortography was the dominant modality before 1998, and the use of chest CT has increased to 50% of patients with aortic injuries as of 2001. Isolated aortic, branch vessel, or combined injuries were found in 71 (84%), 11 (13%), and 3 (4%) patients, respectively. All 14 patients with branch vessel injuries were diagnosed by aortography. Ninety-eight percent of patients with aortography were true-positives, and 20% of patients with chest CT had indirect signs of aortic injury.CONCLUSIONOur institution has increased the use of chest CT to evaluate blunt thoracic trauma. Patients with indirect signs of aortic injuries shown on chest CT require further evaluation. In our experience, angiography remains the optimal diagnostic modality for evaluating aortic branch vessel injuries.

PURPOSEAccess for percutaneous nephrostolithotomy (PNL) using conventional fluoroscopic guidance may carry an increased risk of damage to surrounding organs in patients with renal calculi and aberrant anatomy. In these situations cross-sectional anatomical imaging may facilitate safe percutaneous access. We describe our experience with computerized tomography (CT) guided percutaneous access for such patients undergoing PNL.MATERIALS AND METHODSBetween June 2000 and December 2001, 154 patients underwent PNL at our institution. Five of these patients (3%) required a total of 6 percutaneous access tracks under CT guidance. All patients in this group had anatomical abnormalities precluding standard access to the collecting system without risk to adjacent organs. These abnormalities included a retrorenal colon in 2 and a severely distorted body habitus due to spinal dysraphism in 3.RESULTSPercutaneous access was achieved without complication in all cases. At subsequent PNL 5 of the 6 renal units (83%) were rendered completely stone-free.CONCLUSIONCT guided percutaneous access is infrequently required for PNL. However, there is a select group of patients with anatomical anomalies that may predictably require this procedure to facilitate safe and efficacious PNL.

Spectrum of Endometrial Hyperplasia and Its Mimics on Saline HysterosonographyJohanna R. Jorizzo1, Michael Y. M. Chen, Deena Martin, Raymond B. Dyer and Therese M. WeberAudio Available | Share

Minimally invasive therapy in the urinary tract begins with renal access by means of percutaneous nephrostomy. Indications for percutaneous nephrostomy include urinary diversion, treatment of nephrolithiasis and complex urinary tract infections, ureteral intervention, and nephroscopy and ureteroscopy. Bleeding complications can be minimized by entering the kidney in a relatively avascular zone created by branching of the renal artery. The specific site of renal entry is dictated by the indication for access with consideration of the anatomic constraints. Successful percutaneous nephrostomy requires visualization of the collecting system for selection of an appropriate entry site. The definitive entry site is then selected; ideally, the entry site should be subcostal and lateral to the paraspinous musculature. Small-bore nephrostomy tracks can be created over a guide wire coiled in the renal pelvis. A large-diameter track may be necessary for percutaneous stone therapy, nephroscopy, or antegrade ureteroscopy. The most common extension of percutaneous nephrostomy is placement of a ureteral stent for treatment of obstruction. Transient hematuria occurs in virtually every patient after percutaneous nephrostomy, but severe bleeding that requires transfusion or intervention is uncommon. In patients with an obstructed urinary tract complicated by infection, extensive manipulations pose a risk of septic complications.

The recent increase in usage of ureteral stents in the management of a variety of urinary tract disease processes mandates familiarity with these devices, their consequences, and their potential complications, which at times can be devastating. Radiology plays an important role in the routine monitoring of stents and in the evaluation of these consequences and complications. It may also offer solutions for their correction. Stents should be monitored while in place, promptly removed when no longer needed, and changed periodically if chronically indwelling. Risk factors for complications should be minimized with high fluid intake, timely evaluation of clinical complaints, and aggressive treatment of documented infection. Certain patients may not be best served by indwelling stent placement, and urinary diversion by means of other mechanisms may be indicated. The implanting physician is responsible for informing the patient of the requirements, consequences, and complications associated with stent placement. Failure to do so has obvious management and potential medicolegal implications.

Intravenous urography has long been the cornerstone of the imaging evaluation of urinary tract disease. However, other imaging modalities such as ultrasonography, computed tomography, and magnetic resonance imaging are being used with increasing frequency. The declining use of urography in clinical practice presents a challenge for instruction in urographic technique and interpretation. In addition, alternative modalities also have their limitations, and despite their increasing use, the ideal "global" urinary tract examination remains controversial. Nevertheless, urography may still be important in the diagnosis of some urinary tract disease processes. It is frequently performed in the evaluation of hematuria. Urography may also be performed in the pre- or posttherapeutic evaluation of stone disease that has been discovered with other imaging modalities. The urographic imaging sequence is designed to optimize depiction of specific portions of the urinary tract during maximal contrast material opacification, and a tailored urographic study may provide diagnostic detail beyond the current capabilities of other imaging modalities. However, this can be accomplished only with good technique, an understanding of the limitations of the procedure, and adherence to basic rules of interpretation. The ability to relate urographic findings of disease processes to other imaging modalities will remain an important skill until the ideal urinary tract imaging technique emerges.

The use of noncontrast helical CT (NHCT) to assess patients with acute flank pain and hematuria for potential urinary tract stone disease was first reported in 1995. After several years of experience with the technique, sensitivity and specificity of NHCT has proven to be better than intravenous urography for evaluating ureteral stones. NHCT imaging findings for urinary calculi and the differential diagnosis are discussed in this article. Various extraurinary diseases found while using NHCT in searching for stone disease are addressed and illustrated. As experience with the use of NHCT has increased, clinicians have broadened the indications for this technique, which has a lower charge than standard CT, beyond the specific evaluation of urinary colic. This indication creep has increased the number of NHCT examinations ordered. It has also reduced the rate of stone positivity and increased the diagnostic yield for extraurinary disease.

The purpose of this pictorial review is to facilitate recognition and understanding of calcifications seen on conventional radiographs of the abdomen. Calcifications can be categorized by organ system and location in the abdomen. Both common and rare calcifications in the urinary tract, liver, gallbladder, spleen, pancreas, adrenal glands, digestive tract, genital tract, peritoneal cavity, and retroperitoneum are illustrated. Abnormal calcifications in the urinary tract are subcategorized by kidneys, ureters, bladder, and urethra. The density, shape, size, margins, pattern, position, and mobility of calcifications are emphasized for differential diagnoses.

OBJECTIVE:Unenhanced helical CT for urolithiasis detection is a limited CT examination that was designed specifically for the detection of urolithiasis. The purpose of this study was to repeat a prior study to assess whether clinicians had broadened the indications and changed the yield and findings of unenhanced helical CT.MATERIALS AND METHODS:One hundred consecutive patients with suspected renal colic or flank pain referred for unenhanced helical CT were selected for this study. We reviewed the original radiographic reports for each patient and recorded the presence of ureteral calculi. Other urinary abnormalities and extraurinary lesions were also recorded and compared with the results of the previous study.RESULTS:In this study, 56% of the patients who underwent unenhanced helical CT had symptoms of urinary colic, and 44% of patients had unspecified flank pain, compared with 100% of patients with symptoms of urinary colic 1 year earlier. The sensitivity and specificity of unenhanced helical CT in detecting ureteral calculi were 96% and 99%, respectively. Ureteral calculi were identified in only 28% of the patients versus 49% of patients (p < .01) 1 year earlier. Extraurinary lesions were identified in 45% of the patients versus 16% (p < .01) 1 year before.CONCLUSION:As clinicians developed familiarity with this technique, the indications for performance of unenhanced helical CT were expanded with a consequent reduction in the rate of detection of stone disease and identification of an increased number of extraurinary lesions, which suggests a demand for emergency abdominal CT studies.

CT of the ureteral wall.R B Bechtold, M Y Chen, R B Dyer and R J ZagoriaAudio Available | Share

No AccessJournal of UrologyUrological Survey: Abstracts: Imaging1 Apr 1999The Small Renal Mass: Detection, Characterization, and Management R.J. Zagoria and R.B. Dyer R.J. ZagoriaR.J. Zagoria More articles by this author and R.B. DyerR.B. Dyer More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(01)61719-1AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "The Small Renal Mass: Detection, Characterization, and Management." The Journal of Urology, 161(4), p. 1404 Department of Radiology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina© 1999 by American Urological Association, Inc.FiguresReferencesRelatedDetails Volume 161 Issue 4 April 1999 Page: 1404 Advertisement Copyright & Permissions© 1999 by American Urological Association, Inc.Metrics Author Information R.J. Zagoria More articles by this author R.B. Dyer More articles by this author Expand All Advertisement PDF downloadLoading ...

A wide variety of calcifications may develop in the urinary tract. Calculi, the most common form of urinary tract calcification, are usually radiopaque due to their calcium content, whereas cystine stones tend to be less opaque. In cortical nephrocalcinosis, calcification may be spotty or may appear as a thin rim outlining the cortex. Intracystic calcification is usually thin and peripheral and is often described as having an "eggshell" appearance. In renal masses, pure central calcification usually indicates malignancy, although malignancy may also be present with pure peripheral calcification. An incomplete ring of calcification seen over the central portion of the kidney should suggest the presence of an abnormal vascular structure. A sloughed papilla may lead to calcification that is usually triangular or ring-shaped or has a broken rim pattern. Ureteral calculi usually have a uniform radiopacity, whereas phleboliths are often less opaque centrally. Like renal calculi, bladder calculi usually contain a calcium component; they may be laminated, faceted, spiculated, or seedlike in appearance. Urachal carcinoma is commonly associated with tumor calcification, which typically occurs at the dome of the bladder. Schistosomiasis of the bladder may produce mural calcification with a typical thin arcuate pattern and may be associated with calcification in other portions of the urinary tract. Although urinary tract calcifications may be difficult to characterize specifically, they can be classified according to location, appearance, and relation to various pathologic conditions.

From its humble beginnings as a method of expediently decompressing the obstructed kidney, the field of interventional uroradiology has evolved in the hands of urologists and interventional radiologists to a means of addressing myriad problems in the urinary tract and has changed the day-to-day practice of urology. The foundation of interventional uroradiology is the creation of an appropriate entry into the urinary system. After a review of this basic procedure, extensions of the technique and new applications of emerging technology are reviewed.