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Objective: This study aimed to describe the computed tomographic (CT) imaging appearance of renal epithelioid angiomyolipomas (eAMLs)., Methods: The CT scans and electronic medical records of 8 patients with histologically confirmed eAMLs identified by biopsy and/or surgical excision who had available imaging performed between 1995 and 2012 were reviewed. Preoperative CT imaging appearance, histologic features, and clinical follow-up were recorded for each patient., Results: Macroscopic fat was identified in 3 (38%) of 8 eAMLs on preoperative CT imaging. Seven of the eAMLs demonstrated postcontrast enhancement of greater than 20 Hounsfield units. None of the eAMLs showed evidence of local invasion, vascular involvement, or distant metastases on the initial preoperative CT; however, 1 patient developed local recurrence and another developed distant metastatic disease on follow-up imaging., Conclusions: Epithelioid angiomyolipomas may or may not demonstrate macroscopic fat. Those with macroscopic fat do not possess any CT imaging characteristics that allow them to be distinguished from typical angiomyolipomas. Epithelioid angiomyolipomas without macroscopic fat are indistinguishable from renal cancers.

Objective: To assess the impact of imaging on pancreatic lesion management in von Hippel-Lindau disease (VHL)., Methods: We reviewed sequential computed tomography (CT) and magnetic resonance examinations (1997-2008) of 33 patients with VHL who had at least 1 pancreatic lesion., Results: One hundred sixty-seven imaging studies demonstrated innumerable simple pancreatic cysts and 58 complex pancreatic masses: 24 were complex cystic and 34 were solid (30 small [2 cm]). Aggregate annual growth was significant in complex cystic and solid masses (mean, 0.39 cm/y [P = 0.006] and 0.14 cm/y [P = 0.045]). Solid mass growth differed by size (small: 0.06 cm/y [range, -0.09 to 0.31 cm/y]; large: 1.28 cm/y [range, 0-1.98 cm/y]). Thirteen masses were excised. No patient developed metastases. Arterial-phase CT improved (P = 0.0003) solid mass detection, but 28% of studies still underreported the total number., Conclusions: Most pancreatic masses in VHL do not require annual surveillance. Arterial-phase CT improves mass detection, but many masses remain prospectively missed.

Objective: To determine uroradiologists' opinions and practices regarding computed tomographic (CT) urography., Methods: A Web-based survey was sent via e-mail to all 259 members of the Society of Uroradiology. Of the 229 successfully delivered e-mails, 90 (39%) members responded., Results: Of 90 uroradiologists, 87% perform CT urography. Compared with intravenous (IV) urography, 69% of uroradiologists use CT urography more than 75% of the time urinary tract imaging is requested; 27% stated that CT urography has completely replaced IV urography. Most uroradiologists perform CT urography using multidetector-row CT alone (79%) and use a 3-phase technique (52%) using a single injection (76%) of contrast material at 3 mL/s (52%) without a compression device (81%) and with the patient in supine position (80%)., Conclusions: Most uroradiologists use CT urography in their practice today; some no longer perform IV urography. Variability in multidetector-row CT technique suggests that more research is needed to determine the optimal protocol.

Purpose: To investigate changes in usage of computed tomography urography (CTU), indications for CTU, and rates of positive findings over time., Methods: Retrospective review of data from April 2000 to December 2005 assessed rates of overall positive findings, rates of suspected transitional cell carcinomas (TCCs), benign genitourinary (GU), and significant non-GU findings. Data were analyzed based on specialty of ordering physicians and on requisition indications., Results: One thousand two hundred seventy-one patients had 1746 CTUs, including 952 men (1259 studies) and 319 women (487 studies) with mean age of 61 years. Computed tomography urographies increased from 265 in 2001 to 443 in 2004. Eighty-nine percent were ordered by urologists, 4% by oncologists, 1% by emergency physicians, and 6% by other specialties. Sixty-two percent of first-time studies were ordered for possible GU malignancy, 24% for hematuria, and 14% for other reasons. Eight hundred sixty-one examinations (49%) showed significant findings. The rate of all positive examinations, analyzed in 6-month periods, varied from 37% to 54%, but no time trend was identified. First-time patient examinations had positive examinations in 46% to 62% of cases. Similarly, no trends were found for examinations interpreted as possible TCC (17%-32%), renal stones (9%-18%), renal masses (1%-6%), causes of hematuria (15%-26%), and acute non-GU findings (2%-9%). The rate of positive findings by ordering specialty varied minimally from 49% to 53%. No change occurred in the proportions of indications for CTU over time., Conclusions: In 5 years, the number of CTU examinations per year increased 1.5-fold. The rate of CTU findings positive for suspected TCC, stones, and other causes of hematuria showed no decline or increase. If precautions are taken regarding proper indications for CTU, the overall rates of positive findings may not substantially change over time, thereby only submitting high-risk patients to this examination.

Objective: To compare urinary tract distension and opacification obtained with single-bolus 3-phase and split-bolus 2-phase multidetector row computed tomographic urography (CTU) techniques., Methods: Twenty-six single-bolus 3-phase CTU examinations were retrospectively compared with 26 split-bolus 2-phase examinations. Two readers reviewed excretory-phase imaging to record quantitative measurements of urinary tract distension and qualitative measurements of urinary tract opacification., Results: Single-bolus 3-phase CTU technique provided better overall urinary tract distension than did split-bolus 2-phase technique (P = 0.05). Single-bolus CTU images demonstrated superior lower pole and interpolar region intrarenal collecting system distension when compared with split-bolus CTU images (P < or = 0.04). Qualitative opacification scores for the lower urinary tract were significantly higher, using single-bolus technique for only 1 of 2 reviewers. No significant differences between techniques in intrarenal collecting system opacification, ureteral distension, or ureteral opacification were identified., Conclusions: Improved urinary tract distension is obtained with single-bolus 3-phase CTU technique.

To determine the CT findings postfundoplication, we retrospectively compared CT in 22 postfundoplication patients with CT in 22 patients with unrepaired hiatal hernias and gastroesophageal (GE) junction abnormalities and 24 patients with gastric or esophageal carcinoma involving the GE junction. Seventeen of the 22 postfundoplication patients had undergone a Nissen procedure. Of the 22 patients, 11 had esophageal dilatation, 14 had GE junction masses, 4 had esophageal wall thickening, 7 had surgical clips, and none had hepatic metastases or upper abdominal lymphadenopathy. Statistically, on CT, postfundoplication patients are more likely to have a GE junction mass (p = 0.023) and least likely to have wall thickening (p = 0.021). Nonetheless, because the findings occur frequently in each group, they are not diagnostic in the individual patient. However, 11 of 12 post-Nissen masses had the unique finding of an oval or linear central fat density within the mass. This finding was absent in the other postfundoplication masses and in those patients with repaired hiatal hernia or tumor. We conclude that pseudomasses occur on CT postfundoplication and can be indistinguishable from hiatal hernias and GE junction neoplasms unless a central fat density is present.

We compared the relative toxicities of standard concentrations of two magnetic resonance imaging (MRI) contrast agents, ionic gadolinium diethylenetriaminepentacetic acid (DTPA) and low-osmolar gadolinium-1, 4, 7 tris (carboxymethyl)-10-(2'-hydroxypropyl)-1, 4, 7, 10 tetra-azacyclododecane (HP-DO3A) with that of the conventional radiographic contrast medium meglumine diatrizoate, when extravasated into the deep dermal tissues of laboratory rats. Gadolinium-DTPA caused moderate necrosis, hemorrhage, and edema which was not statistically different than meglumine diatrizoate. In contrast, gadolinium HP-DO3A was significantly less toxic than meglumine diatrizoate. Additional experience will be needed in order to determine whether these laboratory results will be clinically relevant in humans.

Two thousand thirty-four consecutive patients presented for excretory urography within a 22-month period. Of 57 observed adverse reactions (incidence 2.8%), 54 occurred in 1219 low-risk patients injected with conventional ionic contrast media (HOCM) (incidence 4.4%) while three reactions were noted in the 815 high-risk patients receiving low-osmolar contrast media (LOCM) (incidence 0.4%). Despite strict enforcement of an unchanging list of high-risk criteria by the same pool of radiologists, LOCM use was not constant, increasing in use over time from 26.5% to 55.3% of urograms. In addition, frequency of LOCM selection increased transiently (from 33% to 52%) following a single life-threatening reaction to HOCM. Our results suggest that strict guidelines for use of LOCM are subject to loose individual physician interpretation. Physicians' perceptions of safety made it increasingly difficult to withhold LOCM and progressively more patients were included in high-risk groups.

The CT studies of 29 patients with renal or perirenal lymphoma were retrospectively reviewed. Four patterns of disease were identified. Seventeen of 29 patients (59%) had bilateral renal masses. Only seven of these patients had associated enlarged retroperitoneal lymph nodes. Eight patients (28%) had single renal or perirenal lesions adjacent to or contiguous with bulky retroperitoneal lymphadenopathy. Three patients had infiltration of the perirenal space without significant renal parenchymal involvement, and one patient had a solitary renal mass. No patients in this series had diffuse involvement of the kidney without a focal mass. Renal involvement with lymphoma should be considered in any patient who develops multiple homogeneous solid renal or perirenal masses, even in the absence of other retroperitoneal disease.

We compared the damage resulting from intradermal injection of four commonly used radiographic contrast media in laboratory rats. Sixty percent meglumine diatrizoate (Reno M 60) and ioxaglate (Hexabrix) produced significantly more ulceration and crusting on gross inspection and more necrosis, edema, and hemorrhage on histologic evaluation than iopamidol 300 (Isovue) or 0.9% (normal) saline. Thirty percent meglumine diatrizoate (Reno M Dip) had an intermediate toxicity, resulting in significantly more visible swelling and more microscopically detected hemorrhage than iopamidol or saline, but less ulceration/crusting and necrosis than Reno M 60 and ioxaglate. Since the three contrast agents of similar osmolality produced different degrees of tissue damage, our results suggest that factors other than high osmolality are partially responsible for determining the severity of injuries from extravasated contrast media.

Five cases are presented that illustrate the utility of obtaining limited CT prior to fluoroscopically guided biopsy in patients who have lung or mediastinal lesions that cannot be adequately localized by chest radiography. Each case describes a unique setting in which the CT images facilitate accurate and safe biopsy needle placement. The rare requirement for biopsy using CT alone, which can be considerably more time consuming, is emphasized.

The infectious complications of percutaneous biliary drainage were reviewed in 132 patients with obstructive jaundice. Cholangitic or septic episodes occurred more frequently in patients with malignant (54%) than in those with benign (22%) disease, and frequently were not related to catheter insertions or manipulations. The frequency and mechanisms of bacterial colonization of bile and blood in patients with obstructive jaundice before and after biliary drainage are reviewed. The significant morbidity and mortality related to postdrainage infectious episodes is stressed, and the efficacy of antibiotic prophylaxis is discussed. The significant risks and complications of percutaneous biliary drainage must be considered prior to catheter placement, particularly in the most debilitated patients.

Intravenous digital subtraction renal angiography (IV-DSRA) is frequently used in the preoperative evaluation of living-related (LR) kidney donors. However, the true accuracy of IV-DSRA in the donor population is difficult to assess since abnormalities of the kidney and its circulation are uncommon in this group. Therefore, we evaluated IV-DSRA in a group of patients more likely to have anomalies and abnormalities that would affect LR donor selection, donor nephrectomy, and subsequent transplantation. Hypertensive adults being evaluated for renovascular hypertension had IV-DSRA and conventional renal arteriograms, which were interpreted independently. We determined the accuracy of IV-DSRA, compared with conventional arteriography, in detecting multiple renal arteries, renal artery stenosis, fibromuscular dysplasia, and abnormal renal parenchyma. Technically unsatisfactory studies were excluded from analysis. Of 59 patients evaluated, 37 had abnormalities or anomalies. IV-DSRA failed to detect 28 of 50 findings in these 37 patients. In 21 patients with multiple renal arteries, IV-DSRA underestimated the number of main renal arteries in 8. Significant renal artery stenosis, present in 16 patients, was undetected by IV-DSRA in 3 of these patients. Mild fibromuscular dysplasia was not detected by IV-DSRA in any of the 5 patients with this condition, and abnormalities of renal parenchyma were not detected in 6 of the 8 patients with scarred or cystic kidneys. When compared with conventional renal arteriography in a hypertensive population, the IV-DSRA does not accurately detect abnormalities of the kidney and its circulation. If these data are confirmed in nonhypertensive subjects, preoperative evaluation of LR kidney donors using IV-DSRA alone may fail to detect potentially important anatomic abnormalities.

Major interventional uroradiologic techniques including percutaneous nephrostomy, vascular augmentation and reduction procedures, percutaneous cyst aspiration, chronic peritoneal dialysis catheter manipulation and urethroplasty are reviewed. A brief history of the development and techniques for performing these procedures are included. The results of clinical series are assessed and their role in patient management is addressed. The development of these procedures has had a significant impact on patient care by providing effective nonoperative therapy.

The records of 121 patients who presented for PTC and biliary drainage within a five-year period were reviewed. Fifty-eight bile samples had been obtained from 38 of these patients for cytologic analysis. Malignancy was detected in 14 of 32 patients with carcinoma (sensitivity 44%). Repeat sampling was positive in four of nine patients whose initial specimen contained no tumor cells. Bile duct carcinoma, pancreatic carcinoma, and metastatic disease were all detected. An approach to biliary cytodiagnosis is offered that, it is hoped, will further minimize future false negative results.

The CT findings in 70 patients with masses in or adjacent to the porta hepatis/hepatoduodenal ligament were analyzed. Underlying disease processes included metastatic disease (44 cases), lymphoma/leukemia (10 cases), biliary carcinoma (seven cases), hepatoma (four cases), benign disease (three cases), and gallbladder carcinoma (two cases). Location of the mass was confirmed in 62 patients and showed six patterns: four along the hepatoduodenal ligament or within the porta hepatis; another within the liver impinging on the hepatoduodenal ligament/porta hepatis; the sixth, an intraductal mass. Of the masses along the hepatoduodenal ligament or within the porta hepatis the four patterns were well defined nodular masses caused by discrete nodes; matted masses due to confluent adenopathy; mixed, well defined and confluent masses in various locations along the hepatoduodenal ligament; infiltrating, enhancing soft tissue densities obscuring the portal vein margins. No disease specific pattern was seen; nonetheless, knowledge of these patterns is very helpful in detection of masses in this region.

The CT appearance of hemiazygos continuation of a left-sided inferior vena cava is presented along with discussion of associated anomalies.

Seventeen renal transplant patients with pelvic lymphatic fluid collections were treated with percutaneous drainage. Eleven of 16 patients with lymphoceles (69%) were successfully managed without surgery, although seven of these patients required repeat catheter insertions, and three patients developed local infections. The patient with an ovarian cystadenoma was treated with surgery. The mean duration of catheter insertion was ten days for initial drainage and 16 days for repeat drainage. Elevated serum creatinines decreased in 14 of the patients with lymphoceles (88%), including all five patients without pelvocaliectasis, but never returned to baseline in six instances. This observation may reflect the inadequate therapy of frequently encountered concurrent renal parenchymal abnormalities (rejection, cyclosporine toxicity, acute tubular necrosis). While percutaneous management of lymphoceles is technically easy and usually ultimately effective, the interventional radiologist should be prepared for long duration of catheter insertions, repeat interventions, and variable clinical courses. Differentiation of lymphoceles from other fluid collections, such as cystic ovarian neoplasms, may be difficult.

Six patients with small solid renal tumors were evaluated by computed tomography (CT). Two patients had renal oncocytomas, three had small renal cell adenocarcinomas, and one had separate foci of each of these tumors in the same kidney. We describe several features that may alert the clinician to the possible presence of oncocytoma. We found, however, that unless the dense central scar that can be seen in larger oncocytomas is visualized on CT (as was the case in one of our patients), differentiation between oncocytomas and renal cell carcinomas by CT is not possible.

The CT examinations and medical records of 33 patients with primary retroperitoneal malignancies were reviewed. Computed tomography findings were then compared with those from scans performed on 122 patients with non-Hodgkin lymphoma who presented during the same time interval. Primary retroperitoneal neoplasms had three distinct CT appearances. Twenty-one patients (64%) had large soft tissue masses. Seven patients (21%) had masses with fatty density components, and five patients (15%) had tumors that were primarily of water attenuation. With the exception of those liposarcomas that contained recognizable fat, CT could not distinguish among the different cell types. Seventeen patients with non-Hodgkin lymphoma had large dominant retroperitoneal soft tissue masses that resembled primary retroperitoneal malignancies. In most cases, however, CT was able to differentiate these tumor masses from primary retroperitoneal tumors. Although 19 of 20 sarcomas of soft tissue attenuation were heterogeneous, only six of the 17 lymphomas presenting as dominant masses had such an appearance. Computed tomography is extremely helpful in initially evaluating patients with primary retroperitoneal tumors and in assisting the surgeon in planning his or her approach by accurately defining tumor extent.

We report the CT findings in a case of primary seminal vesicle carcinoma. These consisted of unilateral enlargement of a seminal vesicle with associated stranding extending into the surrounding fat. This soft tissue stranding corresponded pathologically to direct tumor invasion.

A case of diffuse xanthogranulomatous pyelonephritis of the kidney with an associated renocolic fistula is reported. Computed tomography demonstrated typical findings with an enlarged poorly functioning kidney with multiple near-water-density masses replacing the renal parenchyma surrounding a central staghorn calculus. A mottled gas collection within the renal parenchyma was secondary to a renocolic fistula rather than a pyogenic abscess.