MATERIALS AND METHODS. We retrospectively reviewed the renal sonograms of 271 patients with surgically proven primary hyperparathyroidism. All patients had undergone renal imaging within 6 months before parathyroid surgery. Our control group consisted of 500 age-matched subjects who had right upper quadrant sonograms obtained for various reasons.

RESULTS. Nineteen (7.0%) of the 271 patients with primary hyperparathyroidism had renal stones, and eight (1.6%) of the 500 subjects in the control group had stones. Pearson's chi-square analysis showed that this difference in prevalence is significant (p < 0.0001).

CONCLUSION. Our results showed a fourfold increased prevalence of asymptomatic renal stone disease in patients with surgically proven primary hyperparathyroidism compared with subjects not affected by the disorder. The National Institutes of Health consensus conference on asymptomatic primary hyperparathyroidism recommended that patients with renal stone disease undergo parathyroid surgery. These patients should undergo surgery even if they have minimal or no elevation of the total serum calcium value and no other metabolic manifestations of hyperparathyroidism. The finding of nephrocalcinosis or nephrolithiasis is, therefore, a significant finding in evaluating patients for parathyroid surgery. Routine imaging of the kidneys is necessary when primary hyperparathyroidism is documented.

MATERIALS AND METHODS. The true volumes of 20 animal kidneys of various sizes were obtained by fluid displacement. Each kidney was examined using two different MR units. Three-dimensional proton density–weighted acquisitions with an incremental slice thickness were performed. The MR volume was then measured with a segmentation algorithm based on the belief functions theory. Two independent observers performed all segmentations twice. Accuracy, intraobserver variability, and interobserver variability were evaluated by the Bland-Altman method. The number and type of manual corrections were recorded as well as the entire processing time.

RESULTS. The mean renal volume estimated by fluid displacement was 114 mL (range, 38–224 mL). With regard to the renal volumes obtained from assessments of adjacent axial MR images, the maximal SDs of the difference were 2.2 mL (accuracy), 0.6 mL (intraobserver variability), and 1.8 mL (interobserver variability). Segmentation of axial slices provided better accuracy and reproducibility than coronal slices. Overlapped coronal slices yielded poor results because of the partial volume effect. The mean processing time including optional manual modifications was less than 75 seconds.

CONCLUSION. The belief functions theory can be considered an accurate and reproducible mathematic method to assess renal volume from MR adjacent images.

MATERIALS AND METHODS. From the electronic medical records of an academic medical center, adults with creatinine determinations on five consecutive days who had not received contrast material during the previous 10 days were identified. The first creatinine level was compared with those on subsequent days. We calculated the frequency with which these levels exceeded thresholds used to identify contrast nephropathy in previous publications.

RESULTS. Among 32,161 patients, more than half showed a change of at least 25% and more than two fifths, a change of at least 0.4 mg/dL. Among patients with baseline creatinine levels of 0.6–1.2 mg/dL, increases of at least 25%, 33%, and 50% occurred in 27%, 19%, and 11% of patients, respectively. Increases of 0.4, 0.6, and 1.0 mg/dL occurred in 13%, 7%, and 3% of patients. Among patients with baseline creatinine levels greater than 2.0 mg/dL, increases of at least 25%, 33%, and 50% occurred in 16%, 12%, and 7%. Increases of 0.4, 0.6, and 1.0 mg/dL occurred in 33%, 26%, and 18%. These increases were not different from the incidences of contrast nephropathy previously published.

CONCLUSION. The creatinine level increases in patients who are not receiving contrast material as often as it does in published series of patients who are receiving contrast material. The role of contrast material in nephropathy may have been overestimated.

CONCLUSION. Until more rigorous studies including an appropriate control group address the issue of CIN, our understanding of the actual risk of CIN when administering IV contrast media is limited.

CONCLUSION. Most patients with testicular GCTs can now be expected to be cured, so the focus on management moves toward identifying patients who need more aggressive treatment and avoiding long-term complications. CT remains central in the selection of a management strategy, although the roles of MRI and PET continue to evolve.

MATERIALS AND METHODS. The medical literature from 1995 to 2007 was searched using PubMed, Medline, and Cochrane Library databases for articles on studies that used low-dose CT (< 3 mSv dose applied for the entire CT examination) as a diagnostic test for the detection of urolithiasis. Prospective and retrospective studies were included if they separately reported the rate of true-positive, true-negative, false-positive, and false-negative diagnoses of urolithiasis from low-dose CT compared with the positive and negative rates of normal-dose CT or a combination of diagnostic tests. Two readers assessed the quality of the studies.

RESULTS. The pooled sensitivity and specificity of low-dose CT for the diagnosis of urolithiasis were 0.966 (95% CI, 0.950–0.978) and 0.949 (95% CI, 0.920–0.970), respectively.

CONCLUSION. The results of this meta-analysis suggest that a low-dose CT protocol can be used as the initial imaging technique in the workup of patients with suspected urolithiasis.

MATERIALS AND METHODS. Contrast-enhanced MDCT was performed in 104 patients with thoracoabdominal vascular disease using an 8-MDCT scanner. Both axial and multiplanar images were reviewed by two radiologists. The following points regarding the right adrenal vein were evaluated: degree of visualization; relationship to accessory hepatic or other veins; anatomy, including location of the orifice in relation to the surrounding structures; direction from the inferior vena cava; and length and diameter.

RESULTS. The right adrenal vein was detected in 79 (76%) of 104 patients. The right adrenal vein formed a common trunk with the accessory hepatic vein in six (8%) of the 79 patients. The orifice was craniocaudally located between the level of vertebrae T11 and L1. Among the 73 patients, the right adrenal vein joined the inferior vena cava in the right posterior quadrant in 71 patients (97%) and in the left posterior quadrant in two (3%). The transverse direction from the inferior vena cava was posterior and rightward in 56 patients (77%) and posterior and leftward in 17 (23%); the vertical direction from the inferior vena cava was caudal in 65 (89%) and cranial in eight (11%) patients. The length and diameter averaged 3.8 and 1.7 mm, respectively.

CONCLUSION. MDCT enabled the identification of the right adrenal vein and delineation of its anatomy, including its position and relationship to surrounding structures.

MATERIALS AND METHODS. For IV injections of nonionic iodinated contrast media between January 1, 1999, and December 31, 2005, contrast reaction reports and medical records of patients in whom contrast reactions occurred were reviewed. Data collected included patient sex and age, symptoms, reaction manifestations, treatment, and long-term sequelae. The appropriateness and efficacy of patient management were assessed.

RESULTS. Allergic-type reactions occurred in 545 (0.6%) of patients injected with nonionic iodinated contrast media: 418 (77%) reactions were mild, 116 (21%) were moderate, and 11 (2%) were severe. Two hundred twenty-one patients (41%) received treatment. The most commonly administered medication was diphenhydramine (145 patients or 27%). Corticosteroids were administered to 17 patients, nebulized albuterol to 16, and epinephrine to 15. Although 99% of the treatments did not result in any complication, three patients may have had short-term sequelae as a result of receiving a nonrecommended treatment.

CONCLUSION. Patients usually do well after developing acute allergiclike reactions to nonionic iodinated contrast media. Fortunately, in our series, this was true even in the rare cases in which the instituted treatment was considered to be inappropriate. Reacting patients rarely develop serious long-term sequelae.

CONCLUSION. In this article, we discuss and illustrate the spectrum of the appearances of transitional cell neoplasm of the upper urinary tract on 16- and 64-MDCT with multiplanar reformation and 3D imaging.

CONCLUSION. Familiarity with the realm of imaging manifestations of retroperitoneal fibrosis is vital to ensure correct diagnosis and optimal treatment.

MATERIALS AND METHODS. One hundred thirty-two adrenal nodules were identified in 104 patients with lung cancer who underwent PET/CT. Sixty-five nodules were classified as lipid-rich adenomas if they had an unenhanced CT attenuation of less than or equal to 10 H. Thirty-one masses were classified as lipid-poor adenomas if they had an unenhanced CT attenuation greater than 10 H and stability for more than 1 year. Thirty-six masses were classified as lung cancer metastases if they showed rapid growth in 1 year (n = 27) or were biopsy-proven (n = 9). Histogram analysis was performed for all lesions to provide the mean attenuation value and percentage of negative pixels.

RESULTS. All lipid-rich adenomas had more than 10% negative pixels; 51.6% of lipid-poor adenomas had more than 10% negative pixels and would have been classified as indeterminate nodules on the basis of mean attenuation alone. None of the metastases had more than 10% negative pixels. Using an unenhanced CT mean attenuation threshold of less than 10 H yielded a sensitivity of 68% and specificity of 100% for the diagnosis of an adenoma. Using an unenhanced CT threshold of more than 10% negative pixels yielded a sensitivity of 84% and specificity of 100% for the diagnosis of an adenoma.

CONCLUSION. CT histogram analysis is superior to mean CT attenuation analysis for the evaluation of adrenal nodules and may help decrease referrals for additional imaging or biopsy.

CONCLUSION. Renal Doppler sonography resistive index and pulsatility index values can serve as early radiologic predictors of renovascular changes in sickle cell disease. Thereby, these findings can guide clinicians in the use of more intensive monitoring of laboratory values and initiating adequate treatment at an early stage.

CONCLUSION. Five healthy volunteers were imaged on a 3-T clinical MR scanner using the balanced steady-state free precession (SSFP) Dixon method. We were able to image the proximal renal arteries with high conspicuity within a 3-minute overall scanning time. The balanced-SSFP Dixon method shows potential for unenhanced MR angiography of the proximal renal arteries.