MATERIALS AND METHODS. A computer search of abdominal CT reports using the term "adrenal" was performed in 65,231 consecutive patients with examinations performed from January 2000 to December 2003. An adrenal mass was identified in 3,307 (5%) patients. Patients with no known malignancy and no suspicion for a hyperfunctioning adrenal mass were further isolated. Nine hundred seventy-three patients with 1,049 adrenal masses fulfilled the study criteria. The nature of each lesion was determined by histopathology; imaging characterization with CT, MRI, or washout; a minimum of 1 year of stability on follow-up imaging; or clinical follow-up of at least 2 years.

RESULTS. One thousand forty-nine adrenal masses were characterized with the following methods: histopathology (n = 12), imaging characterization (n = 909), imaging follow-up (n = 87), and clinical follow-up (n = 41). There were 788 adenomas constituting 75% of all lesions. There were 68 myelolipomas (6%), 47 hematomas (4%), and 13 cysts (1%). Three pheochromocytomas (0.3%) and one cortisol-producing adenoma (0.1%) were found incidentally. One hundred twenty-eight lesions (12%) were presumed to be benign by imaging or clinical stability. No malignant adrenal masses were found, even among the 14 patients who later developed malignancy elsewhere.

CONCLUSION. In 973 consecutive patients with an incidental adrenal mass and no history of cancer, no malignant lesions were identified. Adenomas (75%) and myelolipomas (6%) were the most common lesions.

MATERIALS AND METHODS. Twenty urinary stones of different sizes (1.4–4.2 mm in short-axis diameter) were placed in plastic containers. The containers were consecutively filled with different concentrations of iodine solution (21, 43, 64, 85, and 107 mg/dL; CT attenuation value range, 510–2,310 H at 120 kVp). Dual-energy CT was repeated with 80–140 and 100–140 kVp pairs, two collimation–slice thickness combinations, and the presence or absence of a 4-cm-thick oil gel around the phantom. The iodine-subtraction virtual unenhanced images were reconstructed using commercial software. The images were evaluated by three radiologists in consensus for the visibility of the stones and the presence of residual nonsubtracted iodine. Stone visibility rates were compared between the 80–140 and 100–140 kVp pairs and the five different iodine concentrations.

RESULTS. Stone visibility rates with the 80–140 kVp pair were 99%, 93%, 96%, 94%, and 3% and those with the 100–140 kVp pair were 98%, 95%, 99%, 94%, and 99% for an iodine concentration of 21, 43, 64, 85, and 107 mg/dL, respectively. The poor visibility rate with 80–140 kVp and 107 mg/dL iodine concentration was due to the failure of iodine subtraction.

CONCLUSION. Dual-energy CT iodine-subtraction virtual unenhanced technique is capable of depicting urinary stones in iodine solutions of a diverse range of concentrations in a phantom study.

MATERIALS AND METHODS. We performed a retrospective study encompassing all acute trauma patients admitted to our institution over a 42-month period found to have renal parenchyma injuries on initial MDCT and also to have undergone a follow-up CT performed at least 1 month after trauma. We identified 54 patients who sustained blunt (n = 44) or penetrating (n = 10) abdominal trauma. The renal injuries were graded by two radiologists according to the Organ Injury Scaling Committee of the American Association for the Surgery of Trauma (AAST), grades I through V. Follow-up CT was reviewed for the presence of parenchymal distortion, scarring, or perfusion defects.

RESULTS. Of the 54 patients, 12 had grade I injury, eight had grade II injury, 22 had grade III injury, 10 had grade IV injury, and two had grade V injury. Grades I and II traumatic renal injuries were undetectable on follow-up CT. Grade III injuries resulted in the development of renal scars in 14 of 22 (64%) patients. Scarring resulted in all patients with grades IV and V injuries.

CONCLUSION. Grades I and II renal injuries heal completely, whereas higher grades of renal trauma result in permanent parenchymal scarring. Hence, incidentally discovered renal scars in patients with a history of minor renal trauma should be attributed tentatively to other causes that may or may not require additional investigation.

MATERIALS AND METHODS. Twenty-seven patients who had increased levels of prostate-specific antigen after high-intensity focused ultrasonic ablation underwent MRI and endorectal biopsy. The MR images and biopsy results were correlated for six prostate sectors. Residual or recurrent prostate cancer after treatment was defined as local tumor progression if the biopsy results showed cancer foci. Two readers blinded to the clinical findings and biopsy results used a 5-point scale to independently assess DCE-MR images and T2-weighted and diffusion-weighted MR images. The results were compared by use of the McNemar test with Bonferroni correction, generalized estimating equations, and receiver operating characteristic analysis.

RESULTS. After high-intensity focused ultrasonic ablation, local tumor progression was pathologically detected in 54 (33%) of 162 sectors in 18 patients. The sensitivities of DCE-MRI and T2-weighted MRI with DWI were 80% and 63% for reader 1 (p = 0.004) and 87% and 70% for reader 2 (p = 0.004). The specificities of DCE-MRI and T2-weighted MRI with DWI were 68% and 78% for reader 1 (p = 0.002) and 63% and 74% for reader 2 (p < 0.001). The accuracy rates of DCE-MRI and T2-weighted MRI with DWI were 72% and 73% for reader 1 (p > 0.05) and 71% and 73% for reader 2 (p > 0.05). The areas under the receiver operating characteristic curve for DCE-MRI and T2-weighted MRI with DWI were 0.77 and 0.77 for reader 1 and 0.85 and 0.81 for reader 2.

CONCLUSION. For prediction of local tumor progression of prostate cancer after high-intensity focused ultrasonic ablation, DCE-MRI was more sensitive than T2-weighted MRI with DWI, but T2-weighted MRI with DWI was more specific than DCE-MRI.

MATERIALS AND METHODS. A total of 51 patients who had undergone radical prostatectomy for prostatic adenocarcinoma 10 months to 6 years before underwent a combined endorectal coil MRI and dynamic gadolinium-enhanced MRI before endorectal sonographically guided biopsy of the prostatic fossa. The MRI combined with MR dynamic imaging results were correlated with the presence of recurrence defined as a positive biopsy result or reduction in prostate-specific antigen level after radiation therapy.

RESULTS. Overall data of 46 (25 recurred, 21 nonrecurred) out of 51 evaluated patients were analyzed. All recurrences showed signal enhancement after gadolinium administration and, in particular, 22 of 24 patients (91%) showed rapid and early signal enhancement. The overall sensitivity and specificity of MR dynamic imaging was higher compared with MRI alone (88%, [95% CI] 69–98% and 100%, 84–100% compared with 48%, 28–69% and 52%, 30–74%). MRI combined with dynamic imaging allowed better identification of recurrences compared with MRI alone (McNemar test: chi-square₁ = 16.67; p = < 0.0001).

CONCLUSION. MRI combined with dynamic contrast-enhanced MRI showed a higher sensitivity and specificity compared with MRI alone in detecting local recurrences after radical prostatectomy.

SUBJECTS AND METHODS. Eighty-five patients with 92 simple renal cysts were randomly assigned to two groups in a prospective controlled trial. One group was treated with sonographically guided continuous catheter drainage with negative pressure and the other group with single-session alcohol sclerotherapy. Patient demographics, clinical characteristics, treatment outcome, and complications were analyzed.

RESULTS. The initial volume of the cysts did not differ significantly between the groups, but the final volume was significantly smaller in the continuous drainage group (p = 0.026). During the 24-month follow-up period, 37 (40%) of the cysts disappeared completely: 24 (52%) of the 46 cysts in the drainage group and 13 (28%) of the 46 cysts in the sclerotherapy group (p = 0.033). In the sclerotherapy group, the probability of disappearance of the cysts was highly dependent on cyst size, being less for giant cysts (p = 0.01). Cyst size was not a significant factor in probability of disappearance in the drainage group (p = 0.15). The probability of disappearance of giant cysts (volume > 500 mL) differed significantly between the groups (p = 0.009), but there was no difference in probability of disappearance of moderately large cysts (p = 0.16). Three of 14 patients with giant cysts in the drainage group and 10 of 13 such patients in the sclerotherapy group had recurrences that necessitated additional treatment (p = 0.007). They were successfully treated with continuous catheter drainage.

CONCLUSION. Continuous catheter drainage with negative pressure is more efficient than single-session alcohol sclerotherapy in the management of giant cysts. For moderately large cysts, the two methods have similar results.

SUBJECTS AND METHODS. A total of 62 consecutively registered patients were selected. MR spectroscopy of the prostate was performed with PFC in the endorectal coil for 34 of the patients and with air for 28. In the cases of 13 of the 28 patients, MR spectroscopy was repeated with a PFC-filled endorectal coil. The spectral line widths and the spectral separations from MR spectroscopy with an air-filled endorectal coil were compared with those obtained with a PFC-filled coil.

RESULTS. In all 62 patients, the mean line width values were reduced, from 13.3 ± 3.0 Hz with air to 7.3 ± 2.0 Hz with PFC (p = 0.0001, Student's t test). In 13 patients who underwent MR spectroscopy with air followed by MR spectroscopy with PFC, the mean line width values were reduced, from 14.8 ± 3.4 Hz with air to 7.0 ± 1.5 Hz with PFC (p = 0.0001, Student's t test). In 72 voxels analyzed for spectral separation, clear separations between the choline, polyamine, and creatine peaks were found in 57 voxels with PFC and four with air. Better splitting of the citrate peaks was found in 35 voxels with PFC and one with air.

CONCLUSION. The use of PFC compound in the endorectal coil is a safe and cost-effective way to consistently generate high-quality prostate MR spectroscopic results and to substantially improve quantitation of prostatic metabolites. These improvements should increase the diagnostic value of MR spectroscopy in the care of patients with prostate cancer.