Three-Dimensional Fast Spin-Echo Imaging without Fat Suppression of the Knee: Diagnostic Accuracy Comparison to Fat-Suppressed Imaging on 1.5T MRI

PURPOSE: To evaluate the diagnostic performance of three-dimensional fast spin-echo (3D FSE-Cube) without fat suppression (NFS) for detecting knee lesions, using comparison to 3D FSE-Cube with fat suppression (FS). MATERIALS AND METHODS: One hundred twenty-four patients who underwent 1.5T knee magnetic resonance imaging (MRI) scans and 25 subsequent arthroscopic surgeries were retrospectively reviewed. Using arthroscopic results and two-dimensional images as reference standards, diagnostic performances of 3D FSE-Cube-NFS and FS imaging about lesions of ligament, meniscus, subchondral bone marrow edema (BME), and cartilage were compared. Scan parameters of 3D FSE-Cube imaging were previously optimized by a porcine knee phantom. RESULTS: No significant differences were observed between detection rates of NFS and FS imaging for detecting lesions of meniscus and cartilage (p>0.05). However, NFS imaging had lower sensitivity for detection of medial collateral ligament (MCL) tears, and lower sensitivity and specificity for detection of BME lesions, compared to FS imaging (p<0.05). CONCLUSION: 3D FSE-Cube-NFS imaging showed similar diagnostic performance for detecting lesions of meniscus or cartilage compared to FS imaging, unlike MCL or BME lesions.

Should We Recommend Ultrasonography for an Incidental Thyroid Nodule on Additional Cervicothoracic Sagittal T2-Weighted Image of Lumbar Spine MRI?

PURPOSE: To determine whether we should recommend ultrasonography (US) for an incidental thyroid nodule identified by additional cervicothoracic sagittal T2-weighted image (C-T sag T2WI) of lumbar spine magnetic resonance imaging (MRI). MATERIALS AND METHODS: A retrospective study of 61 patients who underwent both lumbar spine MRI and thyroid US between December 2011 and April 2015 was conducted. For all US-found thyroid nodules > 1 cm, investigators evaluated whether there was any correlation between thyroid nodule detectability by C-T sag T2WI and US features such as echogenicity, composition, or suspicion of malignancy. RESULTS: Solid hypoechoic (2/4; 50%) or mixed echoic nodules (4/8; 50%) appeared to be found relatively more easily by C-T sag T2WI than more benign-looking solid isoechoic (1/4; 25%) or spongiform nodules (0/6; 0%). Among six nodules with ultrasonographic suspicion for malignancy, only one nodule was detected by C-T sag T2WI. CONCLUSION: If an incidental thyroid nodule is seen by C-T sag T2WI, it would be better to recommend thyroid US for identifying malignancy.

Effects of Post Biopsy Digital Rectal Compression on Improving Prostate Cancer Staging Using Magnetic Resonance Imaging in Localized Prostate Cancer

PURPOSE: To evaluate the effectiveness of digital rectal-compression immediately after transrectal prostate biopsy (P-bx) for improving the accuracy of prostate cancer (PCa) staging. MATERIALS AND METHODS: Between July 2008 and June 2010, 94 consecutive patients who had a radical prostatectomy were included in our retrospective analysis. The exclusion criteria included a history of previous P-bx and surgery, a biopsy performed in another hospital, a number of biopsy cores different from 12, or a condition interfering with bleeding assessment. The subjects were divided into two groups, compression and non-compression. All enrolled patients took magnetic resonance imaging (MRI) for PCa staging. RESULTS: The compression and non-compression groups were comparable with respect to several baseline characteristics. However, the total hemorrhage score of intraprostatic bleeding was significantly different between the groups, even with adjustment for the time from biopsy to MRI (compression:15.4+/-2.32, non-compression: 24.9+/-2.43, p<0.001). The intra-prostatic cancer location matching rate was higher in the compression group (78.0%) than in the non-compression group (70.2%) (p=0.011). Overall accuracy of staging in compression and non-compression groups was 84.7% and 77.3%, respectively. CONCLUSION: Our results demonstrate that digital rectal compression performed immediately after prostate biopsy to reduce intraprostatic hemorrhage improves the accuracy for detection of PCa using MRI.

Retroaortic Renal Vein / 대한비뇨기과학회지

The retroaortic renal vein is located posterior to the aorta due to congenital and developmental anomalies, which goes anterior to the aorta, normally. Even though a developmental retroaortic vein is the common congenital variation (3.3-16%), it is usually symptom free and is generally overlooked in many cases. However, after a kidney transplant, this kind of anatomical variation influences the technical feasibility of the operation, and special attention is needed. In addition, in surgery on an abdominal aneurysm, which needs mobilization of aorta, a retroaortic vein is important. This article reports a case of a retroaortic renal vein in 66 year-old female who had surgery for radical nephrectomy due to a tumor in the left kidney.

Usefulness of MR Imaging for Diseases of the Small Intestine: Comparison with CT

OBJECTIVE: To evaluate the usefulness of MR imaging for diseases of the small intestine, emphasizing a comparison with CT. MATERIALS AND METHODS: Thirty-four patients who underwent both CT and MR imaging using FLASH 2D and HASTE sequences were analyzed. All patients had various small bowel diseases with variable association of peritoneal lesions. We compared the detectabilities of CT and MR imaging using different MR pulse sequences. The capability for analyzing the characteristics of small intestinal disease was also compared. RESULTS: MR imaging was nearly equal to CT for detecting intraluminal or peritoneal masses, lesions in the bowel and mesentery, and small bowel obstruction, but was definitely inferior for detecting omental lesions. The most successful MR imaging sequence was HASTE for demonstrating bowel wall thickening, coronal FLASH 2D for mesenteric lesions, and axial FLASH 2D for omental lesions. MR imaging yielded greater information than CT in six of 12 inflammatory bowel diseases, while it was equal to CT in six of seven neoplasms and inferior in five of seven mesenteric ischemia. In determining the primary causes of 15 intestinal obstructions, MR imaging was correct in 11 (73%) and CT in nine (60%) patients. CONCLUSION: MR imaging can serve as an alternative diagnostic tool for patients with suspected inflammatory bowel disease, small intestinal neoplasm or obstruction. is a high-speed, heavily T2-weighted sequence with a great sensitivity for fluid (11). This advance may make it possible to use breath-hold turbo spin-echo MR.

Detection of Hepatocelluar Carcinoma in MR Arterial Portography; Diagnostic Significance as a Pre-Operative Evaluation

PURPOSE: To evaluate the usefulness of fast magnetic resonance (MR) sequences combined with MR arterialportography in the preoperative assessment of hepatocellular carcinoma. MATERIALS AND METHODS: Twelve patients suffering from nodular hepatocellular carcinoma complicated by liver cirrhosis underwent T2-weighted turbo spinecho and T1-weighted multisection FLASH with and without fat-suppression MR imaging during single breath-holdsession in each sequence. MR arterial portography was performed with Gd-DTPA injected through a catheter into the superior mesenteric or splenic artery during the T1-weighted FLASH sequence. The pathologic findings of surgical specimen or follow-up lipiodol CT findings were compared with the MR imaging. RESULTS: MR arterial portography depicted 17 of the 19 masses (sensitivity, 89%) and the sensitivity of non-contrast fast MR sequences was 74%(14/19). The sensitivity for combined interpretation of all the above sequences was 89% (17/19). MR arterial portography showed perfusion defects from two cysts, one hemangioma, one inflammatory mass, and innumerable tiny regenerating nodules. Static T1-and T2-weighted imaging clearly differentiated, however, benign lesions and true hepatocellular carcinoma. CONCLUSION: MR arterial portography combined with other fast MR imaging allows tissue characterization as well as high detection rate in the evaluation of hepatocellular carcinoma complicated with cirrhosis.