Renal inflammatory myofibroblastic tumor: a rare tumor indistinguishable from renal cell carcinoma­report of two cases.

Renal inflammatory myofibroblastic tumor (IMT) is a rare soft-tissue tumor of controversial etiology with a potential for local recurrence after incomplete surgical resection. The radiological findings in renal IMT are not well described. We report two cases in adults with a renal mass treated with nephrectomy on suspicion of malignancy.

Contrast-enhanced FDG-PET/CT vs. SPIO-enhanced MRI vs. FDG-PET vs. CT in patients with liver metastases from colorectal cancer: a prospective study with intraoperative confirmation.

BACKGROUND: The choice of imaging before liver surgery is debated regarding the use of magnetic resonance (MR) imaging, computed tomography (CT), and positron emission tomography (PET). No studies have compared contrast-enhanced PET/CT with superparamagnetic iron oxide (SPIO)-enhanced MR imaging. PURPOSE: To compare PET/CT with superparamagnetic iron oxide (SPIO)-enhanced MR imaging, PET, and CT in the detection of liver metastases (LM) and extrahepatic tumor from colorectal cancer (CRC). MATERIAL AND METHODS: Thirty-five patients with suspected LM underwent PET/CT with a contrast-enhanced CT protocol and SPIO-enhanced MR imaging. Readers independently analyzed images from MR imaging, PET/CT, and the CT part and PET part of the PET/CT study. Imaging findings were compared with surgical and histological findings. RESULTS: Lesion-by-lesion sensitivity and accuracy for liver lesions was 54% and 77% for PET alone, 66% and 83% for PET/CT, 82% and 82% for SPIO-enhanced MR imaging, and 89% and 77% for CT alone, respectively. CT and SPIO-enhanced MR imaging were less specific but significantly more sensitive than PET (P<0.0001). For extrahepatic tumor, sensitivity and specificity was 83% and 96% for PET/CT and 58% and 87% for CT, respectively. CONCLUSION: CT and SPIO-enhanced MR imaging are more sensitive but less specific than PET in the detection of LM. PET/CT can detect more patients with extrahepatic tumor than CT alone.

Multidetector computed tomography and neuroendocrine pancreaticoduodenal tumors.

PURPOSE: To investigate the accuracy of dedicated pancreatic multidetector computed tomography (MDCT) in the diagnosis of neuroendocrine pancreaticoduodenal tumors (NPTs). MATERIAL AND METHODS: MDCT and other imaging studies in patients with suspected NPTs were identified. Thirty dedicated MDCT studies were done in 23 patients. Fourteen patients (16 operations) subsequently had surgery. Imaging reports were reviewed and findings compared with surgical findings and findings in other imaging studies. RESULTS: Patients with surgery: 19 NPTs (16 extrapancreatic gastrinomas and 3 pancreatic NPTs) were identified at surgery. MDCT identified 16 and somatostatin receptor scintigraphy (SRS) 11 out of 19 tumors. Endoscopic ultrasound detected 11 out of 14 NPTs. Patients without surgery: In 4 out of 9 patients, no NPTs were identified at MDCT. CONCLUSION: Dedicated MDCT of the pancreas can identify many NPTs, including small duodenal and periduodenal tumors, and the detection rate is better than reported in the older literature on CT.

Multiplanar reconstruction in MR imaging of the knee. Comparison with standard sagittal and coronal images.

PURPOSE: To compare standard MR sagittal and coronal imaging of the knee with the MR technique of finer sagittal imaging and subsequent reconstruction in any plane. MATERIAL AND METHODS: Forty-seven patients took part in the study. Two radiologists each made two independent interpretations in every case, based on images of: a) 4-mm sagittal and coronal slices; and b) 1.2-mm sagittal slices with subsequent reconstruction. RESULTS: We found no significant difference in diagnostic efficacy between the two MR techniques. The reconstruction in any desired plane involved a potential reduction of 10 min in examination time but an increase of approximately 20 min in postprocessing time. CONCLUSION: The use of multiplanar reconstruction offered no additional diagnostic value and no saving of time.

MRI preferable to diagnostic arthroscopy in knee joint injuries. A double-blind comparison of 47 patients.

We compared the findings of low-field MRI of the knee with those of subsequent arthroscopy. In a double-blind set-up, 47 patients with knee joint injuries were enrolled. Two radiologists independently interpreted the MRI examinations and consensus was obtained in case of discrepancy. Arthroscopy was performed without knowledge of the MRI findings. The accuracy rates of MRI for evaluating the medial meniscus, lateral meniscus and anterior cruciate ligament were 77%, 91% and 96%, respectively, when arthroscopy was considered the "golden standard". When MRI was considered the standard, the figures for arthroscopy were 74%, 91% and 96%. MRI found the indication for treatment in 18 of 21 patients who were treated at the arthroscopy. In 17 patients, neither MRI nor arthroscopy detected any lesion. In the remaining 9 patients, MRI demonstrated a lesion, but no lesion was found at the subsequent arthroscopy. Our conclusion is that low-field MRI can be used as a first-line diagnostic examination in patients with suspected meniscus or cruciate ligament injuries and thus a substantial number of negative diagnostic arthroscopies can be avoided.

MR imaging before arthroscopy in knee joint disorders?

PURPOSE: To review the current literature examining the relative merits of arthroscopy and MR imaging of the knee. MATERIAL AND METHODS: All papers comparing MR imaging with arthroscopy published within the last 10 years according to Medline were collected and read. RESULTS: Technology has improved considerably during recent years allowing detailed non-invasive visualization of the knee. In particular, the development of cheaper whole-body and dedicated low-field MR units has opened up for non-invasive inspection of the knee at reasonable cost. Meniscal tears can be detected with accuracy rates of around 90% and rupture of the anterior cruciate ligament with accuracy rates of around 93% compared to arthroscopy. However, arthroscopy is not the ideal gold standard, since it has weak points, e.g. peripheral meniscal tears or osteochondritis without apparent damage to the cartilage. CONCLUSION: Based on the overwhelming literature it seems safe to conclude that MR examinations of the knee should be performed before arthroscopy is undertaken.