Clinical value of fluorine-18-fluorodeoxyglucose PET/MRI for liver metastasis in colorectal cancer: a prospective study.

PURPOSE: To evaluate the diagnostic performance of liver 18F-FDG PET/MRI in addition to whole-body PET/CT and to compare it with MRI in the detection and clinical management of liver metastasis in patients with colorectal cancer (CRC). MATERIAL AND METHODS: Seventy-eight patients with CRC who underwent whole-body 18F-FDG PET/CT followed by liver PET/MRI were prospectively included. Histopathological confirmation and/or at least 3 months of clinical follow-up after PET/MRI were accepted as gold standard. Lesion and patient-based analyses were performed to evaluate the diagnostics performances of PET/CT, PET/MRI and MRI. In addition, changes of clinical management were evaluated. RESULTS: On lesion-based analysis, for PET/CT, PET/MRI and MRI; sensitivity (Se): 55.6%, 97.2% and 100%; specificity (Sp): 98.5%, 100% and 80.5%; and accuracy (Acc): 70.7%, 98.2% and 93.1% were calculated, respectively. Se and Acc of PET/MRI and MRI were significantly superior than PET/CT (P < 0.001). Se and Acc of PET/MRI and MRI were comparable; however, Sp of PET/MRI was significantly better than MRI (P < 0.001). On patient-based analysis, Se: 75.6%, 100% and 100%; Sp: 97.3%, 100% and 86.5%; and Acc: 85.9%, 100% and 93.5% were calculated, respectively. Se and Acc of PET/MRI were significantly superior than PET/CT (P < 0.001). Also, Se of MRI was significantly superior than PET/CT (P < 0.001). Se of PET/MRI and MRI were comparable, but Sp and Acc of PET/MRI were significantly better than MRI. The additional information obtained from liver PET/MRI changed treatment strategy in 14/78 (18%) patients compared to PET/CT or alone liver MRI. CONCLUSION: Diagnostic performances of PET/MRI and MRI for detection of CRC liver metastasis is superior to PET/CT. PET/MRI especially helps in the accurate detection of liver metastases that are suspicious on MRI and has the potential to change the clinical management of especially oligometastatic patients by identifying uncertain liver lesions.

MRCP evaluation of biliary system following vagotomy and gastric surgery.

OBJECTIVE: The aim of this study was to show the usefulness of MR cholangiopancreatography (MRCP) in demonstrating biliary system pathologies in patients with a history of vagotomy and Billroth II operations. METHODS: The hepatobiliary system of eight patients with a history of vagotomy and Billroth II operations was evaluated with MRCP. Three-dimensional fast spin-echo technique was used at a 1.0-T scanner with following parameters: TR=2857-4615 ms, TE=850-1117 ms, BW=31.2, FOV=40, 21-28 slices, NEX=0.5, scan time = 90 s. RESULTS: Eight patients were evaluated with MRCP. Three patients had cholecystectomy. In one patient the gall bladder wall was thickened, accompanied with an irregular, unknown filling defect at the level of the fundus. Four of these patients had common bile duct stones. Two patients had gallstones and one patient had a stone in the common hepatic duct. A capping deformity of the distal common bile duct was observed in all of the patients. CONCLUSION: We conclude that MRCP can be used effectively for evaluation of biliary system of patients with previous history of biliary or gastric operations.