OBJECTIVE: To evaluate the value of a dedicated interpretation of the CT images in the differential diagnosis of benign vs. malignant primary bone lesions with 18 fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT). MATERIALS AND METHODS: In 50 consecutive patients (21 women, 29 men, mean age 36.9, age range 11-72) with suspected primary bone neoplasm conventional radiographs and 18F-FDG-PET/CT were performed. Differentiation of benign and malignant lesions was separately performed on conventional radiographs, PET alone (PET), and PET/CT with specific evaluation of the CT part. Histology served as the standard of reference in 46 cases, clinical, and imaging follow-up in four cases. RESULTS: According to the standard of reference, conventional 17 lesions were benign and 33 malignant. Sensitivity, specificity, and accuracy in assessment of malignancy was 85%, 65% and 78% for conventional radiographs, 85%, 35% and 68% for PET alone and 91%, 77% and 86% for combined PET/CT. Median SUV(max) was 3.5 for benign lesions (range 1.6-8.0) and 5.7 (range 0.8-41.7) for malignant lesions. In eight patients with bone lesions with high FDG-uptake (SUV(max) >or= 2.5) dedicated CT interpretation led to the correct diagnosis of a benign lesion (three fibrous dysplasias, two osteomyelitis, one aneurysmatic bone cyst, one fibrous cortical defect, 1 phosphaturic mesenchymal tumor). In four patients with lesions with low FDG-uptake (SUV(max) < 2.5) dedicated CT interpretation led to the correct diagnosis of a malignant lesion (three chondrosarcomas and one leiomyosarcoma). Combined PET/CT was significantly more accurate in the differentiation of benign and malignant lesions than PET alone (p = .039). There was no significant difference between PET/CT and conventional radiographs (p = .625). CONCLUSION: Dedicated interpretation of the CT part significantly improved the performance of FDG-PET/CT in differentiation of benign and malignant primary bone lesions compared to PET alone. PET/CT more commonly differentiated benign from malignant primary bone lesions compared with conventional radiographs, but this difference was not significant. The Additional Value of CT Images Interpretation in the Differential Diagnosis of Benign vs. Malignant Primary Bone Lesions with 18F- FDG-PET/CT Abstract ObjectiveTo evaluate the value of a dedicated interpretation of the CT images in the differential diagnosis of benign vs. malignant primary bone lesions with 18F-FDG-PET/CT. MethodsIn 50 consecutive patients (21 female, 29 male, mean age 36.9, age range 11 -72) with suspected primary bone neoplasm conventional radiographs and 18F-FDG-PET/CT were performed. Differentiation of benign and malignant lesions was separately performed on conventional radiographs, PET alone (PET) and PET/CT with specific evaluation of the CT part. Histology served as the standard of reference in 46 cases, clinical and imaging follow-up in four cases. ResultsAccording to the standard of reference conventional 17 lesions were benign and...

18 F-FDG PET/CT has gained wide acceptance for evaluation of recurrent colorectal carcinoma. However in clinical practice, contrast-enhanced CT (ceCT) is still the first-line restaging tool. The aim of this study was to investigate the value of contrastenhanced PET/CT (cePET/CT) as a first-line restaging tool with a special focus on the importance of the use of intravenous contrast. Methods: Fifty-four patients (17 women, 37 men; mean age, 60.3 y), referred for restaging of colorectal carcinoma, were examined with cePET/CT. Retrospective analysis was performed by 2 experienced readers by consensus: first, ceCT alone; second, non-cePET/CT; and third, cePET/CT. The number, localization, and diagnostic certainty of lesions were evaluated. Additionally, the therapeutic impact of the findings was determined. In 29 patients, histology, clinical imaging, and clinical follow-up served as the reference standard. In 25 patients, clinical follow-up and imaging served as the reference standard. Results: Overall, non-cePET/CT delivered correct additional information to the ceCT findings in 27 of 54 patients (50%). This occurred in (a) 20 of 30 patients, where ceCT was found to be inconclusive, and in (b) 7 of 24 patients with conclusive ceCT findings, where non-cePET/CT found additional lesions, leading to a therapy modification in 5 patients. Compared with non-cePET/ CT, cePET/CT revealed additional information in 39 of 54 patients (72%), with therapeutic relevance in 23 patients. This large number was primarily due to correct segmental localization of liver metastases, which is crucial for surgical therapy planning. Conclusion: On the basis of its higher accuracy and therapeutic impact compared with ceCT, our data suggest that cePET/CT might be considered as the first-line diagnostic tool for restaging in patients with colorectal cancer.

Purpose:To evaluate the use of a dynamic keyhole magnetic resonance angiography (MRA) sequence combined with sensitivity encoding (SENSE) for hemodialysis shunts, because surveillance with conventional contrast-enhanced MRA (CE-MRA) is limited by its low temporal resolution, resulting in arteriovenous overlay. Materials and Methods:A total of 12 patients with Brescia-Cimino shunts were investigated prospectively using the new technique. During the contrast passage (gadoterate, Gd-DOTA) a series of five to nine dynamic central k-space measurements (10% for upper-arm shunt, 25% for lower-arm shunt) followed by a full reference data set were acquired. The outer k-space data of the single reference scan were used to complete the dynamic data sets.Results: All studies were diagnostic (17 stenoses, three aneurysms) without complications. The acquisition times for a single dynamic scan of the upper-and lower-arm shunts were 2.2 and 3.2 seconds, respectively, while the reference scan needed 13 and 22.4 seconds, respectively. The dynamic angiograms allowed the differentiation of arterial and venous filling despite a mean peak delay time of only 4.2 seconds in the shoulder region. Image quality qualified in consensus by two experienced readers was rated "good" in 19 cases and "intermediate" in five cases with high mean values for signal-to-noise ratios (SNRs) and contrast-to-noise-ratios (CNRs). Conclusion:We have successfully implemented a fast, dynamic, CE-MRA technique with CE timing robust angiography (CENTRA) keyhole and SENSE in clinical routine. High spatial and temporal resolution improve the diagnostics of dialysis shunts and allow the assessment of detailed, dynamic, four-dimensional (4D) information.

F-18 fluorodeoxyglucose (FDG)-PET-CT is increasingly used in the management of patients with ovarian cancer. However, there is a considerable overlap in the imaging features of malignant and benign ovarian lesions because physiological FDG-uptake in the ovaries can occur, depending on the menstrual cycle in premenopausal women.We present a case of FDG uptake in the ovary co-occurring with an intensely FDG active tumor of the abdominal wall in a 44-year-old woman. PET-CT findings, together with medical history, raised the suspicion for a metastasizing ovarian cancer. However, histologic examination demonstrated benign findings, namely abdominal wall leiomyoma and an ovarian follicular cyst.

No abstract