Diffusion tensor imaging applications in multiple sclerosis patients using 3T magnetic resonance: a preliminary study.

OBJECTIVES: This study evaluated patients with multiple sclerosis using diffusion tensor imaging (DTI) to obtain fractional anisotropy (FA) and mean diffusivity (MD) values. METHODS: We investigated the possible statistically significant variation of MD and FA in different MS patients, compared simultaneously, putting in comparison their normal appearing white matter (NAWM) and white matter affected by disease (plaques), both during activity and in remission, with normal white matter (NWM) of control subjects. RESULTS: Statistical analysis using Levene's test for comparison of variances revealed significant (P < 0.05) differences between FA values of the NWM of the controls and those of NAWM and active or inactive lesions, of the patients in the study. However, the differences between MD values of the NWM of the controls and those of NAWM and active or inactive lesions of the patients in the study were judged not significant (P > 0.05). CONCLUSION: Imaging of MS using MRI techniques is constantly searching for reproducible quantitative parameter. This study shows how these parameters can be identified in the MD and FA values, and thus suggests the implementation of MRI routine protocols for diagnosing MS with the DTI analysis, since it can provide valuable information otherwise unobtainable. KEY POINTS: Magnetic resonance imaging is widely performed in multiple sclerosis (MS) patients Diffusion tensor imaging (DTI) can be implemented using a 3T magnet DTI provides quantitative parameters as mean diffusivity (MD) and fractional anisotropy (FA) MD and, especially, FA can help evaluate the lesion load in MS patients and also assess variation in normal appearing white matter (NAWM) in MS.

CT and MR findings in synovial chondromatosis of the temporo-mandibular joint: our experience and review of literature.

OBJECTIVE: To compare Computed Tomography (CT) and Magnetic Resonance (MR) features and their diagnostic potential in the assessment of Synovial Chondromatosis (SC) of the Temporo-Mandibular Joint (TMJ). MATERIALS AND METHODS: Eight patients with symptoms and signs compatible with dysfunctional disorders of the TMJ underwent CT and MR scan. We considered the following parameters: soft tissue involvement (disk included), osteostructural alterations of the joints, loose bodies and intra-articular fluid. These parameters were evaluated separately by two radiologists with a "double blinded method" and then, after agreement, definitive assessment of the parameters was given. CT and MR findings were compared. RESULTS: Histopathological results showed metaplastic synovia in all patients and therefore confirmed diagnosis of SC. MR resulted better than CT in the evaluation of all parameters except the osteostructural alterations of the joints, estimated with more accuracy by CT scan. CONCLUSIONS: CT scan is excellent to define bony surfaces of the articular joints and flogistic tissue but it fails in the detection of loose bodies when these are not yet calcified. MR scan therefore is the gold standard when SC is suspected since it can visualize loose bodies at early stage and also evaluate disk condition and eventual extra-articular tissues involvement. The use of T2-weighted images and contrast medium allows identifying intra-articular fluid, estimating its entity and discriminating from sinovial tissue.

MDCT of the breast.

OBJECTIVE: The purpose of this study was to evaluate retrospectively the accuracy of low-dose MDCT in the differentiation of breast lesions suspected on mammography and sonography. MATERIALS AND METHODS: MDCT was performed on 61 patients with mammographic or sonographic findings suggestive of breast cancer who could not undergo MR mammography. For each lesion, morphologic features, attenuation, and time-attenuation curve pattern were evaluated. The 1-minute cut point of attenuation was analyzed on the images. CT findings were compared with histopathologic results, which were the reference standard. RESULTS: Forty-seven of 61 patients underwent surgery, and the pathologic findings revealed 27 malignant and 20 benign lesions. With CT 25 of 27 malignant lesions and all 20 benign lesions were diagnosed correctly. CT had a sensitivity of 92.6%, specificity of 100%, positive predictive value of 100%, negative predictive value of 90.9%, and accuracy of 95.74%. The cutoff attenuation value, which had the best validity for differentiating malignant and benign lesions, was calculated to be 90 H on the 1-minute images. CONCLUSION: Our results confirm and strengthen the importance of all imaging parameters and not one in particular. Dynamic MDCT can be used in the evaluation of selected patients with suspected breast tumors.