Evidence of nerve hypertrophy in patients with inclusion body myositis on lower limb MRI.

INTRODUCTION/AIMS: Inclusion body myositis (IBM) is a myopathic condition but in some patients has been associated with an axonal length-dependent polyneuropathy. In this study, we quantified the cross-sectional area of the sciatic and tibial nerves in patients with IBM comparing with Charcot-Marie-Tooth disease type 1A (CMT1A) and healthy controls using magnetic resonance neurography (MRN). METHODS: MRN of the sciatic and tibial nerves was performed at 3T using MPRAGE and Dixon acquisitions. Nerve cross-sectional area (CSA) was measured at the mid-thigh and upper third calf regions by an observer blinded to the diagnosis. Correlations were performed between these measurements and clinical data. RESULTS: A total of 20 patients with IBM, 20 CMT1A and 29 healthy controls (age- and sex-matched) were studied. Sciatic nerve CSA was significantly enlarged in patients with IBM and CMT1A compared to controls (sciatic nerve mean CSA 62.3 ± 22.9 mm2 (IBM) vs. 35.5 ± 9.9 mm2 (controls), p < 0.001; and 96.9 ± 35.5 mm2 (CMT1A) vs. 35.5 ± 9.9 mm2 (controls); p < 0.001). Tibial nerve CSA was also enlarged in IBM and CMT1 patients compared to controls. DISCUSSION: MRN reveals significant hypertrophy of the sciatic and tibial nerves in patients with IBM and CMT1A compared to controls. Further studies are needed to correlate with neurophysiological measures and assess whether this finding is useful diagnostically.

De novo Portal Vein Thrombosis in Non-Cirrhotic Non-Alcoholic Fatty Liver Disease: A 9-Year Prospective Cohort Study.

Background and Aims: Approximately 30-40% of portal vein thrombosis (PVT) remains of unknown origin. The association between non-alcoholic fatty liver disease (NAFLD) and PVT is a matter of debate. This study aimed to investigate the association between PVT and NAFLD. Methods: We included 94 out of 105 consecutive NAFLD patients in this prospective cohort study in addition to 94 from the healthy control group. We evaluated biochemical, clinical, immunological, and histopathological parameters; waist circumference (WC); leptin; adiponectin; and leptin/adiponectin ratio (LAR) for all participants at baseline and every 3 years thereafter. We described the characteristics of participants at baseline and showed individual WC, LAR, and PVT characteristics. Potential parameters to predict PVT development within 9 years were determined. Results: PVT developed in eight (8.5%) patients, mainly in the portal trunk. Univariate analysis showed three PVT-associated factors: diabetes mellitus (P = 0.013), WC (P < 0.001), and LAR (P = 0.002). After adjusting multiple confounding variables, the multivariate model showed that the only significant variables were WC and LAR. By applying the receiver operating characteristic curve, WC had 98.8% specificity, 87.5% sensitivity, and 0.894 area under the curve (AUC) for prediction of PVT (P < 0.001) at cutoff values of > 105 cm. In comparison, LAR had 60.5% specificity, 87.5% sensitivity, and 0.805 AUC for PVT prediction (P < 0.001) at cutoff values of >7.5. Conclusions: This study suggests that increased central obesity and LAR were independently associated with PVT development in non-cirrhotic NAFLD patients, and they should be considered risk factors that may participate in PVT multifactorial pathogenesis.

Differentiation malignant from benign parotid tumors in children with diffusion-weighted MR imaging.

PURPOSE: To differentiate pediatric solid malignant from the benign parotid tumors with diffusion-weighted MR imaging (DWI). MATERIALS AND METHODS: A retrospective study comprising 38 children with parotid tumors (21 boys and 17 girls aged from 2 months to 17 years) was conducted using (DWI) of the parotid gland. Apparent diffusion coefficient (ADC) maps were generated. The ADC value of the parotid tumors was calculated. RESULTS: The mean ADC value of malignant parotid tumors (1.08 ± 0.1, 1.04 ± 0.1 × 10-3mm2/s) was significantly lower [P = 0.001] than that of benign lesions (1.69 ± 0.2, 1.72 ± 0.3 × 10-3mm2/s). A threshold of ADC of 1.40, 1.33 × 10-3mm2/s was used for differentiating malignant parotid tumors from benign lesions and led to the best results of the area under the curve of 0.940, 0.929, accuracy of 86, 89%, sensitivity of 94, 94%, specificity of 80, 85%, negative predictive value of 94.1, 94.4%, and positive predictive value of 81, 85%. There was insignificant difference in ADC values of malignant lesions (P = 0.23, 0.30) as well as within benign lesions (P = 0.25, 0.08). CONCLUSION: DWI is an innovative anticipating imaging technique that can be used in the differentiation of pediatric solid malignant parotid tumors from benign lesions.

Diffusion Tensor Imaging of the Lateral Rectus Muscle in Duane Retraction Syndrome.

AIM: This study aimed to assess metrics of diffusion tensor imaging in evaluating microstructural abnormalities of the lateral rectus muscle in Duane retraction syndrome (DRS). PATIENT AND METHODS: A prospective study was conducted on 27 patients with DRS and 16 age- and sex-matched controls who underwent diffusion tensor imaging of orbit and forced duction test (FDT). Fractional anisotropy (FA) and mean diffusivity (MD) of the lateral rectus were calculated by 2 observers. RESULTS: Fractional anisotropy of the lateral rectus in patients (0.62 ± 0.07 and 0.59 ± 0.06) was significantly higher (P = 0.001) than that in controls (0.49 ± 0.06 and 0.51 ± 0.06). Selection values of 0.53 and 0.52 as cutoff points of FA of the lateral rectus to differentiate patients from controls revealed areas under the curve of 0.92 and 0.86 and accuracy values of 84.8% and 80.4% by both observers, respectively. Mean diffusivity of the lateral rectus by both observers in patients (1.19 ± 0.13 and 1.23 ± 0.19 × 10 mm/s) was significantly lower (P = 0.001) than that in controls (1.54 ± 0.18 and 1.49 ± 0.16 × 10 mm/s). Selection values of 1.35 and 1.40 × 10 mm/s as cutoff points of MD of the lateral rectus to differentiate patients from the control groups revealed areas under the curve of 0.93 and 0.85 and accuracy values of 91.3% and 80.4% by both observers, respectively. Interobserver agreement for MD and FA of the lateral rectus by both observers were excellent (r = 0.870 and, 0.959). Diffusion tensor imaging metrics of the lateral rectus muscle did not differ significantly between patients with unilateral and bilateral disease (P = 0.05) and patients with DRS type I and type III (P = 0.05). Diffusion tensor imaging metrics of the lateral rectus muscle differed significantly between FDT grades I and II versus grades III and IV, and these metrics were well correlated with the degree of FDT. CONCLUSION: Diffusion tensor imaging metrics are valuable noninvasive tools in evaluating the microstructural abnormalities of the lateral rectus in DRS and are well correlated with degree of FDT.