Extra-axial cranial nerve enhancement: a pattern-based approach.

Cranial nerve enhancement is a common and challenging MRI finding that requires a meticulous and systematic evaluation to identify the correct diagnosis. Literature mainly describes the various pathologies with the associated clinic-radiological characteristics, while the radiologist often needs a reverse approach that starts from the radiological findings to reach the diagnosis. Therefore, our aim is to provide a new and practical pattern-based approach to cranial nerve enhancement, which starts from the radiological findings and follows pattern-driven pipelines to navigate through multiple differential diagnoses, guiding the radiologist to reach the proper diagnosis. Firstly, we reviewed the literature and identified four patterns to categorize the main pathologies presenting with cranial nerve enhancement: unilateral linear pattern, bilateral linear pattern, unilateral thickened pattern, and bilateral thickened pattern. For each pattern, we describe the underlying pathogenic origin, and the main radiological features are displayed through high-quality MRI images and illustrative panels. A suggested MRI protocol for studying cranial nerve enhancement is also provided. In conclusion, our approach for cranial nerve enhancement aims to be an easy tool immediately applicable to clinical practice for converting challenging findings into specific pathological patterns.

Comparison of quantitative muscle ultrasound and whole-body muscle MRI in facioscapulohumeral muscular dystrophy type 1 patients.

INTRODUCTION: Muscle ultrasound is a fast, non-invasive and cost-effective examination that can identify structural muscular changes by assessing muscle thickness and echointensity (EI) with a quantitative analysis (QMUS). To assess applicability and repeatability of QMUS, we evaluated patients with genetically confirmed facioscapulohumeral muscular dystrophy type 1 (FSHD1), comparing their muscle ultrasound characteristics with healthy controls and with those detected by MRI. We also evaluated relationships between QMUS and demographic and clinical characteristics. MATERIALS AND METHODS: Thirteen patients were included in the study. Clinical assessment included MRC sum score, FSHD score and The Comprehensive Clinical Evaluation Form (CCEF). QMUS was performed with a linear transducer scanning bilaterally pectoralis major, deltoid, rectus femoris, tibialis anterior and semimembranosus muscles in patients and healthy subjects. For each muscle, we acquired three images, which were analysed calculating muscle EI by computer-assisted grey-scale analysis. QMUS analysis was compared with semiquantitative 1.5 T muscle MRI scale. RESULTS: All muscles in FSHD patients showed a significant increased echogenicity compared to the homologous muscles in healthy subjects. Older subjects and patients with higher FSHD score presented increased muscle EI. Tibialis anterior MRC showed a significant inverse correlation with EI. Higher median EI was found in muscles with more severe MRI fat replacement. CONCLUSIONS: QMUS allows quantitative evaluation of muscle echogenicity, displaying a tight correlation with muscular alterations, clinical and MRI data. Although a confirmation on larger sample is needed, our research suggests a possible future application of QMUS in diagnosis and management of muscular disorders.

Hydro-MDCT for Gastric Adenocarcinoma Staging. A Comparative Study With Surgical and Histopathological Findings for Selecting Patients for Echo-endoscopy.

BACKGROUND/AIM: In local staging of gastric adenocarcinoma CT is the modality of choice. Less frequently used in a few selected patients is echo-endoscopy. Aim of this study was to evaluate the accuracy of hydro-multidetector-computed tomography (hydro-MDCT) in the evaluation of gastric adenocarcinomas with subsequent surgical and histopathological correlation to select cases for echo-endoscopy. PATIENTS AND METHODS: A total of 65 patients with gastric adenocarcinomas, diagnosed by endoscopy and biopsy, underwent contrast-enhanced hydro-MDCT with subsequent tumor, nodes, metastases (TNM) classification. The distension of the gastric lumen was obtained after the oral administration of 500 ml of water. RESULTS: Hydro-MDCT always detected gastric cancer and in 49/65 patients the assessment of T-parameter was identical to the histopathological results (accuracy: 75%). We found overstaging in 12 and understaging in 4 cases. N-parameter with MDCT was in agreement with histo-pathology in 69%of patients; in metastatic disease hydro-MDCT had an accuracy of 99%. Hydro-MDCT has proven to be a reliable diagnostic technique in evaluating gastric cancer T3-T4 stages in comparison to T1 and T2: in defining T2-stage we found the highest number of errors (37%). CONCLUSION: Hydro-MDCT is a reliable technique in the preoperative staging of gastric adenocarcinoma. Echo-endoscopy could be particularly useful in doubtful cases to evaluate the muscularis propria infiltration (T2 vs. T3) and characterize the peri-gastric lymph nodes.

Evaluation of Skull Base Tumors with Dynamic TurboFLASH MRI during Gadolinium Injection.

Background and Purpose This study was aimed to investigate the role of dynamic TurboFLASH gadolinium (Gd) magnetic resonance (MR) imaging in improving the differential diagnosis of skull base tumors. Methods Eleven patients with skull base tumors underwent standard MR and ultrafast TurboFLASH sequence during gadolinium injection. Results The characterization of tumor vascularity was performed. Different patterns of gadolinium uptake for each tumor type were observed. This is particularly important to identify tumors at high risk of intraoperative bleeding. All glomus tumors, typically highly vascularized, showed an enhancement at the arterial phase, reflecting the arterialization of these tumors which is not detectable on conventional MR. No signal increase at the arterial phase was instead observed in other cases in which the ruling out of a glomus tumor was important because of the location of the lesion. Moreover TurboFLASH identified the pathognomonic "filling-in" profile of cavernous sinus cavernous hemangiomas (CSCH), that is, the progressive centripetal enhancement of the lesion at the beginning of the venous phase. Conclusion The dynamic analysis of tumor contrast enhancement with the TurboFLASH sequence provides useful additional information to that obtained with conventional MR, improving the differential diagnosis of skull base tumors, particularly in the distinction between glomus and nonglomus tumors and in diagnosing CSCH.