Shear wave elastography is a valuable tool for diagnosing and grading carpal tunnel syndrome.

OBJECTIVE: To quantify the shear velocity and stiffness of the median nerve (MN) with shear wave elastography (SWE) at the carpal tunnel entrance and determine whether SWE is useful for diagnosing and staging carpal tunnel syndrome (CTS). MATERIALS AND METHODS: The study included 58 patients (79 wrists) with clinical and electroneuromyographic diagnoses of CTS and 55 healthy controls (63 wrists). MN shear velocity and stiffness were measured by SWE on the axial plane in both groups. The differences between CTS patients and controls and between different grades of CTS based on electrodiagnostic tests were studied using Student's t test and ANOVA with ROC analysis. RESULTS: The mean MN shear velocity and stiffness were significantly greater in CTS patients (2.5 ± 0.37 m/s and 19.4 ± 5.8 kPa) than in controls (1.91 ± 0.24 m/s and 11.1 ± 3.0 kPa) (p < 0.001) and greater in the severe CTS group (2.69 ± 0.39 m/s and 22.4 ± 7.1 kPa) than in the mild CTS group (2.37 ± 0.35 m/s and 17.3 ± 4,8 kPa). The cutoff value for the shear velocity was 2.13 m/s, with 86% and 82% sensitivity and specificity, respectively, and the cutoff value for stiffness was 13.6 kPa, with 87% and 82% sensitivity and specificity. CONCLUSION: MN shear velocity and stiffness are significantly higher in CTS patients. SWE can be used to diagnose CTS and distinguish between patients with mild and severe disease.

Lung radiofrequency ablation: post-procedure imaging patterns and late follow-up.

PURPOSE: To describe expected imaging features on chest computed tomography (CT) after percutaneous radiofrequency ablation (RFA) of lung tumors, and their frequency over time after the procedure. METHODS: In this double-center retrospective study, we reviewed CT scans from patients who underwent RFA for primary or secondary lung tumors. Patients with partial ablation or tumor recurrence during the imaging follow-up were not included. The imaging features were assessed in pre-defined time points: immediate post-procedure, ≤4 weeks, 5-24 weeks, 25-52 weeks and ≥52 weeks. Late follow-up (3 and 5 years after procedure) was assessed clinically in 48 patients. RESULTS: The study population consisted of 69 patients and 144 pulmonary tumors. Six out of 69 (9%) patients had primary lung nodules (stage I) and 63/69 (91 %) had metastatic pulmonary nodules. In a patient-level analysis, immediately after lung RFA, the most common CT features were ground glass opacities (66/69, 96 %), consolidation (56/69, 81 %), and hyperdensity within the nodule (47/69, 68 %). Less than 4 weeks, ground glass opacities (including reversed halo sign) was demonstrated in 20/22 (91 %) patients, while consolidation and pleural thickening were detected in 17/22 patients (77 %). Cavitation, pneumatocele, pneumothorax and pleural effusions were less common features. From 5 weeks onwards, the most common imaging features were parenchymal bands. CONCLUSIONS: Our study demonstrated the expected CT features after lung RFA, a safe and effective minimally invasive treatment for selected patients with primary and secondary lung tumors. Diagnostic and interventional radiologists should be familiar with the expected imaging features immediately after RFA and their change over time in order to avoid misinterpretation and inadequate treatments.

Abdominal manifestations of fishbone perforation: a pictorial essay.

PURPOSE: The present article provides an overview of the spectrum of abdominal presentations of fishbone (FB) ingestion and its complications. METHODS: In image data from 9 patients, FB perforations were found in different levels of the gastrointestinal tract (GIT), including duodenal, jejunal, and sigmoid perforations; in 4 asymptomatic patients, FBs were observed in the mesentery, falciform ligament, and intestinal bowel. RESULTS: The main imaging features of FB perforation were focal gastric or intestinal wall thickening, fat stranding, bowel obstruction, ascites, localized pneumoperitoneum, intra-abdominal abscess, liver abscess, and a linear hyperdense structure in the abdominal cavity in the GIT or within a parenchymal organ often surrounded by inflammatory changes. Free pneumoperitoneum was rare. CONCLUSION: Although in most cases, a FB does not cause any serious complications, an inflammatory process and complications may occur when it perforates the stomach or bowel loops. Radiologists need to be aware of the possibility of FB perforation, especially in high-risk patients, because it is not always considered in the differential diagnosis by referring physicians and can mimic other inflammatory conditions and tumoral lesions.