MRI of the Carpal Tunnel 3 and 12 Months After Endoscopic Carpal Tunnel Release.

OBJECTIVE. The purpose of this study was to study changes in the median nerve, retinaculum, and carpal tunnel on MRI after successful endoscopic carpal tunnel release (ECTR). SUBJECTS AND METHODS. In this prospective study, 35 wrists in 32 patients (five men, 27 women; mean age, 56.7 ± 6.8 [SD] years) with nerve conduction test-confirmed primary carpal tunnel syndrome were evaluated from May 2013 to September 2016. Clinical scores ranging from 0 to 4 (no improvement to symptoms completely resolved) and MRI morphologic features of median nerve and carpal tunnel were evaluated at baseline and 3 and 12 months after ECTR. The paired t test was used to compare MRI parameters before and after ECTR and their relationships to clinical improvement scores. RESULTS. All patients' conditions improved after ECTR with mean clinical improvement scores of 2.94 ± 1.0 at 3 months and 3.49 ± 0.56 at 12 months. Although median nerve swelling did decrease proximally, the nerve remained swollen (> 15 mm2) and flattened in all areas, even 12 months after ECTR. Additional changes occurred in median nerve caliber-change ratio, relative signal intensity, and carpal tunnel cross-sectional area. A retinacular gap was present in 33 (94%) wrists 3 months and six (17%) wrists 12 months after ECTR, and increased retinacular bowing persisted. CONCLUSION. After ECTR, undue swelling and flattening of the median nerve persist as long as 12 months after surgery, even in patients with a good surgical outcome. One should be wary of using these MRI findings as signs of persistent neural compression. The retinaculum reforms in most patients within 12 months of surgery but with a more bowed configuration.

Inadvertent arterial & venous injury by bone marrow biopsy needle: case report on rescue embolization techniques.

BACKGROUND: Bone marrow biopsy is a common medical procedure for diagnosis and characterization of haematological diseases. It is generally regarded as a safe procedure with low rate of major complications. Inadvertent vascular injury is however an uncommon but important complication of bone marrow biopsy procedure. The knowledge of a safe and effective embolization method is crucial for interventional radiologists to reduce significant patient morbidity and mortality, shall such inadvertent vascular injury occurs. CASE PRESENTATION: Bedside bone marrow biopsy was performed for an elderly gentleman to evaluate for his underlying acute leukaemia. Biopsy needle inadvertently injured the internal iliac artery and vein during the procedure. Coil embolization was carefully performed across injured arterial segment via the culprit biopsy needle until contrast cessation. Concomitant venous injury was subsequently confirmed on angiography when the needle was withdrawn for a short distance from the iliac artery. This venous injury was tackled by further withdrawing the biopsy needle to distal end of the bone marrow tract for tract embolization with coils and gelatin sponges. High caution was made to avoid coil dislodgement into the iliac vein, to prevent pulmonary embolism. Patient was clinically stable throughout the procedure. Post-procedure contrast CT shows no pelvic haematoma or contrast extravasation. CONCLUSIONS: This case illustrates rescue embolization techniques for rare life-threatening concomitant internal iliac arterial and venous injuries by a bone marrow biopsy needle. Interventional radiologists can play an important role in carrying out precise embolization to avoid significant patient morbidity and mortality in the case of life-threatening haemorrhage.

Percutaneous Portal Vein Embolization Using a Simplified Sheathless 18-Gauge Trocar Needle Approach: Review of Efficacy and Safety.

PURPOSE: Portal vein (PV) embolization (PVE) is traditionally performed via a PV sheath with selective embolization of PV branches. Here, the efficacy and safety of PVE with the use of only an 18-gauge needle is reported. MATERIALS AND METHODS: Consecutive patients who underwent PVE from 2009 through 2017 were retrospectively reviewed. Forty-five patients (mean age, 60 y ± 7.6; 38 men) underwent 45 PVE procedures. Hepatocellular carcinoma, cholangiocarcinoma, and metastases accounted for 26 (58%), 13 (29%), and 6 (13%) patients, respectively. PVE was performed by puncturing a branch of right PV with an 18-gauge needle under US guidance. Via the same needle, direct portography was performed, followed by PVE with an N-butyl cyanoacrylate/Lipiodol mixture. Percentage increase of future liver remnant (FLR) volume and increase in ratio of FLR to total liver volume were estimated as measures of efficacy. Complications were reported according to Society of Interventional Radiology classification. Fluoroscopy time, procedure time, and dose-area product (DAP) were recorded. RESULTS: Technical success rate was 100%. The median DAP, fluoroscopy time, and procedure time were 74,387 mGy·cm2 (IQR, 90,349 mGy·cm2), 3.5 min (IQR, 2.10 min), and 24 min (IQR, 10.5 min). Among the 23 patients with complete CT volumetry data, mean increase in the ratio of FLR to total liver volume and percentage increase of FLR volume were 12.5% ± 7.7 and 50% ± 33, respectively. There were 3 minor complications (asymptomatic nonocclusive emboli in FLR) and 3 major complications (1 hepatic vein emboli, 1 subphrenic collection, and 1 hepatic infarct). CONCLUSIONS: PVE via a sheathless 18-gauge needle approach is feasible, with satisfactory FLR hypertrophy.

CT brain artefact due to air bubbles in the oil cooling system: characteristic band-like configuration on sagittal reformatted image.

PURPOSE: To retrospectively review the imaging characteristics of CT artefacts due to air bubbles within the oil cooling system of the X-ray tube housing. MATERIALS AND METHODS: Air bubbles were introduced into the oil cooling system of the X-ray tube housing during tube replacement in one of the CT scanners in the authors' institution. All 126 CT brain studies performed in this period were retrospectively reviewed. One hundred and four studies were negative for artefacts. Artefacts were confirmed in 5 and considered probable in 17 studies, respectively. The imaging characteristics of artefacts in these 22 cases were analysed. RESULTS: All artefacts manifested as ill-defined hypoattenuations in the periventricular/subcortical white matter of bilateral cerebral hemispheres with/without involvement of the internal capsule and basal ganglia. The posterior fossa was also involved in two (40%) confirmed and four (24%) probable studies. A band-like configuration of hypoattenuations on sagittal images was observed in five (100%) confirmed and eight (47%) probable studies. CONCLUSION: Air bubble artefacts manifested as hypoattenuations in the periventricular/subcortical white matter of the supratentorial brain. A characteristic band-like configuration was observed in the sagittal reformatted image, which is useful for differentiating it from periventricular small vessel disease.