Orthopaedic metallic artefact reduction algorithm facilitates CT evaluation of the urinary tract after hip prosthesis.

AIM: To examine the improvement in the visualisation of bladder and ureteric pathologies next to a hip prosthesis with metallic artefact reduction for orthopaedic implants (O-MAR). MATERIALS AND METHODS: Thirty-four patients who underwent pelvic computed tomography (CT) for non-prosthesis-related causes were enrolled retrospectively. Portal venous phase scans were reconstructed both with standard iterative reconstruction (ITR) and with O-MAR. The density of the ureters and the bladder was measured at both sides in the plane of the prosthesis. A semi-quantitative score was also used to assess visibility. The R (version 3.4.1) package was used for statistical analysis. RESULTS: The average (µ) density of the 41 prosthesis side ureters was significantly lower on ITR images (µ=-94.76±150.48 [±SD] HU) than on O-MAR images (µ=-13.40±36.37 HU; p<0.0004). The difference between the ITR and O-MAR (µ=-138.62±182.64 versus -35.55±40.21 HU; p<0.0003) was also significant at the prosthesis side of the bladder. The visibility of the prosthesis side ureters was improved: 53.7% was obscured on ITR series compared to 4.9% on O-MAR. The visibility score was also better across all levels (p<0.001) with O-MAR. In four cases (13%), the O-MAR images significantly changed the diagnosis: in two cases ureteric stones, in one case each a bladder stone and a bladder tumour were discovered. CONCLUSIONS: O-MAR reconstruction of CT images significantly improves the visibility of the urinary tract adjacent to metallic hip implants. Thus, O-MAR is essential for detecting ureteric and bladder pathologies in patients with a hip prosthesis.

Prognostic value of pre-embolisation MRI features of uterine fibroids in uterine artery embolisation.

AIM: To evaluate the prognostic value of pretreatment pelvic magnetic resonance imaging (MRI) features in uterine artery embolisation (UAE) for symptomatic fibroids. MATERIALS AND METHODS: MRI characteristics of 109 fibroids (≥3 cm) in 70 patients were analysed retrospectively. Imaging was performed 1.8±1.3 (SD) months before and 6.6±1.8 months after UAE. On pretreatment images, signal intensity (SI) of fibroids was compared with that of the myometrium and skeletal muscle on T1- and T2-weighted sequences; the contrast enhancement pattern and localisation of fibroids were also analysed. Fibroid volume reduction (VR) was assessed by control imaging. The numerical analogue quality-of-life score was obtained before and after UAE. Statistical analysis was performed using the Mann-Whitney U-test, Kruskal-Wallis test, and Wilcoxon signed-rank test. RESULTS: The mean fibroid volume decreased by 51.1±30.8% during the 6.6±1.8 months (p<0.001). Mean quality-of-life score improved by 48.2±27.6 points (p<0.001). The mean VR of submucosal fibroids (82.1±18.5%) was greater than that of intramural (49.4±30.7%) and subserosal (43±28.3%) fibroids (p<0.001 for both). Fibroids that were isointense/hyperintense to myometrium on T2-weighted images showed a better response than hypointense fibroids (63.7±25.8% versus 48.6±31.3%, respectively; p=0.041). On contrast-enhanced images, isointense/hyperintense fibroids showed a better VR than hypointense fibroids (61.3±27.4% versus 47.6±31.6%, respectively; p=0.035). Baseline fibroid volume of <50 cm3 was also associated with favourable imaging outcome (p=0.021). T2 SI compared to skeletal muscle and T1 SI compared to myometrium or skeletal muscle did not show association with VR. CONCLUSIONS: Localisation, T2 SI, contrast enhancement, and <50 cm3 fibroid volume were associated with better VR; these may help with treatment decisions.

Ultrasonography in the diagnosis and monitoring of ascites in acute abdominal attacks of hereditary angioneurotic oedema.

BACKGROUND: Hereditary angioneurotic oedema (HAE) is a rare cause of ascites. As acute abdominal attacks of the disease can mimic surgical emergencies, prompt and accurate diagnosis is essential. This study was undertaken to evaluate the usefulness of serial abdominal ultrasound (US) examinations. PATIENTS AND METHODS: Seventy patients with HAE were followed up for almost a decade. All patients presenting with an acute oedematous attack underwent abdominal US, which was then repeated 24 and 48 h after appropriate therapy. RESULTS: Twenty-two acute oedematous attacks with abdominal complaints severe enough to justify hospital admission occurred in the study population. Abdominal US performed during the attack showed oedematous thickening of the intestinal wall in 80% of cases and invariably demonstrated the presence of free peritoneal fluid in all patients. Rapid symptomatic relief achieved by treatment was accompanied by the significant regression of US abnormalities. CONCLUSIONS: Transitory ascites demonstrated by abdominal US is a clue to the diagnosis of an acute abdominal attack of HAE. The possibility of HAE should always be considered whenever unexplained abdominal pain recurs with or without ascites.