MRI-based detection of renal artery abnormalities related to renal denervation by catheter-based radiofrequency ablation in drug resistant hypertensive patients.

OBJECTIVES: Endovascular renal denervation (RDN) using catheter-based radiofrequency (RF) ablation has emerged as a potential treatment option for drug-resistant hypertension. Its efficacy is currently under debate. We aimed to evaluate the capability of contrast-enhanced magnetic resonance imaging (MRI) to assess the effects of RDN on the renal arterial wall in patients presenting with drug-resistant hypertension. METHODS: Patients were included prospectively following institutional review board approval and written informed consent. Renal arteries were imaged using a two-dimensional T1-weighted TSE sequence pre- and post-administration of a gadolinium-based contrast agent, before (D0), 2 days (D2) and 6 months (M6) after RDN. Mean enhancement of the wall (mENH) and mean wall thickness (mWT) were compared across time using an ANOVA with repeated measures and post-hoc paired t-test. RESULTS: Follow-up was completed for 23 patients (median age, 57 years; 16 men). The mENH at D2 (96.3 ± 36.0 %) was significantly higher than at D0 (61.1 ± 26.3%, p < 0.001) and M6 (66.1±22.7%, p < 0.001). Similarly, mWT was significantly higher at D2 (3.1 ± 0.4 m) than at D0 (2.7 ± 0.4mm, p < 0.001) and M6 (2.9 ± 0. 5 mm, p = 0.002). CONCLUSIONS: MRI demonstrated abnormalities of the arterial wall 2 days after RDN that had resolved at 6 months. KEY POINTS: • Contrast-enhanced MRI provides anatomic evidence of renal artery RF ablation • Temperature increase related to RF ablation induces transient arterial wall inflammation • Morphological effects observed 2 days post RF ablation are not visible after 6 months.

Placenta percreta: urologic complication after successful conservative management by uterine arterial embolization: a case report.

We report a case of placenta accreta that was managed conservatively by uterine arterial embolization and subsequently was complicated by hematuria. Ultrasound revealed a calcified mass at the posterior bladder wall. A careful resection under cystoscopy was carried out without hemorrhagic complication. Pathologic examination showed placental tissue that confirmed placenta percreta.

3D black blood MR angiography of the carotid arteries. A simple sequence for plaque hemorrhage and stenosis evaluation.

OBJECTIVES: To evaluate the diagnostic performance of a new three-dimensional T1-weighted turbo-spin-echo sequence (3D T1-w TSE) compared to 3D contrast-enhanced angiography (CE-MRA) for stenosis measurement and compared to 2D T1-w TSE for intra-plaque hemorrhage (IPH) detection. METHODS: Eighty three patients underwent carotid MRI, using a new elliptic-centric phase encoding T1-weighted 3D TSE sequence in addition to the clinical protocol. Two observers evaluated image quality, presence of flow artifacts, and presence of intra-plaque hemorrhage, and computed the NASCET degree of stenosis for CE-MRA and for the new sequence. Inter-observer agreement and correlation between 3D TSE and CE-MRA for NASCET stenosis was estimated using Cohen's kappa, and correlation using linear regression and Bland-Altman plots. Histology was performed on endarterectomy samples for 18 patients. Sensitivity and specificity of 2D and 3D TSE for IPH diagnosis were computed. RESULTS: 3D TSE showed better image quality than 2D TSE (p<0.05). Interobserver agreement was good (kappa≥0.86). Correlation between 3D TSE and CE-MRA was excellent (R=0.95) for NASCET stenosis. Sensitivity and specificity for IPH diagnosis was 50% and 100% for 2D TSE and 100% and 83% for the 3D TSE. CONCLUSIONS: The new 3D T1-w TSE allows both reliable measures of carotid stenosis, with a slight overestimation compared to CE-MRA (5%), and improved IPH identification, compared to 2D TSE.

Recurrent bleeding within 24 hours after uterine artery embolization for severe postpartum hemorrhage: are there predictive factors?

PURPOSE: To retrospectively identify predictive factors of recurrent bleeding within 24 h after uterine artery embolization (UAE) for postpartum hemorrhage (PPH). MATERIALS AND METHODS: A total of 194 patients underwent UAE for PPH between August 1999 and April 2009 at our institution. Twelve patients experienced recurrent bleeding within the next 24 h; a second attempt at UAE was thus necessary, which was successful in 10 cases. In two cases, hemostatic hysterectomy was performed. Epidemiological, gynecological-obstetrical, anatomic, and biological data were analyzed. RESULTS: Complete data were available for 148 of the 194 (76%) included patients. Sixty-four (43%) were primiparous, 18 (12.2%) had a placenta accreta, 21 (14%) had a coagulopathy, and 28 (18.9%) had an anatomic variant of the uterine arterial vasculature. Mean age and pregnancy term were similar in both recurring and nonrecurrent bleeding groups. After multivariate analysis, three criteria emerged as risk factors of recurrent bleeding: primiparity (10 patients, 83%; odds ratio [OR]=18.84; P=0.014), coagulation disorders (6 patients, 50%; OR=12.08; P=0.006), and anatomic variant of the uterine arterial vasculature (28 patients; OR=9.83; P=0.003). CONCLUSION: Search for uterine collaterals must be performed before UAE for PPH. Primiparity and coagulation disorders increase the risk of recurrent bleeding after UAE for PPH.