Artificial Intelligence-Based 3D Angiography for Visualization of Complex Cerebrovascular Pathologies.

BACKGROUND AND PURPOSE: By means of artificial intelligence, 3D angiography is a novel postprocessing method for 3D imaging of cerebral vessels. Because 3D angiography does not require a mask run like the current standard 3D-DSA, it potentially offers a considerable reduction of the patient radiation dose. Our aim was an assessment of the diagnostic value of 3D angiography for visualization of cerebrovascular pathologies. MATERIALS AND METHODS: 3D-DSA data sets of cerebral aneurysms (n CA = 10), AVMs (n AVM = 10), and dural arteriovenous fistulas (dAVFs) (n dAVF = 10) were reconstructed using both conventional and prototype software. Corresponding reconstructions have been analyzed by 2 neuroradiologists in a consensus reading in terms of image quality, injection vessel diameters (vessel diameter [VD] 1/2), vessel geometry index (VGI = VD1/VD2), and specific qualitative/quantitative parameters of AVMs (eg, location, nidus size, feeder, associated aneurysms, drainage, Spetzler-Martin score), dAVFs (eg, fistulous point, main feeder, diameter of the main feeder, drainage), and cerebral aneurysms (location, neck, size). RESULTS: In total, 60 volumes have been successfully reconstructed with equivalent image quality. The specific qualitative/quantitative assessment of 3D angiography revealed nearly complete accordance with 3D-DSA in AVMs (eg, mean nidus size3D angiography/3D-DSA= 19.9 [SD, 10.9]/20.2 [SD, 11.2] mm; r = 0.9, P = .001), dAVFs (eg, mean diameter of the main feeder3D angiography/3D-DSA= 2.04 [SD, 0.65]/2.05 [SD, 0.63] mm; r = 0.9, P = .001), and cerebral aneurysms (eg, mean size3D angiography/3D-DSA= 5.17 [SD, 3.4]/5.12 [SD, 3.3] mm; r = 0.9, P = .001). Assessment of the geometry of the injection vessel in 3D angiography data sets did not differ significantly from that of 3D-DSA (vessel geometry indexAVM: r = 0.84, P = .003; vessel geometry indexdAVF: r = 0.82, P = .003; vessel geometry indexCA: r = 0.84, P <.001). CONCLUSIONS: In this study, the artificial intelligence-based 3D angiography was a reliable method for visualization of complex cerebrovascular pathologies and showed results comparable with those of 3D-DSA. Thus, 3D angiography is a promising postprocessing method that provides a significant reduction of the patient radiation dose.

MRzero - Automated discovery of MRI sequences using supervised learning.

PURPOSE: A supervised learning framework is proposed to automatically generate MR sequences and corresponding reconstruction based on the target contrast of interest. Combined with a flexible, task-driven cost function this allows for an efficient exploration of novel MR sequence strategies. METHODS: The scanning and reconstruction process is simulated end-to-end in terms of RF events, gradient moment events in x and y, and delay times, acting on the input model spin system given in terms of proton density, T1 and T2 , and ΔB0 . As a proof of concept, we use both conventional MR images and T1 maps as targets and optimize from scratch using the loss defined by data fidelity, SAR penalty, and scan time. RESULTS: In a first attempt, MRzero learns gradient and RF events from zero, and is able to generate a target image produced by a conventional gradient echo sequence. Using a neural network within the reconstruction module allows arbitrary targets to be learned successfully. Experiments could be translated to image acquisition at the real system (3T Siemens, PRISMA) and could be verified in the measurements of phantoms and a human brain in vivo. CONCLUSIONS: Automated MR sequence generation is possible based on differentiable Bloch equation simulations and a supervised learning approach.

[Renal cell carcinoma of the kidney transplant: The French guidelines from CTAFU]. / Recommandations françaises du Comité de transplantation de l'association française d'urologie (CTAFU) : Carcinome à cellules rénales du transplant rénal.

OBJECTIVE: To propose recommendations for the management of renal cell carcinomas (RCC) of the renal transplant. METHOD: Following a systematic approach, a review of the literature (Medline) was conducted by the CTAFU to evaluate prevalence, diagnosis and management of RCC arousing in the renal transplant. References were assessed according to a predefined process to propose recommendations with levels of evidence. RESULTS: Renal cell carcinomas of the renal transplant affect approximately 0.2% of recipients. Mostly asymptomatic, these tumors are mainly diagnosed on a routine imaging of the renal transplant. Predominant pathology is clear cell carcinomas but papillary carcinomas are more frequent than in general population (up to 40-50%). RCC of the renal transplant is often localized, of low stage and low grade. According to tumor characteristics and renal function, preferred treatment is radical (transplantectomy) or nephron sparing through partial nephrectomy (open or minimally invasive approach) or thermoablation after percutaneous biopsy. Although no robust data support a switch of immunosuppressive regimen, some authors suggest to favor the use of mTOR inhibitors. CTAFU does not recommend a mandatory waiting time after transplantectomy for RCC in candidates for a subsequent renal tranplantation when tumor stage

[Localized Prostate cancer in candidates for renal transplantation and recipients of a kidney transplant: The French Guidelines from CTAFU]. / Recommandations françaises du Comité de transplantation de l'Association française d'urologie (CTAFU) : cancer de la prostate localisé chez le patient transplanté rénal ou en attente de transplantation.

OBJECTIVE: To define guidelines for the management of localized prostate cancer (PCa) in kidney transplant (KTx) candidates and recipients. METHOD: A systematic review (Medline) of the literature was conducted by the CTAFU to report prostate cancer epidemiology, screening, diagnosis and management in KTx candidates and recipients with the corresponding level of evidence. RESULTS: KTx recipients are at similar risk for PCa as general population. Thus, PCa screening in this setting is defined according to global French guidelines from CCAFU. Systematic screening is proposed in candidates for renal transplant over 50 y-o. PCa diagnosis is based on prostate biopsies performed after multiparametric MRI and preventive antibiotics. CCAFU guidelines remain applicable for PCa treatment in KTx recipients with some specificities, especially regarding lymph nodes management. Treatment options in candidates for KTx need to integrate waiting time and access to transplantation. Current data allows the CTAFU to propose mandatory waiting times after PCa treatment in KTx candidates with a weak level of evidence. CONCLUSION: These French recommendations should contribute to improve PCa management in KTx recipients and candidates, integrating oncological objectives with access to transplantation.

[Lower urinary tract symptoms and urinary incontinence in renal transplant recipients and candidates: The French guidelines from CTAFU]. / Recommandations françaises du Comité de transplantation de l'association française d'urologie (CTAFU) : symptômes du bas appareil urinaire et incontinence urinaire chez le patient transplanté ou en attente de transplantation rénale.

OBJECTIVE: To propose surgical recommendations for the management of lower urinary tract symptoms (LUTS) and urinary incontinence in kidney transplant recipients and candidates. METHOD: Following a systematic approach, a review of the literature (Medline) was conducted by the CTAFU focusing on medical and surgical treatment of LUTS and urinary incontinence in kidney transplant recipients and candidates. References were assessed according to a predefined process to propose recommendations with levels of evidence. RESULTS: Functional bladder capacity and bladder compliance are impaired during dialysis. LUTS, related to pre-kidney transplantion alterations, frequently improve spontaneously after kidney transplantation. LUTS secondary to benign prostatic hyperplasia (BPH) may be underestimated before kidney transplantation due to oliguria, low bladder compliance and low bladder capacity. In LUTS associated with BPH, anticholinergics require dosage adjustment with creatinine clearance. If surgery is indicated after kidney transplantation, procedure can be safely performed in the early post-transplant course after removal of ureteral stent. Surgical management of urinary incontinence does not seem to be associated with an icreased risk for infectious complications in kidney transplant recipients. Particular attention should be paid to the management of postvoid residual and bladder pressures in case of neurological bladder disease. Optimal care of neurological bladder should be provided prior to transplantation: with a cautious management, and despite an increased occurrence of febrile urinary tract infections, transplant survival is not compromised. CONCLUSION: These recommendations must contribute to improve the management of lower urinary tract symptoms and urinary incontinence in kidney transplant patients and kidney transplant candidates.

[Urinary stones in renal transplant recipients and donors: The French guidelines from CTAFU]. / Recommandations françaises du Comité de transplantation de l'association française d'urologie (CTAFU) : lithiase urinaire chez le receveur ou le donneur en transplantation rénale.

OBJECTIVE: To define guidelines for the management of kidney stones in kidney transplant (KTx) donor or recipients. METHOD: Following a systematic approach, a review of the literature (Medline) was conducted by the CTAFU to report kidney stone epidemiology, diagnosis and management in KTx donors and recipients with the corresponding level of evidence. RESULTS: Prevalence of kidney stones in deceased donor is unknown but reaches 9.3% in living donors in industrialized countries. Except in Maastrich 2 donors, diagnosis is done on systematic pre-donation CT scan according to standard french procedure. No prospective study has compared therapeutic strategies available for the management of kidney stones in KTx donor: ureteroscopy or an extra corporeal lithotripsy in case of living donor prior to donation, ex vivo approach (pyelotomy or ureteroscopy), ureterocopy in the KTx recipient or surveillance. De novo kidney stones result from a lithogenesis process to be identified and treated in order to avoid recurrences. The context of solitary functional kidney renders the prevention of recurrence of great importance. Diagnosis is suspected when identification of a renal graft dysfunction, hematuria or urinary tract infection with renal pelvis dilatation. Stone size and location are determined by computed tomography. There are no prospective, controlled studies on kidney stone management in the KTx. The therapeutic strategies are similar to standard management in general population. CONCLUSION: These French recommendations should contribute to improve kidney stones management in KTx donor and recipients.

Quantitative and Qualitative Comparison of 4D-DSA with 3D-DSA Using Computational Fluid Dynamics Simulations in Cerebral Aneurysms.

BACKGROUND AND PURPOSE: 4D-DSA allows time-resolved 3D imaging of the cerebral vasculature. The aim of our study was to evaluate this method in comparison with the current criterion standard 3D-DSA by qualitative and quantitative means using computational fluid dynamics. MATERIALS AND METHODS: 3D- and 4D-DSA datasets were acquired in patients with cerebral aneurysms. Computational fluid dynamics analysis was performed for all datasets. Using computational fluid dynamics, we compared 4D-DSA with 3D-DSA in terms of both aneurysmal geometry (quantitative: maximum diameter, ostium size [OZ1/2], volume) and hemodynamic parameters (qualitative: flow stability, flow complexity, inflow concentration; quantitative: average/maximum wall shear stress, impingement zone, low-stress zone, intra-aneurysmal pressure, and flow velocity). Qualitative parameters were descriptively analyzed. Correlation coefficients (r, P value) were calculated for quantitative parameters. RESULTS: 3D- and 4D-DSA datasets of 10 cerebral aneurysms in 10 patients were postprocessed. Evaluation of aneurysmal geometry with 4D-DSA (r maximum diameter = 0.98, P maximum diameter <.001; r OZ1/OZ2 = 0.98/0.86, P OZ1/OZ2 < .001/.002; r volume = 0.98, P volume <.001) correlated highly with 3D-DSA. Evaluation of qualitative hemodynamic parameters (flow stability, flow complexity, inflow concentration) did show complete accordance, and evaluation of quantitative hemodynamic parameters (r average/maximum wall shear stress diastole = 0.92/0.88, P average/maximum wall shear stress diastole < .001/.001; r average/maximum wall shear stress systole = 0.94/0.93, P average/maximum wall shear stress systole < .001/.001; r impingement zone = 0.96, P impingement zone < .001; r low-stress zone = 1.00, P low-stress zone = .01; r pressure diastole = 0.84, P pressure diastole = .002; r pressure systole = 0.9, P pressure systole < .001; r flow velocity diastole = 0.95, P flow velocity diastole < .001; r flow velocity systole = 0.93, P flow velocity systole < .001) did show nearly complete accordance between 4D- and 3D-DSA. CONCLUSIONS: Despite a different injection protocol, 4D-DSA is a reliable basis for computational fluid dynamics analysis of the intracranial vasculature and provides equivalent visualization of aneurysm geometry compared with 3D-DSA.

[Renal, vascular and urological variations and abnormalities in living kidney donor candidates]. / Variations et anomalies néphrologiques, vasculaires et urologiques chez les candidats au don vivant rénal.

INTRODUCTION: The aim of this study was to determine the prevalence of anatomic variations (renal, vascular and urological) and acquired renal pathologies in living kidney donor candidates (LKDC). METHODS: This is a retrospective study of all LKDC referred to our center between April 2003 and September 2014. Of the 491 LKDC, 189 were initially excluded for medical reasons (n=140) or others reasons (n=49), without undergoing a radiological assessment. In total, 302 had a radiological assessment (angio-CT or MRI) in anticipation of the donation and 226/302 (73.5%) could donate a kidney. RESULTS: One or more anatomical variations and/or acquired abnormalities were observed in 178/302 (58.9%) of the LKDC. The most frequent were arterial variations or abnormalities (multiple arteries, fibrodysplasia, aneurysms, stenosis≥70%) which where observed in 39.3% of the LKDC, followed by the venous abnormalities (27.8%). Kidney stones were observed in 5.6% of the LKDC and the urinary abnormalities (duplication/ureteral bifidity) were found in 3% of the LKDC. No malignant tumour was diagnosed, while 4 benign tumours (1.3%) were identified, and one of them required additional investigations. CONCLUSION: We found a high prevalence of anatomical variations and acquired abnormalities in a population of LKDC. However, these findings resulted in the exclusion of only 4% of the candidates, because they did not contraindicate the donation or, in most of cases, the contralateral kidney could be used. LEVEL OF EVIDENCE: 3.

Ultraearly assessed reperfusion status after middle cerebral artery recanalization predicting clinical outcome.

OBJECTIVES: Mechanical thrombectomy has high evidence in stroke therapy; however, successful recanalization guarantees not a favorable clinical outcome. We aimed to quantitatively assess the reperfusion status ultraearly after successful middle cerebral artery (MCA) recanalization to identify flow parameters that potentially allow predicting clinical outcome. MATERIALS AND METHODS: Sixty-seven stroke patients with acute MCA occlusion, undergoing recanalization, were enrolled. Using parametric color coding, a post-processing algorithm, pre-, and post-interventional digital subtraction angiography series were evaluated concerning the following parameters: pre- and post-procedural cortical relative time to peak (rTTP) of MCA territory, reperfusion time, and index. Functional long-term outcome was assessed by the 90-day modified Rankin Scale score (mRS; favorable: 0-2). RESULTS: Cortical rTTP was significantly shorter before (3.33 ± 1.36 seconds; P = .03) and after intervention (2.05 ± 0.70 seconds; P = .003) in patients with favorable clinical outcome. Additionally, age (P = .005) and initial National Institutes of Health Stroke Scale score (P = .02) were significantly different between the patients, whereas reperfusion index and time as well as initially estimated infarct size were not. In multivariate analysis, only post-procedural rTTP (P = .005) was independently associated with favorable clinical outcome. 2.29 seconds for post-procedural rTTP might be a threshold to predict favorable clinical outcome. CONCLUSIONS: Ultraearly quantitative assessment of reperfusion status after successful MCA recanalization reveals post-procedural cortical rTTP as possible independent prognostic value in predicting favorable clinical outcome, even determining a threshold value might be possible. In consequence, focusing stroke therapy on microcirculatory patency could be valuable to improve outcome.

Surgical management of renal cell carcinoma with levels III and IV tumor thrombus using the « flush ¼ technique.

OBJECTIVE: To determinate feasibility and results of the flush technique by hands for the surgical management of renal cell carcinoma (RCC) with levels III and IV inferior vena cava thrombus (VCT). MATERIALS AND METHODS: We conducted a retrospective study for all patients who underwent a surgical treatment for RCC with levels III and IV VCT in our department between June 2010 and July 2017. Sixteen patients were identified. RESULTS: All tumors were resected using a subcostal incision for right RCC and a chevron incision for the left RCC. Vena cava control was performed only on its subhepatic portion. After renal artery ligature, anesthesiologists were asked to generate a positive pressure in the small circulation. Subsequently, the vena cava was incised longitudinally to the orifice of the renal vein and the thrombus dissected and extracted of the upper part of the vena cava. Only once the supra-renal part of the vena cava was free of thrombus, the supra-renal portion of the vena cava could be clamped. We never had to perform neither thoracotomy nor hepatic mobilization. Therefore, support of a hepatic, vascular or cardiac surgeon was not necessary. The mean operative time was 201 min. The mean estimated blood loss was 2040 ml. No patient died during hospitalization, and mean hospitalization stay duration was 16.6 days. CONCLUSION: The flush technique allows a limitation of the dissection extent. It requires neither hepatic mobilization nor thoracotomy. This results in a decrease in the operative time and blood loss.

Overall survival and oncological outcomes after partial nephrectomy and radical nephrectomy for cT2a renal tumors: A collaborative international study from the French kidney cancer research network UroCCR.

BACKGROUND: Partial nephrectomy (PN) is recommended as first-line treatment for cT1 stage kidney tumors because of a better renal function and probably a better overall survival than radical nephrectomy (RN). For larger tumors, PN has a controversial position due to lack of evidence showing good cancer control. The aim of this study was to compare the results of PN and RN in cT2a stage on overall survival and oncological results. METHOD: A retrospective international multicenter study was conducted in the frame of the French kidney cancer research network (UroCCR). We considered all patients aged≥18 years who underwent surgical treatment for localized renal cell carcinoma (RCC) stage cT2a (7.1-10cm) between 2000 and 2014. Cox and Fine-Gray models were performed to analyze overall survival (OS), cancer specific survival (CSS) and cancer-free survival (CFS). Comparison between PN and RN was realized after an adjustment by propensity score considering predefined confounding factors: age, sex, tumor size, pT stage of the TNM classification, histological type, ISUP grade, ASA score. RESULTS: A total of 267 patients were included. OS at 3 and 5 years was 93.6% and 78.7% after PN and 88.0% and 76.2% after RN, respectively. CSS at 3 and 5 years was 95.4% and 80.2% after PN and 91.0% and 85.0% after RN. No significant difference between groups was found after propensity score adjustment for OS (HR 0.87, 95% CI: 0.37-2.05, P=0.75), CSS (HR 0.52, 95% CI: 0.18-1.54, P=0.24) and CFS (HR 1.02, 95% CI: 0.50-2.09, P=0.96). CONCLUSION: PN seems equivalent to RN for OS, CSS and CFS in cT2a stage kidney tumors. The risk of recurrence is probably more related to prognostic factors than the surgical technique. The decision to perform a PN should depend on technical feasibility rather than tumor size, both to imperative and elective situation. LEVEL OF EVIDENCE: 4.

Management of renal transplant urolithiasis: a multicentre study by the French Urology Association Transplantation Committee.

PURPOSE: Urolithiasis is rare among renal transplant recipients and its management has not been clearly defined. METHODS: This multicentre retrospective study was organised by the Comité de Transplantation de l'Association Française d'Urologie (French Urology Association transplantation committee). Statistical analysis was performed with SPSS 19 software. RESULTS: Ninety-five patients were included in this study. Renal transplant urolithiasis was an incidental finding in 55% of cases, mostly on a routine follow-up ultrasound examination. One half of symptomatic stones were due to urinary tract infection and the other half were due to an episode of acute renal failure. The initial management following diagnosis of urolithiasis was double J stenting (27%), nephrostomy tube placement (21%), or watchful waiting (52%). Definitive management consisted of: watchful waiting (48%), extracorporeal lithotripsy (13%), rigid or flexible ureteroscopy (26%), percutaneous nephrolithotomy (11%) and surgical pyelotomy (2%). All transplants remained functional following treatment of the stone. The main limitation is the retrospective design. CONCLUSIONS: The incidence of lithiasis could be higher in kidney transplanted patients due to a possible anatomical or metabolical abnormalities. The therapeutic management of renal transplant urolithiasis appears to be comparable to that of native kidney urolithiasis.

4D DSA for Dynamic Visualization of Cerebral Vasculature: A Single-Center Experience in 26 Cases.

BACKGROUND AND PURPOSE: 4D DSA allows acquisition of time-resolved 3D reconstructions of cerebral vessels by using C-arm conebeam CT systems. The aim of our study was to evaluate this new method by qualitative and quantitative means. MATERIALS AND METHODS: 2D and 4D DSA datasets were acquired in patients presenting with AVMs, dural arteriovenous fistulas, and cerebral aneurysms. 4D DSA was compared with 2D DSA in a consensus reading of qualitative and quantitative parameters of AVMs (eg, location, feeder, associated aneurysms, nidus size, drainage, Martin-Spetzler Score), dural arteriovenous fistulas (eg, fistulous point, main feeder, diameter of the main feeder, drainage), and cerebral aneurysms (location, neck configuration, aneurysmal size). Identifiability of perforators and diameters of the injection vessel (ICA, vertebral artery) were analyzed in 2D and 4D DSA. Correlation coefficients and a paired t test were calculated for quantitative parameters. The effective patient dose of the 4D DSA protocol was evaluated with an anthropomorphic phantom. RESULTS: In 26 patients, datasets were acquired successfully (AVM = 10, cerebral aneurysm = 10, dural arteriovenous fistula = 6). Qualitative and quantitative evaluations of 4D DSA in AVMs (nidus size: r = 0.99, P = .001), dural arteriovenous fistulas (diameter of the main feeder: r = 0.954, P = .03), and cerebral aneurysms (aneurysmal size: r = 1, P = .001) revealed nearly complete accordance with 2D DSA. Perforators were comparably visualized with 4D DSA. Measurement of the diameter of the injection vessel in 4D DSA was equivalent to that in 2D DSA (P = .039). The effective patient dose of 4D DSA was 1.2 mSv. CONCLUSIONS: 4D DSA is feasible for imaging of AVMs, dural arteriovenous fistulas, and cerebral aneurysms. 4D DSA offers reliable visualization of the cerebral vasculature and may improve the understanding and treatment of AVMs and dural arteriovenous fistulas. The number of 2D DSA acquisitions required for an examination may be reduced through 4D DSA.

Prostate cancer before renal transplantation: A multicentre study.

INTRODUCTION: The surgical issues of renal transplantation (RT) after localized prostate cancer (PC) treatment and oncological outcomes after transplantation in patients on the waiting list with a history of PC were unknown. We conducted a retrospective multicentre study including all patients with PC diagnosed before the kidney transplantation. METHODS: Fifty-two patients were included from December 1993 to December 2015. The median age at diagnosis of PC was 59.8years old. RESULTS: The median PSA rate at diagnosis was 7ng/mL. Twenty-seven, Twenty-four, and one PC were respectively low, intermediate and high risk according to d'Amico classification. Forty-three patients were treated by radical prostatectomy (RP): 28 retropubic, 15 laparoscopic and 3 by a perineal approach. Eighteen patients had a lymph node dissection. Four patients were treated with external radiotherapy and 2 by brachytherapy. Eight patients underwent radiotherapy after surgery. The median time between PC treatment and RT was 35.7 months. The median operating time for the renal transplantation was 180min (IQR 150-190; min 90-max 310) with a median intraoperative bleeding of 200mL (IQR 100-290; min 50-max 2000). A history of lymphadenectomy did not significantly lengthen operative time (P=0.34). No recurrence of PC was observed after a median follow of 36months. CONCLUSION: PC discovered before RT should be treated with RP to assess the risk of recurrence and decrease waiting for a RT. If the PC is at low risk of recurrence, it seems possible to shorten the waiting time before the RT after a multidisciplinary discussion meeting. LEVEL OF EVIDENCE: 4.

FRED Flow Diverter: A Study on Safety and Efficacy in a Consecutive Group of 50 Patients.

BACKGROUND AND PURPOSE: Endovascular flow diverters are increasingly used for the treatment of cerebral aneurysms. We assessed the safety and efficacy of the Flow-Redirection Endoluminal Device (FRED) in a consecutive series of 50 patients. MATERIALS AND METHODS: Inclusion criteria were wide-neck, blister-like, or fusiform/dissecting aneurysms independent of size, treated with the FRED between February 2014 and May 2015. Assessment criteria were aneurysm occlusion, manifest ischemic stroke, bleeding, or death. The occlusion rate was assessed at 3 months with flat panel CT and at 6 months with DSA by using the Raymond classification and the O'Kelly-Marotta grading scale. RESULTS: Fifty patients with 52 aneurysms were treated with 54 FREDs; 20 patients were treated with the FRED and coils. Aneurysm size ranged from 2.0 to 18.5 mm. Deployment of the FRED was successful in all cases. There were no device-associated complications. One patient developed mild stroke symptoms that fully receded within days. There have been no late-term complications so far and no treatment-related mortality. Initial follow-up at 3 months showed complete occlusion in 72.3% of the overall study group, Six-month follow-up showed total and remnant-neck occlusion in 87.2% of patients, distributed over 81.5% of the FRED-only cases and 95.0% of the cases with combined treatment. CONCLUSIONS: The FRED flow diverter is a safe device for the treatment of cerebral aneurysms of various types. Our data reveal high occlusion rates at 3 and 6 months, comparable with those in other flow diverters. Long-term occlusion rates are expected.

Evaluation of Collaterals and Clot Burden Using Time-Resolved C-Arm Conebeam CT Angiography in the Angiography Suite: A Feasibility Study.

BACKGROUND AND PURPOSE: The assessment of collaterals and clot burden in patients with acute ischemic stroke provides important information about treatment options and clinical outcome. Time-resolved C-arm conebeam CT angiography has the potential to provide accurate and reliable evaluations of collaterals and clot burden in the angiographic suite. Experience with this technique is extremely limited, and feasibility studies are needed to validate this technique. Our purpose was to present such a feasibility study. MATERIALS AND METHODS: Ten C-arm conebeam CT perfusion datasets from 10 subjects with acute ischemic stroke acquired before endovascular treatment were retrospectively processed to generate time-resolved conebeam CTA. From time-resolved conebeam CTA, 2 experienced readers evaluated the clot burden and collateral flow in consensus by using previously reported scoring systems and assessed the clinical value of this novel imaging technique independently. Interobserver agreement was analyzed by using the intraclass correlation analysis method. RESULTS: Clot burden and collateral flow can be assessed by using the commonly accepted scoring systems for all eligible cases. Additional clinical information (eg, the quantitative dynamic information of collateral flow) can be obtained from this new imaging technique. Two readers agreed that time-revolved C-arm conebeam CTA is the preferred method for evaluating the clot burden and collateral flow compared with other conventional imaging methods. CONCLUSIONS: Comprehensive evaluations of clot burden and collateral flow are feasible by using time-resolved C-arm conebeam CTA data acquired in the angiography suite. This technique further enriches the imaging tools in the angiography suite to enable a "one-stop- shop" imaging workflow for patients with acute ischemic stroke.

Comparison of Intracranial Aneurysms Treated by 2-D Versus 3-D Coils: A Matched-Pairs Analysis.

OBJECTIVE: Knowledge on the influence of 2D and 3D coils to occlude intracranial aneurysms is poor. Therefore, aim of our analysis was to evaluate whether the use of 3-D versus 2-D coils alone may improve the efficacy of endovascular aneurysm treatment. PATIENTS AND METHODS: We performed a matched pair analysis comparing aneurysms treated by 3-D coils as initial "framing" coils to aneurysms treated exclusively by 2-D coils. Number of coils, implanted coil length/volume, and associated packing density were calculated. Aneurysmal occlusion was assessed and monitored 6 months (DSA; magnetic resonance angiography (MRA)) and 18 months (MRA) after embolization. Periprocedural complications and retreatment rate of each group were analyzed. RESULTS: Our retrospective analysis revealed 50 pairs. Concerning the 3-D group, number of coils (353 in total, median 7; p = 0.002), implanted coil length (55.69 ± 48.4 cm), implanted coil length per volume (5.92 mm/mm3), and packing density (30 %; p = 0.017) was higher than in the 2-D group (259 in total, median 5 coils; 38.52 ± 43.13 cm; 4.54 mm/mm3; 23 %). Occlusion was not significantly different immediately after treatment but at 6 and 18 months follow-up in favor of 3-D coils. Retreatment was performed in 2 cases of the 3-D group and in 3 cases of the 2-D group and therefore in a similar range (p = 0.564). CONCLUSION: Initial use of 3-D coils revealed a higher packing density and a higher long-term occlusion. Therefore, we recommend initial use of 3-D coils.

[Polycystic kidney disease and kidney transplantation]. / Prise en charge de la polykystose rénale autosomique dominante avant transplantation rénale.

OBJECTIVES: To perform a state of the art about autosomal dominant polykystic kidney disease (ADPKD), management of its urological complications and end stage renal disease treatment modalities. MATERIAL AND METHODS: An exhaustive systematic review of the scientific literature was performed in the Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of the following keywords (MESH): "autosomal dominant polykystic kidney disease", "complications", "native nephrectomy", "kidney transplantation". Publications obtained were selected based on methodology, language, date of publication (last 10 years) and relevance. Prospective and retrospective studies, in English or French, review articles; meta-analysis and guidelines were selected and analyzed. This search found 3779 articles. After reading titles and abstracts, 52 were included in the text, based on their relevance. RESULTS: ADPKD is the most inherited renal disease, leading to end stage renal disease requiring dialysis or renal transplantation in about 50% of the patients. Many urological complications (gross hematuria, cysts infection, renal pain, lithiasis) of ADPKD required urological management. The pretransplant evaluation will ask the challenging question of native nephrectomy only in case of recurrent kidney complications or large kidney not allowing graft implantation. The optimum timing for native nephrectomy will depend on many factors (dialysis or preemptive transplantation, complication severity, anuria, easy access to transplantation, potential living donor). CONCLUSION: Pretransplant management of ADPKD is challenging. A conservative strategy should be promoted to avoid anuria (and its metabolic complications) and to preserve a functioning low urinary tract and quality of life. When native nephrectomy should be performed, surgery remains the gold standard but renal arterial embolization may be a safe option due to its low morbidity.

MIF-CD74 signaling impedes microglial M1 polarization and facilitates brain tumorigenesis.

Microglial cells in the brain tumor microenvironment are associated with enhanced glioma malignancy. They persist in an immunosuppressive M2 state at the peritumoral site and promote the growth of gliomas. Here, we investigated the underlying factors contributing to the abolished immune surveillance. We show that brain tumors escape pro-inflammatory M1 conversion of microglia via CD74 activation through the secretion of the cytokine macrophage migration inhibitory factor (MIF), which results in a M2 shift of microglial cells. Interruption of this glioma-microglial interaction through an antibody-neutralizing approach or small interfering RNA (siRNA)-mediated inhibition prolongs survival time in glioma-implanted mice by reinstating the microglial pro-inflammatory M1 function. We show that MIF-CD74 signaling inhibits interferon (IFN)-γ secretion in microglia through phosphorylation of microglial ERK1/2 (extracellular signal-regulated protein kinases 1 and 2). The inhibition of MIF signaling or its receptor CD74 promotes IFN-γ release and amplifies tumor death either through pharmacological inhibition or through siRNA-mediated knockdown. The reinstated IFN-γ secretion leads both to direct inhibition of glioma growth as well as inducing a M2 to M1 shift in glioma-associated microglia. Our data reveal that interference with the MIF signaling pathway represents a viable therapeutic option for the restoration of IFN-γ-driven immune surveillance.

C-Arm Conebeam CT Perfusion Imaging in the Angiographic Suite: A Comparison with Multidetector CT Perfusion Imaging.

BACKGROUND AND PURPOSE: Perfusion imaging in the angiography suite may provide a way to reduce time from stroke onset to endovascular revascularization of patients with large-vessel occlusion. Our purpose was to compare conebeam CT perfusion with multidetector CT perfusion. MATERIALS AND METHODS: Data from 7 subjects with both multidetector CT perfusion and conebeam CT perfusion were retrospectively processed and analyzed. Two algorithms were used to enhance temporal resolution and temporal sampling density and reduce the noise of conebeam CT data before generating perfusion maps. Two readers performed qualitative image-quality evaluation on maps by using a 5-point scale. ROIs indicating CBF/CBV abnormalities were drawn. Quantitative analyses were performed by using the Sørensen-Dice coefficients to quantify the similarity of abnormalities. A noninferiority hypothesis was tested to compare conebeam CT perfusion against multidetector CT perfusion. RESULTS: Average image-quality scores for multidetector CT perfusion and conebeam CT perfusion images were 2.4 and 2.3, respectively. The average confidence score in diagnosis was 1.4 for both multidetector CT and conebeam CT; the average confidence scores for the presence of a CBV/CBF mismatch were 1.7 (κ = 0.50) and 1.5 (κ = 0.64). For multidetector CT perfusion and conebeam CT perfusion maps, the average scores of confidence in making treatment decisions were 1.4 (κ = 0.79) and 1.3 (κ = 0.90). The area under the visual grading characteristic for the above 4 qualitative quality scores showed an average area under visual grading characteristic of 0.50, with 95% confidence level cover centered at the mean for both readers. The Sørensen-Dice coefficient for CBF maps was 0.81, and for CBV maps, 0.55. CONCLUSIONS: After postprocessing methods were applied to enhance image quality for conebeam CT perfusion maps, the conebeam CT perfusion maps were not inferior to those generated from multidetector CT perfusion.