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 size_{3D 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 feeder_{3D angiography/3D-DSA}= 2.04 [SD, 0.65]/2.05 [SD, 0.63] mm; r = 0.9, P = .001), and cerebral aneurysms (eg, mean size_{3D 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 index_AVM: r = 0.84, P = .003; vessel geometry index_dAVF: r = 0.82, P = .003; vessel geometry index_CA: 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.

[Lower urinary tract symptoms and urinary incontinence in renal transplant recipients and candidates: The French guidelines from CTAFU]

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.

[Renal cell carcinoma of the kidney transplant: The French guidelines from CTAFU]

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<T3 and low ISUP grade.

CONCLUSION

These French recommendations should contribute to improving the oncological and functional prognosis of renal transplant recipients by improving the management of RCC of the renal transplant.

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, T 1 and T 2 , and Δ B 0 . As a proof of concept, we use both conventional MR images and T 1 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.

[Localized Prostate cancer in candidates for renal transplantation and recipients of a kidney transplant: The French Guidelines from CTAFU]

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.

[Urinary stones in renal transplant recipients and donors: The French guidelines from CTAFU]

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.

OP0117 LONGITUDINAL CHANGE IN THE CENTRAL NERVOUS SYSTEM PAIN RESPONSE AFTER TREATMENT WITH CERTOLIZUMAB OR PLACEBO. A POST-HOC ANALYSIS FROM THE PRECEPRA TRIAL

Background:

Tumor necrosis factor inhibitors have revolutionized the treatment of rheumatoid arthritis (RA). However, only about 50% of the patients respond well to TNF inhibitors. Therefore, markers that predict response to TNF inhibitors are valuable. Previously we demonstrated that central nervous system (CNS) response to nociceptive stimuli, measured by fMRI of the brain as blood oxygen level dependent (BOLD) signals, decreases already after 24 hours of anti-TNF administration a higher pre-treatment BOLD signal volume seems to predict clinical response to treatment with certolizumabpegol (CZP)1,2. We therefore hypothesized that the baseline volume of BOLD signal in the CNS could predict anti-TNF treatment response.

Objectives:

To perform a randomized placebo controlled trial in active RA patients to test the effect of TNF inhibition on arthritis induced pain activity in the brain and to test whether patients with high-level RA-related brain activation react differently to TNF-inhibitors than patients with low-level brain activation.

Methods:

Adult RA patients fulfilling the 2010 ACR/EULAR classification criteria with a DAS28>3.2 receiving stable DMARD treatment for at least 3 months were eligible. Patients underwent the first fMRI at screening measuring BOLD signal upon MCP joint compression and were stratified into low (< 700 units) and high (>700 units) voxel counts. Then patients were randomized to CZP or placebo with a 2:1 ratio. The second and third fMRI were performed after 12 and 24 weeks, respectively. Control stimulation was done by measuring brain activation after non-painful finger tapping.

Results:

156 RA patients with moderate-to-high disease activity participated in the study. In the finger tapping control, fMRI showed no significant changes in BOLD signal in the CZP-L and CZP-H arms, but a slight but significant decrease (p=0.043) was observed. After joint compression, the CZP-L group showed significant increase in the BOLD signal volume (p=0.043) in fMRI-2 as compared to fMRI-1 with no further significant changes. In contrast, in the CZP-H group, the BOLD signal volume significantly decreased (p=0.037) in fMRI-2 and continued to decrease further, p=0.007. No significant changes were observed in the placebo arm over time.

Conclusion:

TNF inhibition improves arthritis-related brain activity in the subgroup of RA patients with high baseline BOLD activity in the fMRI.

References:

[1]Hess, A.et al.PNAS (2011).

[2]Rech, J. et al. Arthritis & Rheumatism (2013).

Fig 1.

BOLD fMRI responses to painful stimulation

Acknowledgments:

The study was supported by an unrestricted grant of UCB Biopharma SPRL Brussels, Belgium

Disclosure of Interests:

Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Koray Tascilar: None declared, Hannah Schenker: None declared, Melanie Hagen: None declared, Marina Sergeeva: None declared, Mageshwar Selvakumar: None declared, Laura Konerth: None declared, Jutta Prade: None declared, Sandra Strobelt: None declared, Verena Schönau: None declared, Larissa Valor: None declared, Axel Hueber Grant/research support from: Novartis, Lilly, Pfizer, EIT Health, EU-IMI, DFG, Universität Erlangen (EFI), Consultant of: Abbvie, BMS, Celgene, Gilead, GSK, Lilly, Novartis, Speakers bureau: GSK, Lilly, Novartis, David Simon Grant/research support from: Else Kröner-Memorial Scholarship, Novartis, Consultant of: Novartis, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis, Abbvie, Speakers bureau: Novartis, Lilly, Frank Behrens Grant/research support from: Abbvie, Pfizer, Roche, Chugai, Janssen, Consultant of: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, Speakers bureau: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, Christoph Baerwald Consultant of: CGB received speaker or consulting fees from AbbVie, Paid instructor for: CGB received speaker or consulting fees from AbbVie, Speakers bureau: CGB received speaker or consulting fees from AbbVie, Stephanie Finzel: None declared, Reinhard Voll: None declared, Eugen Feist Consultant of: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, Speakers bureau: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, José Antonio P. da Silva Grant/research support from: Pfizer, Abbvie, Consultant of: Pfizer, AbbVie, Roche, Lilly, Novartis, Arnd Doerfler: None declared, Nemanja Damjanov Grant/research support from: from AbbVie, Pfizer, and Roche, Consultant of: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Speakers bureau: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Andreas Hess: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB

SAT0050 PREDICTION OF RESPONSE TO CERTOLIZUMAB PEGOL TREATMENT BY FUNCTIONAL MRI OF THE BRAIN: AN INTERNATIONAL, MULTI-CENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED TRIAL (PRECEPRA)

Background:

Personalization of RA treatment is not optimal due to lack of predictors. We previously demonstrated in RA patients that central nervous system (CNS) pain response to tender joint compression, measured by using functional MRI (fMRI) of the brain rapidly wanes after 24 hours of anti-TNF administration and that a higher pre-treatment BOLD signal volume seems to predict clinical response to treatment with certolizumab-pegol (CZP)1,2. We therefore hypothesized that the CNS pain response upon compression of a painful joint could predict subsequent anti-TNF treatment response.

Objectives:

To compare disease activity after 12-weeks of CZP treatment to that of placebo in DMARD-refractory RA patients based on pre-treatment baseline CNS pain response measured using BOLD fMRI.

Methods:

Adult RA patients fulfilling the 2010 ACR/EULAR classification criteria with a DAS28>3.2 under stable DMARD treatment for at least 3 months were eligible. Patients underwent fMRI scanning of the brain at screening for stratification by CNS pain response. Whole brain BOLD-signal-voxel-count of 700 units classifying between low and high, and were randomized to CZP or placebo (2:1) The primary outcome was low disease activity (LDA, DAS28 ≤3.2) after 12 weeks of treatment.

Results:

156 RA patients, inadequate responders to csDMARD, signed the informed consent. 139 patients (46/47, 46/49 and 42/43) (99 females, 71%) with moderate-high disease activity (mean (SD) DAS-28: 4.83 (1.03)) could be included respectively and completed the 12-week study treatment. Geometric mean (SD) numbers of baseline BOLD signal positive voxels were 559 (10), 81 (12) and 2498 (3) in the 3 arms respectively. The mean DAS28 (SD) scores after 12 weeks of study treatment were Placebo: 3.89 (1.29), CZP-L: 3.42 (1.06) and CZP-H: 3.06 (1.04). LDA was achieved in 12/47 patients (25.5 %) in placebo, 22/49 (44.9%) in the CZP-L, and 25/43, (58.1%) in the CZP-H arm. The linear effect term for the ordinal study group variable supported a linear trend of increasing CZP treatment effect with increasing baseline CNS pain response. RR (95% CI) for achieving LDA with each unit increase in treatment category over placebo was 1.79 (1.24 to 2.74, p=0.003).

Conclusion:

A higher pre-treatment brain activity in response to pain measured with fMRI predicts the chance of achieving low disease activity with CZP treatment.

References:

[1] Hess, A.et al.PNAS (2011)

[2] Rech, J.et al. Arthritis & Rheumatism(2013).

Acknowledgments :

The study was supported by an unrestricted grant from UCB Biopharma SPRL, Brussels, Belgium

Disclosure of Interests:

Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Koray Tascilar: None declared, Hannah Schenker: None declared, Marina Sergeeva: None declared, Mageshwar Selvakumar: None declared, Laura Konerth: None declared, Jutta Prade: None declared, Sandra Strobelt: None declared, Melanie Hagen: None declared, Verena Schönau: None declared, Larissa Valor: None declared, Axel Hueber Grant/research support from: Novartis, Lilly, Pfizer, EIT Health, EU-IMI, DFG, Universität Erlangen (EFI), Consultant of: Abbvie, BMS, Celgene, Gilead, GSK, Lilly, Novartis, Speakers bureau: GSK, Lilly, Novartis, David Simon Grant/research support from: Else Kröner-Memorial Scholarship, Novartis, Consultant of: Novartis, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Frank Behrens Grant/research support from: Abbvie, Pfizer, Roche, Chugai, Janssen, Consultant of: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, Speakers bureau: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, José Antonio P. da Silva Grant/research support from: Pfizer, Abbvie, Consultant of: Pfizer, AbbVie, Roche, Lilly, Novartis, Christoph Baerwald Consultant of: CGB received speaker or consulting fees from AbbVie, Paid instructor for: CGB received speaker or consulting fees from AbbVie, Speakers bureau: CGB received speaker or consulting fees from AbbVie, Stephanie Finzel: None declared, Reinhard Voll: None declared, Eugen Feist Consultant of: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, Speakers bureau: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, Arnd Doerfler: None declared, Nemanja Damjanov Grant/research support from: from AbbVie, Pfizer, and Roche, Consultant of: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Speakers bureau: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Andreas Hess: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB

OP0218 CENTRAL NERVOUS SYSTEM PAIN RESPONSE AND COMPONENTS OF DISEASE ACTIVITY IN RA PATIENTS AFTER TREATMENT WITH CERTOLIZUMAB OR PLACEBO: A POST-HOC ANALYSIS FROM THE PRECEPRA TRIAL

Background:

We have previously observed in RA patients that central nervous system (CNS) response to compression of a painful joint, measured using functional MRI (fMRI) of the brain as the number of blood oxygen level dependent (BOLD) signal positive voxels, is rapidly ameliorated, much earlier than any clinical response with anti-TNF treatment and a high baseline CNS pain response could predict better response to certolizumab pegol (CZP) treatment. Pre-CePRA was designed and conducted to test this effect in a randomized, placebo controlled trial of CZP and showed an incremental linear trend of DAS28 low disease activity (LDA) across study groups treated with placebo, and two CZP arms stratified as low or high pre-treatment CNS pain response.

Objectives:

To explore and describe pre-treatment CNS pain response associations with post treatment course of RA disease activity components and patient-physician discrepancy in global disease assessment.

Methods:

Patients fulfilling the 2010 ACR/EULAR classification criteria with moderate-severe disease activity (DAS-28>3.2) under stable DMARD treatment were recruited. Patients underwent an fMRI scan, stratified by a whole-brain BOLD positive voxel count threshold of 700 units and randomized to treatment with CZP or placebo in a 2:1 ratio. We descriptively assessed components of RA disease activity (Table 1 + 2). We summarized the mean results and 95% confidence intervals of these measurements at study timepoints and compared the 3 study groups at week 12 using one-way ANOVA and post-hoc Tukey tests.

Results:

156 eligible patients were screened and 139 (99 females, 71%) patients with moderate-high disease activity were randomized. ANOVA and pairwise comparisons showed that PGA-VAS improvement was larger in the CZP-H group whereas more similar to that in placebo in the CZP-L group. PhysGA-VAS however was similarly reduced in both CZP groups. Patients in the CZP-L group constantly rated their pain numerically higher than physicians whereas in the CZP-H group an initially higher discrepancy numerically reduced over time.

Conclusion:

These results suggest that improved patient global disease activity assessment could be the main driver of improved DAS-28 LDA rates with CZP treatment in patients with a high CNS pain response. Our findings indicate a potential role of fMRI imaging of the brain to further understand disease activity perception in RA patients.

Figure 1.

Course of disease activity components through trial timepoints. *indicates log-transformed y axis. *#x002A; Discrepancy equals Patient global minus physician global assessment.

Disclosure of Interests:

Hannah Schenker: None declared, Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Koray Tascilar: None declared, Melanie Hagen: None declared, Verena Schönau: None declared, Marina Sergeeva: None declared, Mageshwar Selvakumar: None declared, Laura Konerth: None declared, Jutta Prade: None declared, Sandra Strobelt: None declared, Larissa Valor: None declared, Axel Hueber Grant/research support from: Novartis, Lilly, Pfizer, EIT Health, EU-IMI, DFG, Universität Erlangen (EFI), Consultant of: Abbvie, BMS, Celgene, Gilead, GSK, Lilly, Novartis, Speakers bureau: GSK, Lilly, Novartis, David Simon Grant/research support from: Else Kröner-Memorial Scholarship, Novartis, Consultant of: Novartis, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Frank Behrens Grant/research support from: Abbvie, Pfizer, Roche, Chugai, Janssen, Consultant of: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, Speakers bureau: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, José Antonio P. da Silva Grant/research support from: Pfizer, Abbvie, Consultant of: Pfizer, AbbVie, Roche, Lilly, Novartis, Christoph Baerwald Consultant of: CGB received speaker or consulting fees from AbbVie, Paid instructor for: CGB received speaker or consulting fees from AbbVie, Speakers bureau: CGB received speaker or consulting fees from AbbVie, Stephanie Finzel: None declared, Reinhard Voll: None declared, Eugen Feist Consultant of: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, Speakers bureau: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, Arnd Doerfler: None declared, Nemanja Damjanov Grant/research support from: from AbbVie, Pfizer, and Roche, Consultant of: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Speakers bureau: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Andreas Hess: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB

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]

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 » 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.

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.

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.

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.

[Polycystic kidney disease and kidney transplantation]

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.

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.

Flat-Panel Computed Tomography (DYNA-CT) in Neuroradiology. From High-Resolution Imaging of Implants to One-Stop-Shopping for Acute Stroke

Originally aimed at improving standard radiography by providing higher absorption efficiency and a wider dynamic range, flat-panel detector technology has meanwhile got widely accepted in the neuroradiological community. Especially flat-panel detector computed tomography (FD-CT) using rotational C-arm mounted flat-panel detector technology is capable of volumetric imaging with a high spatial resolution. By providing CT-like images of the brain within the angio suite, FD-CT is able to rapidly visualize hemorrhage and may thus improve complication management without the need of patient transfer. As "Angiographic CT" FD-CT may be helpful during many diagnostic and neurointerventional procedures and for noninvasive monitoring and follow-up. In addition, spinal interventions and high-resolution imaging of the temporal bone might also benefit from FD-CT. Finally, using novel dynamic perfusion and angiographic protocols, FD-CT may provide functional information on brain perfusion and vasculature with the potential to replace standard imaging in selected acute stroke patients.

Dynamic Angiography and Perfusion Imaging Using Flat Detector CT in the Angiography Suite: A Pilot Study in Patients with Acute Middle Cerebral Artery Occlusions

BACKGROUND AND PURPOSE

Perfusion and angiographic imaging using intravenous contrast application to evaluate stroke patients is now technically feasible by flat detector CT performed by the angiographic system. The aim of this pilot study was to show the feasibility and qualitative comparability of a novel flat detector CT dynamic perfusion and angiographic imaging protocol in comparison with a multimodal stroke MR imaging protocol.

MATERIALS AND METHODS

In 12 patients with acute stroke, MR imaging and the novel flat detector CT protocol were performed before endovascular treatment. Perfusion parameter maps (MTT, TTP, CBV, CBF) and MIP/volume-rendering technique images obtained by using both modalities (MR imaging and flat detector CT) were compared.

RESULTS

Comparison of MIP/volume-rendering technique images demonstrated equivalent visibility of the occlusion site. Qualitative comparison of perfusion parameter maps by using ASPECTS revealed high Pearson correlation coefficients for parameters CBF, MTT, and TTP (0.95-0.98), while for CBV, the coefficient was lower (0.49).

CONCLUSIONS

We have shown the feasibility of a novel dynamic flat detector CT perfusion and angiographic protocol for the diagnosis and triage of patients with acute ischemic stroke. In a qualitative comparison, the parameter maps and MIP/volume-rendering technique images compared well with MR imaging. In our opinion, this flat detector CT application may substitute for multisection CT imaging in selected patients with acute stroke so that in the future, patients with acute stroke may be directly referred to the angiography suite, thereby avoiding transportation and saving time.

Ischemia/reperfusion during normothermic perfusion

INTRODUCTION

Cold storage of organs for preservation and transplantation is reaching its limits especially with extended criteria for heart beating donors and donation after cardiac death. We will discuss recent findings and perspectives in normothermic kidney preservation.

METHODS

A literature review was performed from original articles and syntheses selected by the search engine PubMed. Keywords used were: cold ischemia; warm ischemia, normothermic, organ preservation, preconditioning, organ perfusion.

RESULTS

We identified several ways to improve kidney preservation: Ischemic normothermic preconditioning; Pharmacologic normothermic preconditioning; Ex vivo normothermic reperfusion; Remote ischemic transplantation preconditioning; Ischemic postconditioning. In clinical practice, only uses of ECMO for organ preconditioning or ex vivo normothermic organ perfusion were used.

CONCLUSION

Promising experimental and clinical results make challenge cold preservation. The most suitable and physiological method seems to be a normothermic perfusion and conservation with autologous oxygenated blood using Extra Corporeal Membrane Oxygenation or Regional Normothermic Circulation.

Optimized angiographic CT using intravenous contrast injection: a noninvasive imaging option for the follow-up of coiled aneurysms?

BACKGROUND AND PURPOSE

Because recanalization of coiled cerebral aneurysms is reported to occur, follow-up imaging is mandatory, ideally noninvasively. Our study aimed to evaluate the accuracy of an optimized angiographic CT by using intravenous contrast material injection in the assessment of coiled cerebral aneurysms, compared with MR angiography and digital subtraction angiography, the criterion standard.

MATERIALS AND METHODS

We included 69 patients with 76 coiled cerebral aneurysms. In each patient, we performed an angiographic CT with intravenous contrast material injection with a dual rotational acquisition, a time-of-flight MR angiography, and a DSA. The angiographic CT with intravenous contrast material injection data was postprocessed by using newly implemented reconstructions modes and a dual-volume technique. An aneurysm occlusion rate was assessed in angiographic CT with intravenous contrast material injection and MRA; remnants were measured and correlated with DSA, respectively.

RESULTS

Twenty-eight remnants were revealed by DSA with a mean size of 3.1 × 3.1 mm. Angiographic CT with intravenous contrast material injection demonstrated a sensitivity of 93% and a specificity of 96% in remnant detection. MRA showed almost identical accuracy (sensitivity of 93%, specificity of 100%). Assessment of remnant size by angiographic CT with intravenous contrast material injection and by MRA revealed a high significant correlation with DSA, respectively (P < .001).

CONCLUSIONS

Optimized angiographic CT with intravenous contrast material injection and MRA demonstrated accuracy comparable with that of DSA in the follow-up of coiled aneurysms, respectively. The assessment of remnant size showed a high correlation with DSA for both techniques. Due to the lack of radiation exposure, MRA seems to be the preferred technique. However, angiographic CT with intravenous contrast material injection can be considered a reliable, noninvasive alternative in patients with MR imaging contraindications or in cases of compromising artifacts due to metal implants (ie, clips).

Clot Burden and Collaterals in Anterior Circulation Stroke: Differences Between Single-Phase CTA and Multi-phase 4D-CTA

PURPOSE

It has been reported that the extent of intravascular thrombi and the quality of collateral filling in computed tomography (CT) angiography are predictive for the clinical outcome in patients with acute stroke. We hypothesized that multi-phase four-dimensional CTA (4D-CTA) allows better assessment of clot burden and collateral flow compared with arterial single-phase CTA (CTA).

METHODS

In 49 patients (33 female; age: 77 ± 12 years) with acute anterior circulation stroke, CTA and 4D-CTA reconstructed from dynamic perfusion CT data were analyzed for absolute thrombus length (TL), clot burden score (CBS), and collateral score (CS). The length of the filling defect was also defined on thin-slice nonenhanced CT as corresponding hyperdense middle cerebral artery sign (HMCAS) when present.

RESULTS

There was good correlation (r = 0.62, p < 0.01) between the length of HMCAS (1.29 ± 0.62 cm) and TL in 4D-CTA (1.22 ± 0.51 cm). 4D-CTA and CTA significantly varied (p < 0.01) in TL (1.42 ± 0.73 cm (CTA) versus 1.11 ± 0.62 cm (4D-CTA)), CBS (median: 5, interquartile range: 4-7 (CTA) versus median: 6, interquartile range: 5-8 (4D-CTA); p < 0.001), and CS (median: 2, interquartile range: 1-2 (CTA) versus median: 3, interquartile range: 2-3 (4D-CTA); p < 0.001). Accordingly, CTA significantly overrated clot burden and underestimated collateral flow.

CONCLUSIONS

4D-CTA more closely defines clot burden and collateral supply in anterior circulation stroke than CTA, implicating an additional diagnostic benefit.

Nephron sparing surgery for De Novo kidney graft tumor: results from a multicenter national study

Nephron sparing surgery (NSS) results in the transplanted population remain unknown because they are only presented in small series or case reports. Our objective was to study renal sparing surgery for kidney graft renal cell carcinomas (RCC) in a multicenter cohort. Data were collected from 32 French transplantation centers. Cases of renal graft de novo tumors treated as RCC since the beginning of their transplantation activity were included. Seventy-nine allograft kidney de novo tumors were diagnosed. Forty-three patients (54.4%) underwent renal sparing surgery. Mean age of grafted kidneys at the time of diagnosis was 47.5 years old (26.1-72.6). The mean time between transplantation and tumor diagnosis was 142.6 months (12.2-300). Fifteen tumors were clear cell carcinomas (34.9%), and 25 (58.1%) were papillary carcinomas. Respectively, 10 (24.4%), 24 (58.3%) and 8 (19.5%) tumors were Fuhrman grade 1, 2 and 3. Nine patients had postoperative complications (20.9%) including four requiring surgery (Clavien IIIb). At the last follow-up, 41 patients had a functional kidney graft, without dialysis and no long-term complications. NSS is safe and appropriate for all small tumors of transplanted kidneys with good long-term functional and oncological outcomes, which prevent patients from returning to dialysis.

Urological tumors in renal transplantation

The aim of this paper was to review the risk and incidence of urological malignancies and the clinical characteristics and outcomes of renal transplant urological malignancies. Medline/PubMed from January 1980 to February 2013 was searched to identify all medical literature about native kidney, graft bladder and prostate cancers. Comparing to general population, risk of kidney cancer was found to be 7 to 10 times greater and most of them are incidental low-stage, low-grade tumors with a good prognosis. Open and laparoscopic radical nephrectomies without lymph nodes dissection were reported to be safe. Incidence of graft RCC was 0.19%. Papillary carcinomas represented more than 50% of de novo graft carcinomas, which seemed to be low-grade carcinomas with good prognosis. Risk of prostate cancer was two times higher. Open or laparoscopic radical prostatectomy is safe and feasible for management of localized prostate cancer in patients with kidney allograft. Upper urinary tract (UUT) transitional cell carcinoma (TCC) incidence was reported between 0.7% and 3.8%. Reports suggested a 3-fold increased risk of developing bladder TCC. Intravesical BCG in superficial bladder cancer and/or CIS is a valid option. For invasive urothelial tumor, radical cystectomy in renal transplant patients remains the best treatment. Oncological outcomes of urological cancers in renal transplant recipients are good and conservative treatment should be preferred each time it is feasible to prevent returning to dialysis following recommendations of urological cancer treatment. Close monitoring of renal transplant recipient must be performed with at least an abdominopelvic US and PSA measurement once a year.

[Emergency nephrectomies: retrospective monocentric study, about eight cases]

OBJECTIVE

Emergency nephrectomies are rare because of the improvement of the management of urinary tract infections and the development of radio-embolization. Few series of patients have been reported. The objective of our study is to assess the indication, the morbi-mortality and the outcome of the emergency nephrectomy performed in our hospital.

PATIENTS

Between January 2011 and November 2012, eight patients underwent an emergency nephrectomy at the University Hospital Center of Caen. The present review reports the characteristics of this emergency nephrectomy and their morbi-mortality.

RESULTS

Six women and two men were analyzed retrospectively between January 2011 and November 2012. All patients except one needed intensive care for a multiple-organ failure. All these eight emergency nephrectomies concerned a native kidney with a surgical approach as a lombotomy or subcostal laparotomy. Both patients survived. One patient need a renal dialysis support.

CONCLUSION

Emergency nephrectomy are rare. Uncontrolled urinary sepsis represents the main indication. Identifying the population at risk of evolution to the toxic shock is indispensable for a better and faster care and to reduce the mortality bound to the sepsis.

Monitoring of balloon test occlusion of the internal carotid artery by parametric color coding and perfusion imaging within the angio suite: first results

BACKGROUND

Temporary balloon test occlusion (BTO) might be performed prior to procedures in which occlusion of the internal carotid artery (ICA) might be necessary. We tested the hypothesis that parametric color coding (PCC) of angiographic series (digital subtraction angiography (DSA)) along with the assessment of cerebral blood volume (CBV) in the angiography suite would simplify and enhance the identification of candidates who are most likely to tolerate occlusion.

MATERIALS AND METHODS

Fifteen patients underwent angiographic series (DSA) and perfusion imaging before and during BTO. Pre- and postocclusion DSA acquisitions were evaluated for venous delay by conventional methods ("eye balling") and by PCC measurements. Comparison of CBV values between the left and right hemisphere in 6 defined regions was performed.

RESULTS

Values of venous delay by eye balling and PCC showed a high correlation (r = 0.87, p < 0.01). Bland-Altman plot indicated slightly lower values (-0.05 s) by the PCC method. One of the 15 patients developed an asymmetrical CBV map with an increase in CBV of more than one standard deviation in 3 of the 6 regions of interest (ROIs). Acquisition of angiographic series and perfusion imaging did not prolong the test occlusion time.

CONCLUSION

PCC and CBV mapping are feasible during BTO. The use of PCC seems to simplify the ability to measure changes in venous filling delay. Perfusion imaging may show an increase in CBV in patients reaching the limits of cerebral autoregulation. These patients may be at risk for delayed infarction, even though they seem to tolerate temporary occlusion, and could be unsuitable candidates for permanent ICA occlusion.

De novo kidney graft tumors: results from a multicentric retrospective national study

De novo tumors in renal allografts are rare and their prevalence is underestimated. We therefore analyzed renal cell carcinomas arising in renal allografts through a retrospective French renal transplant cohort. We performed a retrospective, multicentric survey by sending questionnaires to all French kidney transplantation centers. All graft tumors diagnosed after transplantation were considered as de novo tumors. Thirty-two centers participated in this study. Seventy-nine tumors were identified among 41 806 recipients (Incidence 0.19%). Patients were 54 men and 25 women with a mean age of 47 years old at the time of diagnosis. Mean tumor size was 27.8 mm. Seventy-four (93.6%), 53 (67%) and 44 tumors (55.6%) were organ confined (T1-2), low grade (G1-2) and papillary carcinomas, respectively. Four patients died of renal cell carcinomas (5%). The mean time lapse between transplantation and RCC diagnosis was 131.7 months. Thirty-five patients underwent conservative surgery by partial nephrectomy (n = 35, 44.3%) or radiofrequency (n = 5; 6.3%). The estimated 5 years cancer specific survival rate was 94%. Most of these tumors were small and incidental. Most tumors were papillary carcinoma, low stage and low grade carcinomas. Conservative treatment has been preferred each time it was feasible in order to avoid a return to dialysis.

Intraprocedural angiographic CT as a valuable tool in the course of endovascular treatment of direct sinus cavernous fistulas

This investigation aimed to demonstrate the potential of intraprocedural angiographic CT in monitoring complex endovascular coil embolization of direct carotid cavernous fistulas. Angiographic CT was performed as a dual rotational 5 s run with intraarterial contrast medium injection in two patients during endovascular coil embolization of direct carotid cavernous fistulas. Intraprocedural angiographic CT was considered helpful if conventional 2D series were not conclusive concerning coil position or if a precise delineation of the parent artery was impossible due to a complex anatomy or overlying coil material. During postprocessing multiplanar reformatted and dual volume images of angiographic CT were reconstructed. Angiographic CT turned out to be superior in the intraprocedural visualization of accidental coil migration into the parent artery where conventional 2D-DSA series failed to reliably detect coil protrusion. The delineation of coil protrusion by angiographic CT allowed immediate correct coil repositioning to prevent parent artery compromising. Angiographic CT can function as a valuable intraprocedurally feasible tool during complex coil embolizations of direct carotid cavernous fistulas. It allows the precise visualization of the cerebral vasculature and any accidental coil protrusion can be determined accurately in cases where conventional 2D-DSA series are unclear or compromised. Thus angiographic CT might contribute substantially to reduce procedural complications and to increase safety in the management of endovascular treatment of direct carotid cavernous fistulas.

Acute-onset migrainous aura mimicking acute stroke: MR perfusion imaging features

BACKGROUND AND PURPOSE

In a very limited number of cases, acute migrainous aura may mimic acute brain infarction. The aim of this study was to recognize patterns of MR perfusion abnormalities in this presentation.

MATERIALS AND METHODS

One thousand eight hundred fifty MR imaging studies performed for the suspicion of acute brain infarction were analyzed retrospectively to detect patients with acute migrainous aura not from stroke. All patients were examined clinically by 2 neurologists and underwent a standard stroke MR imaging protocol, including PWI. Two radiologists reviewed the perfusion maps visually and quantitatively for the presence, distribution, and grade of perfusion abnormalities.

RESULTS

Among 1850 MR imaging studies, 20 (1.08%) patients were found to have acute migrainous aura. Hypoperfusion was found in 14/20 patients (70%) with delayed rMTT and TTP, decreased rCBF, and minimal decrease in rCBV. In contrast to the typical pattern in stroke, perfusion abnormalities were not limited to a single vascular territory but extended to >1. Bilateral hypoperfusion was seen in 3/14 cases. In 11/14 cases, hypoperfusion with a posterior predominance was found. TTP and rMTT were the best maps to depict perfusion changes at visual assessment, but also rCBF maps demonstrated significant hypoperfusion in quantitative analysis. In all patients, clinical and imaging follow-up findings were negative for stroke.

CONCLUSIONS

Acute migrainous aura is rare but important in the differential diagnosis among patients with the suspicion of acute brain infarction. Atypical stroke perfusion abnormalities can be seen in these patients.

Comparison of conventional CTA and volume perfusion CTA in evaluation of cerebral arterial vasculature in acute stroke

BACKGROUND AND PURPOSE

CTA-like datasets can be reconstructed from whole-brain VPCTA. The aim of our study was to compare VPCTA with CTA for detection of intracranial stenosis and occlusion in stroke patients. Omitting CTA from stroke CT could reduce radiation dose.

MATERIALS AND METHODS

One hundred sixty-three patients were included in this retrospective analysis. Inclusion criterion was suspected stroke within 4.5 hours after onset of symptoms. All examinations were performed on a 128-section multidetector CT scanner. Axial, coronal, and sagittal maximum intensity projections were reconstructed from CTA and from peak arterial phase of VPCTA. Images were scored for quality and presence of intracranial stenosis >50% or occlusion. For statistical analysis, the Wilcoxon signed-rank test and Fisher exact test were used, with a 2-tailed P value of .05 or less for statistical significance.

RESULTS

Average image quality was superior in CTA (P < .05). However, image quality dichotomized for diagnostic significance was without difference between CTA and VPCTA (P > .05). Comparative statistical analysis revealed no significant difference for detection of intracranial stenosis and occlusion between CTA and VPCTA (P > .05). Substitution of intracranial CTA by VPCTA would lower radiation dose by 0.5 mSv.

CONCLUSIONS

VPCTA is suited to assess the intracranial vasculature in patients with stroke and might have the potential to decrease radiation dose by substituting for intracranial CTA in stroke CT. Additional studies are necessary to further evaluate potential benefits of the dynamic nature of VPCTA.

[Botulinum toxin A intradetrusor injections in consultation: single center experience during 2 years]

OBJECTIVES

In departments of urology, intradetrusor botulinum toxin injections are routinely performed in ambulatory outpatient clinic. The aim of the study was to assess the satisfaction level of patients treated with this technique.

PATIENTS AND METHODS

A satisfaction questionnaire was carried out by telephone for all patients treated in ambulatory outpatient clinic from 2009 to 2010.

RESULTS

Twenty-six patients were treated in consultation during the studied period for a total of 46 sessions of injections. The average age was 48.81 (±16.78) years. An injection programme containing 20 or 30 points was performed after a local anesthetic. Twenty patients answered the questionnaire. As regards the organization of the injections, 12 patients (60%) declared to have been satisfied and seven very satisfied (35%). Eight patients (40%) were very satisfied with the management of the pain and six (30%) satisfied versus only one (5%) not satisfied at all. For the time spent in the hospital during the injections, 10 (50%) were satisfied and seven (35%) very satisfied. Only 4 patients (20%) would have preferred to be hospitalized in an outpatient facility. In cases of new injections, 18 (90%) patients would have preferred an identical coverage. Finally, 17 (85%) would recommend this procedure to one of their close relations.

CONCLUSION

Our results showed that the majority of patients were completely satisfied with the injection programme. However, as patients are not currently covered by the national health system for these injections, this might hinder the development of this procedure.