Detection of urinary tract stones on submillisievert abdominopelvic CT imaging with deep-learning image reconstruction algorithm (DLIR).

PURPOSE: Urolithiasis is a chronic condition that leads to repeated CT scans throughout the patient's life. The goal was to assess the diagnostic performance and image quality of submillisievert abdominopelvic computed tomography (CT) using deep learning-based image reconstruction (DLIR) in urolithiasis. METHODS: 57 patients with suspected urolithiasis underwent both non-contrast low-dose (LD) and ULD abdominopelvic CT. Raw image data of ULD CT were reconstructed using hybrid iterative reconstruction (ASIR-V 70%) and high-strength-level DLIR (DLIR-H). The performance of ULD CT for the detection of urinary stones was assessed by two readers and compared with LD CT with ASIR-V 70% as a reference standard. Image quality was assessed subjectively and objectively. RESULTS: 266 stones were detected in 38 patients. Mean effective dose was 0.59 mSv for ULD CT and 1.96 mSv for LD CT. For diagnostic performance, sensitivity and specificity were 89% and 94%, respectively, for ULDCT with DLIR-H. There was an almost perfect intra-observer concordance on ULD CT with DLIR-H versus LDCT with ASIR-V 70% (ICC = 0.90 and 0.90 for the two readers). Image noise was significantly lower and signal-to-noise ratio significantly higher with DLIR-H compared to ASIR-V 70%. Subjective image quality was also significantly better with ULDCT with DLIR-H. CONCLUSION: ULD CT with Deep Learning Image Reconstruction maintains a good diagnostic performance in urolithiasis, with better image quality than hybrid iterative reconstruction and a significant radiation dose reduction.

Prospective Comparison of Free-Breathing Accelerated Cine Deep Learning Reconstruction Versus Standard Breath-Hold Cardiac MRI Sequences in Patients With Ischemic Heart Disease.

BACKGROUND. Cine cardiac MRI sequences require repeated breath-holds, which can be difficult for patients with ischemic heart disease (IHD). OBJECTIVE. The purpose of the study was to compare a free-breathing accelerated cine sequence using deep learning (DL) reconstruction and a standard breath-hold cine sequence in terms of image quality and left ventricular (LV) measurements in patients with IHD undergoing cardiac MRI. METHODS. This prospective study included patients undergoing 1.5- or 3-T cardiac MRI for evaluation of IHD between March 15, 2023, and June 21, 2023. Examinations included an investigational free-breathing cine short-axis sequence with DL reconstruction (hereafter, cine-DL sequence). Two radiologists (reader 1 [R1] and reader 2 [R2]), in blinded fashion, independently assessed left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and subjective image quality for the cine-DL sequence and a standard breath-hold balanced SSFP sequence; R1 assessed artifacts. RESULTS. The analysis included 26 patients (mean age, 64.3 ± 11.7 [SD] years; 14 men, 12 women). Acquisition was shorter for the cine-DL sequence than the standard sequence (mean ± SD, 0.6 ± 0.1 vs 2.4 ± 0.6 minutes; p < .001). The cine-DL sequence, in comparison with the standard sequence, showed no significant difference for LVEF for R1 (mean ± SD, 51.7% ± 14.3% vs 51.3% ± 14.7%; p = .56) or R2 (53.4% ± 14.9% vs 52.8% ± 14.6%; p = .53); significantly greater LVEDV for R2 (mean ± SD, 171.9 ± 51.9 vs 160.6 ± 49.4 mL; p = .01) but not R1 (171.8 ± 53.7 vs 165.5 ± 52.4 mL; p = .16); and no significant difference in LVESV for R1 (mean ± SD, 88.1 ± 49.3 vs 86.0 ± 50.5 mL; p = .45) or R2 (85.2 ± 48.1 vs 81.3 ± 48.2 mL; p = .10). The mean bias between the cine-DL and standard sequences by LV measurement was as follows: LVEF, 0.4% for R1 and 0.7% for R2; LVEDV, 6.3 mL for R1 and 11.3 mL for R2; and LVESV, 2.1 mL for R1 and 3.9 mL for R2. Subjective image quality was better for cine-DL sequence than the standard sequence for R1 (mean ± SD, 2.3 ± 0.5 vs 1.9 ± 0.8; p = .02) and R2 (2.2 ± 0.4 vs 1.9 ± 0.7; p = .02). R1 reported no significant difference between the cine-DL and standard sequences for off-resonance artifacts (3.8% vs 23.1% examinations; p = .10) and parallel imaging artifacts (3.8% vs 19.2%; p = .19); blurring artifacts were more frequent for the cine-DL sequence than the standard sequence (42.3% vs 7.7% examinations; p = .008). CONCLUSION. A free-breathing cine-DL sequence, in comparison with a standard breath-hold cine sequence, showed very small bias for LVEF measurements and better subjective quality. The cine-DL sequence yielded greater LV volumes than the standard sequence. CLINICAL IMPACT. A free-breathing cine-DL sequence may yield reliable LVEF measurements in patients with IHD unable to repeatedly breath-hold. TRIAL REGISTRATION. ClinicalTrials.gov NCT05105984.

Robotically assisted deployment of flow diverter stents for the treatment of cerebral and cervical aneurysms.

BACKGROUND: Despite the growing sophistication of robot-assisted surgery, it is necessary to demonstrate that robots can reliably perform complex procedures on site and then remotely. Although a flow diverter stent is one of the most effective and widely used devices, its placement is sometimes challenging. OBJECTIVE: To evaluate the feasibility and safety of the CorPath GRX robotic platform for the embolization of cerebral and cervical aneurysms using flow diverter stents. METHODS: We performed a single-center technical study of the first 10 flow diverter stent deployments with the CorPath GRX Robotic System (Corindus Inc, Waltham, Massachusetts, USA) for the treatment of cerebral aneurysms between April and October 2022. RESULTS: Ten patients underwent robot-assisted embolization with flow diverter stents: there were nine intracranial aneurysms (paraclinoid n=6; posterior communicating artery aneurysm n=1; anterior communicating artery n=2) and one cervical aneurysm. Four procedures were performed with coils plus a flow diverter stent, one was performed with woven endobridge plus a flow diverter stent and four were performed with flow diverter stents alone. Of these procedures, two were performed with telescoping flow diverters.All flow diverter stents were deployed with robotic assistance, with only one partial conversion to a manual technique (caused by guidewire torquability limitations). No perioperative complications were observed. CONCLUSION: Robot-assisted flow diverter stent deployment using the CorPath GRX platform is feasible and appears to be safe. Larger, in-depth studies of the technique's safety and benefits are now warranted.

A novel technique to perform cerebral angiography via the left radial approach: An 80 patients series.

PURPOSE: To demonstrate that left radial access for diagnostic cerebral angiography with Extra backup and 4F vertebral catheters is feasible and safe. MATERIALS AND METHODS: This study is a retrospective review of our prospective database on left radial access for cerebral angiography procedures, using an extra backup catheter associated with a 4Fr vertebral catheter, performed between March and September 2019. Patient demographics, procedural and radiographic metrics as well as clinical data were recorded. RESULTS: Seventy five patients with mean age of 51...years (range 21...73) underwent 80 cerebral angiographies. An average of four vessels were catheterized and mean fluoroscopy times per subject and vessel were was of 13.9 and 3.3...min, respectively. One patient required crossover to transfemoral access because of radial artery spasm. There were one asymptomatic distal radial artery occlusion and one patient presenting with asymptomatic skin blanching area on the forearm, just proximal to the tip of the sheath, that spontaneously resolved within an hour. CONCLUSION: Diagnostic cerebral angiography via left radial access is feasible and safe and allows to preserve the right radial access for future neurointerventions while providing more comfort to the right handed patient.

Phantom study of an in-house amplitude-gating respiratory method with silicon photomultiplier technology positron emission tomography/computed tomography.

PURPOSE: The objective of this phantom study was to determine whether breathing-synchronized, silicon photomultiplier (SiPM)-based PET/CT has a suitable acquisition time for routine clinical use. METHODS: Acquisitions were performed in list mode on a 4-ring SiPM-based PET/CT system. The experimental setup consisted of an external respiratory tracking device placed on a commercial dynamic thorax phantom containing a sphere filled with [F-18]-fluorodeoxyglucose. Three-dimensional sinusoidal motion was imposed on the sphere. Data were processed using frequency binning and amplitude binning (the "DMI" and "OFFLINE" methods, respectively). PET sinograms were reconstructed with a Bayesian penalized likelihood algorithm. RESULTS: Respiratory gating from a 150­sec acquisition was successful. The DMI and OFFLINE methods gave similar activity profiles but both were slightly shifted in space; the latter profile was closest to the reference acquisition. CONCLUSION: With SiPM PET/CT systems, the amplitude-based processing of breathing-synchronized data is likely to be feasible in routine clinical practice.

Portal Vein Pulsatility Index as a Potential Risk of Venous Congestion Assessed by Magnetic Resonance Imaging: A Prospective Study on Healthy Volunteers.

High values of the portal vein pulsatility index (PI) have been associated with adverse outcomes in perioperative or critically ill patients. However, data on dynamic changes of PI related to fluid infusion are scarce. We aimed to determine if dynamic changes in PI are associated with the fluid challenge (FC). To address this challenge, we conducted a prospective single-center study. The population study included healthy subjects. FC consisted in the administration of 500 ml of Ringer lactate infusion over 5 min. The portal blood flow and PI were assessed by magnetic resonance imaging. The responsiveness to FC was defined as an increase in the cardiac stroke volume of at least 10% as assessed by echocardiography. We included 24 healthy volunteers. A total of fourteen (58%) subjects were responders, and 10 (42%) were non-responders. In the responder group, FC induced a significant increase in portal blood flow from 881 (762-1,001) at the baseline to 1,010 (778-1,106) ml min-1 (p = 0.005), whilst PI remained stable (from 31 [25-41] to 35 (25-42) %; p = 0.12). In the non-responder group, portal blood flow remained stable after FC (from 1,042 to 1,034 ml min-1; p = 0.084), whereas PI significantly increased from 32 (22-40) to 48% *(25-85) after FC (p = 0.027). PI was negatively correlated to portal blood flow (Rho coefficient = -0.611; p = 0.002). To conclude, PI might be a sensitive marker of early congestion in healthy subjects that did not respond to FC. This finding requires further validation in clinical settings with a larger sample size.

Pulmonary emphysema quantification at low dose chest CT using Deep Learning image reconstruction.

PURPOSE: Quantitative analysis of emphysema volume is affected by the radiation dose and the CT reconstruction technique. We aim to evaluate the influence of a commercially available deep learning image reconstruction algorithm (DLIR) on the quantification of pulmonary emphysema in low-dose chest CT. METHODS: We performed a retrospective study of low dose chest CT scans in 54 patients with chronic obstructive pulmonary disease (COPD). Raw data were reconstructed using FBP, iterative reconstruction (ASIR-V 70%) and deep learning based algorithms at high, medium and low-strength (DLIR -H, -M, -L). Filtered FBP images served as reference. Pulmonary emphysema volume (proportion of voxels below -950 UH) was measured on each reconstruction dataset and visually assessed by a chest radiologist. Quantitative image quality was assessed by placing 3 regions of interest in the trachea, in air and in a paraspinal muscle. Signal to noise ratio was also measured. RESULTS: The mean CDTIvol was 2.38 ± 0.68 mGy. Significant differences in emphysema volumes between the filtered FBP reference and ASIR-V, DLIR-H, DLIR-M or DLIR-L were observed, (p < 10-3) for all. A strong correlation between filtered FBP volumes and DLIR-H was reported (r = 0.999, p < 10-4), a 10% overestimation with DLIR-H being observed. Noise was significantly reduced in DLIR-H volumes compared to the other reconstruction methods. Signal to noise ratio was improved when using DLIR-H (p < 10-6). CONCLUSION: There are significant differences regarding emphysema volumes between FBP, iterative reconstruction or deep learning-based DLIR algorithm. DLIR-H shows the closest correlation to filtered FBP while increasing SNR.

Diagnostic performance and image quality of deep learning image reconstruction (DLIR) on unenhanced low-dose abdominal CT for urolithiasis.

BACKGROUND: Patients with urolithiasis undergo radiation overexposure from computed tomography (CT) scans. Improvement of image reconstruction is necessary for radiation dose reduction. PURPOSE: To evaluate a deep learning-based reconstruction algorithm for CT (DLIR) in the detection of urolithiasis at low-dose non-enhanced abdominopelvic CT. MATERIAL AND METHODS: A total of 75 patients who underwent low-dose abdominopelvic CT for urolithiasis were retrospectively included. Each examination included three reconstructions: DLIR; filtered back projection (FBP); and hybrid iterative reconstruction (IR; ASiR-V 70%). Image quality was subjectively and objectively assessed using attenuation and noise measurements in order to calculate the signal-to-noise ratio (SNR), absolute contrast, and contrast-to-noise ratio (CNR). Attenuation of the largest stones were also compared. Detectability of urinary stones was assessed by two observers. RESULTS: Image noise was significantly reduced with DLIR: 7.2 versus 17 and 22 for ASiR-V 70% and FBP, respectively. Similarly, SNR and CNR were also higher compared to the standard reconstructions. When the structures had close attenuation values, contrast was lower with DLIR compared to ASiR-V. Attenuation of stones was also lowered in the DLIR series. Subjective image quality was significantly higher with DLIR. The detectability of all stones and stones >3 mm was excellent with DLIR for the two observers (intraclass correlation [ICC] = 0.93 vs. 0.96 and 0.95 vs. 0.99). For smaller stones (<3 mm), results were different (ICC = 0.77 vs. 0.86). CONCLUSION: For low-dose abdominopelvic CT, DLIR reconstruction exhibited image quality superior to ASiR-V and FBP as well as an excellent detection of urinary stones.

Distal radial access for cerebral aneurysm embolization.

OBJECTIVES: To demonstrate the feasibility and safety of distal radial access for embolization of ruptured and unruptured cerebral aneurysms. METHODS: This study is a retrospective review of our prospective cerebral aneurysm embolization database. Between January and September 2019, distal radial access was considered for consecutive subjects addressed for cerebral aneurysm embolization at our institution. All procedures were performed by the same experienced operator. Technical success was defined as distal radial access with insertion of the sheath and completion of the intervention without change of access site to conventional femoral access. Primary safety endpoint was the in hospital + 30 days incidence of radial artery occlusion. Secondary endpoints included intra-procedural complications and neurologic complications at discharge and at 30 days. RESULTS: Fifty-seven patients with cerebral aneurysms underwent 61 embolization procedures. Twenty eight embolizations were performed using coils, 8 used a stent-assisted coil technique, 22 used a balloon-assisted coil technique, and 3 used a flow diverter. One patient (1.6%) required crossover to femoral access. Three patients developed coil-induced thrombus that required intra-arterial Tirofiban injections. Two patients were asymptomatic and one patient presented confusion due to right frontal ischemia. One periprocedural aneurysm rupture occurred without clinical impact. Radial artery occlusion and hand ischemia were not observed. CONCLUSION: Findings of the present study showed the feasibility of distal transradial access for cerebral aneurysm embolization without increasing the risk of the procedure.

Diffusion and Flow MR Imaging to Investigate Hydrocephalus Patients Before and After Endoscopic Third Ventriculostomy.

INTRODUCTION: In patients with noncommunicating hydrocephalus, dilation of the ventricles stresses white matter fibers and alters the cerebral blood flow (CBF) and cerebrospinal fluid (CSF) dynamics. The purpose of this work was to investigate, non-invasively, how endoscopic third ventriculostomy (ETV) impacts white matter, CSF oscillations, and CBF. METHODS: Eleven patients presenting with chronic headaches and noncommunicating hydrocephalus due to aqueductal stenosis were treated by ETV. Phase Contrast-MRI (PCMRI) and Diffusion Tensor Imaging (DTI) were performed before and after surgery to evaluate CSF and CBF as well as white matter stresses in the Corpus Callosum (CC) and Corona Radiata (CR). ETV success was confirmed by quantification of the CSF oscillations through the aperture in the third ventricle. RESULTS: All patients improved after surgery. CSF stroke volume was five times greater than normal ventricular stroke volume. Decrease in cervical CSF oscillations and increase in CBF were observed after ETV. In CR, fiber anisotropy decreased, while water diffusion increased. In CC, anisotropy did not vary, while water diffusion also increased. CONCLUSION: Even if static ICP typically do not increase, CSF and blood flow are impacted. PCMRI and DTI can provide useful information to help neurosurgeons select patients with good chance to improve after ETV.

Ophthalmic Artery and Superior Ophthalmic Vein Blood Flow Dynamics in Glaucoma Investigated by Phase Contrast Magnetic Resonance Imaging.

PRECIS: Ophthalmic artery (OA) and superior ophthalmic vein (SOV) blood flow were quantified by phase contrast magnetic resonance imaging (PC MRI) and seemed lower in glaucoma. Venous flow dynamics was different in glaucoma patients with a significantly decreased pulsatility. INTRODUCTION: Studies using color Doppler imaging and optical coherence tomography flowmetry strongly suggested that vascular changes are involved in the pathophysiology of glaucoma, but the venous outflow has been little studied beyond the episcleral veins. This study measured the OA and the SOV flow by PC MRI in glaucoma patients compared with controls. METHODS: Eleven primary open-angle glaucoma patients, with a mean±SD visual field deficit of -2.3±2.7 dB and retinal nerve fiber layer thickness of 92±13 µ, and 10 controls of similar age, were examined by PC MRI. The mean, maximal and minimal flow over cardiac cycle were measured. The variation of flow (ΔQ) was calculated. RESULTS: The OA mean±SD mean flow was 13.21±6.79 in patients and 15.09±7.62 mL/min in controls (P=0.35) and the OA maximal flow was 25.70±12.08 mL/min in patients, and 28.45±10.64 mL/min in controls (P=0.22). In the SOV the mean±SD mean flow was 6.46±5.50 mL/min in patients and 7.21±6.04 mL/min in controls (P=0.81) and the maximal flow was 9.06±6.67 in patients versus 11.96±9.29 mL/min in controls (P=0.47). The ΔQ in the SOV was significantly lower in patients (5.45±2.54 mL/min) than in controls (9.09±5.74 mL/min) (P=0.04). DISCUSSION: Although no significant difference was found, the mean and maximal flow in the OA and SOV seemed lower in glaucoma patients than in controls. The SOV flow waveform might be affected in glaucoma, corroborating the hypothesis of an impairment of venous outflow in those patients.

Safety and efficacy of percutaneous transhepatic-endoscopic rendezvous procedure in a single session.

PURPOSE: To demonstrate the feasibility and safety of PTE-RV performed in a single session. MATERIALS AND METHODS: This is a retrospective review of a prospective database on ERCP between January 2014 and December 2018. PTE-RV was performed in case of second ERCP failure. Technical success was defined as the establishment of an intestinal access to the biliary tract using a PTE-RV procedure allowing an immediate internal biliary drainage. Safety endpoints included intra-operative complications, morbidity and mortality occurring within 30 days after the procedure. RESULTS: Eighty-four patients (44 M/40F) with a median age of 69 years (range 40-91 years) underwent combined PTE-RV. The PTE-RVs were successfully performed in the same session in 80 subjects, resulting in an overall technical success rate of 95.2%. Adverse events were observed in 19% (16/84) of cases. The mortality rate within 30 days after the procedure was 9.5%. CONCLUSION: Percutaneous transhepatic-endoscopic rendezvous technique is feasible in a single session with acceptable level of risk. A randomized trial is required to compare EUBD and PTE-RV.

MRI Assessment of Right Ventricular Volumes and Function in Patients With Repaired Tetralogy of Fallot Using kat-ARC Accelerated Sequences.

OBJECTIVE. The objective of our study was to assess the accuracy and reproducibility of right ventricular volumes and function measurements in patients with repaired tetralogy of Fallot using two k-adaptive-t autocalibrating reconstruction for cartesian sampling (kat-ARC) accelerated sequences: a morphologic 3D cine sequence and a functional free-breathing 4D flow sequence. SUBJECTS AND METHODS. Seventeen patients who underwent cardiac MRI with gadolinium injection as part of follow-up of repaired tetralogy of Fallot from March 2017 to July 2018 were prospectively included in the initial study population; the final study cohort was composed of 15 of the 17 patients. Ventricle volume measurements were performed on a 3D cine kat-ARC sequence, a 4D flow kat-ARC sequence, and a 2D cine balanced steady-state free precession (bSSFP) sequence. The 2D cine bSSFP sequence was the reference standard in cardiac assessment. Intertechnique and interobserver analyses were performed. Bland-Altman analysis and correlation tests were used to compare quantitative measurements. RESULTS. Ventricular end-diastolic volume (EDV) and end-systolic volume (ESV) values were well correlated in the right ventricle (r = 0.94-0.98) for both 3D and 4D sequences. Ejection fraction (EF) also showed good correlation for both 3D and 4D sequences (r = 0.79 and r = 0.92). Bland-Altman analysis showed good agreement between right and left ventricular volumes, with narrower limits of agreement in the left ventricle, and an intraclass correlation coefficient (ICC) of greater than 0.80. For the 4D flow sequence, ventricular volumes were overestimated, which led to underestimation of the EF (bias for EDV = -10.2 mL, bias for ESV = -22.7 mL, bias for EF = 6.4%). Interobserver agreement was excellent for the ventricular volumes (ICC, 0.93-0.99) and fair to excellent for the EFs (ICC, 0.59-0.83). CONCLUSION. Compared with the reference standard 2D bSSFP sequence, the 3D cine kat-ARC accelerated sequence showed good accuracy and reproducibility for right ventricular measurements in patients with repaired tetralogy of Fallot. The short duration of the 4D flow kat-ARC sequence appears promising for performing volumetric measurements.

Direct aspiration for thrombectomy in ischemic stroke: Impact of dwell time.

OBJECTIVE: To evaluate the impact of dwell time on the efficacy of the direct aspiration thrombectomy in ischemic stroke. METHODS: The study is a review of our prospective cerebral thrombectomy database of subjects admitted from January to December 2017. We performed direct aspiration with 2 min dwell time as recommended by the manufacturer (group 1) and 5 min dwell time (group 2) between January-June and July-December, respectively. The primary outcome was successful reperfusion after the first pass defined as modified Thrombolysis in Cerebral Infarction scores 2 b/3. RESULTS: Eighty-five patients had a cerebral thrombectomy by direct aspiration, 45 in group 1 and 40 in group 2. There was no statistically significant difference between the two groups but a trend toward a better modified Thrombolysis in Cerebral Infarction first pass 2 b/3 rate in group 2 (70% versus 48.8%, p = 0.06). Although not statistically significant (p = 0.07), the ratio of rescue therapy with stent retriever was higher in group 1 (40%) than in group 2 (22.5%). After all passes, modified Thrombolysis in Cerebral Infarction 2 b-3 was obtained in 82.2% (37/45) of cases in group 1 and in 90% (36/40) of cases in group 2. Among 76 patients (89.5%) with modified Rankin Scale assessment at three months, no significant difference (p = 0.3) was found in the proportion of functionally independent individuals between groups 1 and 2 (51.8% versus 55.6%, respectively). CONCLUSION: Although statistical significance was not reached, our retrospective analysis exhibited a strong trend toward modified Thrombolysis in Cerebral Infarction first pass improvement when dwell time was increased from 2 to 5 min.

3D C-Arm cone beam CT for targeting the portal vein during TIPS: Initial clinical experience.

PURPOSE: To evaluate the feasibility, safety and usefulness of 3D CBCT with a new injection protocol for targeting the portal vein during TIPS and to determine if it allows decreasing the duration of the procedure. MATERIALS AND METHODS: 3D CBCT was obtained during creation of TIPS in 15 patients (group 2). Portogram quality score was defined using a 5 points scale. The time required to achieve portal puncture was also recorded and results were compared retrospectively in 15 patients who underwent TIPS without 3D CBCT (group 1). RESULTS: The mean time required to puncture the portal vein was shorter when CBCT was used: 15 min versus 24 min (p = 0.156). We recorded 3 failures requiring a second procedure in group 1. There were no complications and no failure in group 2. We recorded 93% of good portography and 80% of good 3D roadmaps. CONCLUSION: 3D CBCT coupled with this new injection protocol provided high rate of good quality portography allowing to bring positional and directional information to improve the needle pass efficiency and to decrease the duration of the procedure.

Quantification of blood flow in the superior ophthalmic vein using phase contrast magnetic resonance imaging.

Phase contrast magnetic resonance imaging (PC MRI), a validated, non-invasive technique for measuring intracranial blood and cerebrospinal flows, has been recently applied to studies of blood flow of the ophthalmic artery (OA). This study evaluated PC-MRI's ability to quantify blood flow in the superior ophthalmic vein (SOV). We analyzed with 3 T PC MRI the blood flow in the SOV in 11 healthy subjects and, for comparison purpose, in the OA. Segmentation software was used to analyze the PC images and quantify the variation in blood flow over the cardiac cycle in each of the vessels. The anatomy of the orbital veins was also assessed. We were able to measure the blood flow in 19 SOV; the mean ±â€¯standard deviation (SD) SOV flow was 9.13 ±â€¯7.10 mL/min with a mean ±â€¯SD variation of flow during cardiac cycle of 8.45 ±â€¯4.90 mL/min. The mean ±â€¯SD flow in the OA was 12.83 ±â€¯8.36 mL/min. The SOV was constantly present, with a mean cross-sectional area of 2.43 mm2. A medium and an inferior ophthalmic veins were found in 5 and 3 orbits, respectively. In conclusion, PC MRI is able to measure SOV as well as OA flows. To the best of our knowledge, the present study is the first to provide quantitative SOV blood flow values using PC MRI. Investigations of hydrocephalus, intracranial hypertension and even glaucoma might be facilitated by the application of this quantitative imaging modality.

Cerebrospinal Fluid and Cerebral Blood Flows in Idiopathic Intracranial Hypertension.

OBJECTIVES: Cerebrospinal fluid (CSF) and blood flows have a strong relationship during a cardiac cycle. Idiopathic intracranial hypertension (IIH) is a pathology that seems to present hemodynamic and hydrodynamic disturbance. The aim of this study was to establish CSF and blood interaction in IIH. MATERIAL AND METHODS: We retrospectively studied cerebral hydrodynamic and hemodynamic flows by phase-contrast MRI (PCMRI) in 13 IIH subjects (according Dandy's criteria) and 16 controls. We analyzed arterial peak flow, pulsatility index, and resistive index in arterial and venous compartments (PFart, PIart, RIart, PFvein, PIvein, RIvein) and measured arteriovenous and CSF peak flow and stroke volume (PFav, SVVASC, PFCSF, SVCSF). RESULTS: We found no significant difference between IIH and control groups in arterial and venous parameters. Arteriovenous flow analysis showed higher PFav and SVVASC in the IIH group than in the control group (respectively 369 ± 27 mL/min and 286 ± 47 mL/min, p = 0.02; and 1085 ± 265 µL/cardiac cycle and 801 ± 226 µL/cardiac cycle, p = 0.007). PFCSF and SVCSF were higher in the IIH group than in the control group (respectively 206 ± 50 mL/min and 126.6 ± 24.8 mL/min, p = 0.04; and 570 ± 190 µL/cardiac cycle and 430 ± 100 µL/cardiac cycle, p = 0.0007). CONCLUSION: Although no significant change was found in arterial and venous flows, we showed that a small phase shift of venous outflow might cause an increase in the arteriovenous pulsatility and an increasing brain expansion during the cardiac cycle. This arteriovenous flow increase would result in an increase of CSF flushing through the foramen magnum and an increased ICP.

Safety and Efficacy of Femoral Artery Closure with the FemoSeal Device After Cerebral Thrombectomy Using an 8 French Sheath.

PURPOSE: To evaluate the feasibility and safety of using the FemoSeal vascular closure device (VCD) to seal 8F access sites during mechanical thrombectomy for stroke. METHODS: A retrospective review of a prospective database was undertaken to evaluate the safety and efficacy of femoral arterial closure using FemoSeal device in all patients who underwent mechanical thrombectomy using an 8F sheath between January 2015 and July 2017. Efficacy endpoints were the successful deployment of the system and haemostasis success. Safety endpoints included the incidence of in hospital access site haematoma >5 cm, bleeding complications, pseudoaneurysms, arteriovenous fistula, infection, or other complications requiring surgery. RESULTS: 197 patients (96 men; mean age 68 years, range 25-99) were included. Successful haemostasis with FemoSeal was obtained in 98.9% of the patients. Only one haematoma >5 cm (0.5%) was observed, which reabsorbed spontaneously without issue. Nine haematomas <5 cm (4.5%) were also found. No major complications requiring surgical repair or transfusion were observed. There were no pseudoaneurysms, arteriovenous fistulae, or infections. CONCLUSION: The use of the FemoSeal device to close an 8F access sheath puncture site is feasible and safe, with a low complication rate.

Benefits of respiratory-gated 18F-FDG PET acquisition in lung disease.

BACKGROUND: Fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) is a reliable imaging modality for the diagnosis of malignant lung nodules and to assess the latter's prognosis. However, physiological respiratory motion deteriorates PET images and thus decreases the technique's diagnostic and prognostic values. This issue can be overcome by applying respiratory gating to the F-FDG PET/CT acquisitions. PURPOSE: The aim of this study was to evaluate the ability of respiratory-gated F-FDG PET/CT to diagnose malignant lung nodules and to predict recurrence and patient survival. PATIENTS AND METHODS: A total of 103 prospectively enrolled patients with solid lung nodules underwent both ungated and gated F-FDG PET/CT acquisitions. The maximum standardized uptake value (SUVmax) was used to differentiate benign from malignant nodules. Patients have been followed up for at least 36 months to confirm imaging results and assess survival. RESULTS: Gated F-FDG PET/CT was significantly more sensitive than ungated PET/CT for the diagnosis of malignant lung nodules located in the lower lobes (92 vs. 58%; P<0.001) and in patients aged older than 60 years (73 vs. 48%; P<0.001). The same gain was observed for stage I cancers with tumors from 10 to 20 mm. When considering patients aged older than 60 years, those with a low SUVmax on gated PET images had a significantly higher 3-year disease-free survival rate than those with a high SUVmax (76 vs. 47%; P=0.03). CONCLUSION: F-FDG PET/CT is advisable for the assessment of lung nodules in patients aged older than 60 years and/or in the lower lobes.