Quantitative 4D flow MRI-derived thoracic aortic normal values of 2D flow MRI parameters in healthy volunteers.

PURPOSE: To utilize 4 D flow MRI to acquire normal values of "conventional 2 D flow MRI parameters" in healthy volunteers in order to replace multiple single 2 D flow measurements with a single 4 D flow acquisition. MATERIALS AND METHODS: A kt-GRAPPA accelerated 4 D flow sequence was used. Flow volumes were assessed by forward (FFV), backward (BFV), and net flow volumes (NFV) [ml/heartbeat] and flow velocities by axial (VAX) and absolute velocity (VABS) [m/s] in 116 volunteers (58 females, 43 ±â€Š13 years). The aortic regurgitant fraction (RF) was calculated. RESULTS: The sex-neutral mean FFV, BFV, NFV, and RF in the ascending aorta were 93.5 ±â€Š14.8, 3.6 ±â€Š2.8, 89.9 ±â€Š0.6 ml/heartbeat, and 3.9 ±â€Š2.9 %, respectively. Significantly higher values were seen in males regarding FFV, BFV, NFV and RF, but there was no sex dependency regarding VAX and VABS. The mean maximum VAX was lower (1.01 ±â€Š0.31 m/s) than VABS (1.23 ±â€Š0.35 m/s). We were able to determine normal ranges for all intended parameters. CONCLUSION: This study provides quantitative 4 D flow-derived thoracic aortic normal values of 2 D flow parameters in healthy volunteers. FFV, BFV, NFV, and VAX did not differ significantly from single 2 D flow acquisitions and could therefore replace time-consuming multiple single 2 D flow acquisitions. VABS should not be used interchangeably. KEY POINTS: · 4 D flow MRI can be used to replace 2 D flow MRI measurements.. · The parameter absolute velocities can be assessed by 4 D flow MRI.. · There are sex-dependent differences regarding forward, backward, net aortic blood flow and the aortic valve regurgitant fraction..

Comparison of aortic blood flow rotational direction in healthy volunteers and patients with bicuspid aortic valves using volumetric velocity-sensitive cardiovascular magnetic resonance imaging.

Background: The rotational direction (RD) of helical blood flow can be classified as either a clockwise (RD+) or counter-clockwise (RD-) flow. We hypothesized that this simple classification might not be sufficient for analysis in vivo and a simultaneous existence of RD+/- may occur. We utilized volumetric velocity-sensitive cardiovascular magnetic resonance imaging (4D flow MRI) to analyze rotational blood flow in the thoracic aorta. Methods: Forty volunteers (22 females; mean age, 41±16 years) and seventeen patients with bicuspid aortic valves (BAVs) (9 females; mean age, 42±14 years) were prospectively included. The RDs and the calculation of the rotating blood volumes (RBVs) in the thoracic aorta were performed using a pathline-projection strategy. Results: We could confirm a mainly clockwise RD in the ascending, descending aorta and in the aortic arch. Furthermore, we found a simultaneous existence of RD+/RD-. The RD+/--volume in the ascending aorta was significantly higher in BAV patients, the mean RD+/RD- percentage was approximately 80%/20% vs. 60%/40% in volunteers (P<0.01). The maximum RBV always occurred during systole. There was significantly more clockwise than counter-clockwise rotational flow in the ascending aorta (P<0.01) and the aortic arch (P<0.01), but no significant differences in the descending aorta (P=0.48). Conclusions: A simultaneous occurrence of RD+/RD- indicates that a simple categorization in either of both is insufficient to describe blood flow in vivo. Rotational flow in the ascending aorta and in the aortic arch differs significantly from flow in the descending aorta. BAV patients show significantly more clockwise rotating volume in the ascending aorta compared to healthy volunteers.

Diagnosis and Therapy of Female Urinary Incontinence. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry No. 015/091, January 2022): Part 2 with Recommendations on Interventional/Surgical Therapy of Overactive Bladder, Surgical Treatment of Stress Urinary Incontinence and Diagnosis and Therapy of Iatrogenic Urogenital Fistula.

Aim This completely revised interdisciplinary S2k-guideline on the diagnosis, therapy, and follow-up care of female patients with urinary incontinence (AWMF registry number: 015-091) was published in December 2021. This guideline combines and summarizes earlier guidelines such as "Female stress urinary incontinence," "Female urge incontinence" and "Use of Ultrasonography in Urogynecological Diagnostics" for the first time. The guideline was coordinated by the German Society for Gynecology and Obstetrics (Deutsche Gesellschaft für Gynäkologie und Geburtshilfe, DGGG) and the Working Group for Urogynecology and Plastic Pelvic Floor Reconstruction (Arbeitsgemeinschaft für Urogynäkologie und plastische Beckenbodenrekonstruktion e. V., AGUB). Methods This S2k-guideline was developed using a structured consensus process involving representative members from different medical specialties and was commissioned by the Guidelines Commission of the DGGG, OEGGG and SGGG. The guideline is based on the current version of the guideline "Urinary Incontinence in Adults" published by the European Association of Urology (EAU). Country-specific items associated with the respective healthcare systems in Germany, Austria and Switzerland were also incorporated. Recommendations The short version of this guideline consists of recommendations and statements on the surgical treatment of female patients with stress urinary incontinence and urge incontinence. Specific solutions for the diagnostic workup and treatment of uncomplicated and complicated urinary incontinence are discussed. The diagnostics and surgical treatment of iatrogenic urogenital fistula are presented.

Diagnosis and Therapy of Female Urinary Incontinence. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry No. 015/091, January 2022): Part 1 with Recommendations on Diagnostics and Conservative and Medical Treatment.

Aim This completely revised interdisciplinary S2k-guideline on the diagnosis, therapy, and follow-up care of female patients with urinary incontinence (AWMF registry number: 015-091) was published in December 2021. This guideline combines and summarizes earlier guidelines such as "Female stress urinary incontinence," "Female urge incontinence" and "Use of Ultrasonography in Urogynecological Diagnostics" for the first time. The guideline was coordinated by the German Society for Gynecology and Obstetrics (Deutsche Gesellschaft für Gynäkologie und Geburtshilfe, DGGG) and the Working Group for Urogynecology and Plastic Pelvic Floor Reconstruction (Arbeitsgemeinschaft für Urogynäkologie und plastische Beckenbodenrekonstruktion e. V., AGUB). Methods This S2k-guideline was developed using a structured consensus process involving representative members from different medical specialties and was commissioned by the Guidelines Commission of the DGGG, OEGGG and SGGG. The guideline is based on the current version of the guideline "Urinary Incontinence in Adults" published by the European Association of Urology (EAU). Country-specific items associated with the respective healthcare systems in Germany, Austria and Switzerland were also incorporated. Recommendations The short version of this guideline consists of recommendations and statements on the epidemiology, etiology, classification, symptoms, diagnostics, and treatment of female patients with urinary incontinence. Specific solutions for the diagnostic workup and appropriate conservative and medical therapies for uncomplicated and complication urinary incontinence are discussed.

Quantitative normal values of helical flow, flow jets and wall shear stress of healthy volunteers in the ascending aorta.

OBJECTIVES: 4D flow MRI enables quantitative assessment of helical flow. We sought to generate normal values and elucidate changes of helical flow (duration, volume, length, velocities and rotational direction) and flow jet (displacement, flow angle) as well as wall shear stress (WSS). METHODS: We assessed the temporal helical existence (THEX), maximum helical volume (HVmax), accumulated helical volume (HVacc), accumulated helical volume length (HVLacc), maximum forward velocity (maxVfor), maximum circumferential velocity (maxVcirc), rotational direction (RD) and maximum wall shear stress (WSS) as reported elsewhere using the software tool Bloodline in 86 healthy volunteers (46 females, mean age 41 ± 13 years). RESULTS: WSS decreased by 42.1% and maxVfor by 55.7% across age. There was no link between age and gender regarding the other parameters. CONCLUSION: This study provides age-dependent normal values regarding WSS and maxVfor and age- and gender-independent normal values regarding THEX, HVmax, HVacc, HVLacc, RD and maxVcirc. KEY POINTS: • 4D flow provides numerous new parameters; therefore, normal values are mandatory. • Wall shear stress decreases over age. • Maximum helical forward velocity decreases over age.

Physiologic effects and functional outcome after treatment of dysfunctional right ventricular outflow tract in congenital heart disease using a two-stage intervention.

BACKGROUND: Pathophysiological differences in relief of pulmonary stenosis (PS) as opposed to pulmonary regurgitation (PR) by percutaneous pulmonary valve implantation (PPVI) remain elusive, but might impact current assessment of procedural success and ultimately indications. METHODS: Invasive pressure measurements, cardiac magnetic resonance imaging and cardiopulmonary exercise testing were performed before pre-stenting (BMS), after BMS and after PPVI in patients with either PS or PR. RESULTS: In PS (n = 14), BMS reduced the right ventricular (RV) to systemic pressure ratio (0.8 ± 0.2 vs. 0.4 ± 0.1%; p < .01), improved RF EF (53 ± 14 vs. 59 ± 12%; p = .01) but introduced free PR (PR fraction post 39 ± 12%; p < .01) with no changes in effective RV stroke volume (SV). PPVI eliminated PR (PR fraction 5 ± 3%; p < .01) and improved effective RV SV (p < .01) with no changes in RV EF (p = .47). Peak VO2 improved significantly after BMS, with no changes following PPVI (26 ± 9 vs. 30 ± 11 vs. 31 ± 10 ml/kg*min). In PR (n = 14), BMS exaggerated PR (PR fraction post 47 ± 10) with reduction in effective RV SV (pre 43 ± 9 vs. post 38 ± 8 ml/m2; p = .01), which improved after PPVI (post PPVI 49 ± 9 ml/m2; p < .01), secondary to elimination of PR (PR fraction 5 ± 4%; p < .01). RV EF (pre 53 ± 11 vs. post 53 ± 9 vs. post PPVI 50 ± 9%) and Peak VO2 (pre 22 ± 7 vs. post 21 ± 7 vs. post PPVI 23 ± 7 ml/kg*min) remained unchanged. CONCLUSIONS: Exercise capacity in patients with right ventricular outflow tract dysfunction is primarily afterload-dependent.

Automated Quantitative Extraction and Analysis of 4D flow Patterns in the Ascending Aorta: An intraindividual comparison at 1.5 T and 3 T.

4D flow MRI enables quantitative assessment of helical flow. Current methods are susceptible to noise. To evaluate helical flow patterns in healthy volunteers and patients with bicuspid aortic valves (BAV) at 1.5 T and 3 T using pressure-based helix-extraction in 4D flow MRI. Two intraindividual 4D flow MRI examinations were performed at 1.5 T and 3 T in ten healthy volunteers (5 females, 32 ± 3 years) and 2 patients with BAV using different acceleration techniques (kt-GRAPPA and centra). Several new quantitative parameters for the evaluation of volumes [ml], lengths [mm] as well as temporal parameters [ms] of helical flow were introduced and analyzed using the software tool Bloodline. We found good correlations between measurements in volunteers at 1.5 T and 3 T regarding helical flow volumes (R = 0.98) and temporal existence (R = 0.99) of helices in the ascending aorta. Furthermore, we found significantly larger (11.7 vs. 77.6 ml) and longer lasting (317 vs. 769 ms) helices in patients with BAV than in volunteers. The assessed parameters do not depend on the magnetic field strength used for the acquisition. The technique of pressure-based extraction of 4D flow MRI pattern is suitable for differentiation of normal and pathological flow.

Comparison of two accelerated 4D-flow sequences for aortic flow quantification.

To compare two broadly used 4D-flow- with a 2D-flow-sequence in healthy volunteers, regarding absolute flow parameters, image quality (IQ), and eddy current correction (ECC). Forty volunteers (42 ± 11.8 years, 22 females) were examined with a 3T scanner. Thoracic aortic flow was assessed using a 3D-T2w-SPACE-STIR-sequence for morphology and two accelerated 4D-flow sequences for comparison, one with k-t undersampling and one with standard GRAPPA parallel-imaging. 2D-flow was used as reference standard. The custom-made software tool Bloodline enabled flow measurements for all analyses at the same location. Quantitative flow analyses were performed with and without ECC. One reader assessed pathline IQ (IQ-PATH) and occurrence of motion artefacts (IQ-ART) on a 3-point grading scale, the higher the better. k-t GRAPPA allowed a significant mean scan time reduction of 46% (17:56 ± 5:26 min vs. 10:40 ± 3:15 min) and provided significantly fewer motion artefacts than standard GRAPPA (IQ-ART 1.57 ± 0.55 vs. 0.84 ± 0.48; p < 0.001). Neither 4D-flow sequence significantly differed in flow volume nor peak velocity results with or without ECC. Nevertheless, the correlation between both 4D-flow sequences and 2D-flow was better with ECC; the k-t GRAPPA sequence performed best (R = 0.96 vs. 0.90). k-t GRAPPA 4D-flow was not inferior to a standard GRAPPA-sequence, showed fewer artefacts, comparable IQ and was almost two-fold faster.

Acute adverse events in cardiac MR imaging with gadolinium-based contrast agents: results from the European Society of Cardiovascular Radiology (ESCR) MRCT Registry in 72,839 patients.

OBJECTIVES: To assess the incidence of acute adverse events (AAEs) in gadolinium-enhanced cardiac magnetic resonance (CMR) imaging. METHODS: Gadolinium-based contrast agent (GBCA)-enhanced CMR data from the multinational, multicenter European Society of Cardiovascular Radiology MRCT Registry was included. AAE severity was classified according to the American College of Radiology Manual on Contrast Media (mild, moderate, severe). Multivariable generalized linear mixed effect models were used to assess the likelihood of AAEs in various GBCA, adjusting for pharmacological stressor, main indications (i.e., suspected or known coronary artery disease or myocarditis), age, sex, and submitting center as a random effect. RESULTS: In the study population of 72,839 GBCA-enhanced CMRs, a total of 260 AAEs were reported (0.36%), with a minority of severe AAEs (n = 24, 0.033%). Allergic-like AAEs were less likely than physiologic AAEs (29% versus 71%). Patients without pharmacological stress imaging had a lower AAE rate (0.22%) compared to stress imaging (0.75%), with the highest AAE rates for regadenoson (2.95%). AAE rates also varied by GBCA subtype (overall p < 0.001). There was significant interaction between GBCA and pharmacological stressor (interaction p = 0.025), with AAE rates ranging between 0 and 10% for certain GBCA/stressor combinations. There was further marginal evidence that higher GBCA volume was associated with higher AAE incidence (OR = 1.02, p = 0.05). CONCLUSION: GBCA-enhanced CMR imaging demonstrates low AAE rates comparable to those of other body regions. AAE likelihood correlates with GBCA subtype, pharmacological stressor, and imaging indication. Intravenous fluid administration in patients with cardiac impairment might contribute to these findings. KEY POINTS: • Acute adverse event rates in cardiac magnetic resonance (CMR) imaging with gadolinium-based contrast agents (GBCAs) are low (0.36%), especially for severe adverse events (0.033%). • Mild and moderate adverse events are more frequent during stress CMR imaging. • Physiologic AAEs are more common than allergic AAEs in CMR imaging.

Comparison of the lower uterine segment in pregnant women with and without previous cesarean section in 3 T MRI.

BACKGROUND: Prenatal risk stratification of women with previous cesarean section (CS) by ultrasound thickness measurement of the lower uterine segment (LUS) is challenging. There is a wide range of proposed cutoff values and a valuable algorithm for selection before birth is not available. Using 3 T magnetic resonance imaging (MRI), we aimed to identify possible shortcomings of the current protocols used for birth selection after CS. Therefore, we evaluated anatomic and morphologic differences of the LUS and its thickness in patients with CS and those without. Possible impact factors on LUS thickness were studied. METHODS: We retrospectively analyzed 3 T MRI scans of 164 pregnant women in their second or third trimester, with (patient group, n = 60) and without previous CS (control group, n = 104). Sagittal T2-weighted images were studied. Normal findings of the LUS in MRI, reliability of MRI measurements, as well as factors influencing LUS thickness were assessed. MRI findings were compared to intraoperative findings. RESULTS: MRI provided good intra- (ICC 0.872) and fair inter-rater reliability (ICC 0.643). The relationship of the LUS and the cesarean scar to the surrounding anatomical structures and also its morphology varied strongly in patients and controls. Scar identification was possible in only 9/60 (15.0%) patients. The LUS was thinner in patients (1.9 ± 0.7 mm) than in controls (2.7 ± 1.3 mm). An LUS thinning up to 1 mm was observed in 23% of women without a previous CS and in 34% of women with normal intraoperative findings. Suspicion of a uterine dehiscence (LUS thickness < 1 mm) was only found in the patient group (5/59 (8.5%)) and was intraoperatively confirmed. In controls, LUS thickness was influenced by fetal weight, gestational age and amniotic fluid amounts. CONCLUSION: Variability in anatomy, thickness and morphology seem to limit common prenatal LUS imaging diagnostics. Therefore, we consider that diagnostic protocols must be re-evaluated and imaging should be adjusted to the individual patient conditions. Due to its independency of ultrasound limitations, an additional MRI might be useful for altered anatomy and impaired ultrasound conditions. An LUS thinning up to 1 mm might be a normal finding and should be further investigated as reference value.

3D-assessment of RVOT dimensions prior percutaneous pulmonary valve implantation: comparison of contrast-enhanced magnetic resonance angiography versus 3D steady-state free precession sequence.

To compare contrast-enhanced magnetic resonance angiography (ceMRA) and 3D steady-state free precession (SSFP) during systole and diastole for assessment of the right ventricle outflow tract (RVOT) in patients considered for percutaneous pulmonary valve implantation (PPVI) after tetralogy of Fallot (TOF) repair. We retrospectively evaluated 89 patients (male: 45, mean age 19 ± 8 years), who underwent cardiac-MRI after surgical TOF-repair. Datasets covering the whole heart in systole and diastole were acquired using ECG-gated 3D SSFP and non-gated ceMRA. Measurements were performed in SSFP-sequences and in ceMRA in the narrowest region of the RVOT to obtain the minimum, maximum and effective diameter. Invasive balloon sizing as the gold standard was available in 12 patients. The minimum diameter in diastolic SSFP, systolic SSFP and ceMRA were 21.4 mm (± 6.1 mm), 22.6 mm (± 6.2 mm) and 22.6 mm (± 6.0 mm), respectively. Maximum diameter was 29.9 mm (± 9.5 mm), 30.0 mm (± 7.0 mm) and 28.8 mm (± 8.1 mm) respectively. The effective diameter was 23.2 mm (± 5.7 mm), 27.4 mm (± 6.7 mm) and 24.4 mm (± 6.2 mm), differing significantly between diastole and systole (p < 0.0001). Measurements in ECG-gated SSFP showed a better inter- and intraobserver variability compared to measurements in non-ECG-gated ceMRA. Comparing invasive balloon sizing with our analysis, we found the highest correlation coefficients for the maximum and effective diameter measured in systolic SSFP (R = 0.99 respectively). ECG-gated 3D SSFP enables the identification and characterization of a potential landing zone for PPVI. The maximum and effective systolic diameter allow precise sizing for PPVI. Patients with TOF-repair could benefit from cardiac MRI before PPVI.

Validation of two accelerated 4D flow MRI sequences at 3 T: a phantom study.

BACKGROUND: Four-dimensional (4D) flow magnetic resonance imaging (MRI) sequences with advanced parallel imaging have the potential to reduce scan time with equivalent image quality and accuracy compared with standard two-dimensional (2D) flow MRI. We compared 4D flow to standard 2D flow sequences using a constant and pulsatile flow phantom at 3 T. METHODS: Two accelerated 4D flow sequences (GRAPPA2 and k-t-GRAPPA5) were evaluated regarding the concordance of flow volumes, flow velocities, and reproducibility as well as dependency on measuring plane and velocity encoding (Venc). The calculated flow volumes and peak velocities of the phantom were used as reference standard. Flow analysis was performed using the custom-made software "Bloodline". RESULTS: No significant differences in flow volume were found between the 2D, both 4D flow MRI sequences, and the pump reference (p = 0.994) or flow velocities (p = 0.998) in continuous and pulsatile flow. An excellent correlation (R = 0.99-1.0) with a reference standard and excellent reproducibility of measurements (R = 0.99) was achieved for all sequences. A Venc overestimated by up to two times had no impact on flow measurements. However, misaligned measuring planes led to an increasing underestimation of flow volume and mean velocity in 2D flow accuracy, while both 4D flow measurements were not affected. Scan time was significantly shorter for k-t-GRAPPA5 (1:54 ± 0:01 min, mean ± standard deviation) compared to GRAPPA2 (3:56 ± 0:02 min) (p = 0.002). CONCLUSIONS: Both 4D flow sequences demonstrated equal agreement with 2D flow measurements, without impact of Venc overestimation and plane misalignment. The highly accelerated k-t-GRAPPA5 sequence yielded results similar to those of GRAPPA2.

Cesarean section scar in 3 T magnetic resonance imaging and ultrasound: image characteristics and comparison of the methods.

PURPOSE: Uterine rupture during labor is a rare but life-threatening complication after previous cesarean section (CS). Prenatal risk is assessed using ultrasound thickness measurement of the lower uterine segment (LUS). Due to inhomogeneous study results, however, clinical obstetrics still lacks for standard protocols and reliable reference values. As 3 T magnetic resonance imaging (MRI) has not yet been sufficiently studied regarding LUS diagnostics after previous CS, we sought to evaluate its feasibility focusing on thickness measurements and typical characteristics of the CS-scar region in comparison to ultrasound and the intraoperative status. METHODS: In this prospective study, 25 asymptomatic patients with one previous CS and inconspicuous ultrasound findings were included. An additional 3 T MRI with either a T2-weighted Turbo-Spin-Echo or a Half Fourier-Acquired-Single-shot-Turbo-spin-Echo sequence in a sagittal orientation was performed. We analyzed categorical image quality, inter- and intra-rater reliability as well as anatomy, morphology and thickness of the LUS. Results were compared to ultrasound and intraoperative findings. RESULTS: MRI provided good to excellent image quality in all patients. The imaged structures presented with a high variability in anatomy and morphology. Image characteristics indicating the uterine scar were only found in 11/25 (44%) patients. LUS thickness measurements with MRI showed good inter- and intra-rater reliability but poor agreement with ultrasound. CONCLUSIONS: MRI is appropriate for additional LUS diagnostics in patients with previous CS. The strong individual variability of LUS-anatomy and morphology might explain the difficulties in establishing uniform diagnostic standards after CS.

Cross-sectional Areas of the Thoracic Aorta in Children and Adolescents With Repaired Tetralogy of Fallot Obtained by Cardiac Magnetic Resonance Angiography.

PURPOSE: Dilatation of the thoracic aorta is a well-known finding in corrected Tetralogy of Fallot. Complications are rare but can be life-threatening. Standard 1-dimensional (1D) measurements have several limitations. We sought to establish contrast-enhanced magnetic resonance angiography cross-sectional areas of the aorta that could serve as reference values and to identify parameters that are associated with aortic dilatation. MATERIALS AND METHODS: We enrolled 101 children and adolescents. The aortic areas were measured at the level of the aortic sinus (AS), the sinotubular junction (STJ), the ascending aorta (AA), the brachiocephalic trunk (TBC), and the descending aorta (DA). Sex-specific aortic dimensions were presented as percentile curves as well as regression equations. Furthermore volumetric and functional parameters as well as clinical data were analyzed to identify parameters that are associated with aortic dilatation. RESULTS: Aortic areas (mm) for female subjects were 139+366×body surface area (BSA) for the AS, 134+255×BSA for the STJ, 113+239×BSA for the AA, 88+185×BSA proximal to the TBC, and 2.9+88×BSA for the DA. Aortic areas (mm) for male subjects were 162+403×BSA for the AS, 171+258×BSA for the STJ, 151+233×BSA for the AA, 73+206×BSA proximal to the TBC, and 21+80×BSA for the DA. The postoperative interval and age at examination were parameters associated with aortic size. CONCLUSIONS: We provide aortic areas in children and adolescents after correction of Tetralogy of Fallot measured by contrast-enhanced magnetic resonance angiography. Our 2D data may better depict the geometry of enlarged aortae than standard 1D diameters and serve as reference values for evaluating aortic disease in these patients.

Frequency and clinical course of cerebral embolism in patients undergoing transcatheter left atrial appendage closure.

AIMS: The aim of this study was to assess silent and clinically apparent cerebral embolic events in patients undergoing transcatheter left atrial appendage closure. METHODS AND RESULTS: In this prospective single-centre study, 28 patients underwent percutaneous closure of the left atrial appendage. In all patients, a diffusion-weighted magnetic resonance imaging (DW-MRI) study was performed before, the day after the procedure, and during routine follow-up after 45 days. All patients underwent neurological assessment at the time of DW-MRI. Additionally, transcranial Doppler ultrasound monitoring (TCD) for the detection of microembolic material during the procedure was performed. The procedure was successfully completed in all patients. New embolic lesions were detected in nine patients (32%) after the procedure, of which three (33%) were detectable as gliotic lesions at follow-up. One (3.6%) new lesion was observed at 45-day follow-up. Neurological assessment showed no neurological deficits. We observed no relationship between the numbers of microembolic signals on TCD monitoring and the occurrence of cerebral infarctions on DW-MRI. CONCLUSIONS: New cerebral embolic events occur after transcatheter closure of the left atrial appendage. However, most of the lesions demonstrate no gliotic transformation at follow-up. In all patients, the cerebral lesions were clinically unapparent.

Magnetic resonance imaging guided transatrial electrophysiological studies in swine using active catheter tracking - experience with 14 cases.

OBJECTIVES: To evaluate the feasibility of performing comprehensive Cardiac Magnetic resonance (CMR) guided electrophysiological (EP) interventions in a porcine model encompassing left atrial access. METHODS: After introduction of two femoral sheaths 14 swine (41 ± 3.6 kg) were transferred to a 1.5 T MR scanner. A three-dimensional whole-heart sequence was acquired followed by segmentation and the visualization of all heart chambers using an image-guidance platform. Two MR conditional catheters were inserted. The interventional protocol consisted of intubation of the coronary sinus, activation mapping, transseptal left atrial access (n = 4), generation of ablation lesions and eventually ablation of the atrioventricular (AV) node. For visualization of the catheter tip active tracking was used. Catheter positions were confirmed by passive real-time imaging. RESULTS: Total procedure time was 169 ± 51 minutes. The protocol could be completed in 12 swine. Two swine died from AV-ablation induced ventricular fibrillation. Catheters could be visualized and navigated under active tracking almost exclusively. The position of the catheter tips as visualized by active tracking could reliably be confirmed with passive catheter imaging. CONCLUSIONS: Comprehensive CMR-guided EP interventions including left atrial access are feasible in swine using active catheter tracking. KEY POINTS: • Comprehensive CMR-guided electrophysiological interventions including LA access were conducted in swine. • Active catheter-tracking allows efficient catheter navigation also in a transseptal approach. • More MR-conditional tools are needed to facilitate left atrial interventions in humans.

New MRI Criteria for Successful Vaginal Breech Delivery in Primiparae.

BACKGROUND: Even if lower vaginal delivery success rates and impaired neonatal short-term outcomes have been reported for primiparous women with breech presentation, vaginal breech delivery remains an option for carefully selected patients. Because Magnetic resonance imaging (MRI) pelvimetry can provide additional information on maternal pelvic morphology, we sought to identify new MRI parameters that predict successful vaginal breech delivery. METHODS: In this retrospective unicentre study, 240 primiparous women with breech presentation at term underwent MRI pelvimetry. For all patients vaginal delivery was planned, according to German guidelines and if the conjugata vera (CV) was ≥12 cm. The patients with uneventful vaginal deliveries and the patients who underwent a secondary caesarean section were compared according to pelvimetric parameters and outcomes. Regression analyses were performed. RESULTS: In the vaginal delivery group (n = 162, (67.5%)), the distance between the spinae ischiadicae (interspinous diameter, ISD) was significantly enlarged. The ISD significantly influenced the mode of delivery in the regression analyses. The CV did not significantly differ between the groups. The patients with successful vaginal deliveries were significantly younger than the patients who underwent caesarean section. In the receiver operating characteristic (ROC) analysis, the area under the curve (AUC) for ISD was 67.7% (p<0.001, 95% CI [0.303-0.642]) and was higher considering the mother's age (AUC = 73.1%, p<0.001, 95% CI [0.662-0.800]). The neonatal short-term outcomes were comparable in both groups. CONCLUSION: The additional use of ISD may predict successful vaginal breech delivery and may be superior to the CV, which is more commonly used. TRIAL REGISTRATION: DRKS00009957.

Comprehensive Cardiac Magnetic Resonance Imaging in Patients With Suspected Myocarditis: The MyoRacer-Trial.

BACKGROUND: Data suggest that T1 and T2 mapping have excellent diagnostic accuracy in patients with suspected myocarditis. However, the true diagnostic performance of comprehensive cardiac magnetic resonance (CMR) mapping versus endomyocardial biopsy (EMB) has not been determined. OBJECTIVES: This study assessed the performance of CMR imaging, including T1 and T2 mapping, compared with EMB in an unselected, consecutive patient cohort with suspected myocarditis. It also examined the potential role of CMR field strength by comparing 1.5-T versus 3.0-T imaging. METHODS: Patients underwent biventricular EMB, cardiac catheterization (for exclusion of coronary artery disease), and CMR imaging on 1.5- and 3-T scanners. The CMR protocol included current standard Lake Louise criteria (LLC) for myocarditis as well as native T1, calculation of extracellular volume fraction (ECV), and T2 mapping (only on 1.5-T). Patients were divided into 2 groups according to symptom duration (acute: ≤14 days vs. chronic: >14 days). RESULTS: A total of 129 patients underwent 1.5-T imaging. In patients with acute symptoms, native T1 yielded the best diagnostic performance as defined by the area under the curve (AUC) of receiver-operating curves (0.82) followed by T2 (0.81), ECV (0.75), and LLC (0.56). In patients with chronic symptoms, only T2 mapping yielded an acceptable AUC (0.77). On 3.0-T, AUCs of native T1, ECV, and LLC were comparable to 1.5-T with no significant differences. CONCLUSIONS: In patients with acute symptoms, mapping techniques provide a useful tool for confirming or rejecting the diagnosis of myocarditis and are superior to the LLC. However, only T2 mapping has acceptable diagnostic performance in patients with chronic symptoms. (Magnetic Resonance Imaging in Myocarditis [MyoRacer]; NCT02177630).

Real-time magnetic resonance-guided ablation of typical right atrial flutter using a combination of active catheter tracking and passive catheter visualization in man: initial results from a consecutive patient series.

AIMS: Recently cardiac magnetic resonance (CMR) imaging has been found feasible for the visualization of the underlying substrate for cardiac arrhythmias as well as for the visualization of cardiac catheters for diagnostic and ablation procedures. Real-time CMR-guided cavotricuspid isthmus ablation was performed in a series of six patients using a combination of active catheter tracking and catheter visualization using real-time MR imaging. METHODS AND RESULTS: Cardiac magnetic resonance utilizing a 1.5 T system was performed in patients under deep propofol sedation. A three-dimensional-whole-heart sequence with navigator technique and a fast automated segmentation algorithm was used for online segmentation of all cardiac chambers, which were thereafter displayed on a dedicated image guidance platform. In three out of six patients complete isthmus block could be achieved in the MR scanner, two of these patients did not need any additional fluoroscopy. In the first patient technical issues called for a completion of the procedure in a conventional laboratory, in another two patients the isthmus was partially blocked by magnetic resonance imaging (MRI)-guided ablation. The mean procedural time for the MR procedure was 109 ± 58 min. The intubation of the CS was performed within a mean time of 2.75 ± 2.21 min. Total fluoroscopy time for completion of the isthmus block ranged from 0 to 7.5 min. CONCLUSION: The combination of active catheter tracking and passive real-time visualization in CMR-guided electrophysiologic (EP) studies using advanced interventional hardware and software was safe and enabled efficient navigation, mapping, and ablation. These cases demonstrate significant progress in the development of MR-guided EP procedures.