Anatomic estimation of aortic stenosis severity vs "fusion" of data from computed tomography and Doppler echocardiography.

AIM: Two-dimensional, transthoracic echocardiography does not account for the noncircular anatomy of the left ventricular outflow tract (LVOT) and may therefore underestimate LVOT area. Fusion of computed tomography (CT)-derived LVOT area and Doppler-derived flow data has been proposed to improve assessment of aortic valve area (AVA) and classification of aortic stenosis severity. For hemodynamic reasons, effective AVA has to be smaller than anatomic AVA. The aim of the study was to test the "fusion approach" by comparing effective CT-derived AVA with anatomic AVA from CT planimetry. METHODS AND RESULTS: Data of 244 consecutive patients (mean age 81 ± 5 years, 61% female) with aortic stenosis were retrospectively analyzed comparing effective AVA (calculated from the continuity equation using CT-LVOT and transthoracic Doppler measurements) with anatomic AVA based on CT planimetry. Substituting the LVOT area from transthoracic echocardiography (TTE) by the CT-LVOT resulted in an increase in AVA from 0.74 ± 0.15 to 0.92 ± 0.18cm² (P < .01), which was larger than anatomic AVA (0.82 ± 0.15cm²). Similar results were obtained based on planimetry from transesophageal echocardiography (TEE; AVA 0.79 ± 0.14cm², P < .01 vs CT-LVOT) and in the subgroup presenting with low-gradient severe aortic stenosis and preserved ejection fraction (n = 67, AVA from TTE 0.76 ± 0.09; from CT-LVOT 0.97 ± 0.14; CT planimetry 0.86 ± 0.12; TEE planimetry 0.82 ± 0.13cm²). CONCLUSION: Fusion of CT-derived LVOT area with Doppler echocardiography results in a calculated effective AVA that is larger than the corresponding anatomic AVA. Therefore, adjustment of partition values may be warranted when using this approach.

Early hypo-attenuated leaflet thickening in balloon-expandable transcatheter aortic heart valves.

AIMS: We sought to evaluate the frequency of early hypo-attenuated leaflet thickening (HALT) of the SAPIEN 3 transcatheter aortic valve (S3). METHODS AND RESULTS: Of 249 patients who had undergone S3 implantation, we studied 156 consecutive patients (85 women, median age 82.2 ± 5.5 years) by electrocardiogram (ECG)-triggered dual-source computed tomography angiography (CTA) after a median of 5 days post-transcatheter aortic valve implantation. The prosthesis was assessed for HALT. Apart from heparin, peri-interventional antithrombotic therapy consisted of single- (aspirin 29%) or dual- (aspirin plus clopidogrel 71%) antiplatelet therapy. Hypo-attenuated leaflet thickening was found in 16 patients [10.3% (95% confidence interval (CI) 5.5-15.0%)] of the patients. None of the baseline and procedural variables were significantly associated with HALT, nor did we find a significant association with the antithrombotic regimen, either peri-interventionally or at the time of CTA. Hypo-attenuated leaflet thickening was found in 6 of 45 patients with peri-interventional single-antiplatelet therapy and in 10 of 111 patients with dual-antiplatelet therapy at the time of intervention [13.3% (95% CI 3.4-23.3%) vs. 9% (95% CI 3.7-14.3%), P = 0.42]. Hypo-attenuated leaflet thickening was not associated with clinical symptoms, but a small, albeit significant difference in mean pressure gradient at the time of CTA (11.6 ± 3.4 vs. 14.9 ± 5.3 mmHg, P = 0.026). Full anticoagulation led to almost complete resolution of HALT in 13 patients with follow-up CTA. CONCLUSION: Irrespective of the antiplatelet regimen, early HALT occurred in 10% of our patients undergoing transcatheter aortic S3 implantation. Early HALT is clinically inapparent and reversible by full anticoagulation.

Aortic root volume is associated with contained rupture of the aortic annulus in balloon-expandable transcatheter aortic valve replacement.

BACKGROUND: Aortic annulus rupture is a rare, but potentially fatal complication of transcatheter aortic valve replacement (TAVR), especially when it occurs by balloon-expandable devices. In order to improve the predictability of procedures and avoid ruptures we investigated whether or not the aortic root volume measures is a useful indicator of risk, and if it could be useful for the prosthesis size selection. METHODS AND RESULTS: From a retrospective series of 172 TAVR patients, seven experienced contained aortic annulus ruptures. The receiver operating curves were used to illustrate sensitivity and specificity of the different aortic annulus size and aortic root volume measures. The annulus area oversizing of ≥20% resulted in a sensitivity of 100%, specificity of 55.76%, and positive predictive value (PPV) of 8.75%. In patients receiving 26 mm prostheses, the aortic root volume (ARV <13600 mm(3)) provided a better specificity and PPV (79.63 and 18.52%, respectively). A two-step testing procedure considering the area derived average annulus diameter (Darea <23 mm) as a first separating parameter and then the ARV (<13,600 mm(3)) as a further indicator showed the most promising results with the PPV of 31.25%. Regardless of the procedure steps no false negative results were predicted. CONCLUSIONS: Our data show that the ARV provides a better predictive value for correct prosthesis sizing than established annulus measurements, especially in 'borderline' annuli. We suggest a two-step testing procedure for prostheses size selection, considering Darea and ARV to minimize the risk of annulus rupture. Prospective studies and examination of larger datasets are warranted to confirm these findings.

In vivo contact force measurements and correlation with left atrial anatomy during catheter ablation of atrial fibrillation.

AIMS: Lesion formation during catheter ablation crucially depends on catheter-tissue contact. We sought to evaluate the impact of anatomical characteristics of the left atrium (LA) and the pulmonary veins (PVs) on contact force (CF) measurements. METHODS AND RESULTS: An anatomical map of the LA was obtained in 25 patients prior to catheter ablation of atrial fibrillation. Contact force (operator blinded) and local bipolar electrogram amplitudes (EGM) were measured in eight pre-defined segments around the PVs. After unblinding, points with low CF (≤5 g) were corrected to CF >5 g, and the distance between points was measured. In a pre-procedural computed tomography of the heart, LA volume as well as sizes and circumferences of the PV ostia were measured and correlated to CF measurements. Four hundred and twenty-six points in eight pre-defined LA locations were assessed. Low CF (<5 g) was found in 25.0% (43.5%) of points superior, 33.3% (66.7%) anterior, 32.1% (44.4%) inferior, and 15.5% (15.9%) posterior to the right (left) PVs. The mean distance after correction was 5.8 ± 3.4 mm. Local bipolar electrogram amplitudes between low- and high-CF points did not differ (1.21 ± 1.54 vs. 1.13 ± 1.3 mV, P = ns). The mean CF at the left PVs was significantly lower than at the right PVs (7.91 ± 3.74 vs. 13.95 ± 6.34 g, P < 0.001), with the lowest CF anterior to the left PVs (5.2 ± 3.6 g). Contact force measurements did not correlate to LA volume, size, and circumference of the PVs. CONCLUSION: Contact force during LA mapping significantly differs according to the location within the LA. These differences are independent of LA volume and anatomy of the PV ostia.

Anatomical and procedural features associated with aortic root rupture during balloon-expandable transcatheter aortic valve replacement.

BACKGROUND: Aortic root rupture is a major concern with balloon-expandable transcatheter aortic valve replacement (TAVR). We sought to identify predictors of aortic root rupture during balloon-expandable TAVR by using multidetector computed tomography. METHODS AND RESULTS: Thirty-one consecutive patients who experienced left ventricular outflow tract (LVOT)/annular/aortic contained/noncontained rupture during TAVR were collected from 16 centers. A caliper-matched sample of 31 consecutive patients without annular rupture, who underwent pre-TAVR multidetector computed tomography served as a control group. Multidetector computed tomography assessment included short- and long-axis diameters and cross-sectional area of the sinotubular junction, annulus, and LVOT, and the presence, location, and extent of calcification of the LVOT, as well. There were no significant differences between the 2 groups in any preoperative clinical and echocardiographic variables. Aortic root rupture was identified in 20 patients and periaortic hematoma in 11. Patients with root rupture had a higher degree of subannular/LVOT calcification quantified by the Agatston score (181.2±211.0 versus 22.5±37.6, P<0.001), and a higher frequency of ≥20% annular area oversizing (79.4% versus 29.0%, P<0.001) and balloon postdilatation (22.6% versus 0.0%, P=0.005). In conditional logistic regression analysis for the matched data, moderate/severe LVOT/subannular calcifications (odds ratio, 10.92; 95% confidence interval, 3.23-36.91; P<0.001) and prosthesis oversizing ≥20% (odds ratio, 8.38; 95% confidence interval, 2.67-26.33; P<0.001) were associated with aortic root contained/noncontained rupture. CONCLUSIONS: This study demonstrates that LVOT calcification and aggressive annular area oversizing are associated with an increased risk of aortic root rupture during TAVR with balloon-expandable prostheses. Larger studies are warranted to confirm these findings.

Pre-Procedural Assessment of the Femoral Access Route for Transcatheter Aortic Valve Implantation: Comparison of a Non-Contrast Time-of-Flight Magnetic Resonance Angiography Protocol with Contrast-Enhanced Dual-Source Computed Tomography Angiography.

Background: We aimed to evaluate the feasibility of a non-contrast time-of-flight magnetic resonance angiography (TOF-MRA) protocol for the pre-procedural access route assessment of transcatheter aortic valve implantation (TAVI) in comparison with contrast-enhanced cardiac dual-source computed tomography angiography (CTA). Methods and Results: In total, 51 consecutive patients (mean age: 82.69 ± 5.69 years) who had undergone a pre-TAVI cardiac CTA received TOF-MRA for a pre-procedural access route assessment. The MRA image quality was rated as very good (median of 5 [IQR 4-5] on a five-point Likert scale), with only four examinations rated as non-diagnostic. The TOF-MRA systematically underestimated the minimal effective vessel diameter in comparison with CTA (for the effective vessel diameter in mm, the right common iliac artery (CIA)/external iliac artery (EIA)/common femoral artery (CFA) MRA vs. CTA was 8.04 ± 1.46 vs. 8.37 ± 1.54 (p < 0.0001) and the left CIA/EIA/CFA MRA vs. CTA was 8.07 ± 1.32 vs. 8.28 ± 1.34 (p < 0.0001)). The absolute difference between the MRA and CTA was small (for the Bland-Altman analyses in mm, the right CIA/EIA/CFA was -0.36 ± 0.77 and the left CIA/EIA/CFA was -0.25 ± 0.61). The overall correlation between the MRA and CTA measurements was very good (with a Pearson correlation coefficient of 0.87 (p < 0.0001) for the right CIA/EIA/CFA and a Pearson correlation coefficient of 0.9 (p < 0.0001) for the left CIA/EIA/CFA). The feasibility agreement between the MRA and CTA for transfemoral access was good (the right CIA/EIA/CFA agreement was 97.9% and the left CIA/EIA/CFA agreement was 95.7%, Kohen's kappa: 0.477 (p = 0.001)). Conclusions: The TOF-MRA protocol was feasible for the assessment of the access route in an all-comer pre-TAVI population. This protocol might be a reliable technique for patients at an increased risk of contrast-induced nephropathy.

Simultaneous bilateral contrast injection in computed tomography pulmonary angiography.

BACKGROUND: Computed tomography pulmonary angiography (CTPA) has evolved as the gold standard for diagnosing pulmonary embolism. However, subsegmental arteries are often not assessed to do insufficient attenuation. PURPOSE: To evaluate the influence of simultaneous bilateral versus unilateral injection of a fixed amount of contrast media on pulmonary artery opacification and image quality in CTPA. MATERIAL AND METHODS: In this institutional review board-approved prospective study, 180 patients (91 women, mean age 61.9 ± 16.5 years) referred for CTPA (100 kV) due to suspected pulmonary embolism were randomized in groups of 45 patients each, with either unilateral (A:4 mL/s; B:6 mL/s) or bilateral (C: 6 mL/s; D: 8 mL/s) (Y-shaped line) injection of 50 mL contrast media. Attenuation was assessed including the subsegmental arteries (4th order). Image quality was evaluated by two readers in consensus using a three-point grading scale (3 = excellent image quality, no artifacts, 1 = non-diagnostic). RESULTS: Mean pulmonary artery attenuation was significantly higher with bilateral injection (1st to 3rd order: A: 303.6 ± 8.8HU; B: 371.1 ± 11.0HU vs. C: 443.2 ± 24.1HU; D: 562.3 ± 15.3HU, P < 0.001). Evaluation of subsegmental arteries was feasible for all patients in groups B-D, but only in 36/45 (80%) patients in group A. Subsegmental attenuation was significantly higher with bilateral injection (A: 284.7 ± 12.1HU; B: 367.4 ± 12.1HU vs. C: 494.2 ± 21.5HU; D: 562.3 ± 26.7HU, P < 0.001). Image quality was diagnostic for all patients but best for group C (A: 2.15 ± 0.4; B: 2.14 ± 0.5; C: 2.92 ± 0.3, and D: 2.51 ± 0.5). CONCLUSION: Using the same amount of contrast media, bilateral injection yields higher pulmonary artery attenuation and better image quality than unilateral injection. This technique may improve subsegmental pulmonary artery assessment.

Three-dimensional stomach analysis with computed tomography after laparoscopic sleeve gastrectomy: sleeve dilation and thoracic migration.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is frequently performed as a definitive bariatric procedure today. Quantitative data on the detailed anatomy of the stomach after LSG are yet sparse. METHODS: Thirty-two multislice computed tomography (MSCT) data sets acquired in 27 LSG patients (22 female, 5 male) with a dedicated examination protocol and post-processing were evaluated for gastric volume, stomach length, sleeve length, antrum length, staple line length, and maximum cross-sectional sleeve area. Obtained parameters were compared to time after surgery, weight loss, and the occurrence of postsurgical regurgitation. RESULTS: Mean gastric volume was 186.5±88.4 ml. Gastric volume correlated significantly with the time interval after surgery. Sleeve sizes of 105.3±30.2 ml during early follow-up confirmed correct primary sizing of the sleeve, whereas marked dilation to 196.8±84.3 ml was found in patients with a follow-up of 6 months and longer (p=0.038). Sleeve area and staple line length were also positively correlated with time after surgery. No correlation was found between gastric volume and excess weight loss. In ten patients an intrathoracic migration of the staple line could be noted, with four of these patients developing persistent regurgitation after LSG. Regurgitation was present in only 2 of 17 patients without sleeve herniation. CONCLUSION: Multislice computed tomography allows for a comprehensive and quantitative evaluation of the anatomy after LSG and thus provides new insights in the process of sleeve dilation. Intrathoracic migration of the staple line could be identified as a possible cause of persistent regurgitation.

Influence of arm positioning on radiation dose for whole body computed tomography in trauma patients.

BACKGROUND: Multislice whole body computed tomography is regarded as the method of choice for primary investigation of hemodynamically stable patients with multiple injuries. However, a disadvantage of this method is the high level of radiation to which the patient is exposed. Various recommendations on how to position the patient's arms during whole body computed tomography have been given in the literature, but conclusive data are missing. Therefore, the aim of our study was to investigate the relationship between different arm positions and radiation dose in patients undergoing whole body computed tomography. METHODS: In a retrospective analysis of available data derived from former whole body computed tomography screening of patients with multiple injuries, we calculated the effective radiation dose and scanning time for different arm positions (both arms up, both arms at sides, right arm up, and left arm up). Statistical analysis was performed using the independent t test with 95% confidence intervals. Statistical significance was set at 0.05. RESULTS: The data evaluated had been recorded for 956 patients during a period of 18 months. Of these patients, 710 were included in the study. In 487 cases (68%), both arms were up; in 82 cases (12%), down by the sides; in 90 cases (13%), the right arm was up; and in 44 cases (6%), the left arm was up. Overall, the radiation dose was statistically significantly higher with both arms at sides (24.69 mSv ± 6.91 mSv) than with both arms up (19.18 mSv ± 4.99 mSv; p < 0.0000001). Statistically significant differences in effective radiation dose were not found for either the right arm up (23.52 mSv ± 5.23 mSv; p = 0.211) or the left arm up (22.53 mSv ± 5.4 mSv; p = 0.076) compared with both arms down at sides. Comparison of scan lengths for the thorax or abdomen did not yield any significant differences between arms down and any other arm position. Analysis of scanning times did not reveal any significant differences for whole body computed tomography with both arms down (07:31 minutes ± 02:53 minutes) compared with both arms up (07:30 minutes ± 02:04 minutes; p = 0.94), right arm up (07:15 minutes ± 01:43 minutes; p = 0.582), or left arm up (07:18 minutes ± 01:24 minutes; p = 0.707). CONCLUSION: Based on our retrospective investigation, it can be recommended with reference to whole body computed tomography screening that the arms should be in the arms-up position during thorax or abdomen scanning of a severely injured patient, provided there are no clear clinical indications of shoulder injury. For the patient, this position is associated with a significantly reduced radiation dose without noticeable loss of time.

Predictors for low TAVI-prosthesis position assessed by fusion imaging of pre- and post-procedural CT angiography.

BACKGROUND: Low prosthesis position after transcatheter aortic valve implantation (TAVI) is associated with higher rates of new onset conduction disturbances and permanent pacemaker implantations. Purpose of this study was to investigate possible predictors of a low prosthesis position of the SAPIEN 3 (Edwards Lifesciences, Irvine, California, USA) valve type using fusion imaging of pre- and post-procedural computed tomography angiography (CTA). METHODS: CTA fusion imaging was performed in 120 TAVI-patients with 3D-reconstruction of the transcatheter heart valve (THV) position within the device landing zone. A low implantation position was defined according to the manufacturer's recommendations as > 30% of the prosthesis below the native annulus plane. RESULTS: A low THV position was found in 17 patients (14%). Patients with low THV position had less calcification of the annulus region and a smaller annulus size compared to patients with a normal or high THV position (P = 0.003 and 0.041, respectively). The only independent predictor of a low THV position in multivariate logistic regression analysis was the extent of calcification of the cusp region (odds ratio [CI] 0.842 [0.727-0.976], P = 0.022). CONCLUSIONS: Fusion imaging of pre-and post-procedural CTA identified reduced calcification of the cusp region as an independent predictor of a low THV position of the SAPIEN 3. This should be considered when planning the TAVI procedure. Correlation of cusp region calcification and prosthesis position after TAVI.

Dual-energy CT virtual noncalcium technique: detecting posttraumatic bone marrow lesions--feasibility study.

PURPOSE: To evaluate traumatized bone marrow with a dual-energy (DE) computed tomographic (CT) virtual noncalcium technique. MATERIALS AND METHODS: In this prospective institutional review board-approved study, 21 patients with an acute knee trauma underwent DE CT and magnetic resonance (MR) imaging. A software application was used to virtually subtract calcium from the images. Presence of fractures was noted, and presence of bone bruise was rated on a four-point scale for six femoral and tibial regions by two radiologists. CT numbers were obtained in the same regions. Consensus reading of independently read MR images served as the reference standard. Image ratings and CT numbers were subjected to receiver operating characteristic curve analysis. RESULTS: After exclusion of 16 regions owing to artifacts, MR imaging revealed 59 bone bruises in the remaining 236 regions (19 of 114 femoral, 40 of 122 tibial). Fractures were present in eight patients. Visual rating revealed areas under the curve of 0.886 and 0.897 in the femur and 0.974 and 0.953 in the tibia for observers 1 and 2, respectively. For CT numbers, the respective areas under the curve were 0.922 and 0.974. If scores of 1 and 2 (strong or mild bone bruise) were counted as positive, sensitivities were 86.4% and 86.4% and specificities were 94.4% and 95.5% for observers 1 and 2, respectively. The kappa statistic demonstrated good to excellent agreement (femur, kappa = 0.78; tibia, kappa = 0.87). CONCLUSION: This DE CT virtual noncalcium technique can subtract calcium from cancellous bone, allowing bone marrow assessment and potentially making posttraumatic bone bruises of the knee detectable with CT.

Thoracic aorta: prospective electrocardiographically triggered CT angiography with dual-source CT--feasibility, image quality, and dose reduction.

PURPOSE: To prospectively investigate the feasibility, image quality, and radiation dose for prospective electrocardiographically (ECG) triggered sequential dual-source computed tomographic (CT) angiography of the thoracic aorta in comparison to retrospective ECG-gated helical dual-source CT angiography. MATERIALS AND METHODS: This study was approved by the institutional review board; informed consent was obtained. One hundred thirty-nine patients referred for ECG-assisted dual-source CT angiography of the thoracic aorta were prospectively enrolled. Inclusion criteria were stable sinus rhythm and heart rate of 80 beats per minute or less. Tube voltage was adjusted to body mass index (< 25.0 kg/m(2), 100 kV, n = 58; > or = 25.0 kg/m(2), 120 kV, n = 81). In both cohorts, patients were randomly assigned to prospective or retrospective ECG-assisted data acquisition. In both groups, tube current (250 mAs per rotation) was centered at 70% of the R-R cycle. The presence of motion or stair-step artifacts of the thoracic aorta was independently assessed by two readers. Effective radiation dose was calculated from the dose-length product. RESULTS: Subjective scoring of motion and stair-step artifacts was equivalent for both techniques. Scan length was not significantly different (23.8 cm +/- 2.4 [standard deviation] vs 23.7 cm +/- 2.5 for prospective and retrospective ECG-triggered CT angiography, respectively; P = .54). Scanning time was significantly longer for prospective ECG-triggered CT angiography (18.8 seconds +/- 3.4 vs 16.4 seconds +/- 3.3, P < .001). Mean estimated effective dose was significantly lower for prospective data acquisition (100 kV, 1.9 mSv +/- 0.5 vs 4.1 mSv +/- 0.7, P < .001; 120 kV, 5.3 mSv +/- 1.1 vs 9.5 mSv +/- 3.0, P < .001). CONCLUSION: Prospective ECG-gated sequential dual-source CT angiography of the thoracic aorta is feasible, despite the slightly longer acquisition time. Thus, motion-free imaging of the thoracic aorta is possible at significantly lower radiation exposure than retrospective ECG-gated helical dual-source CT angiography in certain patients with a regular heart rate.

Imaging of pulmonary vein anatomy using low-dose prospective ECG-triggered dual-source computed tomography.

OBJECTIVE: To prospectively investigate the feasibility, image quality and radiation dose estimates for computed tomography angiography (CTA) of the pulmonary veins and left atrium using prospective electrocardiography (ECG)-triggered sequential dual-source (DS) data acquisition at end-systole in patients with paroxysmal atrial fibrillation undergoing radiofrequency ablation. METHODS: Thirty-five patients (mean age 66.2 +/- 12.6 years) with paroxysmal atrial fibrillation underwent prospective ECG-triggered sequential DS-CTA with tube current (250 mAs/rotation) centred 250 ms past the R-peak. Tube voltage was adjusted to the BMI (<25 kg/m(2): 100 kV, >25 kg/m(2): 120 kV). Presence of motion or stair-step artefacts was assessed. Effective radiation dose was calculated from the dose-length product. RESULTS: All data sets could be integrated into the electroanatomical mapping system. Twenty-two patients (63%) were in sinus rhythm (mean heart rate 69.2 +/- 11.1 bpm, variability 1.0 +/- 1.7 bpm) and 13 (37%) showed an ECG pattern of atrial fibrillation (mean heart rate 84.8 +/- 16.6 bpm, variability 17.9 +/- 7.5 bpm). Minor step artefacts were observed in three patients (23%) with atrial fibrillation. Mean estimated effective dose was 1.1 +/- 0.3 and 3.0 +/- 0.5 mSv for 100 and 120 kV respectively. CONCLUSION: Imaging of pulmonary vein anatomy is feasible using prospective ECG-triggered sequential data acquisition at end-systole regardless of heart rate or rhythm at the benefit of low radiation dose.

Combined assessment of aortic root anatomy and aortoiliac vasculature with dual-source CT as a screening tool in patients evaluated for transcatheter aortic valve implantation.

OBJECTIVE: The objective of our study was to investigate the feasibility, image quality, and clinical implications of a combined dual-source CT angiography (CTA) protocol to assess aortic root anatomy and aortoiliac vasculature in patients with severe aortic stenosis evaluated for transcatheter aortic valve implantation. SUBJECTS AND METHODS: Eighty consecutive patients (47 women and 33 men; mean age, 82.3 ± 7.8 [SD] years) with severe aortic stenosis evaluated for transcatheter aortic valve implantation underwent a combined single-dose contrast-enhanced dual-source CTA protocol (body weight < 70 kg, 110 mL of contrast medium; ≥ 70 kg, 130 mL) consisting of ECG-gated dual-source CTA of the chest with integrated cardiac CT and ungated CTA of the abdomen and pelvis. Two independent observers measured the dimensions of the aortic root and the aortoiliac vasculature and rated image quality semiquantitatively. Vessel attenuation was assessed. Amenability to transfemoral access was evaluated on the basis of vessel diameter (> 7 mm), anatomy, and the presence of vascular disease. RESULTS: Image quality of the aortic root was diagnostic in all 80 patients, and image quality of the aortoiliac vasculature was diagnostic in 79 patients. Vascular attenuation was greater than 200 HU at any vessel level. The mean diameter of the aortic annulus was 24.1 ± 2.9 (SD) mm. Inter- and intraobserver correlations for aortic root and aortoiliac measurements were high (r = 0.93-0.99). Aortic root dimensions were suitable for transcatheter aortic valve implantation in 65 patients (81%). Thirty-eight patients (48%) were deemed amenable to instant transfemoral access without another vasculature intervention. CONCLUSION: The dimensions of the aortic root and the aortoiliac vasculature can be assessed with a combined single-dose contrast-enhanced dual-source CTA protocol, thereby allowing determination of patient eligibility for transcatheter aortic valve implantation, prosthesis sizing, and evaluation of the access route in one examination.

Prospective ECG-triggered CT angiography of the thoracic aorta in patients with atrial fibrillation or accelerated heart rates: feasibility and image quality.

OBJECTIVE: The objective of our study was to prospectively investigate the feasibility and image quality of and to calculate the radiation dose estimates for CT angiography (CTA) of the thoracic aorta in patients with atrial fibrillation or accelerated heart rates using prospective ECG-triggered sequential dual-source data acquisition in end-systole. CONCLUSION: Prospective ECG-gated sequential dual-source CTA of the thoracic aorta is feasible despite heart rates>80 beats per minute or atrial fibrillation, making motion-free imaging of the thoracic aorta possible at a considerably low radiation dose.

Incidental finding of a pulmonary embolus by intracardiac echocardiography during an atrial fibrillation ablation procedure.

A 71-year-old female patient was referred for catheter ablation of drug-refractory, symptomatic atrial fibrillation. Initial intracardiac echocardiography (ICE) incidentally showed a mobile embolus stuck at a bifurcation of the right pulmonary artery. The procedure was suspended and the finding was subsequently confirmed by computed tomography pulmonary angiography. This case illustrates a potential value of real-time imaging by ICE during invasive procedures.

Influence of prosthesis-related factors on the occurrence of early leaflet thrombosis after transcatheter aortic valve implantation.

AIMS: Early leaflet thrombosis (LT) is a well-described phenomenon after transcatheter aortic valve implantation (TAVI) with an incidence around 15%. Data about predictors of LT are scarce. The purpose of the study was to investigate the influence of prosthesis-related factors on the occurrence of LT. MATERIALS AND RESULTS: Fusion imaging of pre- and post-procedural computed tomography angiography was performed in 55 TAVI patients with LT and 140 selected patients as control groups (85 patients in an unmatched and 55 in a matched control) to obtain a 3D reconstruction of the transcatheter heart valve (THV) within the native annulus region. All patients received a balloon-expandable Sapien 3 THV. The THV length above and below the native annulus was measured within the fused images to assess the implantation depth. The deployed THV area was quantified on three heights (left ventricular outflow tract end, stent centre, and aortic end) to determine the average expansion of the prosthesis as percent of the nominal area. We also calculated the extent of prosthesis waist in percent of maximum area. After multivariate adjustment, the extent of THV waist [odds ratio (OR) per 10% (confidence interval, CI) 0.636 (0.526-0.769), P < 0.001] as prosthesis-related factor and previous oral anticoagulation [OR (CI) 0.070 (0.020-0.251), P < 0.001] had significant, independent influence on the occurrence of LT. The implantation depth showed no influence on LT manifestation (P = 0.704). CONCLUSION: Besides the absence of previous oral anticoagulation, a less pronounced waist of the implanted THV was a prosthesis-position-related independent predictor of LT after TAVI using the Sapien 3.

Assessment of aortic annulus dimensions for transcatheter aortic valve replacement (TAVR) with high-pitch dual-source CT: Comparison of systolic high-pitch vs. multiphasic data acquisition.

OBJECTIVES: To evaluate a systolic ECG-gated high-pitch aortoiliac computed tomography (CT) angiography for planning transcatheter aortic valve implantation (TAVI). METHODS: Patients referred for TAVI underwent a combined CT imaging with retrospective, multiphasic ECG-gating of the heart and systolic ECG-gated high-pitch aortoiliac CT angiography. Consecutive patients were retrospectively included in this study group. Heart rate (HR) and heart rate variability (HRV) were assessed during the high-pitch ECG prediction phase. Aortic annulus area (AAA) was planimetrically quantified on both datasets. While only one moment of cardiac cycle was available for measurements in the high-pitch CT, the point of time in the multiphasic CT was chosen, where AAA yielded maximum size. Hypothetical prosthesis sizing was compared between multiphasic vs. high-pitch CT. RESULTS: Among 61 patients (44.2 % men, mean age: 83.3 ± 5.5 years) average heart rate and HRV were 71.0 ± 13.4 bpm and 7.3 ± 8.5 bpm. 20 patients (32.7 %) had atrial fibrillation at the time of image acquisition. There was a strong correlation of AAA as derived from multiphasic vs. the high-pitch CT (r = 0.98). The difference in AAA was 10.5 ± 17.1mm2 (455.1 ± 83.0 mm2 for multiphasic vs. 444.5 ± 87.2 mm2 for high-pitch CT) and did not reach statistical significance (p = 0.08). Hypothetical prosthesis sizing showed an agreement in 55 of 61 patients (90.2 %). A sizing based on the high-pitch CT resulted in smaller prosthesis choice in 6 patients, all of them suffering from atrial fibrillation. Mean effective radiation dose was 10.9 ± 6.1 mSv for cardiac CTA and 4.1 ± 1.0 mSv for high-pitch CTA. CONCLUSION: For patients with sinus rhythm, systolic high-pitch aortoiliac CTA provides adequate prosthesis size selection as compared with multiphasic ECG-gated cardiac CTA and may result in significantly reduced radiation exposition.

Long-term follow-up of patients with contained annulus ruptures after TAVI: the EuropeaN COntained RupturE (ENCORE) registry.

AIMS: The purpose of this registry was to determine the long-term outcomes in patients with asymptomatic contained annulus rupture (CR) as a rare complication of transcatheter aortic valve implantation (TAVI). METHODS AND RESULTS: The ENCORE registry is a multicentre registry (six centres across Europe) of patients with CR diagnosed on post-TAVI computed tomography angiography (CTA) or transoesophageal echocardiography (TEE). A total of 21 patients (mean age 81.9±4.1 years, 81% balloon-expandable TAVI prostheses) were diagnosed with CR (mean size of lesions was 15.3±6.9 × 8.5±3.3 × 8.5±2.3 mm). Seventeen were diagnosed among a total of 1,602 consecutive routine post-TAVI CTA (incidence 1.1%), two in TEE and two in post-TAVI CTA (each conducted due to suspicion of peri-interventional complications). During a mean follow-up of 2.3±1.7 years (cumulative 48.6 patient-years), nine patients (43%) died from non-cardiac causes. None of the patients exhibited symptoms or underwent interventional treatment related to the CR; no sudden cardiac death occurred. A follow-up CTA, performed in eleven patients 240±176 days post TAVI, revealed stable CR findings in seven, regression in one, and remission in three patients. CONCLUSIONS: The results of our international multicentre registry demonstrate favourable long-term outcomes of CR after TAVI supporting a watch-and-wait strategy in these patients.

Posttraumatic edema of the lower extremities: evaluation of the lymphatic vessels with magnetic resonance lymphangiography.

OBJECTIVE: To assess for the first time the morphology of the lymphatic system in patients with posttraumatic edema of the lower extremities by magnetic resonance (MR) imaging using the interstitial lymphangiography technique MATERIALS AND METHODS: Six patients with posttraumatic edema in eight of their 12 lower extremities were examined by MR lymphangiography. Eighteen mL of gadoteridol and one mL of mepivacainhydrochloride 1% were subdivided into 10 portions and injected intracutaneously. MR imaging was performed with a 1.5-T system equipped with high-performance gradients. For MR lymphangiography, a 3D-spoiled gradient-echo sequence was used. RESULTS: In five of the eight (63%) traumatized lower extremities, enlarged lymphatic vessels were detected, with the largest diameter measuring 5 mm. Additionally, a fast lymphatic outflow was observed in seven of the eight (88%) traumatized legs with enhancement of the inguinal lymph nodes already in the first image acquisition 15 minutes after contrast material injection. In two of the eight (25%) traumatized lower extremities, an extensive network of collateral lymphatic vessels was detected at the level of the calf. In both extremities, lymphatic collateralization involved not only the epifascial but also the subfascial lymphatic system. In one patient, who sustained a trauma of the left lower leg with tibial fracture, a small aneurysmatic widening of 7 mm could be detected at the middle level of the calf. CONCLUSION: MR lymphangiography is a safe and accurate minimal-invasive imaging modality for the evaluation of the lymphatic circulation in patients with posttraumatic edema of the lower extremities. If the extent of lymphatic damage is unclear at the initial clinical examination or requires a better definition for optimal therapeutic planning, MR lymphangiography is able to identify the anatomic and physiological derangements and to establish an objective baseline.