Gated cardiac imaging of the aortic valve on 64-slice multidetector row computed tomography: preliminary observations

PURPOSE: To conduct a pilot study to determine the feasibility of evaluating aortic valve morphology and motion on electrocardiogram-gated 64-slice cardiac MDCT. METHODS: Four-dimensional images of the aortic valve were reviewed in 20 consecutive patients who underwent computed tomography (CT) coronary angiography. A consensus reading of 3 readers was performed of valve visibility, number of leaflets, valve motion, and calcification. Visibility of the valve leaflets and visualization of opening and closing of the valve leaflets were graded as well seen or suboptimally seen. The number of valve leaflets (3 or 2) and presence of valvular calcification were noted. RESULTS: The aortic valve was well seen in all 20 patients. Three leaflets were identified in all cases, and no calcifications were seen. Valve movement with opening and closure of the leaflets during the cardiac cycle was also well seen in all cases. CONCLUSIONS: Visualization of the aortic valve and valvular motion during the cardiac cycle is feasible on CT studies performed for coronary angiography. CT has a potential role in the assessment of aortic valvular pathology.     

The significance of calcific valvular heart disease in Tc-99m pyrophosphate myocardial infarction scanning: radiographic, scintigraphic, and pathological correlation.

Technetium-99m pyrophosphate (PPi) is currently considered the best scanning agent for the diagnosis of acute myocardial infarction. False-positive scans have been reported in association with unstable angina, alcoholic cardiomyopathy, and ventricular aneurysms. In this study, 86% of patients (12/14) with either calcific aortic or mitral valvular heart disease had positive PPi cardiac scintiscans and the location of the PPi uptake was limited to the calcific valve in all (9/9) of the patients who underwent valve replacement surgery. Six patients with valvular disease without radiologic evidence of calcium had negative PPi heart images. Three of these patients had surgical valve replacement, and in none was there increased uptake in the resected valve. Seventy-five percent of the patients with calcified aortic valves had localization of the PPi activity to the area of the aortic valve, whereas 50% of the patients with calcified mitral valves showed a diffuse pattern of uptake on the cardiac image. In vitro demonstration of increased radioactivity in surgically removed cardiac valves warrants the conclusion that Tc-99m PPi is taken up by calcified heart valves. We conclude that while PPi heart scanning is a sensitive indicator of acute myocardial infarction, false-positive scans can occur in the presence of calcific valvular disease, due to localization of PPi in the calcified portion of the valve.     

Visualization of aortic valve leaflets using black blood MRI.

Although magnetic resonance imaging (MRI) is capable of imaging various physiological parameters associated with the heart valves, it has generally been difficult to visualize the valve leaflets directly. The aortic valve was imaged in 120 patients referred for cardiac MRI to assess myocardial volumes or mass. The average patient age was 37 and ranged from 9 to 75 years. Heart rate ranged from 43 to 100 bpm. Imaging was performed on a 1.5 T scanner equipped with enhanced gradients and a cardiac phased-array coil. A double inversion recovery fast spin-echo sequence was used to acquire short-axis images of the aortic valve in a breath-hold (15 +/- 3 seconds). All three leaflets of the aortic valve were seen in 102 of 120 studies (85%). Two leaflets were detected in another 15 subjects. No leaflets were seen in three individuals. Seven cases of a bicuspid or thickened aortic valves were clearly distinguished from normal valves. The signal-to-noise ratio of aortic leaflets (14 +/- 5) was significantly higher than that of the residual blood signal in the aortic root (7 +/- 4, P < 0.001). MR images showed the aortic valve leaflets in a high fraction of people with suspected normal aortic valves and detected seven cases of abnormal aortic valves. The potential of MRI to study both the anatomic and functional consequences of valvular heart disease warrants further study. J. Magn. Reson. Imaging 1999;10:771-777.     

Evaluation of valvular disease by cardiac computed tomography assessment

Cardiac multidetector computed tomography (MDCT) angiography is emerging as a technique to evaluate cardiac valve structure and function. MDCT can provide insights into cardiac valve anatomy and pathologic states, including comparable efficacy in valve area and regurgitant orifice area assessment compared with echocardiography and magnetic resonance imaging. MDCT can also be useful when initial evaluation of valvular disease with echocardiography yields suboptimal images. MDCT provides concurrent visualization of coronary anatomy which may avoid the need for further invasive preoperative testing. Overall, more studies have shown the utility of MDCT in imaging of left-sided valves (aortic and mitral), whereas its ability in assessing right-sided valves (tricuspid and pulmonary) is somewhat limited. MDCT has shown promise as a valuable adjunctive imaging tool to conventional imaging modalities in providing essential anatomic and physiologic data on the sequelae of valvular dysfunction, with the potential of guiding both surgical and percutaneous management. MDCT technology continues to evolve, and more studies are indicated to further refine its precise role in the evaluation of patients with valvular pathology.     

基础心功能状况与急性放射性心脏损伤的相关性研究

目的 探讨胸部放疗基础心功能状况对急性放射性心脏损伤的影响,评价急性期内患者心功能的变化。方法 分析109例胸部肿瘤患者放疗后基础心功能状况对急性放射性心脏损伤的影响,并观察放疗前及急性观察期内心功能的变化。结果 全组患者急性放射性心脏损伤发生率为79.8%,患者临床因素及基础心功能各项指标与急性放射性心脏损伤发生均无明显相关(P>0.05)。放射治疗后急性期内出现左室收缩功能减低24例,舒张功能减低15例;瓣膜病变24例,全部为二尖瓣和(或)主动脉瓣改变,其中反流(轻、中度反流)23例、狭窄(轻度)1例,未见三尖瓣和(或)肺动脉瓣反流与狭窄。左房前后径、主动脉流速、E/A值在放疗前、放疗结束、自放疗开始3个月差异有统计学意义(F=8.552、0.017、0.003,P<0.05)。左房前后径、主动脉流速、E/A值放疗结束较放疗前分别下降了9.19%、7.56%、17.5%,自放疗开始3个月较放疗结束分别恢复7.05%、4.14%、7.58%,其中E/A下降和恢复变化幅度最大。结论 临床因素及基础心功能状况与急性放射性心脏损伤发生无明显相关。放疗导致的瓣膜病变以二尖瓣和(或)主动脉瓣轻、中度反流多见,并可引起左室收缩和舒张功能改变。左房前后径、E/A值放疗后首先降低,随着时间延长逐渐改善,但急性期内未能恢复到正常水平。急性观察期内放疗对心脏舒张功能的影响较收缩功能明显。     

Dual-source CT cardiac imaging: initial experience

The relation of heart rate and image quality in the depiction of coronary arteries, heart valves and myocardium was assessed on a dual-source computed tomography system (DSCT). Coronary CT angiography was performed on a DSCT (Somatom Definition, Siemens) with high concentration contrast media (Iopromide, Ultravist 370, Schering) in 24 patients with heart rates between 44 and 92 beats per minute. Images were reconstructed over the whole cardiac cycle in 10% steps. Two readers independently assessed the image quality with regard to the diagnostic evaluation of right and left coronary artery, heart valves and left ventricular myocardium for the assessment of vessel wall changes, coronary stenoses, valve morphology and function and ventricular function on a three point grading scale. The image quality ratings at the optimal reconstruction interval were 1.24±0.42 for the right and 1.09±0.27 for the left coronary artery. A reconstruction of diagnostic systolic and diastolic images is possible for a wide range of heart rates, allowing also a functional evaluation of valves and myocardium. Dual-source CT offers very robust diagnostic image quality in a wide range of heart rates. The high temporal resolution now also makes a functional evaluation of the heart valves and myocardium possible.     

Coronary artery assessment by multidetector computed tomography in patients with prosthetic heart valves

Objectives

Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT.

Methods

ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of prosthetic heart valves. The best systolic and diastolic axial reconstructions were selected for coronary assessment. Each present coronary segment was scored for the presence of valve-related artefacts prohibiting coronary artery assessment. Scoring was performed in consensus by two observers.

Results

Eighty-two CT angiograms were performed on a 64-slice (n?=?27) or 256-slice (n?=?55) multidetector CT. Eighty-nine valves and five annuloplasty rings were present. Forty-three out of 1160 (3.7%) present coronary artery segments were non-diagnostic due to valve artefacts (14/82 patients). Valve artefacts were located in right coronary artery (15/43; 35%), left anterior descending artery (2/43; 5%), circumflex artery (14/43; 32%) and marginal obtuse (12/43; 28%) segments. All cobalt-chrome containing valves caused artefacts prohibiting coronary assessment. Biological and titanium-containing valves did not cause artefacts except for three specific valve types.

Conclusions

Most commonly implanted prosthetic heart valves do not hamper coronary assessment on multidetector CT. Cobalt-chrome containing prosthetic heart valves preclude complete coronary artery assessment because of severe valve artefacts.

Key Points

? Most commonly implanted prosthetic heart valves do not hamper coronary artery assessment ? Prosthetic heart valve composition determines the occurrence of prosthetic heart valve-related artefacts ? Bj?rk–Shiley and Sorin tilting disc valves preclude diagnostic coronary artery segment assessment     

儿童瓣膜性心脏病的外科治疗

报道87例儿童瓣膜性心脏病患者的外科治疗。其中男58例,女29例,年龄4－14（平均10．2）岁,其中二尖瓣置换36例,主动脉瓣置换13例,二尖瓣和主动脉瓣双瓣置换6例,主动脉瓣成形13例,二尖瓣成形19例。所用心脏瓣膜均为机械瓣。同期处理三尖瓣关闭不全41例,室间隔缺损23例,房间隔缺损9例,佛氏窦瘤破裂8例,动脉导管未闭3例。术后早期并发症包括：低心排综合征7例,呼吸衰竭3例,心律失常5例。早期死亡4例,病死率4．60％。随访0．5－14．5（平均6．51）年,晚期死亡3例,病死率3．61％。儿童瓣膜性心脏病手术治疗时,首先应尽量选择瓣膜成形术;对人工心脏瓣膜替换术者,瓣膜尽量选用成人型号,术后常规行华法林抗凝治疗,并要重视对患儿术后风湿活动的治疗。     

Bicuspid aortic valves: Diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT

Objectives

To assess the diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT for bicuspid aortic valves.

Materials and methods

The standard axial chest CT scans of 20 patients with known bicuspid aortic valves were blindly, randomly analyzed for (i) the appearance of the valve cusps, (ii) the largest aortic sinus area, (iii) the longest aortic cusp length, (iv) the thickest aortic valve cusp and (v) valve calcification. A second blinded reader independently analyzed the appearance of the valve cusps. Forty-two age- and sex-matched patients with known tricuspid aortic valves were used as controls. Retrospectively ECG-gated cardiac CT multiphase reconstructions of the aortic valve were used as the gold-standard.

Results

Fourteen (21%) scans were scored as unevaluable (7 bicuspid, 7 tricuspid). Of the remainder, there were 13 evaluable bicuspid valves, ten of which showed an aortic valve line sign, while the remaining three showed a normal Mercedes-Benz appearance owing to fused valve cusps. The 35 evaluable tricuspid aortic valves all showed a normal Mercedes-Benz appearance (P = 0.001). Kappa analysis = 0.62 indicating good interobserver agreement for the aortic valve cusp appearance. Aortic sinus areas, aortic cusp lengths and aortic cusp thicknesses of ≥3.8 cm², 3.2 cm and 1.6 mm respectively on standard axial chest CT best distinguished bicuspid from tricuspid aortic valves (P < 0.0001 for all). Of evaluable scans, the sensitivity, specificity, positive and negative predictive values of standard axial chest CT in diagnosing bicuspid aortic valves was 77% (CI 0.54–1.0), 100%, 100% and 70% respectively.

Conclusion

The aortic valve is evaluable in approximately 80% of standard chest 64-slice CT scans. Bicuspid aortic valves may be diagnosed on evaluable scans with good diagnostic accuracy. An aortic valve line sign, enlarged aortic sinuses and elongated, thickened valve cusps are specific CT features.     

Untersuchungstechniken und Stellenwert der MRT bei der Diagnostik von Herzklappenerkrankungen

The main indications for cardiac magnetic resonance imaging (MRI) in the evaluation of valvular heart disease are pathologies of the aortic and pulmonary valve. For mitral and tricuspid valve pathologies MRI is not the first line modality as these are usually well visualized by echocardiography. The advantages of MRI in valvular heart disease are a high reliability in the evaluation of ventricular volumes and function as well as the assessment of the perivalvular arterial or atrial structures. This reliability and the limitless access to any imaging plane partially compensates for the lower temporal and spatial resolution in comparison to echocardiography. In patients with congenital heart disease, cardiac MRI is established as a valuable diagnostic tool in daily clinical management, especially for the evaluation of pulmonary valve defects. Nevertheless, echocardiography remains the first-line diagnostic imaging tool for the foreseeable future.     

Untersuchungstechniken und Stellenwert der CT bei der Diagnostik von Herzklappenerkrankungen

Clinical/methodical issue

Cardiac computed tomography (CT) is the first-line modality for coronary assessment. In addition valvular morphology and function can be evaluated.

Standard radiological methods

The method of choice for the evaluation of cardiac valves is echocardiography, followed by magnetic resonance imaging.

Methodical innovations

Recent technical improvements and advances in temporal resolution allow a detailed anatomical and functional evaluation of the cardiac valves.

Performance

Cardiac CT provides an excellent image quality of the aortic and mitral valve thus enabling an evaluation of the morphology. In addition, cardiac CT allows an assessment of aortic valve function with respect to the grading of stenosis and regurgitation.

Achievements

Cardiac CT is not considered the first-line modality for the evaluation of cardiac valves; however, beyond coronary assessment CT provides important information on the morphology and function of cardiac valves.

Practical recommendations

Cardiac CT can be a useful imaging alternative for patients in whom other more commonly used methods, such as echocardiography and magnetic resonance imaging fail to provide the necessary information.     

冠心病合并心脏瓣膜疾病的手术治疗

目的总结冠心病合并心脏瓣膜疾病的外科治疗方法。方法1998年4月-2004年12月，同期治疗57例冠心病合并心脏瓣膜疾病患者，平均年龄60岁（42～78岁）；心功能Ⅱ级9例，Ⅲ级37例，Ⅳ级11例；二尖瓣病变37例，主动脉瓣病变11例，联合瓣膜病变9例；均伴有单支或多支冠状动脉病变。手术在中低温体外循环下进行。心脏停跳后先做静脉桥的远端吻合，然后处理瓣膜。心脏复苏后在升主动脉开放前完成大隐静脉与升主动脉的吻合。乳内动脉的吻合在瓣膜置换或成形后心脏复苏前完成。本组行二尖瓣成形8例，行二尖瓣置换29例，行主动脉瓣置换11例，行双瓣置换9例（其中39例为机械瓣置换，10例为进口生物瓣置换）。冠脉搭桥1～5支，平均2．7支／例。结果术后早期死亡1例，死亡率为1．75％，其余患者住院期间无严重并发症。随访6个月～7年，无死亡，患者生活质量均明显提高，心功能Ⅰ级45例，Ⅱ级11例。结论同期施行冠状动脉旁路术和心脏瓣膜术安全有效。     

Congenital anomalies of coronary arteries in complex congenital heart disease: Diagnosis and analysis with dual-source CT

BackgroundCongenital heart diseases (CHDs) are sometimes associated with coronary artery anomalies (CAAs). Accurate preoperative evaluation of coronary artery anatomy is essential for successful surgical repair of complex CHD.ObjectiveThe aim of this study was to evaluate the incidence of congenital CAAs in patients with complex CHD at dual-source CT.MethodsFour hundred seventeen consecutive patients with complex CHD underwent contrast-enhanced cardiac CT angiography. The results were retrospectively analyzed, including the types and incidences of CAAs in various forms of complex CHD. Each patient was analyzed independently by 2 experienced cardiovascular radiologists. Image quality of coronary arteries was assessed on a 5-point scale with 2 or less being nondiagnostic.ResultsThirty-five of 417 studies were nondiagnostic (8.39%). Sixty-three cases of CAA (15.11%) were detected by anomalous ostia and coronary arteries. CAA was involved in 6 of 108 patients with tetralogy of Fallot (5.56%), 18 of 84 patients with double outlet right ventricle (21.43%), 11 of 97 patients with pulmonary artery atresia (11.34%), 7 of 36 patients with transposition of the great arteries (22.22%), 15 of 41 patients with single ventricle (36.59%), 4 of 12 patients with truncus arteriosus/aortopulmonary window (33.33%), and 2 of 39 patients with interruption of the aortic arch/coarctation of the aorta (5.13%). Twenty of these were accompanied with an anomalous coronary course (31.74%).ConclusionPatients with complex CHD have a higher prevalence of CAAs, which should be considered before surgery. Dual-source CT is an effective technique to visualize and evaluate complex CHD.     

Follow-up examination of 12 heart transplant recipients with cardiac CT

ObjectiveThe aims of this study were to observe the changes of a transplanted heart with cardiac computed tomography (CT) and to evaluate the clinical application of the examination.MethodsCardiac CT was performed on 12 heart transplant recipients, of which 4 cases were also examined by echocardiography. Coronary arteries, the cardiac chamber, and the wall were shown with three-dimensional imaging techniques, and their changes were analyzed and discussed.ResultsTwelve heart transplant recipients were successfully examined by CT. All transplanted hearts were found with good anastomosis at the great vessels and atria. Coronary allograft vasculopathy was found in 7 cases, of which 4 cases were found with ventricular dilation or ventricular septum thickening and 1 with tricuspid regurgitation. Ventricular dilation was found in other 3 cases, of which 1 was found with ventricular septum thickening and 1 with tricuspid regurgitation. No abnormality was found by cardiac CT in the rest 2 cases, which were found with mitral regurgitation by echocardiography.ConclusionCardiac CT can clearly and directly display the changes in the shape of a transplanted heart and coronary artery abnormalities. It will become an ideal noninvasive follow-up method for the heart transplant recipients.     

复发性心脏瓣膜病的多次手术治疗(附28例报告)

目的 总结复发性心脏瓣膜病行多次心脏瓣膜手术治疗的经验.方法 回顾性分析2004年6月-2015年6月行3次或以上瓣膜手术的28例复发性心脏瓣膜病患者的病例资料,其中男15例,女13例,年龄55.6±6.5(44~67)岁,均有2次或以上二尖瓣和(或)主动脉瓣置换或成形手术史,均行再次心脏瓣膜手术,其中二尖瓣置换18例,三尖瓣置换10例.二尖瓣置换在中低温心脏停搏下进行,均同期行三尖瓣成形;三尖瓣置换在体外循环心脏跳动下进行.10例采用股动静脉结合上腔静脉插管,其余18例均常规行动静脉插管.对心脏停搏患者采用主动脉根部灌注停跳液进行心肌保护.结果 全组患者体外循环时间65~300min,平均125min;18例二尖瓣置换患者主动脉阻断时间55~107min,平均80min.全组死亡2例,死因均为严重低心排综合征.术后早期主要并发症包括呼吸衰竭3例,严重低心排综合征2例,因纵隔出血行二次开胸探查止血2例,重症感染性休克1例.随访6~36个月,患者心功能明显改善,置入瓣膜未发现异常.结论 复发性心脏瓣膜病行3次或以上瓣膜手术虽然具有较高的手术风险,但只要准确把握手术时机、采用正确的手术技术及妥善的围术期处理,仍然能取得满意的手术效果.     

Prognostic impact of identifying etiology of prosthetic valve dysfunction with CT

BackgroundIn patients with prosthetic heart valves (PHV), there are distinct treatment implications based on prosthetic valve dysfunction (PVD) etiology. We investigated whether evaluation for PVD etiology on computed tomography (CT) has prognostic value for adverse clinical outcomes.MethodsConsecutive patients with suspected PVD that had a clinically indicated contrast chest CT and echocardiogram done within 1 year of each other were identified retrospectively from the Prosthetic Heart Valve CT Registry at the University of Minnesota. CTs and echocardiograms were assessed for potential PVD etiologies of pannus, structural valve degeneration (SVD) and thrombus, as per standard guidelines. Kaplan-Meier and Cox regression analyses were performed to assess association with a composite outcome of reoperation and all-cause mortality.Results132 patients (51.5% male, mean age 62.1 ?± ?19.3 years) with suspected PVD were included. There were 97 tissue valves, 31 mechanical valves and 4 transcatheter valves. The location of the valve was as follows: 72 aortic, 45 mitral, 8 tricuspid, and 7 pulmonic. A PVD etiology was diagnosed on CT in 80 (60.6%) patients, and on echocardiography in 45 (34.1%) patients, largely driven by a diagnosis of SVD on both modalities. Significant univariate predictors of the composite outcome included CT diagnosis of SVD (P ?< ?0.001), echocardiography diagnosis of SVD (P ?< ?0.001), degree of prosthetic stenosis (P ?< ?0.001) and degree of prosthetic regurgitation (P ?< ?0.001). On multivariable analyses adjusted for age, sex, left ventricular function, degree of prosthetic stenosis and degree of prosthetic regurgitation, CT diagnosis of SVD was significantly associated with the composite outcome (HR: 1.79, 1.09–2.95) whereas echocardiography diagnosis of SVD was not (HR: 1.56, 0.98–2.46).ConclusionIn patients with suspected PVD, CT assessment of SVD had prognostic significance for hard outcomes. CT should be considered in the diagnostic evaluation of patients with suspected PVD.     

Value of knowledge-based iterative model reconstruction in low-kV 256-slice coronary CT angiography

BackgroundMost current iterative reconstruction algorithms for CT imaging are a mixture of iterative reconstruction and filtered back projection. The value of “fully” iterative reconstruction in coronary CT angiography remains poorly understood.ObjectiveWe aimed to assess the value of the knowledge-based iterative model reconstruction (IMR) algorithm on the qualitative and quantitative image quality at 256-slice cardiac CT.MethodsWe enrolled 21 patients (mean age: 69 ± 11 years) who underwent retrospectively ECG gated coronary CT anhgiography at 100 kVp tube voltage. Images were reconstructed with the filtered back projection (FBP), hybrid iterative reconstruction (IR), and IMR algorithms. CT attenuation and the contrast-to-noise ratio (CNR) of the coronary arteries were calculated. With the use of a 4-point scale, 2 reviewers visually evaluated the coronary arteries and cardiac structures.ResultsThe mean CT attenuation of the proximal coronary arteries was 369.3 ± 73.6 HU, 363.9 ± 75.3 HU, and 363.3 ± 74.5 HU, respectively, for FBP, hybrid IR, and IMR and was not significantly different. The image noise of the proximal coronary arteries was significantly lower with IMR (11.3 ± 2.8 HU) than FBP (51.9 ± 12.9 HU) and hybrid IR (23.2 ± 5.2 HU). The mean CNR of the proximal coronary arteries was 9.4 ± 2.4, 20.2 ± 4.7, and 41.8 ± 9.5 with FBP, hybrid IR and IMR, respectively; it was significantly higher with IMR. The best subjective image quality for coronary vessels was obtained with IMR (proximal vessels: FBP, 2.6 ± 0.5; hybrid IR, 3.4 ± 0.5; IMR, 3.8 ± 0.4; distal vessels: FBP, 2.3 ± 0.5; hybrid IR. 3.1 ± 0.5; IMR, 3.7 ± 0.5). IMR also yielded the best visualization for cardiac systems, that is myocardium and heart valves.ConclusionThe novel knowledge-based IMR algorithm yields significantly improved CNR and better subjective image quality of coronary vessels and cardiac systems with reliable CT number measurements for cardiac CT imaging.     

Pre-procedural fit-testing of TAVR valves using parametric modeling and 3D printing

BackgroundSuccessful transcatheter aortic valve replacement (TAVR) requires an understanding of how a prosthetic valve will interact with a patient's anatomy in advance of surgical deployment. To improve this understanding, we developed a benchtop workflow that allows for testing of physical interactions between prosthetic valves and patient-specific aortic root anatomy, including calcified leaflets, prior to actual prosthetic valve placement.MethodsThis was a retrospective study of 30 patients who underwent TAVR at a single high volume center. By design, the dataset contained 15 patients with a successful annular seal (defined by an absence of paravalvular leaks) and 15 patients with a sub-optimal seal (presence of paravalvular leaks) on post-procedure transthoracic echocardiogram (TTE). Patients received either a balloon-expandable (Edwards Sapien or Sapien XT, n = 15), or a self-expanding (Medtronic CoreValve or Core Evolut, n = 14, St. Jude Portico, n = 1) valve. Pre-procedural computed tomography (CT) angiograms, parametric geometry modeling, and multi-material 3D printing were utilized to create flexible aortic root physical models, including displaceable calcified valve leaflets. A 3D printed adjustable sizing device was then positioned in the aortic root models and sequentially opened to larger valve sizes, progressively flattening the calcified leaflets against the aortic wall. Optimal valve size and fit were determined by visual inspection and quantitative pressure mapping of interactions between the sizer and models.ResultsBenchtop-predicted “best fit” valve size showed a statistically significant correlation with gold standard CT measurements of the average annulus diameter (n = 30, p < 0.0001 Wilcoxon matched-pairs signed rank test). Adequateness of seal (presence or absence of paravalvular leak) was correctly predicted in 11/15 (73.3%) patients who received a balloon-expandable valve, and in 9/15 (60%) patients who received a self-expanding valve. Pressure testing provided a physical map of areas with an inadequate seal; these corresponded to areas of paravalvular leak documented by post-procedural transthoracic echocardiography.ConclusionWe present and demonstrate the potential of a workflow for determining optimal prosthetic valve size that accounts for aortic annular dimensions as well as the active displacement of calcified valve leaflets during prosthetic valve deployment. The workflow's open source framework offers a platform for providing predictive insights into the design and testing of future prosthetic valves.     

Dual-source-Computertomographie des Herzens

In a newly developed dual-source computed tomography system (DSCT) the relation of heart rate and image quality and the possible advantages of the system’s superior temporal resolution in the evaluation of left ventricular parameters as compared to results of cardiac magnetic resonance imaging (MRI) were assessed. Coronary CT angiography was performed using a DSCT (Somatom Defintion, Siemens Medical Solutions, Forchheim, Germany) in 21 patients (mean age 62±8; 15 male, 6 female). Image quality of the coronary arteries, the heart valves, and the left ventricular myocardium was assessed using a three-point grading scale. Ten of these patients also underwent cardiac MRI for the assessment of left ventricular function, using a SSFP (steady-state free precession) sequence. Left ventricular ejection fractions (LV-EF), the end-systolic volumes (ESV), and the end-diastolic volumes (EDV) were measured employing MRI and DSCT datasets. The image quality ratings for the coronary arteries at the optimal reconstruction interval were diagnostic even in patients with high heart rates (1.42±0.49). Analysis of global LV function using DSCT quantified from CTA datasets showed a good correlation with results of cardiac MRI [EF: r=0.75 (p=0.01); ESV: r=0.72 (p=0.19); EDV: r=0.71 (p=0.02)]. The dual-source CT system offers robust image quality of the coronary arteries, independent of the heart rate, and provides combined diagnostic imaging of coronary arteries, the heart valves, the myocardium, and the global left ventricular function.     

Imaging the heart valves using ECG-gated 64-detector row cardiac CT

Multi-detector row cardiac CT imaging demonstrates clinical usefulness in valvular heart disease, for which CT has not been traditionally used. Electrocardiographic (ECG)-gated CT coronary angiography also has an established clinical role with an increasingly solid evidence base, and the same data set in these patients also provides valuable information about chamber and valvular structure and function; this information should also be considered when interpreting cardiac CT and non-ECG gated thoracic imaging. Although true flow data cannot be achieved using CT, as with echocardiography and MRI, there are a number of imaging features that may be used when interpreting and inferring valve pathology. This article discusses the role of currently available imaging modalities and the rationale for cardiac CT, while focusing on the CT interpretation of valvular heart disease with respect to the relevant pathophysiology and management options that have importance to the radiologist. A suggested method of post-processing image review is provided with reference to a variety of normal and pathological pictorial illustrations.