Grading mitral regurgitation using 4D flow CMR: Comparison to transthoracic echocardiography.

OBJECTIVES: To determine the 4D Flow Cardiac Magnetic Resonance (CMR) thresholds that achieve the best agreement with transthoracic echocardiography (TTE) for grading mitral regurgitation (MR). METHODS: We conducted a single-center prospective study of patients evaluated for chronic primary MR in 2016-2020. MR was evaluated blindly by TTE and 4D Flow CMR, respectively by two cardiologists and two radiologists with decades of experience. MR was graded with both methods as mild, moderate, or severe. 4D Flow CMR measurements included MR regurgitant volume per beat (RV) and mitral anterograde flow per beat (MF). RF was obtained as the ratio RV/MF. Additionally, MF was compared to left ventricular stroke volume (LVSV) by cine-CMR. RESULTS: We included 33 patients in the initial cohort and 33 in the validation cohort. Inter-observer agreement was excellent for 4D Flow CMR ICC = .94 (95% CI, .86-.97, p < 0.0001). Using recommended TTE thresholds (30 ml, 60 ml, 30%, 50%), agreement was moderate for RV and RF. The best agreement between 4D Flow CMR and TTE was obtained with CMR thresholds of 20 and 40 ml for RV (κ = .93; 95% CI, .8-1) and 20% and 37% for RF (κ = .90; 95% CI, .7-.9). In the validation cohort, agreement between TTE and 4D Flow CMR was good with the optimal thresholds (κ = .78; 95% CI, .61-.94). CONCLUSION: We propose CMR thresholds that provide a good agreement between TTE and CMR for grading MR. Further studies are needed to fully validate 4D-Flow CMR accuracy for primary MR quantification.

Evaluation of a deep learning model on coronary CT angiography for automatic stenosis detection.

PURPOSE: The purpose of this study was to evaluate a deep-learning model (DLM) for classifying coronary arteries on coronary computed tomography -angiography (CCTA) using the Coronary Artery Disease-Reporting and Data System (CAD-RADS). MATERIALS AND METHODS: The DLM was trained with 10,800 curved multiplanar reformatted (cMPR) CCTA images classified by an expert radiologist using the CAD-RADS. For each of the three main coronary arteries, nine cMPR images 40° apart acquired around each arterial circumference were then classified by the DLM using the highest probability. For the validation set composed of 159 arteries from 53 consecutive patients, the images were read by two senior and two junior readers; consensus of the two seniors was the reference standard. With the DLM, the majority vote for the nine images was used to classify each artery. Three groups (CAD-RADS 0, 1-2, or 3-4-5) and 2 groups CAD-RADS 0-1-2 or 3-4-5 (<50% vs. ≥50% stenosis) were used for comparisons with readers and consensus. Performance of the model and readers was compared to the consensus reading using the intraclass coefficient (ICC) and Cohen's kappa coefficient at the artery and patient levels. RESULTS: With the three groups at the artery level, the ICC of the DLM was 0.82 (95% CI: 0.75-0.88) and not significantly different from those of 3/4 readers; accuracy was 81%. With the binary classification, Cohen kappa coefficient of the DLM was 0.85 (95% CI: 0.69-0.94) and not significantly different from that of 3/4 readers; accuracy was 96%. At the patient level, sensitivity and specificity were 93% and 97% respectively, and the negative predictive value was 97%. CONCLUSION: The DLM detected ≥50% stenoses with performances similar to those achieved by senior radiologists.

Diagnosis of functionally significant coronary stenosis with exercise CT myocardial perfusion imaging.

PURPOSE: To assess the feasibility of exercise perfusion computed tomography (CT) in patients suspected of having hemodynamically significant coronary stenosis. MATERIALS AND METHODS: This study had institutional review board approval, and all patients gave informed consent. Thirty-two consecutive patients (26 men [mean age, 63 years] and six women [mean age, 71 years]) with 55 coronary stenoses of at least 50% underwent coronary CT angiography (one stenosis in 13 patients, two stenoses in 15 patients, and three stenoses in four patients). CT myocardial perfusion imaging was performed within 1 minute after patients performed supine exercise on an ergometer secured to the CT table. The pressure-rate product was computed to assess level of exercise. The myocardial enhancement ratio between stenotic and normally perfused territories was determined for each stenosis. Fractional flow reserve less than 0.8, as measured during invasive coronary angiography, was the reference for defining significant stenoses. Receiver operating characteristic curves were constructed to determine the myocardial enhancement ratio cutoff value. RESULTS: In the per-patient analysis, a myocardial enhancement ratio cutoff of 0.8 performed best for identifying functionally significant stenosis: Sensitivity was 95% (21 of 22 patients), specificity was 90% (nine of 10 patients), positive predictive value was 95% (21 of 22 patients), negative predictive value was 90% (nine of 10 patients), and accuracy was 94% (30 of 32 patients). Corresponding values in the per-stenosis analysis were 97% (29 of 30 stenoses), 96% (23 of 24 stenoses), 97% (29 of 30 stenoses), 96% (23 of 24 stenoses), and 96% (52 of 54 stenoses), respectively. CONCLUSION: Exercise CT myocardial perfusion imaging is feasible and accurate for assessment of the functional significance of coronary stenosis.

[Surgical treatment of chronic thromboembolic pulmonary hypertension]. / Traitement chirurgical de l'hypertension pulmonaire post-embolique.

Chronic thromboembolic pulmonary hypertension is a rare but underdiagnosed disease. The development of imaging played a crucial role for the screening and the decision of operability over the past few years. Indeed, chronic thromboembolic pulmonary hypertension is the only type of pulmonary hypertension with a potential curative treatment: pulmonary endarterectomy. It is a complexe surgical procedure performed under cardiopulmonary bypass with deep hypothermia and circulatory arrest. The aim of the procedure is to completely remove the scar tissue inside the pulmonary arteries down to the segmental and sub-segmental levels. Compared to lung transplantation, which carries a postoperative mortality of 15-20% and a 5-year survival of 50%, pulmonary endarterectomy is a curative treatment with a postoperative mortality of less than 3%. However, lung transplantation remains an option for young patients with inoperable distal disease or after pulmonary endarterectomy failure. Considering that medical history of deep venous thrombosis or pulmonary embolism is lacking in 25 to 50%, the diagnosis of chronic thromboembolic pulmonary hypertension remains challenging. The lung V/Q scan is useful for the diagnosis showing ventilation and perfusion mismatches. Lesions located at the level of the pulmonary artery, the lobar or segmental arteries may be accessible to surgical removal. The pulmonary angiogram with the lateral view and the pulmonary CT scan help to determine the level of the intravascular lesions. If there is a correlation between the vascular obstruction assessed by imaging and the pulmonary resistance, pulmonary endarterectomy carries a postoperative mortality of less than 3% and has a high rate of success. If the surgery is performed at a later stage of the disease, pulmonary arteriolitis developed mainly in unobstructed territories and participated in the elevated vascular resistance. At this stage, postoperative risk is higher.

Angiomatoid fibrous histiocytoma of the pulmonary artery: a multidisciplinary discussion.

AIMS: Angiomatoid fibrous histiocytoma (AFH) is a rare neoplastic disease usually occurring in the dermis or subcutis of the extremities of young adults or children. Although sporadic cases in deep soft tissue and visceral organs have been reported, we present here the first description of AFH developing in a large artery. METHODS AND RESULTS: Paraffin sections of the surgical specimen were stained with haematoxylin and eosin, and immunohistochemistry was performed (CKAE1/AE3, EMA, CD34, p63, CD38, smooth muscle actin, and desmin). In addition, FISH and RT-PCR were applied in order to check for EWRS rearrangement. The histomorphological features, and FISH analysis revealing rearrangement of EWSR, indicated the definitive diagnosis of AFH. RT-PCR confirmed EWSR rearrangement, and detected an EWSR1-ATF1 fusion transcript. CONCLUSIONS: A thoracic location of AFH has not been reported until very recently, and shares a differential diagnosis with diverse neoplasms, including spindle cell carcinoma and low-grade sarcoma. We describe the first reported case of thoracic AFH arising in a large vessel, and highlight distinctive histological and molecular features.

Recurrence of thymoma in the right atrium arising from the coronary sinus.

Invasive thymoma is a malignant tumor of the anterior mediastinum that could have intravenous affinity associated with a high recurrence rate. This report highlights the need of coronary sinus exploration when intraatrial thymoma recurrence is diagnosed. Surgical resection of invaded coronary sinus can be achieved safely with a good result.

Low-dose coronary-CT angiography using step and shoot at any heart rate: comparison of image quality at systole for high heart rate and diastole for low heart rate with a 128-slice dual-source machine.

To compare image quality of coronary CT angiography in step-and-shoot mode at the diastolic phase at low heart rates (<70 bpm) and systolic phase at high heart rates (≥70 bpm). We prospectively included 96 consecutive patients then excluded 5 patients with arrhythmia. Coronary CT-angiography was performed using a dual-source 128-slice CT machine, at the diastolic phase in the 55 patients with heart rates <70 bpm (group D) and at the systolic phase in the 36 patients with heart rates ≥70 (group S). Image quality was scored on a 5 point-scale (1, not interpretable; 2, insufficient for diagnosis; 3, fair, sufficient for diagnosis; 4, good; 5, excellent). In addition, we compared the number of stair-step artifacts in the two groups. Mean image quality score was 4 (0.78) in group D and 4.1 (0.34) in group S (NS), with an unequal distribution (p = 0.01). Step artifacts were seen in 44 % of group D and 18 % of group S patients (p = 0.02). In 3 group D patients and no group S patients, the image score was <3 due to artifacts, requiring repeat CT-angiography. When performing dual-source 128-slice CT-angiography, step-and-shoot acquisition provides comparable mean image quality in systole, with less variability and fewer stair-step artifacts, compared to diastole. This method may be feasible at any heart rate in most patients in sinus rhythm, allowing low-dose prospective acquisition without beta-blocker premedication.

Pre- and postoperative magnetic resonance imaging in neonatal arterial switch operation using warm perfusion.

Neurological morbidity is a major concern in pediatric cardiac surgery. Cardiopulmonary bypass is one of the few modifiable factors affecting neurodevelopmental outcome. This study aimed to measure the incidence of abnormalities apparent by magnetic resonance imaging (MRI) after neonatal arterial switch operation using warm surgery. Neonates admitted for transposition of the great arteries underwent pre- and postoperative brain MRI. They were operated on using a warm perfusion method. The data collected included antenatal diagnosis, place of birth, gestational age, total maturation score as described by Childs, weight, cyanosis as assessed by minimal SpO(2) sustained for at least 10 min, balloon atrial septostomy, prostaglandin E1 infusion, need for neonatal intensive care, bypass time, time to extubation, and length of stay in intensive care. All of the MRI results were interpreted by the same senior specialist in pediatric neuroimaging, and lesions were classified as white matter injury, infarct, or hemorrhage. On preoperative exam, nine patients (42%) had one or more lesions, with infarct in four patients, white matter injury in four patients, and hemorrhage in five. We were unable to find any correlation between the data collected and brain injury. On postoperative exam, there was one new infarct, two new cases of white matter injury, and three cases of hemorrhage but no worsening of the preoperative lesions. Based on this initial experience with brain imaging, there is no deleterious effect of warm perfusion and no rationale to postpone surgery in neonates with "subclinical" brain injury.

Heart transplant patient outcomes: 5-year mean follow-up by coronary computed tomography angiography.

BACKGROUNDS: We evaluate the feasibility and safety of coronary computed tomography angiography (CCTA) as the first-line investigation in heart transplant patients and the rate of coronary allograft vasculopathy detected using CCTA. METHODS: From September 2003 to June 2009, we prospectively included 65 heart transplant recipients, retaining 62 who underwent yearly CCTA for coronary allograft vasculopathy detection (261 CCTAs). We used 16-slice, 64-slice, and 2×64-slice CT machines. Patients with coronary artery stenosis by CCTA had a confirmation and a further follow-up exclusively by conventional coronary angiography (CCA). RESULTS: No major coronary events occurred during the study. Of the 62 baseline CCTAs, 37 (60%) were normal, 18 (29%) showed wall thickening, and 7 (11%) known significant stenosis, confirmed by CCA. The mean follow-up duration was 5 years. At the last follow-up, 26 (70%) patients with normal baseline findings remained normal, 9 (24%) had wall thickening, and 2 (6%) significant stenoses. Time to stenosis was consistently greater than 3 years. Of the 18 patients with initially wall thickening, 14 (78%) had wall thickening and 4 (22%) significant stenosis at last follow-up. The mean interval without any coronary lesion was 9.46±3.98 years. The mean interval without de novo significant stenosis was 10.31±4 years. CONCLUSIONS: CCTA seems to be a safe noninvasive tool for monitoring heart transplant patients, and thus obviating the need for CCA. In patients with normal baseline CCTA, a 2-year interval between CCTAs may be safe.

Diagnostic accuracy of dual-source multislice computed tomographic analysis for the preoperative detection of coronary artery anomalies in 100 patients with tetralogy of Fallot.

OBJECTIVES: A detailed preoperative evaluation of coronary anatomy is mandatory before surgical intervention for tetralogy of Fallot. In pediatric patients, the preoperative evaluation of coronary anatomy has relied classically on conventional angiographic analysis and, more recently, on echocardiographic analysis, which have well-known limitations and complications. Recent technological improvements allow the use of multislice computed tomographic analysis to evaluate coronary artery anatomy in very young children, even those with high heart rates. The purpose of this prospective study was to assess the accuracy of preoperative dual-source computed tomographic analysis in detecting coronary artery abnormalities by using surgical findings as the reference standard. METHODS: We prospectively evaluated 100 patients with tetralogy of Fallot before surgical intervention between November 2006 and September 2009 by using dual-source computed tomographic analysis with either retrospective, electrocardiographically gated, helical computed tomographic analysis or prospective, electrocardiographically triggered, sequential computed tomographic acquisition. The patients had a median age of 6.8 months (range, 1.2 months-6.8 years) and a median weight of 7.9 kg (range, 3-30 kg). RESULTS: Compared with surgical findings, dual-source computed tomographic analysis had 100% sensitivity and 100% specificity for detecting coronary artery abnormalities. Major coronary artery abnormalities were found in 7 (7%) patients. The radiation dose was low. CONCLUSIONS: Dual-source computed tomographic analysis is an accurate and noninvasive tool for delineating coronary artery anatomy before surgical intervention in children with tetralogy of Fallot. Dual-source computed tomographic analysis might deserve to be used routinely instead of angiographic analysis and in combination with echocardiographic analysis for the preoperative assessment of patients with tetralogy of Fallot.

Radiation dose for thoracic and coronary step-and-shoot CT using a 128-slice dual-source machine in infants and small children with congenital heart disease.

BACKGROUND: For coronary artery visualization, retrospective ECG-gated acquisition by dual-source computed tomography (DSCT) was superior to spiral non-ECG-gated acquisition in a paediatric population of congenital heart disease (CHD) patients. However, retrospective cardiac CT is associated with substantial radiation doses to the patient. Recently, DSCT with end-systolic reconstruction was found to be robust for imaging the coronary arteries in patients with high heart rates. OBJECTIVE: To evaluate step-and-shoot DSCT with end-systolic reconstruction for evaluating the heart, coronary arteries and other thoracic structures in young children with CHD. MATERIALS AND METHODS: All neonates and children younger than 6 years of age who were referred to our institution for CHD evaluation between September and October 2009 were included in the study. ECG-gated DSCT was performed in sequential prospective mode centred on the systolic phase identified by ECG analysis. To assess the radiation dose, we recorded the dose-length product (DLP) in mGy·cm and the effective dose in mSv estimated from the DLP. Overall image quality was evaluated using a 5-grade scoring system and was assessed by looking at cardiac and vascular structures. The image quality for the proximal and middle segments of the right and left coronary arteries was also evaluated using a 5-grade scale. RESULTS: Images of diagnostic quality (grade ≥ 3) were obtained in all 30 children with a mean image quality grade of 4.7 ± 0.6 (range, 3-5). Mean DLP was 5.7 ± 4.8 mGy*cm (range, 1-22 mGy cm) and mean effective radiation dose was 0.26 ± 0.16 mSv (range, 0.05-0.8 mSv). CONCLUSION: Prospective ECG-gated thoracic DSCT at end-systole usually provides adequate thoracic and coronary artery image quality in neonates, infants and young children with CHD, independent of heart rate. This new method is associated with lower radiation doses compared to previous literature (mean effective dose, 0.26 mSv).

Diagnostic accuracy of multidetector spiral computed tomography for preoperative assessment of sinus venosus atrial septal defects in children.

OBJECTIVES: To prospectively assess the value of multidetector computed tomography (MDCT) for detecting partial anomalous pulmonary venous return (PAPVR) in children with suspected sinus venosus-atrial septal defect (SV-ASD). METHODS: Forty-four children (mean age, 7.3 years; range, nine months-16 years) from whom transthoracic echocardiography (TTE) was inconclusive for the diagnosis underwent MDCT after contrast medium injection. Diagnosis was suspected on TTE by abnormal pulmonary venous return, no visualization of pulmonary venous ostia, or unexpected dilatation of right cavities. The first 11 children also underwent cardiac catheterization. Surgical findings constituted the diagnostic reference standard. RESULTS: Thirty-two (73%) children had SV-ASD with PAPVR. Of the first 11 patients, one had PAPVR by MDCT and 10 by conventional angiography; these 11 patients had PAPVR by surgery. Of the remaining 33 patients, 21 had SV-ASD and 12 had ostium secundum ASD, by both MDCT and surgery. MDCT had 100% sensitivity, 100% specificity, 100% positive predictive value, and 100% negative predictive value for diagnosing PAPVR in patients with suspected SV-ASD. CONCLUSION: Contrast-enhanced MDCT is a highly accurate, minimally-invasive technique for detecting PAPVR associated with SV-ASD. Contrast-enhanced MDCT may be used safely to replace conventional angiography for the definitive diagnosis and preoperative evaluation of children with suspected SV-ASD.

Multidetector CT for congenital heart patients: what a paediatric radiologist should know.

Multidetector CT (MDCT) is increasingly used for imaging congenital heart disease (CHD) patients in addition to echocardiography, due to its ability to provide high quality three-dimensional images, giving a comprehensive evaluation of complex heart malformations. Using 4-slice or 16-slice CT, diagnostic information in CHD patients is limited to extra-cardiac anatomy, mainly the pulmonary arteries, aorta and venous connections. Due to high heart rates in babies however, coronary evaluation and intra-cardiac analysis were not reliable with the first generations of MDCT. Larger detector size with 64-slice CT and faster acquisition time, up to 75 ms for one slice, has progressively improved coronary and intra-cardiac visualization. Because radiation dose is the main concern, especially in children, every attempt to minimize dose whilst preserving image quality is important: the ALARA concept should always be applied in this population. The 80 kVp setting is now well accepted as a standard for more and more radiological teams involved in CT of children. Different acquisition strategies are now possible for childhood coronary imaging, using retrospective or even prospective gating. Using the latest technology, sub-mSv acquisitions are now attainable for scanning a whole thorax, providing a complete analysis of any 3-D cardiac malformation, including coronary artery course visualisation. This review will describe how technological developments have improved image quality with continuous reduction of radiation dose.

Robustness of end-systolic reconstructions in coronary dual-source CT angiography for high heart rate patients.

OBJECTIVES: Reconstruction of cardiac computed tomography (CT) images is challenging when the heart rate is higher than 65 beats per minute (bpm). The optimal reconstruction time is often found to be at the end-systolic phase, but image quality remains uncertain. Using dual-source (DS) CT and 83-ms temporal resolution, we evaluated the robustness of the temporal window with low motion during the end systole. METHODS: We studied 41 DSCT in consecutive patients with a heart rate >65 bpm. Eleven systolic reconstructions were performed every 20 ms between 200 ms and 400 ms of the R-R interval. The end-systolic temporal window (ESTW) was defined as the interval between the first and last selected phases judged adequate for diagnosis. RESULTS: Heart rates varied from 67 to 150 bpm. ESTW was always to be found greater than 100 ms. The mean ESTW was 178 ms (SD: 57 ms), and varied independently of heart rate. All data sets achieved diagnostic quality during the end-systolic phase at a time point between 35 and 50% of the R-R interval. CONCLUSION: Our data suggest that CT with a temporal window below 100 ms may provide acceptable systolic reconstructions at any heart rate, in a large proportion of patients.