CT-Angiographie der Koronarien mit prospektivem EKG-Triggering

Background

The purpose of this study was to evaluate the diagnostic performance of coronary CT angiography (coronary CTA) using prospective ECG triggering (PT) for the detection of significant coronary artery stenosis compared to invasive coronary angiography (ICA).

Methods

A total of 20 patients underwent coronary CTA with PT using a 128-slice CT scanner (Definition? AS+, Siemens) and ICA. All coronary CTA studies were evaluated for significant coronary artery stenoses (≥50% luminal narrowing) by 2 observers in consensus using the AHA-15-segment model. Findings in CTA were compared to those in ICA.

Results

Coronary CTA using PT had 88% sensitivity in comparison to 100% with ICA, 95% to 88% specificity, 80% to 92% positive predictive value and 97% to 100% negative predictive value for diagnosing significant coronary artery stenosis on per segment per patient analysis, respectively. Mean effective radiation dose-equivalent of CTA was 2.6±1 mSv.

Conclusion

Coronary CTA using PT enables non-invasive diagnosis of significant coronary artery stenosis with high diagnostic accuracy in comparison to ICA and is associated with comparably low radiation exposure.     

Evaluation of coronary artery in-stent restenosis with prospectively ECG-triggered axial CT angiography versus retrospective technique: a phantom study

Purpose

This study compared the performance of prospectively electrocardiographically (ECG)-triggered axial computed tomography (CT) angiography with retrospective technique in evaluating coronary artery stent restenosis by 64-slice CT.

Materials and methods

A pulsing cardiac phantom with artificial coronary artery in-stent restenosis was examined by CT angiography with different types of scan modes. The visibility of in-stent restenosis was evaluated with a three-point score. Artificial lumen narrowing [(inner stent diameter-measured lumen diameter)/inner stent diameter], lumen attenuation increase ratio [(in-stent attenuation-coronary artery lumen attenuation)/coronary artery lumen attenuation], measurement error of restenosis percent [(known restenosis percent-measured restenosis percent)/known restenosis percent] and imaging noise were analysed.

Results

Prospective acquisition showed better visibility than retrospective acquisition (p<0.05): 61% of in-stent restenoses had good visibility on the prospective acquisition compared with 17% on the retrospective acquisition. Furthermore, the effective dose was 6.2±0.3 mSv for the prospective technique compared with 18.8±1.1 mSv for the retrospective technique. Artificial lumen narrowing (mean 40%), lumen attenuation increase ratio (mean 33%) and measurement error of restenosis percent were not different between types of CT acquisitions.

Conclusions

Compared with the traditional retrospective technique, prospective coronary CT angiography offers improved image quality and reduces effective radiation dose in evaluating in-stent restenosis.     

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     

Coronary artery anomalies: Role of contrast enhanced MDCT coronary angiography

Objective

The purpose of this study is to evaluate the role of MDCT in the depiction of coronary artery anomalies.

Patients and methods

Sixteen patients were included in this study. Retrospectively gated coronary CT angiography was performed in 11 patients and prospectively gated CT coronary angiography was performed in 5 patients. Post-processing techniques as maximum-intensity projection, curved multiplanar reconstruction, and volume rendering were applied to assess the origin and course of the coronary vessels.

Results

Origin and course anomalies of the central coronary artery segments were seen in 11 patients (67%), anomalies of only coronary artery origin in 2 patients (13%), origin and course anomalies of the peripheral coronary segments in 2 patients (13%) and coronary arterio-venous fistula in one patient (7%). The origin and course anomalies of the central coronary artery segment were more common in the left coronary artery involving 8 patients (73%). Malignant inter-arterial course between aortic root and pulmonary artery or the right ventricle outflow tract was seen in 3 anomalous arteries.

Conclusion

MDCT coronary angiography can precisely depict the origin and course coronary artery anomalies and is recommended in young patients and before cardiac intervention or surgery to prevent possible complications.     

Diagnostic accuracy of dual-source CT coronary angiography with prospective ECG-triggering on different heart rate patients

Objective

To evaluate the diagnostic accuracy of dual-source CT (DSCT) prospective ECG-triggering coronary angiography in patients with different heart rate (HR).

Methods

103 patients with suspected coronary artery disease underwent DSCT prospective ECG-triggered coronary angiography and invasive coronary angiography (ICA). The patients were grouped by HR during CT scans: low HR (??60?bpm, n?=?34); medium HR (60?n?=?36) and high HR (>70?bpm, n?=?33). The sensitivity and specificity of DSCT in detecting ??50% stenosis were compared among subgroups where ICA was the gold standard. Image quality was scored using a 4-point scale.

Results

A total of 1,580 (95.9%) coronary artery segments were evaluable. Sensitivity and specificity were 82.8% and 98.4%, 88.3% and 98.7%, and 80.3% and 98.6% for different subgroups (all p?>?0.05). The overall area under the curve of the receiver-operating characteristic analysis was 0.94. The image quality scores were 3.1?±?0.3, 3.1?±?0.3 and 3.0?±?0.4 for subgroups (p?>?0.05). The overall average effective radiation dose was 3.60?±?1.60?mSv.

Conclusion

DSCT coronary angiography with prospective ECG-triggering could be just as accurate in patients with medium to high HR compared to those with low HR.     

Quantitative coronary arterial stenosis assessment by multidetector CT and invasive coronary angiography for identifying patients with myocardial perfusion abnormalities

Background

Semi-quantitative stenosis assessment by coronary CT angiography only modestly predicts stress-induced myocardial perfusion abnormalities. The performance of quantitative CT angiography (QCTA) for identifying patients with myocardial perfusion defects remains unclear.

Methods

CorE-64 is a multicenter, international study to assess the accuracy of 64-slice QCTA for detecting ??50% coronary arterial stenoses by quantitative coronary angiography (QCA). Patients referred for cardiac catheterization with suspected or known coronary artery disease were enrolled. Area under the receiver-operating-characteristic curve (AUC) was used to evaluate the diagnostic accuracy of the most severe coronary artery stenosis in a subset of 63 patients assessed by QCTA and QCA for detecting myocardial perfusion abnormalities on exercise or pharmacologic stress SPECT.

Results

Diagnostic accuracy of QCTA for identifying patients with myocardial perfusion abnormalities by SPECT revealed an AUC of 0.71, compared to 0.72 by QCA (P?=?.75). AUC did not improve after excluding studies with fixed myocardial perfusion abnormalities and total coronary arterial occlusions. Optimal stenosis threshold for QCTA was 43% yielding a sensitivity of 0.81 and specificity of 0.50, respectively, compared to 0.75 and 0.69 by QCA at a threshold of 59%. Sensitivity and specificity of QCTA to identify patients with both obstructive lesions and myocardial perfusion defects were 0.94 and 0.77, respectively.

Conclusions

Coronary artery stenosis assessment by QCTA or QCA only modestly predicts the presence and the absence of myocardial perfusion abnormalities by SPECT. Confounding variables affecting the relationship between coronary anatomy and myocardial perfusion likely account for some of the observed discrepancies between coronary angiography and SPECT results.     

Prevalence of dual left anterior descending artery variations in CT angiography

PURPOSE

We aimed to evaluate the frequency and features of dual left anterior descending artery (LAD) variants using computed tomography (CT) angiography.

METHODS

A total of 1337 consecutive coronary CT angiography examinations performed between April 2010 and December 2013 were retrospectively evaluated for the presence of dual LAD. CT examinations were performed with either 64- or 320-row multidetector CT scanners. All CT angiography images were evaluated for the presence and morphologic features of dual LAD subtypes.

RESULTS

Fifty-six dual LAD variations (4%) were identified in this study population. Type 1 was the most common type of dual LAD (n=48), while Type 3 (n=3) and Type 4 (n=2) were infrequent and Type 2 was not detected. Additionally, we detected previously unclassified dual LAD variations in three cases.

CONCLUSION

Dual LAD may be a relatively more common variant than described in the medical literature, which is mostly based on catheter angiography studies. Coronary CT angiography seems markedly efficacious for detecting and documenting the anatomical details of dual LAD subtypes, as well as showing other associated cardiocoronary anomalies.Dual left anterior descending (LAD) coronary artery is a rare congenital anomaly (1), basically defined as the existence of two distinct segments of the vessel occupying the anterior interventricular sulcus (AIS) of the heart.First study classifying dual LAD anomalies based on coronary catheter angiography was published in 1983 by Spindola-Franco et al. (2), which has served as a primary classification system. However, individual reports further described previously unclassified LAD variants (3, 4). Most of the recent publications about dual LAD anomalies involve case reports and there is a paucity of large series using coronary computed tomography (CT) angiography (3–8).At present, quite a large number of coronary CT angiography examinations are being performed and recognition of dual LAD variations by CT angiography requires familiarity. Being aware of dual LAD anomalies could be critical for coronary bypass surgery and interventions. Surely, sound knowledge on dual LAD anomalies is a prerequisite for proper management of patients with coronary artery disease.In this study, we aimed to identify the frequency of dual LAD variations, and define the morphoanatomical features based on Spindola-Franco classification, using CT angiography. Appendageal subtypes of this variation were also documented and discussed.     

64-Slice CT coronary angiography versus conventional coronary angiography: activity-based cost analysis

Purpose

This study was done to analyse the costs of 64-slice computed tomography (CT) coronary angiography and conventional coronary angiography and determine the costeffectiveness of the two modalities.

Materials and methods

Detailed activity-based cost analyses of the two modalities were carried out at the departments of radiology and cardiology of a teaching hospital. The differential costs (equipment, variable, personnel), common costs and external costs were estimated. Finally, the full costs of the two procedures were obtained; the full cost of conventional coronary angiography also considered the cost of 1 day in hospital. The cost-effectiveness of the two procedures at different levels of pretest likelihood of coronary artery disease (CAD) was estimated.

Results

The costs of multidetector CT (MDCT) coronary angiography were as follows: differential cost 222.23 €, common cost 5.50 €, external cost 2.30 € and full cost 230.03 €. The costs of conventional coronary angiography were: differential cost 366.18 €, common cost 0.50 €, external cost 9.20 €, hospitalisation cost 1,652 € and full cost 2,027.88 €. Cost-effectiveness analysis showed that the cost per correctly identified CAD patient decreased exponentially with increasing pretest likelihoods of CAD. MDCT coronary angiography was more cost effective than conventional coronary angiography up to a pretest likelihood of 86%.

Conclusions

MDCT coronary angiography has far lower costs than conventional coronary angiography, and its costeffectiveness is better in the large majority of patients.     

Downstream resource utilization following hybrid cardiac imaging with an integrated cadmium-zinc-telluride/64-slice CT device

Purpose

Low yield of invasive coronary angiography and unnecessary coronary interventions have been identified as key cost drivers in cardiology for evaluation of coronary artery disease (CAD). This has fuelled the search for noninvasive techniques providing comprehensive functional and anatomical information on coronary lesions. We have evaluated the impact of implementation of a novel hybrid cadmium-zinc-telluride (CZT)/64-slice CT camera into the daily clinical routine on downstream resource utilization.

Methods

Sixty-two patients with known or suspected CAD were referred for same-day single-session hybrid evaluation with CZT myocardial perfusion imaging (MPI) and coronary CT angiography (CCTA). Hybrid MPI/CCTA images from the integrated CZT/CT camera served for decision-making towards conservative versus invasive management. Based on the hybrid images patients were classified into those with and those without matched findings. Matched findings were defined as the combination of MPI defect with a stenosis by CCTA in the coronary artery subtending the respective territory. All patients with normal MPI and CCTA as well as those with isolated MPI or CCTA finding or combined but unmatched findings were categorized as ??no match??.

Results

All 23 patients with a matched finding underwent invasive coronary angiography and 21 (91%) were revascularized. Of the 39 patients with no match, 5 (13%, p?p?Conclusion Cardiac hybrid imaging in CAD evaluation has a profound impact on patient management and may contribute to optimal downstream resource utilization.     

Role of 128 slice MSCT angiography in evaluation of congenital extra-cardiac intra-thoracic vascular anomalies in children

Purpose

To investigate the value and highlight the role of multi slice computed tomography (MSCT) angiography in evaluation of extra-cardiac intra thoracic vascular anomalies in children.

Correlation of regional distribution and morphological pattern of calcification at CT coronary artery calcium scoring with non-calcified plaque formation and stenosis

Objective

To investigate whether regional calcification patterns at CT coronary artery calcium scoring (CCS) correlate with stenosis and non-calcified plaque formation.

Methods

We studied 106 patients with quantitative catheter angiography (QCA), CCS, and coronary CT angiography (cCTA). CCS was determined globally and for each artery separately. The morphological pattern of each calcification was classified as calcified nodule, shell-like, or diffuse. cCTA studies were evaluated for non-calcified plaque. The global and regional CCS and the calcification pattern were correlated with stenosis ≥50% and non-calcified plaque.

Results

A total of 48/106 patients had stenosis ≥50% on QCA. There was weak correlation (r?=?0.36) of the global CCS with stenosis. Correlation was stronger per vessel (r?=?0.55–r?=?0.67). Shell-like and diffuse calcifications were significantly (p?=?0.0001) more frequently associated with ≥50% stenosis and non-calcified plaque (p?=?0.04) than calcified nodules.

Conclusion

As shown before, the global CCS does not correlate well with stenosis. However, regional calcium distribution and specific patterns of calcification are correlated with stenosis and non-calcified plaque. Thus, the specificity of CT calcium scoring for identifying individuals with obstructive disease could be improved by vessel-based rather than global quantification of calcium and by differentiating specific morphological patterns of calcification.     

Diagnostic accuracy of MDCT coronary angiography in patients referred for heart valve surgery

Purpose

The aim of our study was to evaluate the role of multidetector-row computed tomography (MDCT) in patients referred for heart valve surgery. We studied the diagnostic performance of CT coronary angiography (CTCA) compared with conventional coronary angiography (CCA) before valve surgery.

Materials and methods

During a 13-month period, 55 consecutive patients under evaluation for aortic (40/55) or mitral valve (15/55) disease before potential valve replacement underwent CTCA using a 64-detector-row scanner within 2 months of CCA for comparative purposes. All 17 major coronary artery segments were evaluated by one observer and compared with the reference standard. Patient-based, vessel-based and segment-based analyses of the data were performed.

Results

Prevalence of significant coronary artery disease, defined as having at least one stenosis ≥50% per patient, was 36%. On a patient-based analysis, sensitivity, specificity and positive and negative predictive values were 100%, 91%, 83% and 100%, respectively.

Conclusions

The diagnostic accuracy of 64-row CTCA for ruling out the presence of significant coronary stenoses in patients undergoing valve surgery is excellent and allows CTCA to be used as a gatekeeper for invasive CCA in these patients. MDCT is a necessary preoperative examination that provides useful information for identifying potential operative complications of surgical procedures.     

Postmortem imaging of antemortem myocardial ischaemia

Objectives

To determine the minimum survival time for detection of antemortem myocardial ischaemia with postmortem imaging (PMI) techniques.

Methods

Nine pigs underwent ligation of the left anterior descending (LAD) (8) and/or right coronary artery (RCA) branch (4), and were killed 30 min–6 h after ligation. PMI (MRI and CT angiography) was performed 2–55 h after euthanasia. Signal intensity of myocardial segments was measured. The hearts were removed, the coronary arteries injected to mark perfused segments, and sections submitted for histology.

Results

MRI T2-weighted sequences showed the ischaemic area as hyperintense in 4/4 LAD ligations with ≥4 h of ischaemia but in 0/4 with <4 h. Histological evidence of ischaemia was present in 4/4 animals after 4 h. Right ventricular ischaemic myocardium was visible on MRI T2-weighted sequences after 6 h of ischaemia in one animal. CT angiography showed the occluded coronary artery in all cases.

Conclusions

Ischaemic lesions of the left ventricle, but not of the right, at least 4 h old can be detected as hyperintense areas on T2-weighted postmortem MRI. This technique is most sensitive in the first 24 h after death. Other sequences did not enhance detection.

Key Points

? Left ventricular myocardial ischaemia/infarction can be demonstrated by postmortem imaging (PMI). ? Ischaemia/infarction is better detected if survival time is at least 4 h. ? Right ventricular ischaemia/infarction is not reliably detected by PMI. ? Computed tomography angiography can demonstrate arterial occlusion.     

Effects of metal coverage rate of flow diversion device on neointimal growth at side branch ostium and stented artery: an animal experiment in rabbit abdominal aorta

Introduction

To access the effect of actual metal coverage rate (MCR) on neointimal growth at covered side branch ostium and stented artery after implantation of a flow diversion device.

Methods

Flow diverters (FDs) were implanted into abdominal aortas of 20 New Zealand rabbits. Four weeks and three months after FD implantation, the patency of side branches covered by the devices was assessed by angiography. The animals were sacrificed after angiography at 3?months postsurgery. The local actual MCR was measured under microscope and calculated. The extent of neointimal coverage at the ostia of branches and the neointima within the stent were examined by histology and scanning electron microscopy.

Results

No side branch occlusion was noted, either immediately after implantation or at follow-ups. At 3?months after implantation, the intimal coverage of branch ostia caused by a 30–40% MCR was not significantly different from that caused by an MCR?≤?30% (p?=?0.792), but it was significantly lower than that caused by an MCR?≥?40% (p?=?0.021). Neointimal thickness in the stented abdominal aorta was positively correlated to MCR (r?=?0.523, p?=?0.001). The neointima was composed predominantly of smooth muscle cells and collagen fibers.

Conclusion

The actual MCR exhibited remarkable differences once FD was implanted in vivo. Significantly more intimal coverage at the side branch ostia could be induced when MCR was ≥40%. The neointimal thickness within the stent was positively correlated to device MCR.     

Computed tomography angiography of lower extremities in the emergency room for evaluation of patients with gunshot wounds

Objective

To assess the role of CT angiography in the evaluation of patients with lower extremity gunshot wounds in the emergency room.

Materials and methods

Eighty patients (73 male, 7 female, mean age 26 years) underwent CT angiography for the evaluation of lower extremity gunshot injuries. Imaging was conducted on the basis of standardized protocols utilizing 16-slice and 64-slice multidetector systems and images were qualitatively graded and assessed for various forms of arterial injury.

Results

CT angiography findings indicative of arterial injury were observed in 24 patients (30 %) and a total of 43 arterial injuries were noted; the most common form was focal narrowing/spasm (n?=?16, 37.2 %); the most common artery involved was the superficial femoral artery (n?=?12, 50 %). In qualitative assessment of images based on a 4-point grading system, both readers considered CT angiography diagnostically excellent (grade 4) in most cases. Surgical findings were consistent with CT angiography and follow-up of patients’ medical records showed no arterial injuries in patients with normal findings on initial imaging.

Conclusion

Our findings demonstrate that CT angiography is an effective imaging modality for evaluation of lower extremity gunshot wounds and could help limit more invasive procedures such as catheter angiography to a select group of patients.

Key Points

? CT angiography efficiently evaluates lower extremity gunshot wounds. ? CT angiography provides image quality sufficiently reliable for assessment of gunshot injuries. ? CT angiography could help limit invasive procedures to select patients.     

Computed tomography angiography of carotid and coronary artery via a single-bolus injection protocol: a feasibility study using 320-row multidetector CT

Objectives

To investigate the feasibility of using a single-dose injection protocol in CT angiography (CTA) of the carotid and coronary artery with 320-row multidetector CT.

Methods

A total of 82 consecutive patients with suspected carotid artery disease underwent an original CTA protocol aiming at capturing the extra-cranial carotid arteries and coronary arteries simultaneously using 320-row MDCT. The image quality, attenuation, and CNRs of the carotid and coronary arteries were assessed. The lag time (between two separated volumetric acquisitions) was compared between patients with and without cardiac venous opacification (CVO). The contrast medium volume and radiation dose were recorded.

Results

The image quality was 99.4 % diagnostic in carotid and 86.9 % in coronary artery segments. The mean attenuation of carotid and coronary arteries ranged from 462.2 Hu to 533.7 Hu, 415.9 Hu to 454.7 Hu respectively. The mean CNR of the carotid and coronary artery ranged from 15.8 to 18.9 and 17.7 to 20.4 respectively. The lag time in patients with and without CVO was 5.75?±?1.64 s vs. 4.21?±?1.14 s (p?<?0.05). The mean radiation dose was 6.6?±?4.1 mSv.The mean contrast media volume was 71.9?±?9.1 ml.

Conclusions

The carotid and coronary artery can be imaged simultaneously via our original single-dose injection CTA protocol using 320-row CT with adequate image quality.

Key Points

? Carotid and coronary 320-row CTA can be achieved in a single-dose injection. ? Longer coverage was achieved with two or more volumes using 320-row CT. ? The single-dose protocol allows a reduced contrast agent dose of about 72 ml.     

Role of 64-slice cardiac computed tomography in the evaluation of patients with non-ST-elevation acute coronary syndrome

Purpose

This study was done to evaluate the feasibility, sensitivity and specificity of 64-slice computed tomography (CT) in identifying haemodynamically significant (>50%) coronary artery stenoses in patients with suspected acute coronary syndrome (ACS) by correlating the CT findings with the clinical event and data provided by conventional coronary angiography (CCA).

Materials and methods

Sixty-four patients (38 men and 26 women; mean age 65 years; range±10 years) presenting to our hospital’s emergency department with a clinical suspicion of ACS were studied with 64-slice CT followed by CCA within 24 h of arrival.

Results

Two patients (3.1%) were excluded from the analysis due to artefacts. Per-patient analysis in the remaining 62 patients identified 24 cases (38.7%) of negative CT findings (no stenoses or stenoses <50%), 35 cases of positive CT findings (56.4%) with identification of the culprit lesion, two cases in which the culprit lesion was not identified and one patient with unconfirmed stenosis. Sensitivity and specificity were 94.6% and 96%, respectively. Per-vessel analysis (186 vessels) revealed 17 non-evaluable vessels (9.1%) due to motion artefacts, 61 vessels (32.8%) with stenosis >50%, seven overestimated vessels (3.7%) due to extensive calcifications, three vessels (1.6%) with underestimated stenosis and 98 vessels (52.6%) without stenosis. Sensitivity and specificity were 95.3% and 93.3%, respectively.

Conclusions

In this type of emergency, coronary CT angiography could lead to considerably lower healthcare costs by identifying patients without coronary disease and allowing immediate discharge without any need for further diagnostic procedures.     

Accuracy of automated software-guided detection of significant coronary artery stenosis by CT angiography: comparison with invasive catheterisation

Purpose

True automated detection of coronary artery stenoses might be useful whenever expert evaluation is not available, or as a “second reader” to enhance diagnostic confidence. We evaluated the accuracy of a PC-based stenosis detection tool alone and combined with expert interpretation.

Methods

One hundred coronary CT angiography datasets were evaluated with the automated software alone, by manual interpretation (axial images, multiplanar reformations and maximum intensity projections in free double-oblique planes), and by expert interpretation aware of the automated findings. Stenoses ≥?50 % were noted per-vessel and per-patient, and compared with invasive angiography.

Results

Automated post-processing was successful in 90 % of patients (88 % of vessels). When excluding uninterpretable datasets, per-patient sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 89 %, 79 %, 74 % and 92 % (per-vessel: 82 %, 85 %, 48 % and 96 %). All 100 datasets were evaluable by expert interpretation. Per-patient sensitivity, specificity, PPV and NPV were 95 %, 95 %, 93 % and 97 % (per-vessel: 89 %,98 %, 88 % and 98 %). Knowing the results of automated interpretation did not improve the performance of expert readers.

Conclusion

Automated off-line post-processing of coronary CT angiography shows adequate sensitivity, but relatively low specificity in coronary stenosis detection. It does not increase accuracy of expert interpretation. Failure of post-processing in 10 % of all patients necessitates additional manual image work-up.

Key Points

? Coronary CT angiography is increasingly used for detection of coronary artery stenosis ? Computer assisted diagnosis might facilitate and speed up interpretation ? Performance in properly segmented cases compared favourably with manual image interpretation ? However, automated segmentation failed in about 10 % of cases ? Manual reading is still mandatory; computer assisted diagnosis can provide a useful second read     

Biodegradable flow-diverting device for the treatment of intracranial aneurysm: short-term results of a rabbit experiment

Introduction

One main complication of a flow-diverting device (FD) in treating intracranial aneurysm is stenosis of parent artery (PA) or occlusion of side branches. The use of a biodegradable device may satisfy the need for aneurysm occlusion and eliminate potential complications.

Methods

Twenty elastase-induced aneurysm rabbit models were divided into three groups: in group 1 (n?=?7), polyglycolic acid FDs (PGA-FDs) were implanted across the necks of aneurysms and the abdominal aortas (AA), covering the ostium of a lumbar artery; in group 2 (n?=?7), the PGA-FDs were replaced by metal FDs; and in group 3 (n?=?6), the PGA-FDs were only implanted across the necks of aneurysms. Animals in group 3 underwent angiography at 6 weeks; those in groups 1 and 2 underwent angiography at 3 months. The status of aneurysm embolization and patency of side branches were assessed.

Results

Complete aneurysm occlusion rates in groups 1 and 3 were 83.3 and 66.7 %, respectively, compared with 0 % in group 2. No side branch occlusions were noted. PA neointimal hyperplasia was minimal, and there were no significant differences between groups 1 and 2 (P?=?0.233). The neointimal coverage ratio of the branch ostium in AA in group 1 was not significantly different from that in group 2 (P?=?0.605). The neointima comprised predominantly smooth muscle cells and collagen fibers.

Conclusions

The PGA-FD was an effective device for the treatment of aneurysms and was safe for side branches at the 3-month follow-up.     

Assessment of myocardial fibrosis and coronary arteries in hypertrophic cardiomyopathy using combined arterial and delayed enhanced CT: comparison with MR and coronary angiography

Objectives

We sought to determine the feasibility and accuracy of dual-source computed tomography (DSCT) in assessing coronary artery disease and myocardial fibrosis of hypertrophic cardiomyopathy (HCM) compared with cardiac magnetic resonance (CMR) imaging and coronary angiography (CA).

Methods

Forty-seven consecutive patients with HCM were prospectively enrolled. DSCT images were acquired in the arterial and late phases following intravenous contrast medium. The CMR and CA were performed within 7 days. Independent blinded readers read each study. Patients were classified according to myocardial delayed enhanced (MDE) CMR, coronary artery stenosis by CA, and arterial and MDE-DSCT. The diagnostic accuracy of DSCT in detecting coronary stenosis and MDE was analysed.

Results

Wall thickness determined by DSCT was strongly correlated with MR results (r?=?0.91). DSCT and CMR MDE showed substantial agreement for the detection of myocardial fibrosis on per-patient and per-segment levels. The CT classification of patients by arterial stenosis and delayed enhancement had excellent agreement with MR and CA methods.

Conclusions

The comprehensive cardiac CT examination provides reliable coronary artery and myocardial assessments. MDE-DSCT is a robust alternative method to MDE-CMR in assessing myocardial fibrosis in HCM particularly in patients with pacemakers or other contraindications to CMR.

Key Points

? Enhanced cardiac CT provides comprehensive assessment of patients with hypertrophic cardiomyopathy (HCM). ? Myocardial delayed enhanced-CT has comparable accuracy to MDE-MR in detecting HCM fibrosis. ? MDE-CT provides a robust alternative for HCM patients with MR contraindications.