John Hoe

In a symptomatic patient population, segment-based coronary artery calcification significantly decreased agreement between multidetector CT angiography and quantitative coronary angiography for det... PurposeTo evaluate the influence of cross-sectional arc calcification on the diagnostic accuracy of computed tomography (CT) angiography compared with conventional coronary angiography for the dete...

OBJECTIVE. The purpose of the study was to investigate patient characteristics associated with image quality and their impact on the diagnostic accuracy of MDCT for the detection of coronary artery stenosis.MATERIALS AND METHODS. Two hundred ninety-one patients with a coronary artery calcification (CAC) score of ≤ 600 Agatston units (214 men and 77 women; mean age, 59.3 ± 10.0 years [SD]) were analyzed. An overall image quality score was derived using an ordinal scale. The accuracy of quantitative MDCT to detect significant (≥ 50%) stenoses was assessed using quantitative coronary angiography (QCA) per patient and per vessel using a modified 19-segment model. The effect of CAC, obesity, heart rate, and heart rate variability on image quality and accuracy were evaluated by multiple logistic regression. Image quality and accuracy were further analyzed in subgroups of significant predictor variables. Diagnostic analysis was determined for image quality strata using receiver operating characteristic (ROC) cur...

OBJECTIVE. Evaluations of stents by MDCT from studies performed at single centers have yielded variable results with a high proportion of unassessable stents. The purpose of this study was to evaluate the accuracy of 64-MDCT angiography (MDCTA) in identifying in-stent restenosis in a multicenter trial.MATERIALS AND METHODS. The Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography Using 64 Detectors (CORE-64) Multicenter Trial and Registry evaluated the accuracy of 64-MDCTA in assessing 405 patients referred for coronary angiography. A total of 75 stents in 52 patients were assessed: 48 of 75 stents (64%) in 36 of 52 patients (69%) could be evaluated. The prevalence of in-stent restenosis by quantitative coronary angiography (QCA) in this subgroup was 23% (17/75). Eighty percent of the stents were ≤ 3.0 mm in diameter.RESULTS. The overall sensitivity, specificity, positive predictive value, and negative predictive value to detect 50% in-stent stenosis visually using MDCT compared ...

Chronic total occlusions (CTO) of the coronary arteries are a common finding. A CTO can be underdiagnosed on CT coronary angiography (CTCA) as a high grade stenosis, because of the presence of retrograde collaterals which allow opacification of the vessel distal to the stenosis, or can be missed completely, especially if another adjacent opacified artery is mistaken for occluded artery. CTOs are considered as Type C or high risk lesions with a higher restenosis rate and increased technical failure rate by percutaneous coronary intervention (PCI). CTCA can help identify features that most influence current success rates of PCI such as marked calcifications at the stump, severe tortuosity of the proximal vessel, long length of the occluded segment as well location of the vessel distal to the occlusion, which often may not be well seen on conventional angiography. Identification of these features and displaying the 3D information as the best angiographic projection that demonstrates the length and orientation of the CTO, either as hard copy images or transmitted direct to the angiographic catheter lab for data fusion, allows strategic preprocedural planning and scheduling of the PCI. Myocardial viability of the affected area of the occluded segment is a major factor that influences whether PCI for CTO is attempted but is not currently readily available by cardiac CT. Contrast enhanced cardiac MR imaging is still the gold standard for this and may need to be performed prior to PCI.

The accuracy of multidetector computed tomographic (CT) angiography involving 64 detectors has not been well established.

Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its non-invasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective “CORE-64” trial (“Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors”). This multi-centre trial was unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows.