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Fulltext Feasibility and accuracy of 64-row MDCT coronary imaging from a centre with early experience: a review and comparison with established centres

Ong TK, Chin SP, Chan WL, Liew CK, Seyfarth MT, Liew HB, et al.

Med J Malaysia, 2005 Dec;60(5):629-36.
PMID: 16515115

The accuracy of multi-detector computed tomographic (MDCI) coronary angiography (CTA) is dependant on image quality as well as the experience of the operator. Established centers have reported negative predictive values of over 95%. The aim of our study was to investigate the accuracy and feasibility of CTA for the assessment of haemodynamically significant coronary stenosis in a center with very early experience (<6 months) utilizing the improved spatial and temporal resolutions of the latest generation 64-row MDCI scanner. One hundred and twenty eight patients (93 male, 35 female; mean age 56.2 +/- 9.5 years) with suspected or known coronary artery disease underwent both CIA and conventional coronary angiographv (CCA). The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values for stenoses > or =50% by CIA compared to CCA were 70%, 97%, 70% and 97% respectively. Evaluation of main and proximal segments in patients with good quality images (78% of patients) produced values of 94%, 95%, 74% and 99% respectively. The improved spatial and temporal resolutions of 64-row MJ) CT provided a high negative predictive value in assessing significant coronary artery stenosis even in a centre with very early experience. However, new centers embarking on CTA might not be able to reproduce the results reported by more experienced centers.
Vessel density ratio: A novel approach to identify "culprit" coronary lesion by spiral computed tomography

Chin BS, Ong TK, Seyfarth TM, Liew CK, Chan WL, Rapaee A, et al.

J Comput Assist Tomogr, 2006 7 18;30(4):564-8.
PMID: 16845284

BACKGROUND AND OBJECTIVE: We hypothesized that a "culprit" lesion in acute coronary syndrome (ACS) should have low overall vessel lumen and plaque density on multidetector computed tomography-assisted coronary angiography (MDCTA) because of lower calcification and the presence of occlusive thrombus. However, thrombi and calcification both can themselves blur the demarcation between vessel wall and lumen. If we calculated a "vessel density ratio" (VDR) obtained by measuring the mean density of contrast-enhancement within a region of interest (ROI), which includes the vessel wall, lumen, plaque, and thrombus, and comparing that with the aortic root mean density acting as a reference point, this ratio may be more convenient, standardized, and reproducible to test the feasibility of VDR in identifying "culprit" lesions in ACS.
METHODS: Sixty-four patients-21 exertional angina; 17 unstable angina/non-ST elevation myocardial infarction (NSTEMI); 26 ST elevation myocardial infarction (STEMI)-provided 188 diseased segments on conventional angiography. All underwent MDCTA within a week of angiography. ROI was mapped out from maximum intensity projections of diseased segments in planar view.
RESULTS: One hundred seventy-four segments were evaluated. Patients who presented with ACS (STEMI and unstable angina/non-ST elevation myocardial infarction) had lower mean VDR compared to patients with exertional angina (0.58 vs. 0.66 vs. 0.81; P < 0.001). Culprit lesions in ACS patients also had the lowest mean VDR when compared to nonculprit lesions and lesions in patients without ACS (0.51 vs. 0.68 vs. 0.81; P < 0.001).
CONCLUSIONS: VDR is a new, convenient, and standardized approach in identifying "culprit" lesions by MDCTA.
Use of non-invasive phase contrast magnetic resonance imaging for estimation of atrial septal defect size and morphology: a comparison with transesophageal echo

Piaw CS, Kiam OT, Rapaee A, Khoon LC, Bang LH, Ling CW, et al.

Cardiovasc Intervent Radiol, 2006 Mar-Apr;29(2):230-4.
PMID: 16252078

Transesophageal echocardiography (TEE) is a trusted method of sizing atrial septal defect (ASD) prior to percutaneous closure but is invasive, uncomfortable, and may carry a small risk of morbidity and mortality. Magnetic resonance imaging (MRI) may be useful non-invasive alternative in such patients who refuse or are unable to tolerate TEE and may provide additional information on the shape of the A0SD.
Accuracy of 64-row multidetector computed tomography in detecting coronary artery disease in 134 symptomatic patients: influence of calcification

Ong TK, Chin SP, Liew CK, Chan WL, Seyfarth MT, Liew HB, et al.

Am Heart J, 2006 Jun;151(6):1323.e1-6.
PMID: 16781246

The new 64-row multidetector computed tomography (CT)-assisted angiography can now detect coronary artery disease with shorter breath-hold time and at faster heart rates for symptomatic patients. We aim to determine if the 64-row scanner can also overcome limitations due to mild to moderate calcification.
Subclinical coronary artery disease in Asian rheumatoid arthritis patients who were in remission: a pilot study

Ma NH, Teh CL, Rapaee A, Lau KB, Fong AY, Hi S, et al.

Int J Rheum Dis, 2010 Aug;13(3):223-9.
PMID: 20704618 DOI: 10.1111/j.1756-185X.2010.01533.x

INTRODUCTION: Rheumatoid arthritis (RA) patients who have active disease with longer disease duration have been reported to have increased risk of cardiovascular events compared to the normal population.
OBJECTIVE: The primary aim of our study is to ascertain the prevalence of significant asymptomatic coronary artery disease (CAD) in Asian RA patients who are in remission using multi-detector computed tomography (MDCT). The secondary aims of our study are the usage of pulse wave velocity and the biomarkers N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-senstivity C-reactive protein (hs-CRP) to detect subclinical atherosclerosis in RA patients.
METHODS: We performed a comparative cross-sectional study of 47 RA patients who were in remission with a control group of non-RA patients with a history of atypical chest pain in Sarawak General Hospital from November 2008 to February 2009. All patients underwent 64-slice MDCT, assessment of arterial stiffness using the SphygmoCor test and blood analysis for NT-proBNP and hsCRP.
RESULTS: There were 94 patients in our study with a mean age of 50 +/- 8.8 years. The RA and control patients in each group were matched in terms of traditional CV risk factors. Our RA patients had a median disease duration of 3 years (IQR 5.5). MDCT showed evidence of CAD in nine (19.1%) RA patients and three (6.4%) control patients (P = 0.06). There was no significant association between pulse wave velocity (PWV) and presence of CAD in our RA group. There was no significant correlation between PWV with levels of proBNP or hsCRP in our RA patients.
CONCLUSIONS: In our current pilot study with the limitation of small sample size, RA was not associated with an increased risk of CAD in our RA patients who were in remission. Larger studies of CAD in Asian RA patients are needed to confirm our current finding.
Study site: Sarawak General Hospital, Kuching, Sarawak, Malaysia