Effectiveness of Using Dual-source CT and the Upshot it creates on Both Heart Rate and Image Quality.

BACKGROUND: Early detection of coronary artery disease (CAD) is important because of the high morbidity and mortality rates. As invasive coronary angiography (ICA) is an invasive procedure, an alternative diagnostic method; coronary computed tomography angiography (CTA), has become more widely used by the improvements in detector technology. AIMS: In this study, we aimed to examine the accuracy and image quality of high-pitch 128-slice dual-source CTA taking the ICA as reference technique. We also aimed to compare the accuracy and image quality between different heart rate groups of >70 beates per minute (bpm) and ≤70 bpm. STUDY DESIGN: Retrospective cross-sectional study. METHODS: Among 450 patients who underwent coronary CTA with the FLASH spiral technique, performed with a second generation dual-source computed tomography device with a pitch value of 3.2, 102 patients without stent and/or bypass surgery history and clinically suspected coronary artery disease who underwent ICA within 15 days were enrolled. Image quality was assessed by two independent radiologists using a 4-point scale (1=absence of any artifacts- 4=non-evaluable). A stenosis >50% was considered significant on a per-segment, per-vessel, and per-patient basis and ICA was considered the reference method. Radiation doses were determined using dose length product (DLP) values detected by the computed tomography (CT) device. In addition, patients were classified into two groups according to their heart rates as ≤70 bpm (73 patients) and >70 bpm (29 patients). The relation between the diagnostic accuracy and heart rate groups were evaluated. RESULTS: Overall, 1495 (98%) coronary segments were diagnostic in 102 patients (32 male, 70 female, mean heart rate: 65 bpm). There was a significant correlation between image quality and mean heart rate in the right coronary artery (RCA) segments. The effective radiation dose was 0.98±0.09 mili Sievert (mSv). On a per-patient basis, sensitivity, specificity, and positive and negative predictive values were 93.8%, 88.8%, 93.8% and 88.8%, respectively. These values were also similar in per-vessel and per-segment basis. Two different groups categorized by mean heart rate had almost similar results in terms of the diagnostic power of dual-source CTA. CONCLUSION: CTA with a high pitch value is a reliable, non-invasive diagnostic method that can CAD with low radiation doses not only in patients with a heart rate below 70 bpm, but also in patients with higher heart rates.

Coronary lesion complexity assessed by SYNTAX score in 256-slice dual-source MDCT angiography.

PURPOSE: The SYNTAX Score (SS) has an important role in grading the complexity of coronary artery disease (CAD) in patients undergoing revascularization. Noninvasive determination of SS prior to invasive coronary angiography (ICA) might optimize patient management. We aimed to evaluate the agreement between ICA and multidetector computed tomography (MDCT) while testing the diagnostic effectiveness of SS-MDCT. METHODS: Our study included 108 consecutive patients who underwent both MDCT angiography with a 256-slice dual-source MDCT system and ICA within 14±3 days. SS was calculated for both ICA and MDCT coronary angiography. Spearman's rank correlation coefficient was used to evaluate the association of SS-MDCT with SS-ICA, and Bland-Altman analysis was performed. RESULTS: The degree of agreement between SS-ICA and SS-MDCT was moderate. The mean SS-MDCT was 14.5, whereas the mean SS-ICA was 15.9. After dividing SS into three groups (high [≥33], intermediate [23-32], and low [≤22] subgroups), agreement analysis was repeated. There was a significant correlation between SS-MDCT and SS-ICA in the low SS group (r=0.63, P = 0.043) but no significant correlation in the high SS group (r=0.036, P = 0.677). The inter-test agreement analysis showed at least moderate agreement, whereas thrombotic lesions and the type of bifurcation lesion showed fair agreement. CONCLUSION: The calculation of SS-MDCT by adapting SS-ICA parameters achieved nearly the same degree of precision as SS-ICA and was better than SS-ICA, especially in the low SS group.

Evaluation of hepatocellular carcinoma with computed tomography perfusion imaging.

AIM: To evaluate the role of computed tomography (CT) perfusion imaging in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Seventeen patients (9 men, 8 women) with newly diagnosed HCC, proven by biopsy, were evaluated with 256-slice helical CT. Perfusion parameters of blood flow (BF), blood volume (BV), arterial perfusion (AP), portal perfusion (PP), and hepatic perfusion index (HPI) were calculated in the normal liver parenchyma and HCC samples. RESULTS: A total of 21 histologically proven HCC lesions were evaluated from CT perfusion images. BF, BV, AP, and HPI values were shown to be significantly higher (P < 0.05) in the HCC lesions than in the normal liver parenchyma. Conversely, PP values were found to be significantly lower (P < 0.05) in HCC relative to liver parenchyma. CONCLUSION: CT perfusion imaging has the ability to evaluate tumor assessment, characterization, and neoangiogenesis in HCC.

Multidetector computed tomographic imaging of Erdheim-Chester disease.

Erdheim-Chester disease is a rarely reported disease that can affect nearly every organ and chiefly infiltrates the connective, perivascular, and adipose tissue. The disease is a form of non-Langerhans-cell histiocytosis characterized by the proliferation of foamy histiocytes; its cardiovascular complications carry a severe prognosis. We present the case of a 29-year-old woman who was admitted for analysis of her angina. Our evaluation with use of cardiac multidetector computed tomographic angiography revealed large mediastinal soft tissue that compressed the patient's left anterior descending coronary artery. To our knowledge, this is the first report of the use of low-dose, dual-source, 256-slice multidetector computed tomography to characterize Erdheim-Chester disease that exclusively caused angina and stenosis of a coronary artery in a young adult.

Follow-up of coronary artery bypass graft patency: diagnostic efficiency of high-pitch dual-source 256-slice MDCT findings.

OBJECTIVES: Our aim was to evaluate the diagnostic accuracy of 256-slice, high-pitch mode multidetector computed tomography (MDCT) for coronary artery bypass graft (CABG) patency. METHODS: Eighty-eight patients underwent 256-slice MDCT angiography to evaluate their graft patency after CABG surgery using a prospectively synchronized electrocardiogram in the high-pitch spiral acquisition mode. Effective radiation doses were calculated. We investigated the diagnostic accuracy of high-pitch, low-dose, prospective, electrocardiogram-triggering, dual-source MDCT for CABG patency compared with catheter coronary angiography imaging findings. RESULTS: A total of 215 grafts and 645 vessel segments were analyzed. All graft segments had diagnostic image quality. The proximal and middle graft segments had significantly (P < 0.05) better mean image quality scores (1.18 ± 0.4) than the distal segments (1.31 ± 0.5). Using catheter coronary angiography as the reference standard, high-pitch MDCT had the following sensitivity, specificity, positive predictive value, and negative predictive value of per-segment analysis for detecting graft patency: 97.1%, 99.6%, 94.4%, and 99.8%, respectively. CONCLUSIONS: In conclusion, MDCT can be used noninvasively with a lower radiation dose for the assessment of restenosis in CABG patients.