ABSTRACT
Objective@#To compare the lumen parameters measured by the location-adaptive threshold method (LATM), in which the inter- and intra-scan attenuation variabilities of coronary computed tomographic angiography (CCTA) were corrected, and the scan-adaptive threshold method (SATM), in which only the inter-scan variability was corrected, with the reference standard measurement by intravascular ultrasonography (IVUS). @*Materials and Methods@#The Hounsfield unit (HU) values of whole voxels and the centerline in each of the cross-sections of the 22 target coronary artery segments were obtained from 15 patients between March 2009 and June 2010, in addition to the corresponding voxel size. Lumen volume was calculated mathematically as the voxel volume multiplied by the number of voxels with HU within a given range, defined as the lumen for each method, and compared with the IVUS-derived reference standard. Subgroup analysis of the lumen area was performed to investigate the effect of lumen size on the studied methods.Bland-Altman plots were used to evaluate the agreement between the measurements. @*Results@#Lumen volumes measured by SATM was significantly smaller than that measured by IVUS (mean difference, 14.6 ㎣ ; 95% confidence interval [CI], 4.9–24.3 ㎣ ); the lumen volumes measured by LATM and IVUS were not significantly different (mean difference, -0.7 ㎣ ; 95% CI, -9.1–7.7 ㎣ ). The lumen area measured by SATM was significantly smaller than that measured by LATM in the smaller lumen area group (mean of difference, 1.07 ㎟ ; 95% CI, 0.89–1.25 ㎟ ) but not in the larger lumen area group (mean of difference, -0.07 ㎟ ; 95% CI, -0.22–0.08 ㎟ ). In the smaller lumen group, the mean difference was lower in the Bland-Altman plot of IVUS and LATM (0.46 ㎟ ; 95% CI, 0.27–0.65 ㎟ ) than in that of IVUS and SATM (1.53 ㎟ ; 95% CI, 1.27–1.79㎟ ). @*Conclusion@#SATM underestimated the lumen parameters for computed lumen segmentation in CCTA, and this may be overcome by using LATM.
ABSTRACT
Objective@#To compare the lumen parameters measured by the location-adaptive threshold method (LATM), in which the inter- and intra-scan attenuation variabilities of coronary computed tomographic angiography (CCTA) were corrected, and the scan-adaptive threshold method (SATM), in which only the inter-scan variability was corrected, with the reference standard measurement by intravascular ultrasonography (IVUS). @*Materials and Methods@#The Hounsfield unit (HU) values of whole voxels and the centerline in each of the cross-sections of the 22 target coronary artery segments were obtained from 15 patients between March 2009 and June 2010, in addition to the corresponding voxel size. Lumen volume was calculated mathematically as the voxel volume multiplied by the number of voxels with HU within a given range, defined as the lumen for each method, and compared with the IVUS-derived reference standard. Subgroup analysis of the lumen area was performed to investigate the effect of lumen size on the studied methods.Bland-Altman plots were used to evaluate the agreement between the measurements. @*Results@#Lumen volumes measured by SATM was significantly smaller than that measured by IVUS (mean difference, 14.6 ㎣ ; 95% confidence interval [CI], 4.9–24.3 ㎣ ); the lumen volumes measured by LATM and IVUS were not significantly different (mean difference, -0.7 ㎣ ; 95% CI, -9.1–7.7 ㎣ ). The lumen area measured by SATM was significantly smaller than that measured by LATM in the smaller lumen area group (mean of difference, 1.07 ㎟ ; 95% CI, 0.89–1.25 ㎟ ) but not in the larger lumen area group (mean of difference, -0.07 ㎟ ; 95% CI, -0.22–0.08 ㎟ ). In the smaller lumen group, the mean difference was lower in the Bland-Altman plot of IVUS and LATM (0.46 ㎟ ; 95% CI, 0.27–0.65 ㎟ ) than in that of IVUS and SATM (1.53 ㎟ ; 95% CI, 1.27–1.79㎟ ). @*Conclusion@#SATM underestimated the lumen parameters for computed lumen segmentation in CCTA, and this may be overcome by using LATM.
ABSTRACT
Cardiac computed tomography (CT) has emerged as a noninvasive modality for the assessment of coronary artery disease (CAD), and has been rapidly integrated into clinical cares. CT has changed the traditional risk stratification based on clinical risk to image-based identification of patient risk. Cardiac CT, including coronary artery calcium score and coronary CT angiography, can provide prognostic information and is expected to improve risk stratification of CAD. Currently used conventional cardiac CT, provides accurate anatomic information but not functional significance of CAD, and it may not be sufficient to guide treatments such as revascularization. Recently, myocardial CT perfusion imaging, intracoronary luminal attenuation gradient, and CT-derived computed fractional flow reserve were developed to combine anatomical and functional data. Although at present, the diagnostic and prognostic value of these novel technologies needs to be evaluated further, it is expected that all-in-one cardiac CT can guide treatment and improve patient outcomes in the near future.
Subject(s)
Female , Humans , Male , Middle Aged , Coronary Angiography/methods , Coronary Artery Disease/physiopathology , Prognosis , Risk , Tomography, X-Ray Computed/methodsABSTRACT
BACKGROUND AND OBJECTIVES: Some patients stop statin therapy in spite of their doctors' advice. This study was designed to assess the pattern of lipoprotein profile changes and clinical characteristics of the patients who discontinued statin therapy. SUBJECTS AND METHODS: 69 patients (male 42.0%) were enrolled. The clinical characteristics and laboratory data on the lipoprotein levels were obtained from the medical records. RESULTS: The coexistence of diabetes mellitus (DM) was seen in 28% of the patients, hypertension was noted in 72% and coronary artery disease (CAD) was noted in 42%. The average lipoprotein levels during statin therapy were total cholesterol (TC)=163.8 mg/dL, triglycerides (TG)=174.3 mg/dL, high-density lipoprotein cholesterol (HDL-C)=34.8 mg/dL and low-density lipoprotein cholesterol (LDL-C)=94.2 mg/dL. LDL-C level increased by 44.9% at 2-3 months after ceasing statin therapy and by 54.6% at 4-6 months after ceasing statin therapy (p<0.01). The changes of the lipoprotein levels from baseline to 2-3 months and 4-6 months after discontinuation were +22.6% and +30.0% for the TC level, +20.8% and +24.0% for the TG level, and 0.06% and -0.65% for the HDL-C level respectively (p<0.01 for TC and TG, p=not significant (NS) for HDL-C). The achievement rate of target LDL-C level as suggested by the Adult Treatment Panel III (ATP III) of National Cholesterol Education Program (NCEP) was decreased 62.7% at 2-3 months and then it was decreased to 61.8% at 4-6 months after statin discontinuation. DM and CAD were more frequent in the patients who did not achieve the target LDL-C level even with life style modification. CONCLUSION: After statin discontinuation, TC and LDL-C were increased within 3 months. DM and CAD were highly prevalent in patients who didn't achieve their treatment goal.