[Assessment of Coronary Stenosis Using Coronary CT Angiography in Patients with High Calcium Scores: Current Limitations and Future Perspectives]. / 높은 칼슘 ì ìˆ˜ë¥¼ 가진 환자에서 관상동맥 CT ì¡°ì˜ìˆ ì„ 이용한 협착 평가의 한계와 ì „ë§.

Coronary CT angiography (CCTA) is recognized for its role as a gatekeeper for invasive coronary angiography in patients suspected of coronary artery disease because it can detect significant coronary stenosis with high accuracy. However, heavy plaque in the coronary artery makes it difficult to visualize the lumen, which can lead to errors in the interpretation of the CCTA results. This is primarily due to the limited spatial resolution of CT scanners, resulting in blooming artifacts caused by calcium. However, coronary stenosis with high calcium scores often requires evaluation using CCTA. Technological methods to overcome these limitations include the introduction of high-resolution CT scanners, the development of reconstruction techniques, and the subtraction technique. Methods to improve reading ability, such as the setting of appropriate window width and height, and evaluation of the position of calcified plaque and residual visibility of the lumen in cross-sectional images, are also recommended.

Effect of papillary muscle and trabeculae on left ventricular function analysis via computed tomography: A cross-sectional study.

Deciding whether to include or exclude the papillary muscles and trabeculae to blood pool is essential, because quantifications of left ventricular (LV) functional parameters and myocardial mass are significantly affected. As a result, such inclusion or exclusion might produce different indices for diagnosis and therapy. Using cardiac computed tomography (CT), we obtained standard values of the portion of papillary muscle and trabeculae in normal adults, and to find out how the inclusion or exclusion of papillary muscle and trabeculae affect LV functional parameters depending on the patient group. Excluding the papillary muscles from the LV mass results in easier automated contour detection using CT. The percentage portions of papillary muscle and trabeculae to LV end-diastolic volume (EDV) and LV mass (LVM) were 11.9 ±â€…5.6% and 20.2 ±â€…4.3%, respectively, significantly affecting disease diagnosis. Imaging should be consistent at follow-up and include or exclude the papillary muscles and trabeculae to avoid introducing significant differences between measurements.

Usefulness of Staging Chest CT in Breast Cancer: Evaluating Diagnostic Yield of Chest CT According to the Molecular Subtype and Clinical Stage.

The aim of this study is to investigate the clinical utility of staging chest CT in breast cancer by evaluating diagnostic yield (DY) of chest CT in detection of metastasis, according to the molecular subtype and clinical stage. This retrospective study included 840 patients with 855 breast cancers from January 2017 to December 2018. The number of patients in clinical stage 0/I, II, III and IV were 457 (53.5%), 298 (34.9%), 92 (10.8%) and 8 (0.9%), respectively. Molecular subtype was identified in 841 cancers and there were 709 (84.3%) luminal type, 55 (6.5%) human epidermal growth factor receptor 2 (HER2)-enriched type and 77 (9.2%) triple-negative (TN) type. The DYs in clinical stage 0/I, cII, cIII and cIV were 0.2% (1/457), 1.7% (5/298), 4.3% (4/92) and 100.0% (8/8), respectively. The DYs in luminal type, HER2-enriched type and TN type were 1.7% (12/709), 3.6% (2/55) and 2.6% (2/77), respectively. Clinical stage was associated with the DY (p = 0.000). However, molecular subtype was not related to the DY (p = 0.343). Molecular subtype could not provide useful information to determine whether staging chest CT should be performed in early-stage breast cancer. However, chest CT should be considered in advanced breast cancer.

Clinical utility of early postoperative cardiac multidetector computed tomography after coronary artery bypass grafting.

We evaluated the clinical utility of early postoperative cardiac computed tomography (CT) for evaluating left ventricular (LV) function and predicting prognosis in patients who had undergone coronary artery bypass grafting (CABG). Of the 205 patients who underwent CABG from March 2011 to December 2014, 136 underwent early postoperative cardiac CT (within 30 days after CABG) and were enrolled as the study population. The baseline and postoperative follow-up echocardiographic findings, major adverse cardiac events (MACE), and death were recorded for a follow-up period (mean, 5.9 ± 1.1 years). Functional cardiac CT parameters were compared to echocardiographic measurements. The associations between cardiac CT findings and functional recovery and prognosis were evaluated by logistic regression analyses. The LVEF measured via cardiac CT was significantly higher (56.2 ± 11.5% vs. 61.9 ± 12.9%; p = 0.0002) compared to those via early postoperative echocardiography, but the wall motion score index (WMSI) was not significantly different (1.23 ± 0.33 vs. 1.21 ± 0.28, p = 0.5041) between the two methods. During the follow-up period, 17 patients (12.5%) died and 40 (29.4%) developed MACE. Both the LVEF and WMSI measured with early postoperative echocardiography (p = 0.0202 and odds ratio [OR] = 5.0171, p = 0.0039, respectively), and cardiac CT (OR = 0.9625, p = 0.0091 and OR = 14.3605, p = 0.0001, respectively) predicted MACE OR = 0.9630, but only the WMSI, measured using cardiac CT, predicted all-cause death (OR = 10.6017, p = 0.0035). In CABG patients, LVEF and the WMSI measured with early postoperative cardiac CT were comparable with echocardiography and predicted the development of MACE and all-cause death.

Prognostic Value of Skeletal Muscle Depletion Measured on Computed Tomography for Overall Survival in Patients with Non-Metastatic Breast Cancer.

PURPOSE: The purpose of this study was to evaluate the prognostic value of skeletal muscle depletion measured on computed tomography (CT) in patients with non-metastatic invasive breast cancer. METHODS: This retrospective study included 577 consecutive women (mean age ± standard deviation: 48.9 ± 10.2 years with breast cancer who underwent a preoperative positron-emission tomography (PET)/CT scan and curative surgery between January 2012 and August 2014. The total abdominal muscle area (TAMA), subcutaneous fat area (SFA), and visceral fat area (VFA) were measured on CT images at the L3 vertebral level. Univariate and multivariate Cox proportional-hazard regression analyses were performed to evaluate whether there was an association between sarcopenia and overall survival (OS) outcome. RESULTS: Of the 577 women, 49 (8.5%) died after a mean of 46 months. The best TAMA threshold for predicting OS was 83.7 cm2. The multivariate Cox proportional-hazard analysis revealed that sarcopenia (TAMA ≤ 83.70 cm2) was a strong prognostic biomarker (hazard ratio [HR], 1.951; 95% confidence interval [CI], 1.061-3.586), along with large tumor size, axillary lymph node metastasis, high nuclear grade, estrogen receptor status, and adjuvant radiation therapy. In the subgroup analysis of patients aged ≥ 50 years, TAMA (≤ 77.14 cm2) was a significant independent factor (HR, 2.856; 95% CI, 1.218-6.695). CONCLUSION: Skeletal muscle depletion measured on CT was associated with worse OS outcome in patients with non-metastatic breast cancer.

Correlations of female hormone levels with background parenchymal enhancement and apparent diffusion coefficient values in premenopausal breast cancer patients: Effects on cancer visibility.

PURPOSE: To evaluate the relationships between female hormone levels and background parenchymal enhancement (BPE) or apparent diffusion coefficient (ADC) values of breast parenchyma, as well as the effects of BPE and ADC values on cancer visibility. METHODS: This prospective study was performed in 164 consecutive premenopausal patients who were diagnosed with invasive breast cancer from November 2016 to December 2018. Two radiologists analyzed the qualitative, quantitative BPE and ADC values of normal contralateral breast parenchyma. We also analyzed the cancer visibility using a three-point scale (0: no visibility, 1: slight visibility, 2: excellent visibility). RESULTS: The progesterone level was significantly correlated with qualitative BPE grade and quantitative values of the BPE, as well as with the mean ADC. On contrast enhanced image (CEI), the visibility score was significantly associated with tumor size, qualitative and quantitative BPE. On diffusion weighted image (DWI), tumor size was significantly associated with the visibility score, whereas the ADC value was not. Of four lesions with a score of 0 on CEI, three had a score of 2 and one a score of 1 on DWI. Regarding the visibility score on DWI, tumor size and histologic type were significantly different among the three groups. CONCLUSIONS: Qualitative or quantitative BPE of breast parenchyma was positively correlated with the progesterone level and the mean ADC was negatively correlated. The cancer visibility was affected by BPE on CEI, but not by ADC on DWI. Small-sized cancer and invasive lobular cancer could be the causes of false-negative diagnoses on DWI.

Change in microcalcifications on mammography after neoadjuvant chemotherapy in breast cancer patients: correlation with tumor response grade and comparison with lesion extent.

BACKGROUND: After neoadjuvant chemotherapy (NAC), persistent microcalcifications are often observed in spite of a decrease in the primary tumor size. PURPOSE: To analyze the changes in microcalcifications after NAC and to evaluate the accuracy of residual microcalcifications in predicting the extent of residual cancer. MATERIAL AND METHODS: Eighty patients who received NAC and underwent both mammography and magnetic resonance imaging (MRI) before and after the completion of NAC were included. The location of microcalcifications was classified into two types: inside the mass and outside the mass. RESULTS: The extent of the residual calcifications was larger than the pathologic residual lesion in 14 (74%) of 19 patients with complete response (CR) on MRI, but the discrepancy was <1 cm in eight (42%) patients. The median value of the discrepancy was significantly higher in patients showing CR with outside calcifications compared to CR with inside calcifications (2.0 cm vs. 0.7 cm, P = 0.008). After NAC, the decrease of calcifications was more frequently observed in cancers showing CR on MRI or Miller-Payne grade 5 and the increase of calcifications more frequently occurred in cancers showing progress disease on MRI or Miller-Payne grade 1 ( P < 0.001 and P = 0.044). CONCLUSION: The change in microcalcifications after NAC was correlated with the tumor response to NAC. The discrepancy was highest in the group showing CR on MRI with outside calcifications. In tumors with inside calcifications, the discrepancy was relatively low within an acceptable range.

The feasibility of synthetic MRI in breast cancer patients: comparison of T2 relaxation time with multiecho spin echo T2 mapping method.

OBJECTIVE:: To compare the T2 relaxation times acquired with synthetic MRI to those of multi-echo spin-echo sequences and to evaluate the usefulness of synthetic MRI in the clinical setting. METHODS:: From January 2017 to May 2017, we included 51 patients with newly diagnosed breast cancer, who underwent additional synthetic MRI and multiecho spin echo (MESE) T2 mapping sequences. Synthetic MRI technique uses a multiecho and multidelay acquisition method for the simultaneous quantification of physical properties such as T1 and T2 relaxation times and proton density image map. A radiologist with 9 years of experience in breast imaging drew region of interests manually along the tumor margins on two consecutive axial sections including the center of tumor mass and in the fat tissue of contralateral breast on both synthetic T2 map and MESE T2 map images. RESULTS:: The mean T2 relaxation time of the cancer was 84.75 ms (± 15.54) by synthetic MRI and 90.35 ms (± 19.22) by MESE T2 mapping. The mean T2 relaxation time of the fat was 129.22 ms (± 9.53) and 102.11 ms (± 13.9), respectively. Bland-Altman analysis showed mean difference of 8.4 ms for the breast cancer and a larger mean difference of 27.8 ms for the fat tissue. Spearman's correlation test showed that there was significant positive correlation between synthetic MRI and MESE sequences for the cancer (r = 0.713, p < 0.001) and for the fat (r = 0.551, p < 0.001). The positive estrogen receptor and low histologic grade were associated with little differences between two methods (p = 0.02 and = 0.043, respectively). CONCLUSION:: T2 relaxation times of breast cancer acquired with synthetic MRI showed positive correlation with those of MESE T2 mapping. Synthetic MRI could be useful for the evaluation of tissue characteristics by simultaneous acquisition of several quantitative physical properties. ADVANCES IN KNOWLEDGE:: Synthetic MRI is useful for the evaluation of T2 relaxation times of the breast cancers.

Quantitative analysis of background parenchymal enhancement in whole breast on MRI: Influence of menstrual cycle and comparison with a qualitative analysis.

OBJECTIVE: We quantitatively analyzed background parenchymal enhancement (BPE) in whole breast according to menstrual cycle and compared it with a qualitative analysis method. MATERIALS AND METHODS: A data set of breast magnetic resonance imaging (MRI) from 273 breast cancer patients was used. For quantitative analysis, we used semiautomated in-house software with MATLAB. From each voxel of whole breast, the software calculated BPE using following equation: [(signal intensity [SI] at 1 min 30 s after contrast injection - baseline SI)/baseline SI] × 100%. RESULTS: In total, 53 patients had minimal, 108 mild, 87 moderate, and 25 marked BPE. On quantitative analysis, mean BPE values were 33.1% in the minimal, 42.1% in the mild, 59.1% in the moderate, and 81.9% in the marked BPE group showing significant difference (p = .009 for minimal vs. mild, p < 0.001 for other comparisons). Spearman's correlation test showed that there was strong significant correlation between qualitative and quantitative BPE (r = 0.63, p < 0.001). The mean BPE value was 48.7% for patients in the first week of the menstrual cycle, 43.5% in the second week, 49% in the third week, and 49.4% for those in the fourth week. The difference between the second and fourth weeks was significant (p = .005). Median, 90th percentile, and 10th percentile values were also significantly different between the second and fourth weeks but not different in other comparisons (first vs. second, first vs. third, first vs. fourth, second vs. third, or third vs. fourth). CONCLUSION: Quantitative analysis of BPE correlated well with the qualitative BPE grade. Quantitative BPE values were lowest in the second week and highest in the fourth week.

Metabolic Activity of Normal Glandular Tissue on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: Correlation with Menstrual Cycles and Parenchymal Enhancements.

PURPOSE: The aims of our study were to correlate the degree of metabolic activity in normal glandular tissue measured on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) with qualitative background parenchymal enhancement (BPE) grades on magnetic resonance imaging (MRI), and to investigate the change in standardized uptake value (SUV) according to the patients' menstrual cycles. METHODS: From January 2013 to December 2015, 298 consecutive premenopausal patients with breast cancer who underwent both breast MRI and 18F-FDG PET/CT were identified. BPE was evaluated in the contralateral breast of cancer patients and categorized as minimal, mild, moderate, or marked based on Breast Imaging Reporting and Data System criteria. We analyzed the correlation between BPE and maximum SUV (SUVmax) and mean SUV (SUVmean) values. We also analyzed the metabolic activity of normal glandular tissue according to the patients' menstrual cycles. RESULTS: The mean SUVmax and SUVmean values differed significantly according to BPE grade (p<0001), with the lowest values occurring in the minimal group and the highest values occurring in the marked group. Spearman's correlation coefficients revealed moderate correlations between BPE grade and SUVmax (r=0.472, p<0.001) and BPE and SUVmean (r=0.498, p<0.001). The mean SUVmax and SUVmean values differed significantly according to the patients' menstrual cycles, with the highest values in the 3rd week and the lowest value in the 2nd week. Of 29 patients with low metabolic parenchyma (high BPE but low SUVmean values), 17 (58.6%) were in the 4th week of their menstrual cycle. CONCLUSION: The metabolic activity of normal breast parenchyma, which is highest in the 3rd week and lowest in the 2nd week of the menstrual cycle, correlates moderately with BPE on MRI. Metabolic activity tends to be lower than blood flow and vessel permeability in the 4th week of the menstrual cycle.

Volume-based metabolic parameter of breast cancer on preoperative 18F-FDG PET/CT could predict axillary lymph node metastasis.

The purpose of our study was to evaluate the association between metabolic parameters on FDG PET/CT and axillary lymph node metastasis (ALNM) in patients with invasive breast cancer.From January 2012 to December 2012, we analyzed 173 patients with invasive ductal carcinoma (IDC) who underwent both initial breast magnetic resonance imaging (MRI) and F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) examinations. All metabolic parameters were measured from the tumor volume segmented by a gradient-based method. Once the primary target lesion was segmented, maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were calculated automatically by the MIMvista software.Mean age of 173 patients was 49 years. Of 173 patients, 45 (26%) showed ALNM. On univariate analysis, larger tumor size (>2.2 cm; P = .002), presence of lymphovascular invasion (P < .001), higher SUVmax (>2.82; P = .038), higher SUVmean (>1.2; P = .027), higher MTV (>2.38; P < .001), and higher TLG (>3.98; P = .007) were associated with a higher probability of ALNM. On multivariate analysis, presence of lymphovascular invasion (adjusted odds ratio [OR], 11.053; 95% CI, 4.403-27.751; P < .001) and higher MTV (>2.38) (adjusted OR, 2.696; 95% CI, 1.079-6.739; P = .034) maintained independent significance in predicting ALNM. In subgroup analysis of T2/T3 breast cancer, lymphovascular invasion (adjusted OR, 20.976; 95% CI, 5.431-81.010; P < .001) and higher MTV (>2.38) (adjusted OR, 4.906; 95% CI, 1.616-14.896; P = .005) were independent predictors of ALNM. However in T1 breast cancer, lymphovascular invasion (adjusted OR, 16.096; 95% CI, 2.517-102.939; P = .003) and larger SUV mean (>1.2) (adjusted OR, 13.275; 95% CI, 1.233-142.908; P = .033) were independent predictors while MTV was not.MTV may be associated with ALNM in patients with invasive breast cancer, particularly T2 and T3 stages. In T1 breast cancer, SUVmean was associated with ALNM.

Usefulness of low dose chest CT for initial evaluation of blunt chest trauma.

We aimed to compare the diagnostic performance and inter-observer consistency between low dose chest CT (LDCT) and standard dose chest CT (SDCT) in the patients with blunt chest trauma.A total of 69 patients who met criteria indicative of blunt chest trauma (77% of male; age range, 16-85) were enrolled. All patients underwent LDCT without intravenous (IV) contrast and SDCT with IV contrast using parameters as following: LDCT, 40 mAs with automatic tube current modulation (ATCM) and 100 kVp (BMI <25, n = 51) or 120 kVp (BMI>25, n = 18); SDCT, 180 mAs with ATCM and 120 kVp. Transverse, coronal, sagittal images were reconstructed with 3-mm slice thickness without gap and provided for evaluation of 3 observers. Reference standard images (transverse, coronal, sagittal) were reconstructed using SDCT data with 1-mm slice thickness without gap. Reference standard was established by 2 experienced thoracic radiologists by consensus. Three observers independently evaluated each data set of LDCT and SDCT.Multiple-reader receiver operating characteristic analysis for comparing areas under the ROC curves demonstrated that there was no significant difference of diagnostic performance between LDCT and SDCT for the diagnosis of pulmonary injury, skeletal trauma, mediastinal injury, and chest wall injury (P > 0.05). The intraclass correlation coefficient was measured for inter-observer consistency and revealed that there was good inter-observer consistency in each examination of LDCT and SDCT for evaluation of blunt chest injury (0.8601-1.000). Aortic and upper abdominal injury could not be appropriately compared as LDCT was performed without using contrast materials and this was limitation of this study.The effective radiation dose of LDCT (average DLP = 1.52 mSv⋅mGy cm) was significantly lower than those of SDCT (7.21 mSv mGy cm).There is a great potential benefit to use of LDCT for initial evaluation of blunt chest trauma because LDCT could maintain diagnostic image quality as SDCT and provide significant radiation dose reduction. A further study of LDCT with IV contrast for evaluation of aortic and upper abdominal injury is needed.

Effect of sarpogrelate, a selective 5-HT2A receptor antagonist, on characteristics of coronary artery disease in patients with type 2 diabetes.

BACKGROUND AND AIMS: Sarpogrelate, a 5-hydroxytryptamine type 2A antagonist, is a potential antiplatelet agent. We performed a randomized study to evaluate the effect of sarpogrelate on vascular health in Korean patients with diabetes. METHODS: Forty diabetic patients aged 58.6 ± 6.8 years with 10-75% coronary artery stenosis, as assessed by coronary computed tomography angiography, were randomly assigned to sarpogrelate 300 mg/day plus aspirin 100 mg/day (SPG + ASA group) or aspirin 100 mg/day alone (ASA group) for 6 months. The primary endpoint of this study was the change in coronary artery disease including the calcium score (CACS), maximal stenosis, and plaque volume (calcified vs. noncalcified). The secondary endpoints were changes in biochemical parameters related to glucose and lipid metabolism, and in subclinical atherosclerosis assessed by ankle-brachial index and pulse wave velocity. RESULTS: After 6-month treatment, there was no significant difference in the changes in CACS, coronary stenosis, ankle-brachial index, and pulse wave velocity, between groups. The total plaque volume decreased from 82.4 ± 14.5 mm3 to 74.6 ± 14.4 mm3 in the SPG + ASA group, but increased from 64.9 ± 16.0 mm3 to 68.6 ± 16.3 mm3 in the ASA group (p < 0.05), mainly driven by changes in the noncalcified component (SPG + ASA group 15.6 ± 4.6 mm3 to 11.2 ± 3.7 mm3vs. ASA group 21.2 ± 6.2 mm3 to 22.8 ± 6.6 mm3, p < 0.01). Serum C-reactive protein levels and homeostasis model assessment of insulin resistance tended to decrease in the SPG + ASA group, but they were not altered in the ASA group. CONCLUSIONS: The present study demonstrated that sarpogrelate treatment may decrease coronary artery plaque volume, particularly the noncalcified portion, in patients with diabetes.

Clinical Utility of Real-Time MR-Navigated Ultrasound with Supine Breast MRI for Suspicious Enhancing Lesions Not Identified on Second-Look Ultrasound.

This study evaluated the usefulness of magnetic resonance (MR)-navigated ultrasound (US) for evaluation of magnetic resonance imaging (MRI)-detected lesions not visible on second-look US and analyzed differences in lesion-to-nipple distance between supine and prone positions. Of the 831 consecutive patients who were diagnosed with breast cancer and examined with breast MRI from June 2013 to September 2015, 40 lesions in 37 patients who underwent MR-navigated US for MRI-detected lesions that were not visible on second-look US were included. First, MRI was performed in a prone position using a 1.5-T imager, and second, MRI was performed in a supine position for MR-navigated US. Of 40 lesions, 31 (78%) were identified with MR-navigated US, whereas 5 (13%) lesions disappeared on supine MRI and 4 (10%) exhibited no correlation on MR-navigated US. Of 31 lesions with pathologic confirmation, 7 (23%) were malignant, 2 (6%) were high-risk lesions and 22 (71%) were benign lesions. Comparison of the US findings of benign and malignant lesions revealed that orientation of the lesion differed significantly (p = 0.045), whereas lesion shape, margin and echo pattern did not significantly differ between the two groups (p = 0.088, p = 0.094 and p = 0.412, respectively). Median difference in lesion-to-nipple distance on supine and prone MRI was 8 mm (0-34 mm) in the horizontal direction and 5 mm (0-39.5 mm) in the vertical direction. Thirteen lesions exhibited a >1-cm difference in both horizontal and vertical directions. In conclusion, MR-navigated US was useful for the evaluation of MRI-detected lesions that were not visible on second-look US in breast cancer patients.

Value of volume-based metabolic parameters for predicting survival in breast cancer patients treated with neoadjuvant chemotherapy.

We evaluated the role of metabolic parameters in the prediction of disease recurrence in operable invasive ductal breast cancer patients treated with neoadjuvant chemotherapy (NAC).We retrospectively evaluated 139 female patients (mean age, 46.5 years; range: 27-72 years) with invasive ductal breast cancer, treated with NAC followed by surgery. All patients underwent F-fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging at baseline and after completion of NAC before surgery. The prognostic significance of clinicopathological and imaging parameters for disease-free survival (DFS) was evaluated.Recurrence of cancer was detected in 31 of 139 patients (22.3%; follow-up period: 6-82 months). Baseline maximum standardized uptake value, metabolic tumor volume (MTV), and reduction rate (RR) of MTV after NAC were significant independent prognostic factors for DFS in a multivariate analysis (all P < 0.05). The survival functions differed significantly between low and high histological grades (P < 0.001). DFS of the patients with high baseline MTV (≥5.23 cm) was significantly poorer than that of low MTV patients (P = 0.019). The survival function of the group with low RR of MTV after NAC (≤90.72%) was poorer than the higher RR of the MTV group (P = 0.008).Our findings suggest that breast cancer patients who have a high histological grade, large baseline MTV, or a small RR of MTV after NAC should receive great attention to check for possible recurrence.

Physiological Severity of Coronary Artery Stenosis Depends on the Amount of Myocardial Mass Subtended by the Coronary Artery.

OBJECTIVES: This study investigated the role of fractional myocardial mass (FMM), a vessel-specific myocardial mass, in the evaluation of physiological severity of stenosis. Using computed tomography angiography, the study investigated fractional myocardial mass, a concept of myocardial mass subtended by specific vessel, which could reduce anatomical-physiological mismatch. BACKGROUND: Discordance between anatomical stenosis and physiological severity is common but remains poorly understood. METHODS: This multicenter study enrolled 463 patients with 724 lesions, who underwent coronary computed tomography angiography (CCTA) and invasive coronary angiography with fractional flow reserve (FFR) measurement. FMM was assessed by allometric scaling analysis of arterial tree length and myocardial mass from CCTA. RESULTS: FFR <0.80, a criteria for vessel-specific physiological stenosis, was found in 281 vessels (39%). FMM decreased consistently according to the vessel downstream (p < 0.001, all). The frequency of FFR <0.80 increased in proportion to FMM and inverse proportion to angiographic minimal luminal diameter (MLD) (p < 0.001). In per-vessel analysis, FMM per MLD (FMM/MLD) showed good correlation with FFR (r = 0.61) and was superior to diameter stenosis (DS) for FFR <0.80 by receiver operating characteristic and reclassification analysis (C-statistics = 0.84 versus 0.74, net reclassification improvement [NRI] = 0.63, integrated discrimination improvement [IDI] = 0.18; p < 0.001, all). The optimal cutoff of FMM/MLD was 29 g/mm, with sensitivity = 75%, specificity = 77%, positive predictive value = 68%, negative predictive value = 83%, and accuracy = 77%. Addition of FMM/MLD to DS could further discriminate vessels with FFR <0.80 (C-statistic = 0.86 vs. 0.84, NRI = 0.34, IDI = 0.03; p < 0.005, all). In per-range classification analysis, agreement between FFR and FMM/MLD maintained >80% when the severity of disease was away from cutoff. CONCLUSIONS: FMM/MLD could find physiological severity of coronary artery with higher accuracy than anatomical stenosis. FMM may explain the anatomical-physiological discordance.

Relationship between indexed epicardial fat volume and coronary plaque volume assessed by cardiac multidetector CT.

We explored whether baseline indexed epicardial fat volume (EFVi) and serial changes in EFVi were associated with increase in coronary plaque volume as assessed by multidetector computed tomography.We retrospectively reviewed 87 patients with coronary artery plaque, identified during either baseline or follow-up cardiac computed tomography (CT) examinations. Each plaque volume was measured in volumetric units using a semiautomatic software tool. EFVi was quantified by calculating the total volume of epicardial tissue of CT density -190 to -30 HU, indexed to the body surface area. Clinical cardiovascular risk factors were extracted by medical record review at the time of the cardiac CT examinations. The relationship between EFVi and coronary plaque volume was explored by regression analysis.Although the EFVi did not change significantly from baseline to the time of the follow-up CT (65.7 ±â€Š21.8 vs 66.0 ±â€Š21.8 cm/m, P = 0.620), the plaque volumes were increased significantly on the follow-up CT scans. The annual change in EFVi was not accompanied by a parallel change in coronary plaque volume (P = 0.096-0.500). On univariate analysis, smoking, hypercholesterolemia, 10-year coronary heart disease risk, obesity, and baseline EFVi predicted rapid increases in lipid-rich and fibrous plaque volumes. On multivariate analysis, baseline EFVi (odds ratio = 1.029, P = 0.016) was an independent predictor of a rapid increase in lipid-rich plaque volume.EFVi was shown to be an independent predictor of a rapid increase in lipid-rich plaque volume. However, changes in EFVi were not associated with parallel changes in coronary plaque volume.

Comparison of Iohexol-380 and Iohexol-350 for Coronary CT Angiography: A Multicenter, Randomized, Double-Blind Phase 3 Trial.

OBJECTIVE: This multi-center, randomized, double-blind, phase 3 trial was conducted to compare the safety and efficacy of contrast agents iohexol-380 and iohexol-350 for coronary CT angiography in healthy subjects. MATERIALS AND METHODS: Volunteers were randomized to receive 420 mgI/kg of either iohexol-350 or iohexol-380 using a flow rate of 4 mL/sec. All adverse events were recorded. Two blinded readers independently reviewed the CT images and conflicting results were resolved by a third reader. Luminal attenuations (ascending aorta, left main coronary artery, and left ventricle) in Hounsfield units (HUs) and image quality on a 4-point scale were calculated. RESULTS: A total of 225 subjects were given contrast media (115 with iohexol-380 and 110 with iohexol-350). There was no difference in number of adverse drug reactions between groups: 75 events in 56 (48.7%) of 115 subjects in the iohexol-380 group vs. 74 events in 51 (46.4%) of 110 subjects in the iohexol-350 group (p = 0.690). No severe adverse drug reactions were recorded. Neither group showed an increase in serum creatinine. Significant differences in mean density between the groups was found in the ascending aorta: 375.8 ± 71.4 HU with iohexol-380 vs. 356.3 ± 61.5 HU with iohexol-350 (p = 0.030). No significant differences in image quality scores between both groups were observed for all three anatomic evaluations (all, p > 0.05). CONCLUSION: Iohexol-380 provides improved enhancement of the ascending aorta and similar attenuation of the coronary arteries without any increase in adverse drug reactions, as compared with iohexol-350 using an identical amount of total iodine.

Analysis of kinetic curve and model-based perfusion parameters on dynamic contrast enhanced MRI in breast cancer patients: Correlations with dominant stroma type.

OBJECTIVE: Our purpose was to evaluate imaging findings of breast cancers according to the dominant stroma type by using kinetic curve analysis and model-based perfusion parameters from dynamic contrast-enhanced magnetic resonance imaging. METHODS: From March 2011 to September 2011, 64 cancers in 64 patients were included for data analysis. Kinetic curve analysis and model based perfusion parameters (Ktrans, Kep and Ve) were obtained using dynamic contrast-enhanced magnetic resonance imaging and post-processing software. Imaging characteristics were analyzed according to the tumor-stroma ratio and dominant stroma type. RESULTS: Ve values were significantly lower in tumors with more than 50% cellularity (0.44 vs. 0.29, p=0.008). Histologic grade, estrogen receptor status and subtype of cancer (triple negative versus non-triple negative) were significantly different (p=0.009, p=0.019 and p=0.03, respectively). Median Kep values were different between collagen dominant, fibroblast dominant and lymphocyte dominant groups. By post hoc comparisons, mean Kep values were significantly higher in lymphocyte dominant group than collagen dominant group (p=0.003). Ktrans and Ve values were not significantly different according to dominant stroma type (p=0.351 and p=0.257, respectively). In multivariate regression analysis, nuclear grade (p=0.021) and dominant stroma type (collagen dominant, p=0.017) were independently correlated with Kep values. In terms of the dominant stroma type, the collagen dominant type showed a decrease of 0.247 in Kep values, compared with the fibroblast-dominant type (p=0.017). CONCLUSIONS: Ve values were significantly lower in tumors with high tumor-stroma ratio. Kep values were significantly lower in breast cancers with dominant collagen type and higher in cancers with high nuclear grade.