The chest CT signs for pulmonary veno-occlusive disease correlate with pulmonary haemodynamics in systemic sclerosis.

OBJECTIVE: Pulmonary arterial hypertension associated with systemic sclerosis (PAH-SSc) sometimes accompanies pulmonary veno-occlusive disease (PVOD). We aimed to reveal the relation between clinical signs of PVOD and severing of pulmonary vasculopathy in SSc. METHODS: This study comprised 52 consecutive SSc patients who had pulmonary haemodynamic abnormalities (mPAP > 20 mmHg, PVR > 2 W.U. or PAWP > 15 mmHg). The chest CT scan was evaluated in all patients. Patients were divided into two groups, the 0-1 group and the 2-3 group, according to the number of chest CT signs for PVOD, including 1) mediastinal lymph node enlargement, 2) thickened interlobular septal wall, and 3) ground glass opacity. Pulmonary haemodynamics, echocardiography and MRI-based cardiac function, pulmonary function, and serum biomarkers were compared between the two groups. RESULTS: Mediastinal lymph node enlargement, thickened interlobular septal wall, and ground glass opacity were observed in 11 (21%), 32 (62%), and 11 (21%) patients, respectively. The 2-3 group (n = 15) had higher mPAP (p= 0.02) while lower DLco/VA (p= 0.02) compared with the 0-1 group (n = 37). Other parameters, including PAWP, cardiac output, left ventricular ejection fraction, left atrial diameter, forced vital capacity, brain natriuretic peptide, and Krebs von den Lunge-6 were not different between the two groups. CONCLUSION: The CT signs for PVOD had positive correlation with mPAP but negative correlation with DLco in SSc patients, indicating that PAH-SSc may reflect a spectrum of pulmonary vascular disease that ranges from the pulmonary artery to the vein.

A Deep Learning-Based Model for Classifying Osteoporotic Lumbar Vertebral Fractures on Radiographs: A Retrospective Model Development and Validation Study.

Early diagnosis and initiation of treatment for fresh osteoporotic lumbar vertebral fractures (OLVF) are crucial. Magnetic resonance imaging (MRI) is generally performed to differentiate between fresh and old OLVF. However, MRIs can be intolerable for patients with severe back pain. Furthermore, it is difficult to perform in an emergency. MRI should therefore only be performed in appropriately selected patients with a high suspicion of fresh fractures. As radiography is the first-choice imaging examination for the diagnosis of OLVF, improving screening accuracy with radiographs will optimize the decision of whether an MRI is necessary. This study aimed to develop a method to automatically classify lumbar vertebrae (LV) conditions such as normal, old, or fresh OLVF using deep learning methods with radiography. A total of 3481 LV images for training, validation, and testing and 662 LV images for external validation were collected. Visual evaluation by two radiologists determined the ground truth of LV diagnoses. Three convolutional neural networks were ensembled. The accuracy, sensitivity, and specificity were 0.89, 0.83, and 0.92 in the test and 0.84, 0.76, and 0.89 in the external validation, respectively. The results suggest that the proposed method can contribute to the accurate automatic classification of LV conditions on radiography.

Predicting the response to pulmonary vasodilator therapy in systemic sclerosis with pulmonary hypertension by using quantitative chest CT.

OBJECTIVES: Systemic sclerosis (SSc) is associated with pulmonary vascular disease and interstitial lung disease, making it difficult to differentiate pulmonary arterial hypertension and pulmonary hypertension (PH) due to lung diseases and/or hypoxia and to decide treatments. We aimed to predict the response to pulmonary vasodilators in patients with SSc and PH. METHODS: Eighty-four SSc patients were included with 47 having PH. Chest computed tomography was evaluated using software to calculate the abnormal lung volume (ALV). To define the response to vasodilators, Δ mean pulmonary artery pressure (mPAP)/basal mPAP was used (cut-off value: 10%). The predictive value was evaluated by using the receiver operating characteristic curve. RESULTS: The mean (±standard deviation) value of ALV was 26.8 (±32.2) %. A weak correlation was observed between ALV and forced vital capacity (FVC) (R = -0.46). The predictive value of ALV [area under curve (AUC) = 0.74] was superior to that of FVC (AUC = 0.62) for the response to vasodilators. No hemodynamic parameters differed between patients with high and low ALV, whereas survival was worse in high ALV. CONCLUSIONS: Quantitative chest computed tomography well predicted the response to vasodilators in patients with SSc and PH. Our results suggest its utility in differentiating the dominance of pulmonary vascular disease or interstitial lung disease.

Feasibility of edoxaban for asymptomatic cancer-associated thrombosis in Japanese patients with gastrointestinal cancer: ExCAVE study.

BACKGROUND: Although initial therapy with a parenteral anticoagulant is required before edoxaban, this strategy is frequently avoided in actual clinical practice because of its complexity. This study assessed the feasibility of edoxaban without initial heparin usage for asymptomatic cancer-associated thrombosis (CAT) in Japanese patients with gastrointestinal cancer (GIC) at high risk of bleeding. METHODS: In this multicenter prospective feasibility study conducted at 10 Japanese institutions, patients with active GIC who developed accidental asymptomatic CAT during chemotherapy were recruited. Edoxaban was orally administered once daily without initial parenteral anticoagulant therapy within 3 days after detecting asymptomatic CAT. The primary outcome was the incidence of major bleeding (MB) or clinically relevant non-major bleeding (CRNMB) during the first 3 months of edoxaban administration. RESULTS: Of the 54 patients enrolled from October 2017 to September 2020, one was excluded because of a misdiagnosis of CAT. In the remaining 53 patients, the primary outcome occurred in six patients (11.3%). MB occurred in four patients (7.5%), including gastrointestinal bleeding in three patients and intracranial hemorrhage in one patient. CRNMB occurred in two patients (3.8%), including bleeding from the stoma site and genital bleeding in one patient each. There were no deaths attributable to bleeding, and all patients who experienced MB or CRNMB recovered. CONCLUSIONS: The risk of bleeding after edoxaban without heparin pretreatment was acceptable, demonstrating new treatment options for asymptomatic CAT in patients with GIC.

Usefulness of ultrasonography and elastography in diagnosing oxaliplatin-induced sinusoidal obstruction syndrome.

BACKGROUND: Sinusoidal obstruction syndrome (SOS) refers to liver injury caused by hematopoietic stem cell transplantation (HSCT) and anticancer drugs including oxaliplatin. Increased splenic volume (SV) on computed tomography (CT) indicates oxaliplatin-induced SOS. Similarly, ultrasonography and liver stiffness measurement (LSM) by shear-wave elastography (SWE) can help diagnose SOS after HSCT; however, their usefulness for diagnosing oxaliplatin-induced SOS remains unclear. We investigated the usefulness of the Hokkaido ultrasonography-based scoring system with 10 ultrasonographic parameters (HokUS-10) and SWE in diagnosing oxaliplatin-induced SOS early. METHODS: In this prospective observational study, ultrasonography and SWE were performed before and at 2, 4, and 6 months after oxaliplatin-based chemotherapy. HokUS-10 was used for assessment. CT volumetry of the SV was performed in clinical practice, and an SV increase ≥ 30% was considered the diagnostic indicator of oxaliplatin-induced SOS. We assessed whether HokUS-10 and SWE can lead to an early detection of oxaliplatin-induced SOS before an increased SV on CT. RESULTS: Of the 30 enrolled patients with gastrointestinal cancers, 12 (40.0%) with an SV increase ≥ 30% on CT were diagnosed with SOS. The HokUS-10 score was not correlated with an SV increase ≥ 30% (r = 0.18). The change in rate of three HokUS-10 parameters were correlated with an SV increase ≥ 30% (r = 0.32-0.41). The change in rate of LSM by SWE was correlated with an SV increase ≥ 30% (r = 0.40). CONCLUSIONS: The usefulness of HokUS-10 score was not demonstrated; however, some HokUS-10 parameters and SWE could be useful for the early diagnosis of oxaliplatin-induced SOS.

Preoperative CT Findings for Predicting Acute Exacerbation of Interstitial Pneumonia After Lung Cancer Surgery: A Multicenter Case-Control Study.

BACKGROUND. Acute exacerbation (AE) is a life-threatening complication of inter-stitial pneumonia (IP). Thoracic surgery may trigger AE. OBJECTIVE. The purpose of this study is to explore the role of preoperative CT findings in predicting postoperative AE in patients with IP and lung cancer. METHODS. This retrospective case-control study included patients from 22 institutions who had IP and underwent thoracic surgery for lung cancer. AE was diagnosed on the basis of symptoms and imaging findings noted within 30 days after surgery and the absence of alternate causes. For each patient with AE, two control patients without AE were identified. After exclusions, the study included 92 patients (78 men and 14 women; 31 with AE [the AE group] and 61 without AE [the no-AE group]; mean age, 72 years). Two radiologists independently reviewed preoperative thin-slice CT examinations for pulmonary findings and resolved differences by consensus. The AE and no-AE groups were compared using the Fisher exact and Mann-Whitney U tests. Multivariable logistic regression was performed. Interreader agreement was assessed by kappa coefficients. RESULTS. A total of 94% of patients in the AE group underwent segmentectomy or other surgery that was more extensive than wedge resection versus 75% in the no-AE group (p = .046). The usual IP pattern was present in 58% of the AE group versus 74% of the no-AE group (p = .16). According to subjective visual scoring, the mean (± SD) ground-glass opacity (GGO) extent was 6.3 ± 5.4 in the AE group versus 3.9 ± 3.8 in the no-AE group (p = .03), and the mean consolidation extent was 0.5 ± 1.2 in the AE group versus 0.1 ± 0.3 in the no-AE group (p = .009). Mean pulmonary trunk diameter was 28 ± 4 mm in the AE group versus 26 ± 3 mm in the no-AE group (p = .02). In a model of CT features only, independent predictors of AE (p < .05) were GGO extent (odds ratio [OR], 2.8), consolidation extent (OR, 9.4), and pulmonary trunk diameter (OR, 4.2); this model achieved an AUC of 0.75, a PPV of 71%, and an NPV of 77% for AE. When CT and clinical variables were combined, undergoing segmentectomy or more extensive surgery also independently predicted AE (OR, 8.2; p = .02). CONCLUSION. The presence of GGO, consolidation, and pulmonary trunk enlargement on preoperative CT predicts AE in patients with IP who are undergoing lung cancer surgery. CLINICAL IMPACT. Patients with IP and lung cancer should be carefully managed when predictive CT features are present. Wedge resection, if possible, may help reduce the risk of AE in these patients. TRIAL REGISTRATION. University Hospital Medical Information Clinical Trial Registry UMIN000029661.

Deep convolutional neural networks to predict cardiovascular risk from computed tomography.

Coronary artery calcium is an accurate predictor of cardiovascular events. While it is visible on all computed tomography (CT) scans of the chest, this information is not routinely quantified as it requires expertise, time, and specialized equipment. Here, we show a robust and time-efficient deep learning system to automatically quantify coronary calcium on routine cardiac-gated and non-gated CT. As we evaluate in 20,084 individuals from distinct asymptomatic (Framingham Heart Study, NLST) and stable and acute chest pain (PROMISE, ROMICAT-II) cohorts, the automated score is a strong predictor of cardiovascular events, independent of risk factors (multivariable-adjusted hazard ratios up to 4.3), shows high correlation with manual quantification, and robust test-retest reliability. Our results demonstrate the clinical value of a deep learning system for the automated prediction of cardiovascular events. Implementation into clinical practice would address the unmet need of automating proven imaging biomarkers to guide management and improve population health.

Radiomics versus Visual and Histogram-based Assessment to Identify Atheromatous Lesions at Coronary CT Angiography: An ex Vivo Study.

Background Visual and histogram-based assessments of coronary CT angiography have limited accuracy in the identification of advanced lesions. Radiomics-based machine learning (ML) could provide a more accurate tool. Purpose To compare the diagnostic performance of radiomics-based ML with that of visual and histogram-based assessment of ex vivo coronary CT angiography cross sections to identify advanced atherosclerotic lesions defined with histologic examination. Materials and Methods In this prospective study, 21 coronary arteries from seven hearts obtained from male donors (mean age, 52.3 years ± 5.3) were imaged ex vivo with coronary CT angiography between February 23, 2009, and July 31, 2010. From 95 coronary plaques, 611 histologic cross sections were coregistered with coronary CT cross sections. Lesions were considered advanced if early fibroatheroma, late fibroatheroma, or thin-cap atheroma was present. CT cross sections were classified as showing homogeneous, heterogeneous, or napkin-ring sign plaques on the basis of visual assessment. The area of low attenuation (<30 HU) and the average Hounsfield unit were quantified. Radiomic parameters were extracted and used as inputs to ML algorithms. Eight radiomics-based ML models were trained on randomly selected cross sections (training set, 75% of the cross sections) to identify advanced lesions. Visual assessment, histogram-based assessment, and the best ML model were compared on the remaining 25% of the data (validation set) by using the area under the receiver operating characteristic curve (AUC) to identify advanced lesions. Results After excluding sections with no visible plaque (n = 134) and with heavy calcium (n = 32), 445 cross sections were analyzed. Of those 445 cross sections, 134 (30.1%) were advanced lesions. Visual assessment of the 445 cross sections indicated that 207 (46.5%) were homogeneous, 200 (44.9%) were heterogeneous, and 38 (8.5%) demonstrated the napkin-ring sign. A radiomics-based ML model incorporating 13 parameters outperformed visual assessment (AUC = 0.73 with 95% confidence interval [CI] of 0.63, 0.84 vs 0.65 with 95% CI of 0.56, 0.73, respectively; P = .04), area of low attenuation (AUC = 0.55 with 95% CI of 0.42, 0.68; P = .01), and average Hounsfield unit (AUC = 0.53 with 95% CI of 0.42, 0.65; P = .004) in the identification of advanced atheromatous lesions. Conclusion Radiomics-based machine learning analysis improves the discriminatory power of coronary CT angiography in the identification of advanced atherosclerotic lesions. Published under a CC BY 4.0 license.

Assessment of Coronary Flow Velocity Reserve in the Left Main Trunk Using Phase-contrast MR Imaging at 3T: Comparison with 15O-labeled Water Positron Emission Tomography.

PURPOSE: The aim of this study was to verify coronary flow velocity reserve (CFVR) on the left main trunk (LMT) in comparison with myocardial flow reserve (MFR) by 15O-labeled water positron emission tomography (PET) (MFR-PET) in both the healthy adults and the patients with coronary artery disease (CAD), and to evaluate the feasibility of CFVR to detect CAD. METHODS: Eighteen healthy adults and 13 patients with CAD were evaluated. CFVR in LMT was estimated by 3T magnetic resonance imaging (MRI) with phase contrast technique. MFR-PET in the LMT territory including anterior descending artery and circumflex artery was calculated as the ratio of myocardial blood flow (MBF)-PET at stress to MBF-PET at rest. RESULTS: There was a significant positive relationship between CFVR and MFR-PET (R = 0.45, P < 0.0001). Inter-observer calculations of CFVR showed good correlation (R2 = 0.93, P < 0.0001). The CFVR in patients with CAD was significantly lower than that in healthy adults (1.90 ± 0.61 vs. 2.77 ± 1.03, respectively, P = 0.01), which were similar to the results of MFR-PET (2.23 ± 0.84 vs. 3.96 ± 1.04, respectively, P < 0.0001). For the detection of patients with CAD, the area under the curve was 0.78 (P = 0.01). The sensitivity was 0.77 and specificity was 0.72 when a cut-off of 2.15 was used. CONCLUSION: CFVR by 3T was validated with MFR-PET. CFVR could detect the patients with CAD. This method is a simple and reliable index without radiation or contrast material.

Diagnostic value of quantitative coronary flow reserve and myocardial blood flow estimated by dynamic 320 MDCT scanning in patients with obstructive coronary artery disease.

We have developed the method for dynamic 320-row multidetector computed tomography (MDCT)-derived quantitative coronary flow reserve (CFRCT) and hyperemic myocardial blood flow (MBFCT). We evaluated diagnostic value of CFRCT and hyperemic MBFCT for detecting obstructive coronary artery disease (CAD) in per-patient and per-vessel analysis, and their relations with the severity of CAD burden.Adenosine stressed and rest dynamic myocardial perfusion MDCT were prospectively performed in patients with known or suspected CAD. Per-patient and per-vessel MBFCT were estimated from dynamic perfusion images in rest and hyperemic phases, and per-patient and per-vessel CFRCT were calculated from the ratio of rest and hyperemic MBFCT. Degree of stenosis was evaluated by coronary CT angiography (CTA) and invasive coronary angiography (ICA). Obstructive stenosis was defined as ≥70% stenosis in ICA. CAD burden with MDCT was calculated by logarithm transformed coronary artery calcium (CAC) score and the CTA-adapted Leaman risk score (CT-LeSc). A logistic regression analysis was used to measure the receiver-operating characteristic curve and corresponding area under the curve (AUC) for the detection of obstructive CAD.Twenty-seven patients and 81 vessels were eligible for this study. Sixteen patients had obstructive CAD, and 31 vessels had obstructive stenosis. Using an optimal cutoff, the CFRCT and hyperemic MBFCT had the moderate diagnostic values in per-patient (AUC = 0.89 and 0.86, respectively) and per-vessel (AUC = 0.79 and 0.76, respectively). Per-patient CFRCT and hyperemic MBFCT exhibited a moderate inverse correlation with CAC score and the CT-LeSc.Per-patient and per-vessel CFRCT as well as hyperemic MBFCT had moderate diagnostic value for detecting obstructive CAD. These per-patient values exhibited a moderate inverse correlation with CAD burden. CFRCT and hyperemic MBFCT might add quantitative functional information for evaluating patients with CAD.

Heterogeneity of longitudinal and circumferential contraction in relation to late gadolinium enhancement in hypertrophic cardiomyopathy patients with preserved left ventricular ejection fraction.

PURPOSE: To evaluate heterogeneity of myocardial contraction in relation to extensive late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) patients with preserved left ventricular ejection fraction, using fast strain-encoded magnetic resonance imaging. MATERIALS AND METHODS: Twenty-two HCM patients and 24 age-matched control subjects were included in this retrospective study. The regional and global peak values of longitudinal and circumferential strain (LSregional, LSglobal, CSregional, CSglobal), and their regional heterogeneities were evaluated using coefficients of variation (LSCoV, CSCoV) in relation to LGE. Receiver operating characteristic curve analysis was performed to identify patients with a total left ventricular myocardial LGE ≥ 15%. RESULTS: LSglobal in HCM patients was significantly decreased compared to that in controls (- 14.4 ± 2.4% vs - 17.2 ± 2.0%; p = 0.0004), while CSglobal was not (p = 1.0). Negative LGE segments demonstrated decreased LSregional in HCM patients compared to in controls (p < 0.0001), while CSregional was not decreased. CSCoV demonstrated the largest area under the curve (AUC) (0.91), with high sensitivity (83%) and specificity (94%) for detection of HCM patients with extensive LGE, while the AUC of LSCoV was low (0.49). CONCLUSION: The heterogeneity in CSregional has a high diagnostic value for detection of HCM patients with extensive LGE.

The usefulness of (18)F-FDG PET/CT for assessing methotrexate-associated lymphoproliferative disorder (MTX-LPD).

BACKGROUND: Methotrexate-associated lymphoproliferative disorder (MTX-LPD) is a benign lymphoid proliferation or malignant lymphoma in patients who have been treated with MTX. MTX withdrawal and observation for a short period should be considered in the initial management of patients who develop LPD while on MTX therapy. Here we evaluated the diagnostic accuracy and predictive value of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) for MTX-LPD. METHODS: We retrospectively investigated the cases of 15 patients clinically suspected of having MTX-LPD. A total of 324 anatomic regions (207 nodal and 117 extranodal regions) were assessed by (18)F-FDG PET/CT and by multi-detector row CT (MDCT). Each anatomic region was classified as either malignant or benign. The uptake of (18)F-FDG was assessed semi-quantitatively with the standardized uptake value maximum (SUVmax), the whole-body metabolic tumor volume (WBMTV), and the whole-body total lesion glycolysis (WBTLG) in order to investigate predictive factors of spontaneous regression after the withdrawal of MTX. RESULTS: MTX-LPD lesions were observed in 92/324 (28.4 %) regions. (18)F-FDG PET/CT showed 90.2 % sensitivity, 97.4 % specificity, and 95.4 % accuracy, values which were significantly higher than those of MDCT (59.8, 94.8, and 84.9 %, respectively. p < 0.002). After the withdrawal of MTX, 9/15 patients (60.0 %) achieved complete response (CR). The SUVmax, WBMTV and WBTLG values of the CR patients were 9.2 (range 2.8-47.1), 44.3 (range 0-362.6) ml, 181.8 (range 0-2180.9) ml, respectively, which were not significantly different from those of the non-CR patients: 10.6 (range 0-24.9), 15.7 (range 0-250.1) ml, and 97.4 (range 0-1052.1) ml. CONCLUSIONS: Although (18)F-FDG PET/CT was a useful tool to detect MTX-LPD lesions, none of the (18)F-FDG PET parameters before the withdrawal of MTX could be used to predict CR after the withdrawal of MTX.

Prediction of pancreatic anastomotic failure after pancreatic head resection using preoperative diffusion-weighted MR imaging.

PURPOSE: To determine whether the preoperative pancreatic apparent diffusion coefficient (ADC) can be used to predict the development of postoperative pancreatic anastomotic failure (PAF). MATERIALS AND METHODS: We retrospectively examined the cases of 79 patients who underwent pancreatic head resection between January 2010 and October 2013. The patients underwent 1.5-T MR imaging including diffusion-weighted imaging before surgery. The main pancreatic duct diameter (MPD), the pancreatic parenchymal thickness (PT), and the ADC of the pancreatic remnant parenchyma were measured. Two radiologists blinded to the patients' outcomes performed the measurements. The imaging parameters were compared between the patients who developed PAF and those who did not. The cut-off ADC for the development of PAF was calculated with a receiver operating characteristic analysis. RESULTS: The imaging parameters were highly correlated between the two observers. The MPD and PT did not differ significantly among the patients. The mean pancreatic ADCs were significantly higher in the patients with PAF than in those without PAF. An ADC higher than 1.50 × 10(-3) mm(2)/s (Az = 0.719, observer-1) or 1.35 × 10(-3) mm(2)/s (Az = 0.752, observer-2) was optimal for predicting the development of postoperative PAF. CONCLUSION: Measuring the preoperative non-tumorous pancreatic ADC may be useful for the prediction of a postoperative PAF.

Cardiac magnetic resonance performs better in the detection of functionally significant coronary artery stenosis compared to single-photon emission computed tomography and dobutamine stress echocardiography.

BACKGROUND: Fractional flow reserve (FFR) measured on catheterization is now widely used for the diagnosis of functional myocardial ischemia in patients with coronary artery disease (CAD). FFR, however, is invasive and carries potential procedural complications. Therefore, the aim of this study was to compare the diagnostic capability in functionally significant stenosis identified on FFR, between cardiac magnetic resonance myocardial perfusion imaging (CMR-MPI), single-photon emission computed tomography MPI (SPECT-MPI), and dobutamine stress echocardiography (DSE) in patients with CAD. METHODS AND RESULTS: A total of 25 patients who had at least 1 angiographic stenosis ≥50% on coronary angiography was studied. CMR-MPI, SPECT-MPI and DSE were done before FFR measurement. FFR was measured in all 3 major epicardial coronary arteries. Out of 71 vascular territories excluding 4 territories due to inadequate imaging, 29 (41%) had FFR <0.80. The sensitivity of CMR-MPI was significantly higher than that of SPECT-MPI and DSE (P=0.02 and P=0.001, respectively). The area under the receiver operating characteristic curve (AUC) for CMR-MPI (AUC, 0.92) was significantly greater than for SPECT-MPI (AUC, 0.73; P=0.006) and DSE (AUC, 0.69; P<0.001). CONCLUSIONS: CMR-MPI performed well in the detection of functionally significant stenosis defined according to FFR, and had the highest diagnostic sensitivity among the 3 modalities tested in patients with CAD.

Quantification of myocardial blood flow using dynamic 320-row multi-detector CT as compared with ¹5O-H2O PET.

OBJECTIVES: This study introduces a method to calculate myocardium blood flow (MBF) and coronary flow reserve (CFR) using the relatively low-dose dynamic 320-row multi-detector computed tomography (MDCT), validates the method against (15)O-H2O positron-emission tomography (PET) and assesses the CFRs of coronary artery disease (CAD) patients. METHODS: Thirty-two subjects underwent both dynamic CT perfusion (CTP) and PET perfusion imaging at rest and during pharmacological stress. In 12 normal subjects (pilot group), the calculation method for MBF and CFR was established. In the other 13 normal subjects (validation group), MBF and CFR obtained by dynamic CTP and PET were compared. Finally, the CFRs obtained by dynamic CTP and PET were compared between the validation group and CAD patients (n = 7). RESULTS: Correlation between MBF of MDCT and PET was strong (r = 0.95, P < 0.0001). CFR showed good correlation between dynamic CTP and PET (r = 0.67, P = 0.0126). CFRCT in the CAD group (2.3 ± 0.8) was significantly lower than that in the validation group (5.2 ± 1.8) (P = 0.0011). CONCLUSIONS: We established a method for measuring MBF and CFR with the relatively low-dose dynamic MDCT. Lower CFR was well demonstrated in CAD patients by dynamic CTP. KEY POINTS: • MBF and CFR can be calculated using dynamic CTP with 320-row MDCT. • MBF and CFR showed good correlation between dynamic CTP and PET. • Lower CFR was well demonstrated in CAD patients by dynamic CTP.

Imaging characteristics of cardiac dominant diffuse large B-cell lymphoma demonstrated with MDCT and PET/CT.

PURPOSE: To investigate the specific imaging findings of multidetector row CT (MDCT) and PET/CT with(18)F-FDG in cardiac dominant diffuse large B-cell lymphoma (DLBCL) in comparison with other cardiac tumours. METHODS: Five patients with DLBCL and 12 patients with other cardiac tumours including pericardial tumours were retrospectively reviewed. Among the patients with other cardiac tumours, seven had metastatic tumours, three had benign tumours, and two had other malignant cardiac tumours. The location of the cardiac mass, the encasement of the coronary artery surrounded by the mass, and pericardial effusion were evaluated using MDCT. The disease activity of the cardiac tumour was also evaluated by PET/CT. RESULTS: Four of the five DLBCL patients had primarily right-sided cardiac lesions, which was seen significantly more frequently in DLBCL than in other cardiac tumours (p = 0.028). All cardiac DLBCL lesions were located around the atrioventricular groove and encased the coronary arteries. ECG-gated cardiac MDCT showed that there was no apparent stenosis of the coronary arteries. Large amounts of pericardial effusion were seen in all DLBCL patients. PET/CT revealed significantly higher FDG uptake in DLBCL than in other cardiac malignant tumours, with no overlap (p = 0.0007). CONCLUSION: The combination of a right-sided cardiac mass with a large pericardial effusion and no apparent stenosis of the encased coronary artery revealed by MDCT and a high maximum standard uptake value were the specific findings in cardiac dominant DLBCL.

Systemic oxidative stress is associated with lower aerobic capacity and impaired skeletal muscle energy metabolism in patients with metabolic syndrome.

OBJECTIVE: Systemic oxidative stress is associated with insulin resistance and obesity. We tested the hypothesis that systemic oxidative stress is linked to lower aerobic capacity and skeletal muscle dysfunction in metabolic syndrome (MetS). RESEARCH DESIGN AND METHODS: The incremental exercise testing with cycle ergometer was performed in 14 male patients with MetS and 13 age-, sex-, and activity-matched healthy subjects. Systemic lipid peroxidation was assessed by serum thiobarbituric acid reactive substances (TBARS), and systemic antioxidant defense capacity was assessed by serum total thiols and enzymatic activity of superoxide dismutase (SOD). To assess skeletal muscle energy metabolism, we measured high-energy phosphates in the calf muscle during plantar flexion exercise and intramyocellular lipid (IMCL) in the resting leg muscle, using (31)P- and (1)proton-magnetic resonance spectroscopy, respectively. RESULTS: Serum TBARS were elevated (12.4 ± 7.1 vs. 3.7 ± 1.1 µmol/L; P < 0.01), and serum total thiols and SOD activity were decreased (290.8 ± 51.2 vs. 398.7 ± 105.2 µmol/L, P < 0.01; and 22.2 ± 8.4 vs. 31.5 ± 8.5 units/L, P < 0.05, respectively) in patients with MetS compared with healthy subjects. Peak VO2 and anaerobic threshold normalized to body weight were significantly lower in MetS patients by 25 and 31%, respectively, and inversely correlated with serum TBARS (r = -0.49 and r = -0.50, respectively). Moreover, muscle phosphocreatine loss during exercise was 1.4-fold greater in patients with MetS (P < 0.05), and IMCL content was 2.9-fold higher in patients with MetS (P < 0.01), indicating impaired skeletal muscle energy metabolism, and these indices positively correlated with serum TBARS (r = 0.45 and r = 0.63, respectively). CONCLUSIONS: Systemic oxidative stress was associated with lower aerobic capacity and impaired skeletal muscle energy metabolism in patients with MetS.