Quantitative computed tomography angiography evaluation of the coronary fractional flow reserve in patients with left anterior descending artery myocardial bridging.

PURPOSE: To quantitatively investigate the effect of myocardial bridge (MB) in the left anterior descending artery (LAD) on the fractional flow reserve (FFR). MATERIALS AND METHODS: Three-hundred patients with LAD MB who had undergone coronary artery CT angiography (CCTA) were retrospectively enroled, and 104 normal patients were enroled as the control. The CCTA-derived fractional flow reserve (FFRCT) was measured at the LAD 10 mm proximal (FFR1) and 20-40 mm distal (FFR3) to the MB and at the MB location (FFR2). RESULTS: FFR2 and FFR3 of the MB (with BM only) and MBLA (with both MB and atherosclerosis) groups were significantly (p < 0.01) lower than those of the control. The FFR3 distal to the MB was significantly lower (p < 0.01) than that of the control. The FFRCT of the whole LAD in the MBLA group was significantly (p < 0.05) lower than that of the MB and control group (p < 0.05). MB length (OR 1.061) and MB muscle index (odds ratio or OR 1.007) were two risk factors for abnormal FFRCT, and MB length was a significant independent risk factor for abnormal FFRCT (OR = 1.077). LAD stenosis degree was a risk factor for abnormal FFRCT values (OR 3.301, 95% confidence interval [CI] 1.441-7.562, p = 0.005) and was also a significant independent risk factor (OR = 3.369, 95% CI: 1.392-8.152; p = 0.007) for abnormal FFRCT. CONCLUSION: MB significantly affects the FFRCT of distal coronary artery. For patients with MB without atherosclerosis, the MB length is a risk factor significantly affecting FFRCT, and for patients with MB accompanied by atherosclerosis, LAD stenotic severity is an independent risk factor for FFRCT.

Neuralgic amyotrophy: sensitivity and specificity of magnetic resonance neurography in diagnosis: A retrospective study.

BACKGROUND: Neuralgic amyotrophy (NA) is a clinically acute or subacute disease. To study the characteristics of brachial plexus magnetic resonance neurography (MRN) in patients with NA, and to explore the clinical application value of MRN combined with electromyography (EMG) in the diagnosis of NA. METHODS: Brachial plexus MRN images of 32 patients with NA were retrospectively analyzed, and their characteristics were investigated. The accuracy, sensitivity and specificity of MRN, EMG, and the combination of the 2 methods for NA diagnosis were compared. RESULTS: Among the 32 patients with NA, 28 (87.5%) cases of unilateral brachial plexus involvement, 18 (56.3%) cases of multiple nerve roots involvement. In 10 cases, C5 nerve roots were involved alone, and in 9 cases, C5 to C6 nerve roots were involved together. The T2 signal intensity of the affected nerve increased, and 19 cases showed thickened and smooth nerve root edges. Twelve cases showed uneven thickening and segmental stenosis of the involved nerve roots. The diagnostic accuracy, sensitivity, and specificity of MRN for NA were higher than those of EMG. Combining MRN and EMG could improve the sensitivity and specificity of diagnosis. CONCLUSION: The main feature of MRN in patients with NA was that it was unilateral brachial plexus asymmetric involvement. The diagnostic effect of MRN was better than that of EMG. The combined diagnosis of MRN and EMG can help clinicians diagnose NA accurately.

[Value of CT Features on Differential Diagnosis of Pulmonary Subsolid Nodules and Degree of invasion Prediction in Pulmonary Adenocarcinoma].

BACKGROUND: Subsolid pulmonary nodules are common computed tomography (CT) findings of primary lung adenocarcinoma. It is of clinical value to determine the clinical treatment strategies based on CT features. The aim of this study is to find the valuable CT characteristics on differential diagnosis and the degree of invasion prediction by a retrospectively analysis of three groups subsolid nodules, including benign, and invasive adenocarcinoma. METHODS: The CT findings of 106 cases of resected sub-solid nodules were retrospectively analyzed. The nodules were firstly divided into benign and malignant groups and the malignant group was further divided into non/micro-invasive group (atypical adenomatous hyperplasia/adenocarcinoma in situ/minimally invasive adenocarcinoma) and invasive adenocarcinoma group. The nodule size, proportion of solid components, tumor-lung interface, shape, margin, pleural traction, air bronchus sign, vascular abnormalities inside the nodule were evaluated. The univariate analysis (χ2 test, non-parametric test Mann-Whitney U test) was performed to screen statistically significant variables and then enrolled in further multivariate Logistic regression analysis. RESULTS: Multivariate logistic regression analysis showed that a clear tumor-lung interface, air bronchus sign, and pulmonary vascular abnormalities were important indicators of malignant nodules with hazard ratios of 38.1 (95%CI: 5.0-287.7; P<0.01), 7.9 (95%CI: 1.3-49.3; P=0.03), 7.2 (95%CI: 1.4-37.0; P=0.02), respectively. The proportion of solid components was the only significant indicator for identifying invasive adenocarcinoma from AAH/AIS/MIA , with a risk ratio of 1.04 (95%CI: 1.01-1.06, P=0.01). CONCLUSIONS: SSNs with clear tumor-lung interface, air bronchus sign, and pulmonary vascular abnormality inside nodule are more likely to be malignant. A higher percentage of solid components indicates a higher likelihood to be an invasive lesion in malignant SPNs.

[Analysis of Growth Curve Type in Pulmonary Nodules with
Different Characteristics].

BACKGROUND: Background and objective Follow up by computed tomography (CT) and growth evaluation are routine methods for the differential diagnosis of indeterminate pulmonary nodules in clinical practice. Pulmonary nodules with diverse biological behaviors may show different growth patterns and velocities. The aim of this study is to identify the volume growth curve of both benign and malignant pulmonary nodules. This work also intends to determine these nodules' growth patterns and provide evidence for the establishment of a follow-up strategy. METHODS: The CT data of 111 pulmonary nodules (54 solid, 57 subsolid) were retrospectively evaluated using 3D volumetric software. All of these nodules have been followed up at least twice. Of these nodules, 35 were confirmed as lung cancers, whereas 5 were confirmed as benign by pathology or histology. Moreover, 71 nodules showed no growth in more than 2 years. Stable nodules were defined as low-risk nodules, as confirmed by reevaluation from experts. On the basis of their densities and diameters, the nodules were classified into four types: benign/low-risk solid nodules, malignant solid nodules (diameter ≤1 cm and >1 cm), benign/low-risk subsolid nodules, and malignant subsolid nodules (diameter ≤1 cm and >1 cm). The follow-up interval time (d) were plotted on the x-axis, and the nodules' volume (mm3) and logarithmic volume were plotted on the y-axis. Two radiologists subjectively determined the type of growth curve. Chi-square test was performed to compare the growth curves of benign/low-risk and malignant nodules. RESULTS: Of 18 solid cancers, 12 cases (66%) were found with steep ascendant growth curves. Those of 3 cases (16.7%) were flat ascendant, 2 cases (11.1%) slowly ascendant, and 1 (5.56%) case flat. Of 17 subsolid cancers, 8 cases (47.1%) manifested steep ascendant growth curves. Those of 4 cases (23.5%) were slowly ascendant, 3 (17.6%) flat, and 2 (11.8%) descendant-ascendant. Of 36 benign/low-risk solid nodules, 5 cases (13.9%) manifested descendant growth curves, 17 cases (47.2%) flat, 8 cases (21.6%) slowly ascendant, and 6 cases (16.7%) undulate. Of 40 benign/low-risk subsolid nodules, 4 cases (10%) manifested descendant growth curves, 21 cases (52.5%) flat, 9 cases (22.5%) slowly ascendant, and 6 cases (15%) undulate. The distribution of growth curve types significantly differed between benign/low-risk and malignant nodules (χ2=42.4, P<0.01). CONCLUSIONS: The growth curves of lung cancers are heterogeneous. A steep ascendant curve is the main type for lung cancer, with the exception of flat, slowly ascendant, or even descendant curve. A slowly ascendant curve cannot exclude the diagnosis of lung cancer, especially for subsolid nodules.
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[Threshold Segmentation of Pulmonary Subsolid Nodules on CT Images:
Detection and Quantification of the Solid Component].

BACKGROUND: The detection and quantification of solid components in pulmonary subsolid nodules (SSN) are of vital importance on differential diagnosis, pathological speculation and prognosis prediction. However, no objective and wide-accepted criterion has been built up to now. The purpose of this study is to explore the optimal threshold that can be used for the detection and quantification of solid components in SSNs by using threshold segmentation method on computed tomography (CT) images. METHODS: CT images of 102 SSNs were retrospectively analyzed. To establish a reference standard, the observers made judgments on whether the solid component existed in every SSN and did manual measurements of the volume of solid component with the help of software. Threshold segmentations of every nodule were then performed using different threshold settings and all of the measured volumes were assumed to be solid volumes, then solid-to-total volume ratios were calculated. The results were compared with the reference standards using the receiver operating characteristic curve and Wilcoxon test. RESULTS: The application of thresholds as -250 HU or -300 HU resulted in high diagnostic value on the detection of solid component, with area under curve values as 0.982 and 0.977, respectively; the cut-off values of solid-to-total volume ratio were 1.10% and 6.14%, respectively; the median volumes of solid components were 202.7 mm3 (598.2 mm3), 247.1 mm3(696.0 mm3), which were not significantly different from the reference standard[199.5 mm3 (743.1 mm3)](P=0.125,1, 0.061,3). CONCLUSIONS: Threshold segmentation on chest CT images is valuable to detect and quantify the solid component on SSNs, the thresholds as -250 HU and -300 HU are recommended.
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