Quantitative analysis of lung parenchymal involvement in Behçet's disease by the novel automatic program.

OBJECTIVES: We aimed to quantitatively analyze lung parenchymal changes in Behçet's patients and to detect early parenchymal quantitative changes that occur in the absence of positive visual radiological findings. METHODS: In our study, a total of 31 patients with Behçet's disease, 17 with positive radiological findings and 14 patients without positive radiological findings, and a control group of 33 individuals were evaluated. The automatic program determined lung volumes, lung densities, and opacity volume percentages by evaluating the contrast-enhanced lung computed tomography scans. RESULTS: The total lung volume was 3632.98 ± 1100.53 mL in the Behçet's disease patient group and 4925.70 ± 1098.88 mL in the control group, and there was a significant decrease in the total lung volume in Behçet's disease patients (P < 0.0001). The mean lung density was -723.73 ± 65.16 in the Behçet's disease patient group and -767.35 ± 41.17 in the control group, and there was a significant increase in the mean density in the Behçet's patients (P = 0.0023). A significantly higher correlation was observed between lung density and lung volume in Behçet's patients (P < 0.0001, r = -0.795). The lung volume of Behçet's disease patients with negative radiological findings was significantly lower than that of the control group (P = 0.0342). CONCLUSIONS: Lung volumetric changes in Behçet's disease patients are the quantitative data most affected by the disease. In addition, lung volume decreases in Behçet's patients who do not have visual parenchymal involvement.

Effect of contrast medium on early detection and analysis of mediastinal lymph nodes in computed tomography.

OBJECTIVE: This study aimed to evaluate the diagnostic efficiency of contrast-to-noise and signal-to-noise ratios created by the contrast medium in detecting lymph nodes. METHODS: In this study, 57 short-axis subcentimeter lymph nodes in 40 cardiac computed tomography patients with noncontrast- and contrast-enhanced phases were evaluated. The contrast-to-noise ratios and signal-to-noise ratios of noncontrast- and contrast-enhanced lymph node-mediastinal fat and aortic-mediastinal fat tissues were determined. In addition, lymph nodes in noncontrast- and contrast-enhanced series were evaluated subjectively. RESULTS: There was a significant difference in lymph node-mediastinal fat signal-to-noise values between the contrast and noncontrast phases (p=0.0002). In the contrast phase, aortic density values were found to be 322.04±18.51 HU, lymph node density values were 76.41±23.41 HU, and mediastinal adipose tissue density values were -65.73±22.96 HU. Aortic-mediastinal fat contrast-to-noise ratio value was 20.23±6.92 and the lymph node-mediastinal fat contrast-to-noise ratio value was 6.43±2.07. A significant and moderate correlation was observed between aortic-mediastinal fat and lymph node-mediastinal fat contrast-to-noise ratio values in the contrast phase (r=0.605; p<0.001). In the contrast-enhanced series, there was a significant increase in the subjective detection of lymph nodes (p=0.0001). CONCLUSION: In the detection of paratracheal lymph nodes, the contrast agent increases the detection of short-axis subcentimeter lymph nodes quantitatively and qualitatively. Contrast enhances and facilitates the detection of paratracheal lymph nodes.