A Computer-based Analysis for Identification and Quantification of Small Airway Disease in Lung Computed Tomography Images: A Comprehensive Review for Radiologists.

Computed tomography (CT) imaging is being increasingly used in clinical practice for detailed characterization of lung diseases. Respiratory diseases involve various components of the lung, including the small airways. Evaluation of small airway disease on CT images is challenging as the airways cannot be visualized directly by a CT scanner. Small airway disease can manifest as pulmonary air trapping (AT). Although AT may be sometimes seen as mosaic attenuation on expiratory CT images, it is difficult to identify diffuse AT visually. Computer technology advances over the past decades have provided methods for objective quantification of small airway disease on CT images. Quantitative CT (QCT) methods are being rapidly developed to quantify underlying lung diseases with greater precision than subjective visual assessment of CT images. A growing body of evidence suggests that QCT methods can be practical tools in the clinical setting to identify and quantify abnormal regions of the lung accurately and reproducibly. This review aimed to describe the available methods for the identification and quantification of small airway disease on CT images and to discuss the challenges of implementing QCT metrics in clinical care for patients with small airway disease.

The Relation of Calcium Volume Score and Stenosis of Carotid Artery.

OBJECTIVE: The aim of this study was to investigate the value of extracranial carotid artery calcium score in predicting severity of carotid arterial stenosis. MATERIAL AND METHODS: 200 patients who had indication of contrast neck multi detector computed tomography were included. Calcium volume score of each calcified plaque (density more than 130 HU) was determined by multiplying area of calcified plaque in slice increment and presented as cubic centimeter (cc). Calcium score of each side (right or left) and each patient were determined. Severity of carotid stenosis in axial images was estimated and categorized. Statistical analysis was performed. RESULTS: 87 cases were female with mean age of 58.90 ± 10.67 and 113 cases were male with mean age of 59.61 ± 11.89 years old. The mean of volume score for all evaluated 800 vessels was .079 ± .046 cc. There was no significant difference between calcium score of right and left side (P value = .16). The mean "patient score" was .080 ± .049 cc (range: 0-.15 cc).Nine patients had volume score of 0 and all of them had no evidence of luminal stenosis. Significant increase in severity of stenosis was seen with increase in "patient score".(P value < .001, r = .875).According to receiver operating characteristic analysis, "patient score" of .09 cc with sensitivity of 97% and "patient score" of .12 cc with sensitivity of 95% can predict 50% and 70% stenosis, respectively. CONCLUSIONS: Promising role of calcium score for predicting severity of carotid stenosis could be considered.