Comparing color Doppler ultrasonography and angiography to assess traumatic arterial injuries of the extremities.

BACKGROUND: Traumatic events are one of the major causes of arterial injuries. Physical examination is not a good predictor of the extent of injuries and arteriography is considered as the gold standard for this purpose. In the recent years, noninvasive modalities are increasingly replacing diagnostic arteriography. Color Doppler ultrasonography (USG) is an excellent method to investigate arterial diseases. OBJECTIVES: The present study aimed to evaluate the diagnostic value of color Doppler USG compared to conventional angiography in traumatic arterial injuries of extremities. PATIENTS AND METHODS: Seventy-five patients with extremity trauma suspicious for arterial injury were examined by color Doppler USG just before angiography. Doppler pattern and flow states were assessed, then angiography was performed. The results of duplex USG were compared with angiography. RESULTS: Color Doppler USG had a sensitivity of 95% and specificity of 98% in diagnosis of arterial injury. Positive and negative predictive values of Doppler USG were 92.5% and 94.2%, respectively. CONCLUSIONS: Color Doppler USG can be used as a reliable modality with acceptable sensitivity and specificity values to screen hemodynamically stable patients with limb trauma suspicious for arterial injury.

Fully automatic lung segmentation and rib suppression methods to improve nodule detection in chest radiographs.

Computer-aided Diagnosis (CAD) systems can assist radiologists in several diagnostic tasks. Lung segmentation is one of the mandatory steps for initial detection of lung cancer in Posterior-Anterior chest radiographs. On the other hand, many CAD schemes in projection chest radiography may benefit from the suppression of the bony structures that overlay the lung fields, e.g. ribs. The original images are enhanced by an adaptive contrast equalization and non-linear filtering. Then an initial estimation of lung area is obtained based on morphological operations and then it is improved by growing this region to find the accurate final contour, then for rib suppression, we use oriented spatial Gabor filter. The proposed method was tested on a publicly available database of 247 chest radiographs. Results show that this method outperformed greatly with accuracy of 96.25% for lung segmentation, also we will show improving the conspicuity of lung nodules by rib suppression with local nodule contrast measures. Because there is no additional radiation exposure or specialized equipment required, it could also be applied to bedside portable chest x-rays. In addition to simplicity of these fully automatic methods, lung segmentation and rib suppression algorithms are performed accurately with low computation time and robustness to noise because of the suitable enhancement procedure.

Radiological features of osteoid osteoma: pictorial review.

Osteoid osteoma is a benign bone tumor of undetermined etiology, composed of a central zone named nidus which is an atypical bone completely enclosed within a wellvascularized stroma and a peripheral sclerotic reaction zone. There are three types of radiographic features: cortical, medullary and subperiosteal. Forty-four patients with osteoid osteoma were studied retrospectively. In plain films, 35 patients presented as the cortical type, six cases were located in the medullary zone and three had subperiosteal osteoid osteoma. In all the cases, the nidus was visualized on computed tomography (CT) scan. The nidus was visible in four out of five patients who had also undergone magnetic resonance imaging (MRI). Double-density sign, seen on radionuclide bone scans was positive in all patients. MRI is more sensitive in the diagnosis of bone marrow and soft tissue abnormalities adjacent to the lesion, and in the nidus that is located closer to the medullary zone. On the other hand, CT is more specific when it comes to detecting the lesion's nidus.