Dual Energy Spectral CT Imaging for Colorectal Cancer Grading: A Preliminary Study.

OBJECTIVES: To assess the diagnostic value of dual energy spectral CT imaging for colorectal cancer grading using the quantitative iodine density measurements in both arterial phase (AP) and venous phase (VP). METHODS: 81 colorectal cancer patients were divided into two groups based on their pathological findings: a low grade group including well (n = 13) and moderately differentiated cancer (n = 24), and a high grade group including poorly differentiated (n = 42) and signet ring cell cancer (n = 2). Iodine density (ID) in the lesions was derived from the iodine-based material decomposition (MD) image and normalized to that in the psoas muscle to obtain normalized iodine density (NID). The difference in ID and NID between AP and VP was calculated. RESULTS: The ID and NID values of the low grade cancer group were, 14.65 ± 3.38 mg/mL and 1.70 ± 0.33 in AP, and 21.90 ± 3.11 mg/mL and 2.05 ± 0.32 in VP, respectively. The ID and NID values for the high grade cancer group were 20.63 ± 3.72 mg/mL and 2.95 ± 0.72 in AP, and 26.27 ± 3.10mg/mL and 3.51 ± 1.12 in VP, respectively. There was significant difference for ID and NID between the low grade and high grade cancer groups in both AP and VP (all p<0.001). ROC analysis indicated that NID of 1.92 in AP provided 70.3% sensitivity and 97.7% specificity in differentiating low grade cancer from high grade cancer. CONCLUSIONS: The quantitative measurement of iodine density in AP and VP can provide useful information to differentiate low grade colorectal cancer from high grade colorectal cancer with NID in AP providing the greatest diagnostic value.

Chest X-ray and CT findings of early H7N9 avian influenza cases.

BACKGROUND: The H7N9 strain of bird flu is a new type of avian flu that was identified at the end of March 2013. The disease is concerning because most patients have become severely ill. PURPOSE: To study the X-ray and computed tomography (CT) findings of early H7N9 avian influenza cases. MATERIAL AND METHODS: Chest radiography and CT were performed in six patients with H7N9 avian influenza within 1-20 days after onset. The CT examinations included conventional spiral CT and high-resolution CT. The findings on the radiography and CT images were analyzed. RESULTS: Abnormal X-ray and CT findings were present in all of the patients. All of the cases had acute onset. In the early stage, the right lung was more commonly affected (particularly in the right upper and middle lobes). The lesions rapidly expanded to the entire lungs and were characterized primarily by ground-glass opacities (GGOs) combined with consolidation. Diffuse GGO was observed in all six cases (1 was symmetric, and 5 were non-symmetric). Local consolidation was found in four cases, and lobar consolidation was found in two cases. Normal lung tissue was observed between the lesions. Pleural thickening was common and was combined with pleural/pericardial effusion or mediastinal lymph node enlargement. Reticular changes, centrilobular nodules, and the tree-in-bud sign were observed in some cases, but reticular changes, bronchial wall thickening, and hyperinflation were not found. CONCLUSION: Radiological changes associated with both acute pneumonia and acute interstitial inflammation were observed in early H7N9 avian influenza cases. Serial chest X-rays were useful for the diagnosis and severity assessment of the disease. CT may provide a more accurate assessment of the lung pathology.

Pulmonary CT findings in relapsing polychondritis.

BACKGROUND: Relapsing polychondritis (RPC) is a rare rheumatic disease characterized by recurrent inflammation of cartilaginous structures, with airway involvement a major cause of morbidity and mortality. PURPOSE: To retrospectively evaluate airway and lung abnormalities in RPC with computed tomography (CT). MATERIAL AND METHODS: From January 2004 to May 2009, 21 patients with RPC (12 men, 9 women; 13-65 years old) underwent chest CT examinations. Two chest radiologists evaluated the CT images retrospectively. Abnormal findings, including airway stenosis, airway malacia, air trapping, and airway wall thickening with or without calcifications, were observed and noted. RESULTS: Major abnormal CT findings were observed in eight patients (38.1%), which included airway wall thickening (n=7), airway stenosis (n=6), airway malacia (n=6), airway wall calcification (n=8), and air trapping (n=3). Mediastinal lymph nodes were found in 12 patients. Lung infection was identified in four patients and interstitial lung disease in six patients. CONCLUSION: The CT findings in patients with RPC consisted mainly of airway wall thickening, airway stenosis, airway malacia, airway wall calcification, and air trapping.