ABSTRACT. The purpose of this study was to determine the usefulness of first-pass whole nodule perfusion imaging in the differentiation of benign and malignant solitary pulmonary nodules (SPNs). 77 patients with non-calcified SPNs (46 malignant, 22 benign and 9 active inflammatory) underwent first-pass perfusion imaging with a 64-detector row CT scanner. Perfusion, peak enhancement intensity (PEI), time to peak (TTP) and blood volume (BV) were measured and statistically compared among different groups. Mean perfusion, PEI and BV for benign SPNs were significantly lower than those for malignant nodules (p,0.05) and active infections (p,0.05), but the differences were not statistically significant between malignant tumours and active infections (p.0.05). Receiver operating characteristic (ROC) curve analysis showed that SPNs with perfusion greater than 30.6 ml min -1 ml -1 , PEI higher than 23.3 HU or BV larger than 12.2 ml per 100 g were more likely to be malignant. In conclusion, first-pass perfusion imaging with 64-detector row CT is a feasible way of assessing whole nodule perfusion and helpful in differentiating benign from malignant SPNs. The differentiation of solitary pulmonary nodules (SPNs) as benign or malignant remains a diagnostic challenge for thoracic radiology. During the past decade, promising results for more specific differentiation of malignant and benign nodules using dynamic contrast material-enhanced CT have been reported [1][2][3][4][5][6]. Techniques in these studies rely on single-level acquisition with long time intervals, which were considered to be problematic for quantitative assessment of whole tumour perfusion because the blood flow within tumours is spatially and temporally heterogeneous [7,8]. Nevertheless, current technological advances in multidetector row CT (MDCT), specifically sequential volume acquisition and data processing, allow for more accurate evaluation of tissue haemodynamics than that attainable with previous CT techniques. A recent study on MDCT perfusion techniques assessed whole tumour perfusion with the volume coverage of 40 mm in patients with non-small-cell lung carcinoma and achieved good measurement reproducibility [8].To the best of our knowledge, no data exist on the application of first-pass perfusion CT for the differentiation of benign and malignant SPNs [1][2][3][4][5][6]8]. The purpose of our study, therefore, was to determine the utility of first-pass whole nodule perfusion imaging in the differentiation of benign and malignant SPNs. Methods and materialsBetween August 2006 and May 2007, a total of 93 patients with a newly detected SPN at cross-sectional imaging or conventional radiography (61 men and 32 women; age range 22-79 years; mean age 54.9 years) were recruited prospectively according to the following criteria: presence of SPN 30 mm or less in diameter, without evidence of calcification or fat attenuation, absence of contraindication to the administration of contrast medium and probable ability to co-operate with the procedure. Of these, 77 p...

DCEUS is a valuable method for evaluating angiogenesis in colorectal tumours in vivo. The AUC has a positive linear correlation with MVD and could form a new index for assessing angiogenesis and the biological behaviour of colorectal tumours.

BACKGROUND AND PURPOSE:White matter abnormalities have been demonstrated to play an important role in minimal hepatic encephalopathy. In this study, we aimed to evaluate whether WM diffusion tensor imaging can be used to identify minimal hepatic encephalopathy among patients with cirrhosis.