Influence of lesion ratio on diagnostic performance of in-phase/opposed-phase imaging and apparent diffusion coefficient for differentiating acute benign vertebral fractures and metastases / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The usefulness of in-phase/opposed-phase imaging and diffusion weighted imaging (DWI) in differentiating benign and neoplastic vertebral fractures has been described. In this study, we aimed to evaluate the influence of the severity of vertebral damage on the diagnostic performance of these two technologies.</p><p><b>METHODS</b>Totally 59 patients with 68 acute benign vertebral fractures and 43 patients with 79 vertebral metastases were included in this study. The MR protocol included DWIs and sagittal in-phase/opposed-phase gradient recalled sequence. The severity of vertebral damage was expressed by lesion ratio (LR, the ratio of lesion area to vertebral area on the slices of largest abnormal signal area in the T1-weighted sequence). Quantitative (signal intensity ratio (SIR) defined as signal intensity (SI) on opposed-phase gradient recalled echo (GRE) images divided by SI on in-phase; apparent diffusion coefficient (ADC) value derived from DWI analysis was performed, the relationships between LR and the measurements of these two technologies were analyzed using linear regression. The covariate-specific receiver operating characteristic (ROC) curves were also fitted to evaluate the influence of LR on the diagnostic performance of ADC and SIR.</p><p><b>RESULTS</b>The difference in both SIR and ADC for vertebral metastasis and acute benign vertebral fractures was significant (P < 0.001). A positive correlation between the LR and the SIR was found in benign fractures (P < 0.05). The severity of vertebral damage had a significant influence on the AUC (area under ROC curve) for SIR (P < 0.05) but ADC (P > 0.05). More severe cases were associated with increased AUC for SIR.</p><p><b>CONCLUSIONS</b>LR is capable of affecting the diagnostic performances of chemical shift imaging. Thus, when applying these tests to make diagnoses on vertebral fractures, the severity of the vertebral damage should be taken into account. The covariate-specific ROC model is recommended because it substantially improves the ability to avoid bias when evaluating tests.</p>

The value of three-phase pulmonary helical CT in diagnosing peripheral pulmonary cancer (diameter

<p><b>OBJECTIVE</b>To evaluate the value of three-phase pulmonary helical CT in diagnosing peripheral pulmonary cancer (diameter </= 3 cm).</p><p><b>METHODS</b>Serial single-slice dynamic scans were obtained with helical CT before and after injection of 100 ml contrast material in 60 patients with solitary pulmonary nodules (SPNs, diameter <or= 3 cm). The three-phase pulmonary helical CT was established by analyzing enhancement feature of thoracic aorta and pulmonary artery, and then the enhancement feature of three-phase pulmonary helical CT was analyzed.</p><p><b>RESULTS</b>The delayed times of three-phase pulmonary helical CT were pulmonary artery phase (15 second), bronchial artery phase (36 second), equilibrium phase (90 second) respectively. The prevalence model of density change for three-phase pulmonary helical CT: no enhancement, marked enhancement, moderate-enhancement in pulmonary cancer; slight or moderate-enhancement, marked-enhancement, marked-enhancement in inflammatory nodules; no enhancement or light-enhancement in tuberculoma and metastatic nodules. The enhanced branch and small spot vessels were demonstrated by bronchial artery phase in 82.9% of pulmonary cancer nodules.</p><p><b>CONCLUSION</b>The three-phase pulmonary helical CT could reflect the enhancement feature, blood supply of bronchial artery in peripheral pulmonary cancer (diameter </= 3 cm), it is helpful in early diagnosis and differentiation.</p>

Helical dual-phase CT scan in evaluating blood supply of primary heptocellular carcinoma after transcatheter hepatic artery chemoembolization with lipiodol / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the blood supply of low density viable area of primary heptocellular carcinoma after transcatheter hepatic artery chemoembolization using lipiodol (LP-TACE), by helical dual-phase CT scanning and three dimensional CT (3DCT).</p><p><b>METHODS</b>Thirty-four patients with primary heptocellular carcinoma after LP-TACE were examined by hepatic helical dual-phase CT. 3DCT model of the maximum intensity projection (MIP), surface shaded display (SSD) reconstruction of the hepatic artery and portal vein were simultaneously done in 5 cases.</p><p><b>RESULTS</b>Viable tumor areas of 34 cases of primary heptocellular carcinoma after LP-TACE were divided into four types: peripheral, lateral, central and diffused types. Enhanced tumor vessel or tissue in viable tumor area was found during hepatic dual-phase in 17 cases, during hepatic artery-phase only in 8 and hepatic portal vein-phase only in 3. The viable tumor areas were found to have blood supply from the hepatic vein in 2 cases. The viable tumor area unenhanced during hepatic dual-phase was found in 6 cases. In 5 cases, the relation between the viable tumor area and branches of hepatic artery and portal vein was showed by MIP and SSD of hepatic artery and portal vein.</p><p><b>CONCLUSION</b>Hepatic helical dual-phase CT scan with 3DCT is effective in evaluating the blood supply of viable tumor areas and the therapeutic effect of primary heptocellular carcinoma after LP-TACE.</p>