CT pulmonary angiogram for assessing the treatment outcome of acute pulmonary embolism.

OBJECTIVE: To discuss the value of CT pulmonary angiogram (CTPA) for assessing the treatment outcome of acute pulmonary embolism (APE). MATERIALS AND METHODS: CT pulmonary angiogram data and other clinical data were collected for 28 cases diagnosed as APE and analyzed retrospectively. The number and positions of emboli in the pulmonary artery, pulmonary artery obstruction index, right ventricular/left ventricular diameter ratio, main pulmonary artery/ascending aorta diameter ratio and blood oxygen saturation, and pulmonary arterial pressure were compared before and after treatment. RESULTS: Of 28 cases, emboli in the pulmonary artery completely or partially disappeared in 16 and 12 cases, respectively. CPTA indicated that the pulmonary arterial pressure decreased dramatically and the blood oxygen saturation increased after treatment in 26 cases. There were significant differences in the number and positions of pulmonary emboli and in pulmonary artery obstruction index before and after treatment in 28 cases (P < .05). However, no significant differences were found in the right ventricular/left ventricular diameter ratio or main pulmonary artery/ascending aorta diameter ratio (P > .05). CONCLUSION: CT pulmonary angiogram proved reliable for assessing the treatment efficacy of APE, providing more clinical information on the patients' status.

Diagnostic value of 64-slice spiral computed tomography imaging of the urinary tract during the excretory phase for urinary tract obstruction.

The present study aimed to assess the diagnostic value of 64-slice spiral computed tomography (CT) imaging of the urinary tract during the excretory phase for urinary tract obstruction. CT imaging of the urinary tract during the excretory phase was performed in 46 patients that had been diagnosed with urinary tract obstruction by B-mode ultrasound imaging or clinical manifestations. It was demonstrated that out of the 46 patients, 18 had pelvic and ureteral calculi, 12 cases had congenital malformations, 3 had ureteral stricture caused by urinary tract infection and 13 cases had malignant tumors of the urinary tract. The average X-ray dose planned for the standard CT scan of the urinary tract group 1 was 14.11±5.45 mSv, while the actual X-ray dose administered for the CT scan during the excretory phase group 2 was 9.01±4.56 mSv. The difference between the two groups was statistically significant (t=15.36; P<0.01). The results of the present study indicate that CT scanning of the urinary tract during the excretory phase has a high diagnostic value for urinary tract obstruction.

A correlation of computed tomography perfusion and histopathology in tumor edges of hepatocellular carcinoma.

BACKGROUND: The peripheral morphologic characteristics of hepatocellular carcinoma (HCC) reflect tumor growth patterns. Computed tomography (CT) perfusion is a new method to analyze hemodynamic changes in tissues. We assessed the relationship between CT perfusion and histopathologic findings in the periphery of HCC lesions. METHODS: Non-contrast CT, enhanced dual-phase CT, and CT perfusion were performed on 77 subjects (47 patients and 30 controls). Based on the imaging findings of enhanced dual-phase CT, the tumor edges were classified into three types: type I (sharp); type II (blurry); and type III (mixed). The CT perfusion parameters included hepatic blood flow, hepatic arterial fraction, hepatic arterial perfusion, and hepatic portal perfusion. The tissue sections from resected specimens were subjected to routine hematoxylin and eosin staining and immunohistochemical staining for CD34. The correlations between microvessel density (MVD) and the CT perfusion parameters were analyzed using Pearson's product-moment correlation coefficient. Changes in the perfusion parameters in tumor edges of different tumor types were evaluated. RESULTS: Type I (sharp): the pathologic findings showed fibrous connective tissue capsules in the tumor edges, and an MVD ≤30/mm2. Type II (blurry): the histology showed that the edges were clear with no capsules and an MVD>30/mm2. Type III (mixed): the pathology was similar to that of types I and II, and an MVD>30/mm2. Hepatic blood flow, hepatic arterial fraction, hepatic arterial perfusion, and hepatic portal perfusion were significantly increased in the tumor edges of HCC patients compared to those of the controls (P<0.05). The correlation between CT perfusion parameters and MVD was higher in blurry tumor edges of type II than in those of types I or III. CONCLUSION: CT perfusion imaging of tumor edges may be helpful in revealing histopathological features, and indirectly reflect angiogenic changes of HCCs.

CT assessment of liver hemodynamics in patients with hepatocellular carcinoma after argon-helium cryoablation.

BACKGROUND: Assessment of tumor response after argon-helium cryoablation is critical in guiding future therapy for unresectable hepatocellular carcinoma. This study aimed to evaluate liver hemodynamics in hepatocellular carcinoma after argon-helium cryoablation with computed tomography perfusion. METHODS: The control group comprised 40 volunteers without liver disease. The experimental group was composed of 15 patients with hepatocellular carcinoma treated with argon-helium cryoablation. Computed tomography perfusion parameters were measured: hepatic blood flow, hepatic blood volume, mean transit time, permeability of capillary vessel surface, hepatic arterial fraction, hepatic arterial perfusion, and hepatic portal perfusion. RESULTS: After treatment, in the tumor foci, permeability of capillary vessel surface was higher, and hepatic blood flow, hepatic blood volume, hepatic arterial fraction, and hepatic arterial perfusion values were lower (P<0.05). In the liver parenchyma surrounding the tumor, hepatic arterial perfusion was significantly lower (P<0.05); however, there was no significant difference in hepatic blood flow, hepatic blood volume, mean transit time, permeability of capillary vessel surface, hepatic arterial fraction, or hepatic portal perfusion (P>0.05). CONCLUSION: Computed tomography perfusion can evaluate tumor response after argon-helium cryoablation.