Multislice spiral CT angiography for evaluation of acute aortic syndrome.

OBJECTIVE: To discuss the diagnostic value of multislice CT angiography (MSCTA) in acute aortic syndrome (AAS). MATERIALS AND METHODS: The clinical and imaging data of 36 cases diagnosed as AAS by MSCTA were collected. The manifestations of the MSCTA images were reviewed retrospectively, and the average x-ray dose was calculated. RESULTS: Among 36 AAS cases, 16 cases had aortic dissection (AD), 8 cases had penetrating atherosclerotic ulcer (PAU), 7 cases had intramural hematoma (IMH), and 5 cases had unstable thoracic aneurysm (UTA). Of 16 cases with AD, type A and type B accounted for 43.7% (7/16) and 56.3% (9/16), respectively. Of 7 cases with IMH, type A and type B accounted for 42.9% (3/7) and 57.1% (4/7), respectively. CONCLUSION: In spite of the x-ray radiation, MSCTA proves to be a rapid and noninvasive imaging technique for the diagnosis of AAS.

ECG-gated pulmonary artery CTA for evaluation of right ventricular function in patients with acute pulmonary embolism.

OBJECTIVE: To evaluate right ventricular function in patients with acute pulmonary embolism (APE) using electrocardiogram-gated CTA and to discuss the clinical value of pulmonary artery CTA PATIENTS AND METHODS: Based on death risk evaluation, 86 APE patients were divided into high-risk group (n=46) and non-high-risk group (n=40). The CT pulmonary embolism (PE) index and parameters of right ventricular function were analyzed from the CTPA images and compared between the two groups. Potential correlation between the two was also discussed. RESULT: CT PE index (median 24.69%) of the high-risk group was obviously higher than that of the non-high-risk group (median 8.58%) (P<.05). Except the diameter of superior vena cava, all other parameters of right ventricular function were significantly different between the two groups (P<.05). CT PE index was correlated with the parameters of right ventricular function. CONCLUSION: ECG-gated pulmonary artery CTA is suitable for assessing the severity of APE and right ventricular function.

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.

Early changes of hepatic hemodynamics measured by functional CT perfusion in a rabbit model of liver tumor.

BACKGROUND: Early detection and treatment of hepatocellular carcinoma is crucial to improving the patients' survival. The hemodynamic changes caused by tumors can be serially measured using CT perfusion. In this study, we used a CT perfusion technique to demonstrate the changes of hepatic hemodynamics in early tumor growth, as a proof-of-concept study for human early hepatocellular carcinoma. METHODS: VX2 tumors were implanted in the liver of ten New Zealand rabbits. CT perfusion scans were made 1 week (early) and 2 weeks (late) after tumor implantation. Ten normal rabbits served as controls. CT perfusion parameters were obtained at the tumor rim, normal tissue surrounding the tumor, and control liver; the parameters were hepatic blood flow, hepatic blood volume, mean transit time, permeability of capillary vessel surface, hepatic arterial index, hepatic arterial perfusion and hepatic portal perfusion. Microvessel density and vascular endothelial growth factor were correlated. RESULTS: At the tumor rim, compared to the controls, hepatic blood flow, hepatic blood volume, permeability of capillary vessel surface, hepatic arterial index, and hepatic arterial perfusion increased, while mean transit time and hepatic portal perfusion decreased on both early and late scans (P<0.05). Hepatic arterial index increased (135%, P<0.05), combined with a sharp increase in hepatic arterial perfusion (182%, P<0.05) and a marked decrease in hepatic portal perfusion (-76%, P<0.05) at 2 weeks rather than at 1 week (P<0.05). Microvessel density and vascular endothelial growth factor showed significant linear correlations with hepatic blood flow, permeability of capillary vessel surface and hepatic arterial index, but not with hepatic blood volume or mean transit time. CONCLUSION: The CT perfusion technique demonstrated early changes of hepatic hemodynamics in this tumor model as proof-of-concept for early hepatocellular carcinoma detection in humans.

Assessment of tumor vascularization with functional computed tomography perfusion imaging in patients with cirrhotic liver disease.

BACKGROUND: Hepatocellular carcinoma (HCC) is a common malignant tumor in China, and early diagnosis is critical for patient outcome. In patients with HCC, it is mostly based on liver cirrhosis, developing from benign regenerative nodules and dysplastic nodules to HCC lesions, and a better understanding of its vascular supply and the hemodynamic changes may lead to early tumor detection. Angiogenesis is essential for the growth of primary and metastatic tumors due to changes in vascular perfusion, blood volume and permeability. These hemodynamic and physiological properties can be measured serially using functional computed tomography perfusion (CTP) imaging and can be used to assess the growth of HCC. This study aimed to clarify the physiological characteristics of tumor angiogenesis in cirrhotic liver disease by this fast imaging method. METHODS: CTP was performed in 30 volunteers without liver disease (control subjects) and 49 patients with liver disease (experimental subjects: 27 with HCC and 22 with cirrhosis). All subjects were also evaluated by physical examination, laboratory screening and Doppler ultrasonography of the liver. The diagnosis of HCC was made according to the EASL criteria. All patients underwent contrast-enhanced ultrasonography, pre- and post-contrast triple-phase CT and CTP study. A mathematical deconvolution model was applied to provide hepatic blood flow (HBF), hepatic blood volume (HBV), mean transit time (MTT), permeability of capillary vessel surface (PS), hepatic arterial index (HAI), hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP) data. The Mann-Whitney U test was used to determine differences in perfusion parameters between the background cirrhotic liver parenchyma and HCC and between the cirrhotic liver parenchyma with HCC and that without HCC. RESULTS: In normal liver, the HAP/HVP ratio was about 1/4. HCC had significantly higher HAP and HAI and lower HPP than background liver parenchyma adjacent to the HCC. The value of HBF at the tumor rim was significantly higher than that in the controls. HBF, HBV, HAI, HAP and HPP, but not MTT and PS, were significantly higher in the cirrhotic liver parenchyma involved with HCC than those of the controls. Perfusion parameters were not significantly different between the controls and the cirrhotic liver parenchyma not involved with HCC. CONCLUSIONS: CTP can clearly distinguish tumor from cirrhotic liver parenchyma and controls and can provide quantitative information about tumor-related angiogenesis, which can be used to assess tumor vascularization in cirrhotic liver disease.

Comparison between computed tomography and magnetic resonance imaging in clinical diagnosis and treatment of tibial platform fractures.

BACKGROUND: Tibial plateau fracture is one of the common fracture types. It occurs mainly in teenagers and is usually caused by a fall. After the occurrence of fracture, knee swelling, pain, limited activity, etc. greatly affect the patient's exercise habits and lifestyle. X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) were used in this examination. X-rays are relatively new and easy to operate. However, there are some errors in the observation of fracture collapse and fracture displacement. In recent years, CT and MRI have been actively used to diagnose various types of clinical fractures. They have more diagnostic power than X-ray film. However, some scholars believe that CT is also prone to errors in clinical application. The volume effect leads to missed diagnosis and misdiagnosis in some cases, while the multidirection scanning of MRI technology can effectively overcome the shortcomings of CT. To facilitate the selection of clinical examination regimens, this study further observed the diagnostic ability of these two regimens in the diagnosis of tibial plateau fractures. AIM: To explore the value of nuclear MRI and CT in the clinical diagnosis of tibial plateau fractures. METHODS: A total of 120 patients with tibial plateau fractures admitted from September 2017 to August 2019 were included. All patients were examined by nuclear MRI and CT scanning. The results were sent to senior physicians in our hospital to complete the diagnosis. RESULTS: Nuclear magnetic resonance showed the same effects as CT in four aspects: fracture displacement, bone defect, fracture site and fracture comminution. There was no significant difference in the score data (P > 0.05). Nuclear magnetic resonance and CT tended to be consistent in the B3, C2 and C3 fracture diagnosis coincidence rate, combined injury detection rate and fracture detection rate. The diagnostic coincidence rate of type B1, B2 and C1 fractures and the accuracy rate of overall fracture classification indicated that the MRI technique was significantly better than that of CT (P > 0.05). CONCLUSION: MRI and CT have good diagnostic typing in the diagnosis of tibial plateau fractures, but MRI is more accurate and may be preferred.

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.