Chronic thromboembolic pulmonary hypertension (CTEPH) - potential role of multidetector-row CT (MD-CT) and MR imaging in the diagnosis and differential diagnosis of the disease.

Chronic thromboembolic pulmonary hypertension (CTEPH) can be defined as pulmonary hypertension (resting mean pulmonary arterial pressure of 25 mm Hg or more determined at right heart catheterization) with persistent pulmonary perfusion defects. It is a rare, but underdiagnosed disease with estimated incidences ranging from 0.5% to 3.8% of patients after an acute pulmonary embolism (PE), and in up to 10% of those with a history of recurrent PE. CTEPH is the only form of pulmonary hypertension that can be surgically treated leading to normalization of pulmonary hemodynamics and exercise capacity in the vast majority of patients. The challenges for imaging in patients with suspected CTEPH are fourfold: the imaging modality should have a high diagnostic accuracy with regard to the presence of CTEPH and allow for differential diagnosis. It should enable detection of patients suitable for PEA with great certainty, and allow for quantification of PH by measuring pulmonary hemodynamics (mPAP and PVR), and finally, it can be used for therapy monitoring. This overview tries to elucidate the potential role of ECG-gated multidetector CT pulmonary angiography (MD-CTPA) and MR imaging, and summarizes the most important results that have been achieved so far. Generally speaking, ECG-gated MD-CTPA is superior to MR in the assessment of parenchymal and vascular pathologies of the lung, and allows for the assessment of cardiac structures. The implementation of iodine maps as a surrogate for lung perfusion enables functional assessment of lung perfusion by CT. MR imaging is the reference standard for the assessment of right heart function and lung perfusion, the latter delineating typical wedge-shaped perfusion defects in patients with CTEPH. New developments show that with MR techniques, an estimation of hemodynamic parameters like mean pulmonary arterial pressure and pulmonary vascular resistance will be possible. CT and MR imaging should be considered as complementary investigations providing comprehensive information in patients with CTEPH.

Correlation of multislice CT and histomorphology in HCC following TACE: predictors of outcome.

The purpose of this study was to correlate histopathological with CT findings in patients suffering from hepatocellular carcinoma (HCC) eligible for orthotopic liver transplantation (OLT), with a special focus on the antitumoral effect of transarterial chemoembolization (TACE) therapy. A total of 42 consecutive patients suffering from HCC had been treated prior to OLT by means of TACE. TACE was carried out with a mixture of Lipiodol (10-20 ml) and mitomycin C (max. dosage, 10 mg). TACE was performed at 6- to 8-week intervals. Follow-up investigation included contrast-enhanced multislice CT controls and laboratory control. Liver explants were evaluated macroscopically and microscopically to determine the number and size of the tumor lesions as well as the degree of tumor necrosis. Necrosis was investigated in H&E-stained sections. The degree of necrosis was classified as follows: 0-25%, 26-50%, 51-75%, 75-99%, and complete necrosis. Two hundred thirty-one TACE procedures (5.5 +/- 2.9; range, 1-14) were performed. Mean tumor size in CT before and after TACE was 4.1 +/- 2.4 (range, 1.0-12.0 cm) and 2.7 +/- 1.2 (range, 1.0-6.0 cm; p < 0.001). Mean tumor number before and after TACE in CT was 2.5 +/- 1.5 (n = 105; range, 1-8) and 2.4 +/- 2.0 (n = 103; range, 1-6; p = 0.99). In the surgical specimen tumor size and tumor number were 2.8 +/- 1.6 (range, 1.0-7.0 cm; p = 0.78) and 1.9 +/- 1.2 (range, 1-7; p = 0.003). Mean tumor necrosis was 67.8% +/- 28.1%. Tumor necrosis was subtotal or complete in 17 of 42 (40.5%) patients. Tumor necrosis correlated significantly with the degree of arterial devascularization in CT (p = 0.001), the amount of Lipiodol washout (p = 0.002), and the number of tumor lesions (i.e., unifocal vs. multifocal). Furthermore, elevated serum levels of bilirubin (p = 0.005) and decreased albumin (p = 0.004) affected the local antitumoral effect. A poor necrosis rate (< 25%) significantly correlated with the number of TACE procedures accomplished (p = 0.023). In conclusion, TACE provided an acceptable local antitumoral effect in patients scheduled for liver transplantation. Tumor necrosis depended significantly on the degree of arterial devascularization and the accumulation of Lipiodol within the HCC lesions. Unifocal tumors and preserved liver function were positive predictors for a more favorable local antitumoral effect. Poor necrosis rates were found in patients with significant Lipiodol washout and who received a limited number of TACE procedures.

[Transarterial chemoembolization (TACE) of the hepatocellular carcinoma (HCC) in patients with portal vein thrombosis--experiences]. / Transarterielle Chemoembolisation (TACE) des Hepatozellulären Karzinoms (HCC) bei Patienten mit Pfortaderthrombose--Erfahrungen.

PURPOSE: Comparative analysis of the course of disease in patients with initial diagnosis of portal vein thrombosis in HCC treated with sequential TACE. Evaluation of the efficacy and safety of the method in a selected patient cohort. PATIENTS AND METHODS: The study included 22 patients with HCC that were palliatively treated at least 3 times with TACE. All patients presented a portal vein thrombosis in the initial CT investigation. The TACE-procedure was carried out in regular intervals using a suspension consisting of a fixed dosage of Mitomycin C (10 mg) and 10-20 ml Lipiodol. Follow-up investigations were carried out with contrast enhanced Multislice-CT before and after TACE and control of the laboratory panel (i. e. blood count, liver enzymes and coagulation). RESULTS: Mean survival was 15.7 months (95%-CI 11.6-19.8) with a mean follow-up after last TACE of 6.1 +/- 4.8 months. The mean number of TACE procedures was 5.5 +/- 2.7. During the investigation period 17 / 22 (77.3%) patients died. In 23.5% retrospective analysis revealed a liver decompensation as the cause of death and in 58.8% patients died from the tumor disease. The cumulative 1-, 2- and 3-year survival was 55.0, 21.0 and 0%. The mean tumor size was 7.2 +/- 3.4 cm. Unifocal tumors were found in 18.2% of the cases whereas multifocal tumors were found in 81.8%. In 59.1% of the patients tumor extended to both liver lobes. In case of tumor infiltration of the portal vein survival was significantly worse compared to patients with no evidence of a tumor thrombosis (p = 0.01; cumulative 1- and 2-year survival 46% and 8% vs. 77% and 46%). CONCLUSION: The palliative treatment of the HCC with TACE shows an improvement of survival. There was no increase of death due to liver decompensation in our cohort. Patients with a tumor infiltration of the portal vein showed a significantly worsened survival. The presence of a portal vein thrombosis at the initial diagnosis of the HCC is not an absolute contraindication for TACE treatment but patients have to be elected carefully with critical regard to their liver function.

Transarterial chemoembolization (TACE) for inoperable intrahepatic cholangiocarcinoma.

The aim of this retrospective study was to determine the safety and efficacy of chemoembolization (TACE) as palliative treatment for patients with unresectable intrahepatic cholangiocarcinoma (CCA) and to compare the results with those in the literature. Fifteen patients with histology-proven CCA (5 men, 10 women) had received palliative treatment with TACE over a 6-year period. The treatment protocol comprised repeated TACE at a minimum of 8-week intervals. TACE was performed with a mixture of 10 ml Lipiodol and 10 mg mitomycin C injected into the tumor-supplying vessels. Follow-up investigations after 8-10 weeks comprised contrast-enhanced multislice spiral CT and laboratory control. Statistical evaluation included survival analysis using the Kaplan-Meier method. During the investigation period 58 TACEs (3.9 +/- 3.8; 1-15) were performed in 15 patients. Mean tumor size was 10.8 +/- 4.6 cm (range, 2.0-18.0 cm). Unifocal tumor disease was diagnosed in eight patients, and multifocal disease in seven. Mean survival was 21.1 months (95% CI, 9.4-32.5 months). At the end of the investigation period 3 patients are still alive, and 12 patients have died. The 1-, 2-, and 3-year survival rate was 51.3%, 27.5%, and 27.5% respectively. According to RECIST criteria interim best response to therapy was stable disease in 9 of 15 patients, a partial response in 1 of 15 patients, and tumor progression in 4 of 15 patients. No deaths and no acute liver failure occurred under TACE therapy. Major complications were observed in two patients, comprising anaphylactic shock owing to contrast medium administration in one and gastric ulceration due to lipiodol displacement in the second patient. These results demonstrate that TACE is a safe procedure with a moderate number of complications for patients suffering from inoperable CCA. According to recently published data on i.v. chemotherapy we suggest that TACE might be able to prolong survival in selected patients who would succumb under other palliative treatment modalities.