Patterns of splenic arterial enhancement on computed tomography scan are related to portal venous hypertension.

OBJECTIVES: We have previously shown that patterns of splenic arterial enhancement on computed tomography scan change following liver transplantation. We suggested that this is related to changes in portal venous pressure. The aim of this study was to see if similar patterns occur in patients with and without portal hypertension and in patients before and after portal systemic shunts (transjugular portosystemic shunts). METHODS: We evaluated contrast enhanced computed tomography scans in patients being evaluated for liver disease and compared those from patients with and without portal hypertension. In addition we evaluated patients who had computed tomography scans before and after transjugular portosystemic shunts shunts. Splenic arterial enhancement was evaluated using Hounsfield units (pixel counts). RESULTS: Twenty-four patients with clinically significant portal hypertension were compared to 91 without. Mean splenic pixel count was significantly lower in patients with clinically significant portal hypertension (88.2 ± 17.7 vs. 115.2 ± 21.0; m ± SD, P < 0.01). Computed tomography scans were available in 18 patients pre- and post-transjugular portosystemic shunts. Pixel counts were significantly higher in the post-transjugular portosystemic shunts scans (99.7 ± 20.9 vs. 88.9 ± 26.3; P < 0.05). CONCLUSION: This study supports the hypothesis that changes in portal venous pressure are related to changes in splenic arterial enhancement. We suggest that this reflects changes in the splenic micro-circulation. This mechanism may be part of the innate immune response and may also be important in the pathogenesis of hypersplenism.

Finding evidence-based answers to practical questions in radiology: which patients with inoperable hepatocellular carcinoma will survive longer after transarterial chemoembolization?

To some, evidence-based practice (EBP) means the identification of centers that produce evidence reports and technology assessments to support guideline development. To others, EBP is the best research evidence integrated with clinical expertise and patient values. Inherent in the first approach is the implication that only central academic organizations can produce valid, reliable analyses of existing literature, which will then be distributed to ordinary practitioners. The second approach implies that ordinary practitioners can learn to use a stepwise approach and a preprepared set of rules and tools to effectively find the best current literature, appraise it, and then apply local circumstances to these rules and tools in their hospital. Paul Glasziou, director of the Centre for Evidence-based Practice in Oxford, England, has coined the phrases top-down EBP and bottom-up EBP to describe these approaches. In this article, the authors describe how knowledge gaps in an ordinary radiology practice can be addressed by using stepwise bottom-up EBP techniques. The following clinical scenario is used: Your hospital's recently appointed chief hepatobiliary surgeon questions the use of transarterial chemoembolization for inoperable hepatocellular carcinoma because of his concerns after reading a recent review article suggesting that there is no clear survival benefit to using this procedure. What would you do? Here is how the authors would do it.