CT Rule-in and Rule-out Criteria for Clinically Significant Portal Hypertension in Chronic Liver
Disease
https://doi.org/10.1148/radiol.231208
Portal hypertension is an haemodynamic abnormality that usually results from cirrhosis, leading to a variety of complications, including ascites, hepatic encephalopathy, and bleeding from gastroesophageal varices. Clinically significant portal hypertension (CSPH), defined as hepatic venous pressure gradient (HVPG) ≥ 10 mmHg, represents a significant milestone in the natural history of chronic liver disease (CLD), associated with increased morbidity and mortality after liver resection. Although HVPG measurement is the gold standard for diagnosing CSPH, it is invasive and limited to specialized centers. Consequently, there has been great interest in developing noninvasive methods to diagnose CSPH. Currently, transient elastography is the most validated non-invasive method for detecting CSPH; however, CT is widely used to evaluate patients with CLD, and although it may not be the primary method for detecting CSPH, it may provide valuable opportunistic information on portal hypertension. This is a retrospective study focused on assessing the performance of CT-based detection of well-known signs of portal hypertension; namely the presence of splenomegaly, gastroesophageal varices, spontaneous portosystemic shunt (SPSS), and ascites and to determine whether these CT findings alone or in combination can be used to rule in or rule out CSPH in patients with CLD. The final sample comprised 235 patients from a database of two tertiary institutions from January 2001 to December 2019, of which 110 (46.8%) had CSPH and 125 (53.2%) did not. The inclusion criteria were: patients with CLD and age greater than or equal to 18 years having undergone contrast-enhanced CT within 3 months prior to HVPG measurement. The exclusion criteria were: prior liver or spleen surgery, prior treatment for portal hypertension, unreliable HVPG measurement, infiltrative liver disease, and inadequate CT for volume measurement. Two readers independently evaluated the presence of gastroesophageal varix, spontaneous portosystemic shunt (SPSS), and ascites on CT images. Splenomegaly at CT was determined using three methods: personalized or fixed volume criteria, based on spleen volume as measured by a deep learning algorithm, or manually measured spleen diameter. This study demonstrated that the presence of gastroesophageal varix, SPSS, and ascites on CT images had high specificity (range, 93.6%– 96.8%) but low sensitivity (range, 44.5%–78.2%) for diagnosing CSPH. Notably, the presence of both splenomegaly and any one or more of gastroesophageal varix, SPSS, or ascites reliably ruled in CSPH with high specificity (range, 94.4%–97.6%) and positive predictive value (range, 92.1%–96.1%). The presence of at least one of these findings could enable the identification of CSPH with high sensitivity (range, 94.5%– 98.2%) and negative predictive value (range, 94.1%–97.8%). Hence, the absence of these findings enabled a reliable rule-out diagnosis of CSPH. The study also proved that assessment of spleen volume is advantageous for detecting CSPH compared with measuring spleen diameter, and above all, personalized volume criterion achieved higher sensitivities (range, 67.3%–87.3%). However, when splenomegaly alone was used to detect CSPH, the personalized volume criterion showed the lowest specificity (76.8% for both readers) compared with the other criteria (range, 84.0%–85.6%; P < .001 for all). This finding suggests that splenomegaly alone is not a specific finding for diagnosing CSPH agreeing with previous research showing that spleen volume can increase even in the early stages of liver fibrosis before the development of liver cirrhosis and potential onset of CSPH. The authors acknowledge some limitations to this study: its retrospective design with a probable selection bias; the fact that HVPG measurement is not part of routine workup for patients with CLD that might result in a study sample not representative of the general population with CLD; the choice to measure axial spleen diameter might have affected the performance of the spleen diameter criterion in determining CSPH; and for last, there was no comparison with transient elastography and, thus, future studies are necessary to determine which non-invasive method shows the best performance for diagnosing CSPH. In conclusion, the presence or absence of splenomegaly, gastroesophageal varix, spontaneous portosystemic shunt, or ascites at CT could be a useful non-invasive tool for ruling in or ruling out CSPH in patients with CLD.
References:
1. Iranmanesh P, Vazquez O, Terraz S, et al. Accurate computed tomography-based portal pressure assessment in patients with hepatocellular carcinoma. J Hepatol 2014;60(5):969–974.
2. Son JH, Lee SS, Lee Y, et al. Assessment of liver fibrosis severity using computed tomography-based liver and spleen volumetric indices in patients with chronic liver disease. Eur Radiol 2020;30(6):3486–3496.
3. Engelmann C, Clària J, Szabo G, Bosch J, Bernardi M. Pathophysiology of decompensated cirrhosis: Portal hypertension, circulatory dysfunction, inflammation, metabolism and mitochondrial dysfunction. J Hepatol 2021;75(Suppl 1):S49–S66.
4. de Franchis R, Bosch J, Garcia-Tsao G, Reiberger T, Ripoll C; Baveno VII Faculty. Baveno VII - Renewing consensus in portal hypertension. J Hepatol 2022;76(4):959–974. [Published correction appears in J Hepatol 2022;77(1):271.]
Fabiana Muñoz is a first-year radiology resident at “Unidade Local de Saúde do Alto Minho (ULSAM)” in Viana do Castelo, Portugal. She completed her undergraduate medical degree at “Faculty of Medicine of Lisbon University”; and has a wide range of interests in diagnostic imaging, including abdominal, gastrointestinal, and urogenital radiology.