4D flow MRI may reduce frequency of endoscopic screening for varices

In patients with liver cirrhosis, four-dimensional (4D) flow MRI can help indicate the risk of bleeding in gastroesophageal varices and reduce the need for invasive endoscopy procedures, wrote authors of an Oct. 16 Radiology study.

Patients with cirrhosis develop ruptured varices—a dangerous complication—at a rate of seven percent a year, wrote first author Utaroh Motosugi, with the University of Yamanashi in Japan, and colleagues. Invasive endoscopy is commonly used in these patients.

“Endoscopy is invasive and requires sedation with associated potential complications such as perforation, adverse reaction to sedation, infection and bleeding,” Motosugi et al. wrote. “Consequently, a quantitative and noninvasive method for evaluation of at-risk varices could improve patient care by decreasing such complications.”

A total of 23 participants with a mean age of 52 years old were scheduled for both liver MRI and gastroesophageal endoscopy. Patients were grouped at endoscopy according to their risk of variceal bleeding. Eight patients had no risk, eight were low-risk and seven high-risk.

Motosugi and colleagues found 4D flow MRI-based angiography allowed radiologists to view varices in four of 15 patients who had varices. Additionally, they found flow volume greater than 0.1 L/min in the azygos vein and fractional flow change in the main portal vein (PV) of less than zero to be independent indicators of high-risk.

“The results of our pilot study showed that noninvasive quantitative assessment of 4D flow MRI can be used to help detect gastroesophageal varices with high diagnostic accuracy,” the authors wrote. “In particular, flow measurement in the azygos vein and the fractional flow change in PV may be useful to distinguish patients with high-risk varices from patients with no varices or low-risk varices.

The team noted several limitations of their study including a small sample size and a time variance between endoscopy and MRI which could have caused differences in results due to disease progression, they wrote. However, Motosugi and colleagues believe 4D flow MRI can be useful to improve patient care.

“By including four-dimensional flow MRI in the MR protocol for the patients with cirrhosis, it may be possible to reduce the frequency of endoscopic screening for gastroesophageal varices,” the authors concluded.