Early imaging signs associated with subsequent diagnosis of primary sclerosing cholangitis

BACKGROUND

Primary sclerosing cholangitis (PSC) is characterized by multifocal biliary strictures on MRI/MRCP. However, we have observed that young PSC patients often displayed a marked intrahepatic bile duct visibility, sometimes with gallbladder enlargement, before developing biliary strictures. This study aimed to evaluate whether this imaging pattern was associated with subsequent diagnosis of PSC.

PATIENTSAND METHODS

This retrospective two-center study included patients younger than 21 years who had a baseline liver MRI/MRCP, without biliary strictures. The endpoint was a definite diagnosis of large duct PSC during follow-up. The association of baseline imaging findings with the endpoint was evaluated by multivariable logistic regression, Cox models, and Kaplan-Meier analyses.

RESULTS

94 patients were included: 54% women, mean age of 16, 36% with IBD. Over a mean follow-up of 7.75 years, 21 patients were subsequently diagnosed with large duct PSC after a median time of 5.60 years. Marked intrahepatic bile duct visibility and gallbladder enlargement displayed good performance to predict the subsequent diagnosis of PSC (AUC, 0.77 and 0.69, respectively). The presence of both signs displayed a specificity of 1.00. In multivariable analyses, marked intrahepatic bile duct visibility and gallbladder enlargement were independently associated with subsequent PSC diagnosis (OR, 13.35; 95% CI, 3.00– 59.41; p < 0.001 and OR, 12.36; 95% CI, 1.93–79.09; p = 0.008, respectively) and shorter time to diagnosis (HR, 6.42; 95% CI, 1.99–20.75; p = 0.002 and HR, 3.36; 95% CI, 1.22–9.27; p = 0.019, respectively). Survival analyses confirmed the association between these two imaging signs and subsequent PSC diagnosis (HR, 7.78; 95% CI, 2.62–23.16; p < 0.001 and HR, 3.85; 95% CI, 1.64–9.08; p < 0.001, respectively).

CONCLUSIONS

In young patients without biliary strictures, marked intrahepatic bile duct visibility and gallbladder enlargement on MRI/MRCP were strongly associated with subsequent diagnosis of large duct PSC.

IMPACT AND IMPLICATIONS

Diagnosis of PSC relies on the presence of multifocal biliary strictures. However, early diagnosis of PSC is crucial since it could trigger earlier and more effective therapeutic interventions.

In young patients without biliary strictures, we identified two imaging signs significantly associated with the subsequent diagnosis of large duct PSC: marked intrahepatic bile duct visibility and gallbladder enlargement. These findings should encourage closer monitoring of young patients who display these imaging patterns.

HIGHLIGHTS

• Marked intrahepatic bile duct visibility can predict the subsequent diagnosis of large duct PSC.

• Gallbladder enlargement can predict the subsequent diagnosis of large duct PSC.

• These two signs were significantly associated with subsequent diagnosis of large duct PSC.