Related Experiment Video
Updated: Jun 4, 2026
Shunt Surgery, Right Heart Catheterization, and Vascular Morphometry in a Rat Model for Flow-induced Pulmonary Arterial Hypertension
Published on: February 11, 2017
Fractal branching quantifies vascular changes and predicts survival in pulmonary hypertension: a proof of principle
Shahin Moledina1, Annemijn de Bruyn, Silvia Schievano
1Great Ormond Street Hospital, London, UK.
Objectives:
To develop a non-invasive method of assessing disease severity in pulmonary hypertension by quantifying the overall degree of vascular pruning using fractal geometry.
Design:
A retrospective analysis of ECG-gated CT pulmonary angiograms.
Setting:
A single national referral centre for the investigation and treatment of children with pulmonary hypertension.
Patients:
Consecutive CT pulmonary angiograms in children and young adults (mean age 10.3 years, range 0.7-19.1) with pulmonary arterial hypertension assessed between January 2007 and April 2009.
Main Outcome Measures:
The fractal dimension (FD) of skeletonised CT pulmonary angiograms was calculated using the box counting method. The FD was compared with pulmonary vascular resistance, the percentage of predicted 6-min walk distance, WHO functional class and survival.
Results:
Diagnostic plots confirmed that the pulmonary artery angiograms were all fractal. The FD correlated negatively with the pulmonary vascular resistance index (r=-0.55, p=0.01, n=21) and with WHO functional class (p<0.01, n=31) while it correlated positively with the percentage of predicted 6-min walk distance (r=0.43, p=0.04, n=24). A lower FD was associated with poorer survival (HR 5.6; 95% CI 1.2 to 25; p=0.027) for every SD reduction in FD.
Conclusion:
The FD derived from CT can be used to quantify vascular changes in pulmonary hypertension. This non-invasive technique may be useful in monitoring disease progression and response to therapy.
