RT Journal Article
SR Electronic
T1 Fractal branching quantifies vascular changes and predicts survival in pulmonary hypertension: a proof of principle study
JF Heart
JO Heart
FD BMJ Publishing Group Ltd and British Cardiovascular Society
SP 1245
OP 1249
DO 10.1136/hrt.2010.214130
VO 97
IS 15
A1 Shahin Moledina
A1 Annemijn de Bruyn
A1 Silvia Schievano
A1 Catherine M Owens
A1 Carol Young
A1 Sheila G Haworth
A1 Andrew M Taylor
A1 Ingram Schulze-Neick
A1 Vivek Muthurangu
YR 2011
UL http://heart.bmj.com/content/97/15/1245.abstract
AB 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.