BackgroundThe importance of discriminating acute from non-acute thrombus is highlighted. The study aims to investigate the feasibility of readout-segmented diffusion weighted (DW) cardiovascular magnetic resonance (CMR) for discrimination of acute from non-acute deep venous thrombus (DVT).MethodsFor this prospective study from December 2015 to December 2017, 85 participants (mean age=53years, age range=3474) with DVT of lower extremities underwent readout-segmented DW CMR. DVT of <= 14days were defined as acute (n=55) and>14days as non-acute (n=30). DVT visualization on b=0, b=800, and apparent diffusion coefficient (ADC) images were assessed using a 4-point scale (03, poorexcellent). DW CMR parameters were measured using region of interest (ROI). Relative signal intensity (rSI) and ADC were compared between acute and non-acute DVT using a Mann Whitney test. Sensitivity and specificity for ADC and rSI were calculated.ResultsADC maps had higher visualization scores than b=0 and b=800 images (2.70.5, 2.50.6, and 2.4 +/- 0.6 respectively, P<0.05). The mean ADC was higher in acute DVT than non-acute DVT (0.56 +/- 0.17x10(-3) vs. 0.22 +/- 0.12x10(-3)mm(2)/s, P<0.001). Using 0.32x10(-3)mm(2)/s as the cutoff, sensitivity and specificity for ADC to discriminate acute from non-acute DVT were 93 and 90% respectively. Sensitivity and specificity were 73 and 60% for rSI on b=0, and 75 and 63% for rSI on b=800.Conclusions Readout segmented diffusion-weighted CMR derived ADC distinguishes acute from non-acute DVT.Trial registration This study is retrospectively registered. Trial registration number: HUST-TJH-2015-146.