Ocular Blood Flow Measurements in Diabetic Retinopathy Using 3D Pseudocontinuous Arterial Spin Labeling.

Background: Distinguishing between the two broad categories of diabetic retinopathy (DR), nonproliferative DR (NPDR) and proliferative DR (PDR), is significant, as the therapeutic strategies for each are completely different. Purpose: To characterize the ocular blood flow (OBF) of DR patients and evaluate the potential utility of OBF values in categorizing DR. Study type: Prospective. Subjects: A total of 41 DR patients (82 eyes) were recruited in our study. Group 1 comprised 48 eyes with NPDR, and Group 2 comprised 34 eyes with PDR. Field strength/sequence: 3D pseudocontinuous arterial spin labeling (3D-pcASL) with two postlabeling delays (PLDs) was acquired at 3.0T MR. Assessment: OBF values were independently obtained by two doctors from the OBF map. Statistical tests: OBF values and clinical characteristics were compared between the groups using two-sample t-tests and chi-square tests. Receiver operating characteristic (ROC) curves were obtained, and the area under the curve (AUC) was calculated. The consistency of OBF values reported by the two doctors was evaluated using the intraclass correlation coefficient (ICC).

Results: OBF values at PLDs of 1.5 seconds and 2.5 seconds were significantly lower in Group 2 than in Group 1 (P < 0.05 for both PLDs). The OBF values of Group 2 showed a greater increase than those of Group 1 from PLD 1.5 to 2.5 seconds. The AUC of OBF at the 1.5 seconds PLD was 0.90, with a cutoff of 7.73 mL/min/100 g, and the AUC of the OBF at the 2.5 seconds PLD was 0.75, with a cutoff of 8.44 mL/min/100 g. The ICC between the two observers was 0.844 for the OBF at 1.5 seconds PLD and 0.872 for the OBF at 2.5 seconds PLD. Data

Conclusion: PDR can be differentiated from NPDR by the value of OBF as measured by 3D-pcASL. Level of evidence: 1 TECHNICAL EFFICACY STAGE: 1.