Preliminary Discussion Of 3.0T Magnetic Resonance Quantitative ASL In Muscular Perfusion Imaging At Resting/Post-exercise Of The Calf Muscles Of Healthy Volunteers

The purpose of this study is to investigate the feasibility of 3.0T MRI quantitative ASL technique in the muscle at resting state and post-exercise non-enhanced perfusion imaging of healthy volunteers,to evaluate its clinical value in the perfusion imaging of skeletal muscle system,and to provide a simple and reliable method for functional imaging in skeletal muscle.31 healthy volunteers(a total of 62 calves)were randomly selected,including 22 males and 9 females,divided into(A and B)two groups.Group A: 17 volunteers(including 12 males,5 females)did ankle plantar flexion exercise.Group B: 14 volunteers(including 10 males and 4 females)did ankle dorsiflexion exercise.With the ultra-high magnetic field 3.0T MR quantitative ASL technology,the gastrocnemius muscle and the tibialis anterior muscle were scanned,observed and recorded at the maximal cross-section(about the upper 1/4 level).The perfusion images of the two groups observed at rest and at 0 min after exercise with blood flow parameters calculated by ASL post-processing software.The tibialis anterior muscle and gastrocnemius muscle perfusion parameters of 31 of 62 calves were compared by two-sample t-test.The tibialis anterior muscle and gastrocnemius muscle perfusion parameters were compared of 34 calves at 0 min after ankle plantar flexion movement exercise.The tibialis anterior muscle and gastrocnemius muscle perfusion parameters were compared of 28 calves after ankle dorsiflexion exercise,to observe the skeletal muscle imaging at different states.Group C: Another five male patients with clinically diagnosed lower extremity arteriosclerotic obliterans were selected.2 patients underwent ankle joint plantar flexion;the other 3 had ankle dorsiflexion,and the perfusion images were collected in the same condition.62 calves were successfully completed the non-enhanced quantitative ASL examination,obtaining 34 images of the blood perfusion of the calf muscles at resting state and at 0 min after ankle plantar flexion,and obtaining 28 images of the blood perfusion of the lower leg muscles at resting and at 0 min after ankle dorsiflexion.62 calves were incorporated in the statistical data,without motion artifacts.Among the 62 calves,the resting state of the gastrocnemius and tibialis anterior muscle perfusion consistent with the normal distribution;there was no significant difference in tibial anterior muscle and gastrocnemius muscle perfusion at rest(t=1.269,P>0.05).Group A:(1)The blood perfusion of the gastrocnemius muscle was significantly higher than that of the tibialis anterior muscle(t=81.030,P<0.05).(2)The blood perfusion of the gastrocnemius muscle was significantly higher than that of the adjacent muscle group,and there was a clear boundary between the gastrocnemius muscle and the adjacent muscle.Group B:(1)The blood perfusion of the tibialis anterior muscle was significantly higher than that of the gastrocnemius muscle(t=105.374,P<0.05),and there was significant difference in blood perfusion of the gastrocnemius muscle after exercise.(2)The blood perfusion of the tibialis anterior muscle was significantly higher than that of the adjacent muscle group,and there was a clear boundary between the tibialis anterior muscle and the adjacent muscle.Group C: After the 2 min ankle joint plantar flexion or dorsiflexion,5 patients had muscle pain at varying degrees,at different parts of the lower leg.After the movement the soreness persisted,including 1 patient with a slight tremor.After exercise,5 cases of calf muscle perfusion were lower than the same state of the normal blood flow perfusion,of which 4 patients had significantly different blood flow perfusion between their bilateral calf muscles.In the skeletal muscle perfusion imaging,quantitative ASL technology can not only quantitatively measure the blood perfusion of skeletal muscle without exogenous contrast agent,but also repeatedly measure the blood perfusion of skeletal muscle in a short time.Therefore,ASL technology is a safe non-invasive,accurate,reliable and good repeatability of the new perfusion examination method,and can provide the objective image data for the clinical detection of perfusion of skeletal muscle system.