Cine magnetic resonance imaging for quantitative assessment of healthy volunteers and patients with organic small bowel disease ⁎

Abstract

Abstract Objective The aim of the study was to use dynamic magnetic resonance imaging (MRI) to compare quantitative parameters of small bowel motility between healthy volunteers and patients with small bowel diseases in order to investigate the characteristics of normal and impaired bowel peristalsis. Methods A total of 44 healthy volunteers (20 men, 24 women; mean age: 36 years; range: 20-61 years) and 42 patients (28 men, 14 women; mean age: 44 years; range: 15-72 years) with organic small bowel disease were recruited in our hospital (Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China) in this prospective study approved by the hospital institutional review board. Imaging was performed using a 3.0-T scanner 45 minutes after standardized oral administration of 1500 mL non-absorbable fluid (2.5% mannitol). A serial coronal scan was performed at selected planes for two minutes without breath-hold. Time-caliber curves were plotted at two well-distended small bowel loops in both healthy and patient groups regardless of location. Luminal diameter (LD), contraction period (CP), frequency of contraction (FC), and amplitude-diameter ratio (ADR) were measured based on the graph. Results The characteristics of abnormal peristaltic parameters were assessed in different patients and compared to normal curves from healthy volunteers. A total of 37 segments with abnormal motility were confirmed by two readers in consensus, based on curve patterns and the presence of a stationary phase. Compared to normal peristalsis in healthy volunteers, five different patterns of impaired peristalsis were identified: I, consecutive; II, slow; III, giant type; IV, uncoordinated; and V, akinetic. Dilated LDs were detected in all instances of abnormal peristalsis (P < 0.05). Increased frequency was found in type I [(8.73 ± 1.15) /min], while decreased frequency was detected in type III peristalsis [(0.67 ± 0.29) /min]. There were no significant differences in frequency between type II [(3.19 ± 0.43) /min] and normal peristalsis [(3.45 ± 0.57) /min]. Apart from type I [(8.70 ± 0.75) /min], increased FCs were found in all other abnormal patterns. In type II peristalsis, the average ADR value was 0.82 ± 0.08, comparable to the ADR value in the healthy group (0.83 ± 0.13). Conclusion MR cine is an effective method for differentiating normal and abnormal small bowel peristalsis. Plotting time-caliber curves and measuring quantitative MR cine parameters such as LD, CP, FC, and ADR offers more precise information about small bowel motility.