Evaluation of delayed gastric emptying in diabetic patients with autonomic neuropathy by a new magnetic resonance imaging technique and radio-opaque markers.

OBJECTIVE

Our objective was to validate a new noninvasive magnetic resonance imaging (MRI) technique for diagnosis of delayed gastric emptying by using radio-opaque markers (ROMs) in diabetic patients with and without cardiovascular autonomic (CAN) and peripheral sensomotoric neuropathy (PSN).

RESEARCH DESIGN AND METHODS

Fifteen diabetic outpatients were recruited, eight with CAN and PSN (group A, age 28-61 years, mean diabetes duration 27 years) and seven without CAN (group B, age 28-60 years, mean diabetes duration 16 years). Gastric emptying and motility were assessed with ROMs and MRI in random order. After an overnight fast either a test meal (451 kcal) containing a capsule with 10 ROMs is eaten and a supine plain abdominal X ray is taken after 6 h or 500 ml intralipid 10% (550 kcal) is swallowed for the MRI study, using a 1.5 Tesla Gyroscan ACS II (Philips, Eindohoven, The Netherlands). Computer-assisted segmentation of images was used to measure gastric emptying (T1/2, min) over 125 min, contraction frequency (F, min-1), mean contraction amplitude (CA, % basal), and velocity (V, cm/s). Blood glucose was kept constant at 5.0-8.0 mmol/l.

RESULTS

In group A, 6.1 +/- 1.36 ROMs (mean +/- SE) were retained in the stomach after 6 h and 0 ROM in group B, indicating a significant delay of gastric emptying in patients with CAN. The MRI study revealed a significantly longer gastric emptying (P < 0.005) in group A (T1/2 = 124 +/- 10 min) as compared with group B (T1/2 = 85 +/- 18 min). There was no difference in F, CA, and V between the two groups: F 2.9 +/- 0.07 and 2.7 +/- 0.1 (min-1), CA 26.8 +/- 1.2 and 29.6 +/- 1.6 (% basal), V 0.43 +/- 0.02 and 0.40 +/- 0.02 (cm/s), respectively.

CONCLUSIONS

MRI offers the possibility of visualizing and examining exactly the mechanisms responsible for gastric emptying and is characterized by a high specificity but a lower sensitivity as compared with ROMs, which proved to be an ideal screening test for diagnosis of gastroparesis in clinical practice.