Esophageal transit study using a sliding sum image: application to patients with probable and definite systemic...

Esophageal complication is common in systemic sclerosis (SSc), but scintigraphic transit patterns based on each subtype have not been understood well. The aim of this study was to develop a new algorithm for integrating a dynamic esophageal transit study and to apply the method to patients with SSc.

A total of 40 patients suspected of having SSc were examined by a dynamic esophageal transit study. The subtypes included 32 with definite SSc (15 limited cutaneous type and 17 diffuse cutaneous type) and 8 with probable SSc. The serial esophageal images were shifted and summed to a functional image (sliding sum image) and compared to a conventional condensed image analysis. Esophageal retention fraction at 90 s (R (90)) and half-time (T (1/2)) of transit were also measured.

The four patterns of the sliding sum image and condensed image agreed in all patients. Abnormal retention patterns were observed in none of the 8 (0%) patients with the probable SSc and in 15 of 32 (47%) patients with definite SSc (p = 0.014). The severity of scleroderma assessed by modified Rodnan skin thickness score correlated with that of esophageal retention R (90) (p = 0.04).

The sliding sum image is a simple and effective method for integrating esophageal transit. Patients with definite SSc and severe scleroderma had significantly higher retention patterns, while probable SSc patients showed no esophageal dysmotility.