Chronic intestinal pseudo-obstruction (CIPO) is a severe and refractory intestinal motility disorder whose diagnosis currently relies on subjective imaging assessments. Cine magnetic resonance imaging (MRI) may potentially improve the quantitative analysis of gastrointestinal motility; however, suitable CIPO detection parameters should be determined. Cine MRI was performed in seven patients with CIPO and 11 healthy controls. The logarithm of the Mahalanobis distance (x(1)) and distance variation per time (x(2)) were used as the original parameters to determine CIPO diagnostic thresholds. Furthermore, the correlation between cine MRI findings and CIPO severity was investigated. Threshold values of alpha = 1.10 and beta = 0.15 for x(1) and x(2), respectively, produced a CIPO diagnosis sensitivity of 1.00 (7/7) and specificity of 0.82 (9/11). The resulting error was 0.11 (2/18). The two parameters were correlated (Pearson's correlation coefficient: - 0.52). Any of the intestinal tracts of patients with severe CIPO requiring home parenteral nutrition belonged to the region defined by x(1) >= 1.10 and x(2) <= 0.15. Cine MRI is effective for the quantitative evaluation of small intestinal motility and CIPO diagnosis when using the abovementioned parameters and can be useful for treatment decision-making. However, these parameters have a wide distribution in healthy volunteers; this may complicate the detection of other disorders.

Background Chronic intestinal pseudo-obstruction (CIPO) is a severe and refractory intestinal motility disorder. However, due to its rarity and difficult histological investigation, its pathophysiology has not been characterized. Aim Therefore, in this study, we aimed to determine the role of esophageal high-resolution manometry (HRM) in CIPO and the histological and clinical characteristics of the disease. Methods Patients with CIPO were analyzed for clinical characteristics; histological findings; and clinical courses after therapeutic intervention. In addition, HRM was performed to determine the esophageal involvement. Results Eleven patients were diagnosed with CIPO, and five required the long period of parenteral nutrition showing impaired esophageal motility including achalasia and absent contractility diagnosed with HRM. The four of these five cases showed acute onset of the CIPO following the triggering events of pregnancy, appendicitis, and surgery. In contrast, other six patients with normal or Jackhammer esophagus on HRM had moderate severity of CIPO with gradual onset. The histological analyses revealed that the loss of the intestinal neural ganglion cells and layers by inflammation, destruction, and atrophy are related to the severity of the clinical course of the disease and esophageal HRM findings of achalasia and absent contractility. Conclusions HRM may be useful to diagnose the severity of the clinical course and to determine the therapeutic options for CIPO.