The alterations of the sigmoid-rectal junction in diverticular disease of the colon revealed by MR-defecography

Magnetic Resonance Imaging for the diagnosis and management of acute colonic diverticulitis: a review of current and future use

Diverticular disease is one of the most common causes of outpatient visits and hospitalisations across Australia, North America and Europe. According to the Gastroenterological Society of Australia (GESA, 2010), approximately 33% of Australians over 45 years of age and 66% over 85 years of age have some form of colonic diverticulosis. Patients with colonic diverticulosis are known to develop subsequent complications such as acute colonic diverticulitis (ACD), and when more than one attack of diverticulitis occurs, there is a 70-90% chance that the individual will experience ongoing problems and recurring infections throughout their lifetime. Medical imaging is fundamental in the diagnosis, treatment and ongoing management of ACD and its complications, with Computed Tomography (CT) identified as the prevailing gold standard in the last few decades. Cross-database searching highlighted a large gap in the literature regarding the effectiveness of Magnetic Resonance Imaging (MRI) as a non-ionising radiation alternative imaging tool for ACD imaging after the mid-2000s, despite ongoing technological advancements in this modality. This narrative review identified 13 key publications (11 primary prospective cohort studies, 1 systematic review and 1 meta-analysis) that evaluate MRI for ACD imaging, of which five were published within the last decade. Several existing MRI protocols are deemed suitable for ACD imaging, and it is recommended they be re-evaluated in larger cohorts. Future studies should consider the rapidly growing technological improvements of MRI, its cost efficiency and its applicability in modern day healthcare settings when addressing ACD management. This is especially important considering the gradual rise in radiation dose among the Australian population attributable to increased CT referrals, alongside increased reporting of ACD cases in younger individuals.

Changing theories on the pathogenesis and risk factors for diverticulitis

Diverticulitis was thought to be a simple complication of an even simpler disease (diverticulosis), but may in fact result from an entirely new set of complex pathologies. Considering diverticulitis is increasing in annual incidence and becoming more prevalent in younger populations, the implications of appropriate management become more vital than ever. This article reviews old and new understandings of diverticulitis and current recommendations for prevention and clinical management.

Application of dynamic MRI defecography in diagnosis of outlet obstructive constipation

AIM

To assess the application value of dynamic magnetic resonance imaging (MRI) defecography in the diagnosis of outlet obstructive constipation (OCC).

METHODS

Forty-eight patients with suspected OOC at Third Affiliated Hospital of Nanchang University from March 2016 to February 2018 were selected, and they underwent dynamic MRI defecography and X-ray defecography. The situations of dynamic MRI defecography and X-ray defecography were recorded. Using X-ray defecography as the standard, the specificity, sensitivity, negative predictive value, and positive predictive value of dynamic MRI defecography were calculated.

RESULTS

There was no statistical difference in the diagnosis of intersigmoid hernia, puborectalis spasm, hernia, or internal hemorrhoid between dynamic MRI defecography and X-ray defecography (P > 0.05). The detection rates of dynamic MRI defecography in the diagnosis of rectocele, rectal mucosal prolapse, perinaeum descent, intrarectal invaginate, and sigmoid colon zigzagging were lower than those of X-ray defecography (P < 0.05). Dynamic MRI defecography could find lesions that cannot be displayed by X-ray defecography, including muscular rupture, uterine fibroid, cervical accepts cyst, sacral cyst, and mullerian duct cyst. Using X-ray defecography as the gold standard, the specificity and positive predictive value of dynamic MRI defecography in the diagnosis of rectal mucosal prolapse, rectocele, puborectalis spasm, intrarectal invaginate, intersigmoid hernia, hernia, sigmoid colon zigzagging, and perinaeum descent were all 100.00%; the sensitivity and positive predictive value for different diseases had a significant difference, the positive predictive value was generally higher, and the sensitivity was usually lower.

CONCLUSION

MRI and X-ray defecography have their own advantages in the diagnosis of OOC. Dynamic MRI defecography can provide information on the pelvic organ and pelvic wall, pelvic floor function, and morphological structure, and it is a good supplement to X-ray defecography. Dynamic MRI defecography can provide guidance for overall evaluation and comprehensive diagnosis of OOC with pelvic multiple-organ lesions.

Colonic wall changes in patients with diverticular disease - is there a predisposition for a complicated course?

BACKGROUND

The aim of this study was to evaluate colonic wall changes and enteric neuropathy in patients with either uncomplicated (UDD) or complicated diverticular disease (CDD). Furthermore, we evaluated the presence of an anatomic sphincter at the rectosigmoid junction (RSJ).

METHODS

Samples of colonic tissue from fifteen patients with UDD, fifteen patients with CDD and fifteen patients as control were collected. Collagen quotient I/III was measured with the Sirius-red test, expression of MMP-1, MMP-13, innervation (S100), proliferation (Ki67) and apoptosis (TUNEL) in the colonic wall were investigated by immunohistochemical studies. Furthermore, measurements of the different layers were performed to investigate the RSJ.

RESULTS

Patients with either UDD or CDD had lower collagen I/III quotients compared to the control group, significant for CDD (p = 0.007). For MMP-1 and MMP-13 only a slight increase for patients with CDD was found. The percentage of proliferating (Ki67) and apoptotic (TUNEL) cells was significantly higher for patients with CDD than in the control group (p = 0.016; p = 0.037). Upon investigating the S100-expression a significant reduce in glial cells density was found in the myenteric and mucosal plexus for both groups (UDD and CDD) compared to the control group. Measurements of the different colon layers oral, aboral and at the RSJ revealed equal values.

CONCLUSIONS

This study has shown that colonic wall changes and enteric neuropathy seem to play a role in the pathogenesis of colonic diverticulosis. None of our results suggest a predisposition for a complicated diverticular disease. Furthermore, the presence of an anatomic sphincter at the rectosigmoid junction could not be detected.