MRI T2-Weighted Imaging and Fat-Suppressed T2-Weighted Imaging Image Fusion Technology Improves Image Discriminability for the Evaluation of Anal Fistulas

Exploring the relationship between anal fistula and colorectal cancer based on Mendelian randomization and bioinformatics

The association between anal fistula patients and colorectal cancer, as well as the potential pathophysiological mechanisms, remains unclear. To explore the relationship between anal fistula and colorectal cancer and its potential mechanisms. Analysis of GEO and TCGA databases. Disease-related genes were also referenced from Coremine Medical, GeneCard and OMIM. Core hub genes were identified through protein-protein interaction analysis by intersecting differentially expressed genes from the datasets with disease data. On one hand, a prognostic model was developed using genes and its prognostic role was validated. On the other hand, the optimal diagnostic genes were selected through machine learning. Mendelian randomization (MR) analysis was conducted to explore the potential causal link between anal fistula and colorectal cancer. Thirteen core genes were identified (TMEM121B, PDGFRA, MID2, WNT10B, HOXD13, BARX1, SIX2, MMP1, SNAL1, CDKN2A, ITGB3, TIMP1, CALB2). Functional enrichment analysis revealed that the intersecting genes between anal fistula and colorectal cancer were associated with extracellular matrix components, signalling pathways, cell growth, protein modification, as well as important roles in cellular activities, tissue and organ development, and biological function maintenance. These genes were also involved in pathways related to Wnt signalling and colorectal cancer development. Prognostic analysis and immune infiltration analysis indicated a close relationship between core hub genes and the prognosis and immune infiltration in colorectal cancer. Machine learning showed that core genes played an essential role in the diagnostic differentiation of colorectal cancer. MR results suggested no causal relationship between anal fistula and colorectal cancer. This study identified shared core genes between anal fistula and colorectal cancer, involved in various pathways related to tumour development. These genes play crucial roles in prognosis and diagnosis.

An applicability study of rapid artificial intelligence-assisted compressed sensing (ACS) in anal fistula magnetic resonance imaging

Objective

To evaluate the applicability of artificial intelligence-assisted compressed sensing (ACS) to anal fistula magnetic resonance imaging (MRI).

Methods

51 patients were included in this study and underwent T2-weighted sequence of MRI examinations both with ACS and without ACS technology in a 3.0 T MR scanner. Subjective image quality scores, and objective image quality-related metrics including scanning time, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR), were evaluated and statistically compared between the images collected with and without ACS.

Results

No significant difference in the subjective image quality of lesion conspicuity was observed between the two groups. However, ACS MRI decreased the acquisition time with regard to control group (74.00 s vs. 156.00 s). Besides, SNR of perianal and muscle in the ACS group was significantly higher than that of the control group (164.07 ± 33.35 vs 130.81 ± 29.10, p < 0.001; 109.87 ± 22.01 vs 87.61 ± 17.95, p < 0.001; respectively). The CNR was significantly higher in the ACS group than in the control group (54.02 ± 23.98 vs 43.20 ± 21.00; p < 0.001). Moreover, the accuracy rate of the ACS groups in evaluating the direction and internal opening of the fistula was 88.89 %, exactly the same as that of the control group.

Conclusion

We demonstrated the applicability of using ACS to accelerate MR of anal fistulas with improved SNR and CNR. Meanwhile, the accuracy rates of the ACS group and the control were equivalent in evaluating the direction and internal opening of the fistula, based on the results of surgical exploration.

Magnetic Resonance Imaging of the Gastrointestinal Tract: Current Role, Recent Advancements and Future Prospectives

This review focuses on the role of magnetic resonance imaging (MRI) in the evaluation of the gastrointestinal tract (GI MRI), analyzing the major technical advances achieved in this field, such as diffusion-weighted imaging, molecular imaging, motility studies, and artificial intelligence. Today, MRI performed with the more advanced imaging techniques allows accurate assessment of many bowel diseases, particularly inflammatory bowel disease and rectal cancer; in most of these diseases, MRI is invaluable for diagnosis, staging, and disease monitoring under treatment. Several MRI parameters are currently considered activity biomarkers for inflammation and neoplastic disease. Furthermore, in younger patients with acute or chronic GI disease, MRI can be safely used for short-term follow-up studies in many critical clinical situations because it is radiation-free. MRI assessment of functional gastro-esophageal and small bowel disorders is still in its infancy but very promising, while it is well established and widely used for dynamic assessment of anorectal and pelvic floor dysfunction; MRI motility biomarkers have also been described. There are still some limitations to GI MRI related to high cost and limited accessibility. However, technical advances are expected, such as faster sequences, more specific intestinal contrast agents, AI analysis of MRI data, and possibly increased accessibility to GI MRI studies. Clinical interest in the evaluation of bowel disease using MRI is already very high, but is expected to increase significantly in the coming years.

MRI diagnose post-operative anastomotic leak in patients with rectal cancer: preliminary experience

BACKGROUND

Anastomotic leakage (AL) is one of the most serious postoperative complications after colorectal anastomosis. This study aims to evaluate the feasibility and diagnostic accuracy of magnetic resonance imaging (MRI) in the early detection of AL in patients with clinically suspected AL after rectal anterior resection.

METHODS

This was a prospective study including patients who underwent anterior resection and postoperative MRI examination. AL was diagnosed by comprehensive indictors, which were mainly confirmed by clinical signs, symptoms, and retrograde contrast enema (RCE) radiography. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of diagnosing AL with MRI were calculated.

RESULTS

In total, 347 patients received anterior resection for rectal cancer, and 28 patients were suspected to have AL. Finally, 23 patients were included and received MRI examination. The median time interval from surgery to MRI was 10 days (3-21 days). The median distance from anastomosis to anal verge was 4.0 cm (2.0-10 cm), and 11 patients underwent diverted ileostomy. Eighteen patients had an anastomotic leak, including one patient who had a pelvic abscess and five patients who had no evidence of AL in the MRI examination. The overall sensitivity and specificity were 94.4% (95% CI 70.6% to 99.7%) and 80% (95% CI 29.8% to 98.9%), respectively. The PPV was 0.94 (95% CI 0.71 to 0.99) and the NPV was 0.80 (95% CI 0.29 to 0.99). For patients who had anastomosis less than 5 cm, the diagnostic accuracy of MRI was 93.7% (15/16). T2-weighted imaging with fat suppression can effectively reveal the leak track.

CONCLUSIONS

The accuracy of plain MRI examination in diagnosing AL was favorable for patients with a suspected AL. T2-weighted imaging with fat suppression was the best imaging modality to diagnose AL. A multicenter prospective study with more samples is needed to further determine the safety and feasibility of MRI in the diagnosis of AL.

Comparison of contrast-enhanced fat-suppressed T1-3D-VIBE and T1-TSE MRI in evaluating anal fistula

OBJECTIVE

To evaluate the accuracy of contrast-enhanced (CE) fat-suppressed three-dimensional (3D) T1-weighted imaging with volumetric interpolated breath-hold examination (FS-T1-3D-VIBE) and fat-suppressed T1-weighted turbo spin echo (FS-T1-TSE) sequence in characteristics of anal fistula.

METHODS

One hundred and two patients underwent perianal CE-MRI examination on a 3T scanner including FS-T1-3D-VIBE and FS-T1-TSE sequences before surgery. The performance of each sequence was evaluated in terms of fistula classification, clarity of internal opening, number and position of internal openings including the distance between internal opening and anal verge, presence of secondary tracts and blind-ending sinus tracts. MRI findings were compared with surgical findings. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of fistula, gluteus maximus, and subcutaneous fat were compared between CE FS-T1-TSE and CE FS-T1-3D-VIBE.

RESULTS

Compared with CE FS-T1-TSE, CE FS-T1-3D-VIBE displayed more accurate in secondary tract, lithotomy position of the internal opening and the distance between internal opening and anal verge (P < 0.05). CE FS-T1-3D-VIBE was found superior to CE FS-T1-TSE in the clarity of the internal openings and in the diagnostic accuracy of blind-ending sinus tracts and complex fistulas in Standard Practice Task Force classification (P < 0.05). CE FS-T1-3D-VIBE achieved higher SNRs and CNRs in fistula and gluteus maximus than CE FS-T1-TSE (P ≤ 0.001).

CONCLUSION

CE-MRI of FS-T1-3D-VIBE might be a more valuable noninvasive technique than FS-T1-TSE to evaluate the anal fistula on evaluating the lithotomy position of internal opening, distance between internal opening and anal verge, clarity of internal opening, secondary tract, blind-ending sinus tract and classification of the complex fistula. The trial registration number for this prospective trial was Chi-TR1800020206 and the trial registration date was December 20, 2018.

Magnetic resonance imaging findings in patients with initial manifestations of perianal fistulas

BACKGROUND

Crohn's disease (CD) is a serious cause of perianal disease and the incidence is increasing in Saudi Arabia. MR imaging may document specific features that may help to foresee Crohn's disease in patients making an initial presentation.

OBJECTIVE

Present MR imaging findings of perianal fistulas in patients making an initial presentation.

DESIGN

Retrospective, observational.

SETTING

Radiology clinic in in Dhahran.

PATIENTS AND METHODS

All previously undiagnosed and untreated patients who presented for the first time to the outpatient clinics from September 2015-2018 with perianal fistulas were retrospectively evaluated. Previously diagnosed CD patients, post-surgical or intervention cases were excluded. Fistulas were categorized as low or high anal, simple or complex, and were graded per St. James University Hospital Classification. Imaging was interpreted by two experienced readers based on the Van Assche score.

MAIN OUTCOME MEASURES

Fistula features on MR imaging and diagnosis of CD.

SAMPLE SIZE

171 patients.

RESULTS

Of 171 patients, 139 (81.3%) were males with mean age of 37.2 (12.7) years; the 32 females had a mean age of 35.8 (10.6) years. Twenty-one patients (12.3%) had CD. Fourteen (40.4%) patients with complex fistulas had CD in comparison to only 5 (4.8%) simple fistula patients ( P=.0005). More than half of patients with complex and high anal fistulas had CD ( P=.0005). Females were more affected than males ( P=.0005).

CONCLUSION

Complex or high anal fistula on MR imaging may be the initial presentation of CD and warrant further work up to establish the diagnosis.

LIMITATIONS

Retrospective, small sample, single center, and short duration study.

CONFLICT OF INTEREST

None.

Network Pharmacology Reveals the Molecular Mechanism of Cuyuxunxi Prescription in Promoting Wound Healing in Patients with Anal Fistula

Background

The healing process of the surgical wound of anal fistulotomy is much slower because of the presence of stool within the wound. Cuyuxunxi (CYXX) prescription is a Chinese herbal fumigant that is being used to wash surgical wound after anal fistulotomy. This study aimed at investigating the molecular mechanism of CYXX prescription using a network pharmacology-based strategy.

Materials and Methods

The active compounds in each herbal medicine were retrieved from the traditional Chinese medicine systems pharmacology (TCMSP) database and in Traditional Chinese Medicine Integrated Database (TCMID) analysis platform based on the criteria of oral bioavailability ≥40% and drug-likeness ≥0.2. The disease-related target genes were extracted from the Comparative Toxicogenomics Database. Protein-protein interaction network was built for the overlapped genes as well as functional enrichment analysis. Finally, an ingredient-target genes-pathway network was built by integrating all information.

Results

A total of 375 chemical ingredients of the 5 main herbal medicines in CYXX prescription were retrieved from TCMSP database and TCMID. Among the 375 chemical ingredients, 59 were active compounds. Besides, 325 target genes for 16 active compounds in 3 herbal medicines were obtained. Functional enrichment analysis revealed that these overlapped genes were significantly related with immune response, biosynthesis of antibiotics, and complement and coagulation cascades. A comprehensive network which contains 133 nodes (8 disease nodes, 3 drug nodes, 8 ingredients, 103 target gene nodes, 7 GO nodes, and 4 pathway nodes) was built.

Conclusion

The network built in this study might aid in understanding the action mechanism of CYXX prescription at molecular level to pathway level.