Evaluation Of Perianal Fistulas Research Articles

Comparing the Efficacy of a Combination of Diffusion-Weighted Imaging and T2-STIR (Short Tau Inversion Recovery) Imaging With Contrast-Enhanced MRI in the Evaluation of Perianal Fistula.

Perianal fistula is clinically diagnosed and commonly characterized using magnetic resonance imaging (MRI). Diffusion-weighted imaging (DWI) and T2-weighted imaging are emerging techniques that can obviate the need for contrast injection in cases where contrast administration is not feasible or contraindicated. The main objective of our study was to compare the efficacy of the combination of DWI and T2 STIR (short tau inversion recovery) imaging with contrast-enhanced MRI for the diagnosis and characterization of perianal fistula. Sixty-nine patients with clinical perianal fistula with at least one external opening were evaluated with DWI, T2 STIR, and contrast MRI. A comparative cross-sectional study was conducted in the Department of Radiodiagnosis and Imaging, All India Institute of Medical Sciences, Bhopal, India. The chi-square test was done to find the association between categorical variables. The Kappa test was done to estimate the agreement between two different tests in measuring the outcome. The validity of tests was measured using sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. The combination of DWI and T2 STIR is equivalent to contrast-enhanced MRI in the evaluation of primary and complicated perianal fistula. The combination of DWI and T2 STIR is superior to DWI alone in the classification and characterization of perianal fistula. However, DWI is superior to T2 STIR in differentiating perianal inflammation with abscess from perianal inflammation without abscess and can be used as an alternative to post-contrast fat-suppressed T1-WI in the detection of perianal abscesses and disease activity. DWI can be used as an adjunct to T2 STIR, and the combination of DWI and T2 STIR can replace the post-contrast fat-suppressed T1 MRI sequence in the classification and characterization of perianal fistula.

Added Value of Diffusion Weighted Magnetic Resonance Imaging in ‎evaluation of Perianal Fistula at Zagazig University Hospitals

Added Value of Diffusion Weighted Magnetic Resonance Imaging in ‎evaluation of Perianal Fistula at Zagazig University Hospitals

Comparison of Contrast-Enhanced 3D Imaging with 2D Imaging in the Evaluation of Perianal Fistula at 3T: A Prospective Observational Study.

Introduction Perianal fistula and its recurrence is a challenging entity for surgeons. It is a well-establi1shed fact that magnetic resonance imaging (MRI) findings influence surgical procedures and reduce the rate of recurrence. In this study, we assessed the contrast-enhanced (CE) three dimensional T1 sequences [sampling perfection with application optimized contrast using different flip angle evolution (SPACE) and volumetric interpolated breath-hold examination (VIBE)] in a 3T MRI system to evaluate perianal fistulas and compared them with two-dimensional (2D) sequences. Materials and Methods Forty-four patients (mean age, 38.8 ± 15.3 [standard deviation]; 32 males, 12 females) with perianal fistula were included in this prospective study. The patients underwent conventional noncontrast, 2D sequences, diffusion-weighted imaging, followed by postcontrast, 2D T1 images in both axial and coronal planes, and 3D sequences at 3T. Acquisition times were recorded for each sequence. Each postcontrast sequence was evaluated in terms of image quality, presence of artifacts, fistula type, presence of an abscess, visibility, and number of internal orifices. The surgical findings were considered the gold standard. The imaging findings were compared with the surgical findings. Results In all three sequences, the fistula type and abscess were identified correctly in all patients. The sensitivity value for identification of ramifications utilizing CE 3D T1 VIBE sequence, CE 3D T1 SPACE, and CE 2D T1 images was 100, 86, and 36%, respectively. The number of internal orifices was identified by the CE 3D T1 VIBE and CE 3D T1 SPACE sequences in 100 and 92% of patients, respectively. CE 2D T1 images correctly identified internal orifices in 80% of patients. The overall scan time for each 3D sequence was shorter than for the combined postcontrast 2D sequences. Conclusion CE 3D T1 SPACE and CE 3D T1 VIBE sequences outperformed conventional CE 2D sequences in the evaluation of perianal fistulas in terms of visibility and the number of internal orifices with a shorter scanning time. Among the 3D sequences, CE 3D T1 VIBE is slightly superior to CE 3D T1 SPACE sequence.

Magnetic Resonance Imaging (MRI) Evaluation of Perianal Fistula with Surgical Correlation

Objective: This study's goal was evaluate the part magnetic resonance imaging plays in the identification and classification in perianal fistulas to contrast those results with those from surgery. Study Design: Cross Sectional Place & Duration: Study carried out between the periods of January 2022 to Aug 2022 Material & methods: This study was tested on 50 patients in the hospital. Patients who had undergone MRI pelvis with or without contrast study were counted in the current study. Patients who undergone surgery prior or had recurrent perianal illness were not included in the study. Short T1 inversion recovery, T2 weighted (T2W) sagittal, axial, and coronal MRI sequences (STIR), T1W axial, and coronal sequences, and T1W post contrast axial & coronal sequences were all evaluated. Results Reflected: while evaluation by MRI, among 50 patients, 45 which is 90% were man and 5 which is 10% were female gender. In 45 (90%) of the 50 patients overall, postoperative results confirmed perianal fistula. A total of 5(10%) patients had perianal sinus only. The primary tract was found to have a sensitivity and specificity of 97.73% and 83.33%, respectively, whereas the abscess had a sensitivity and specificity of 88.89% and 95.12%. High sensitivity was also acknowledged for accurately locating the internal opening (95.45%), detecting the horseshoeing (90.91%), correctly identifying the secondary ramification (92.86%) with specificity (94.44%). Conclusion: It is found that MRI demonstrated superior performance in evaluating perianal fistula with critical parameters (primary tract and its grading, internal opening, secondary ramification, abscess, horseshoeing). Pre-operative perianal fistula assessment should be correct to prevent problems and recurrence, which will decrease the need for additional surgeries. Practical Implication: As a result of this study, unnecessary radiation and diagnostic time could be avoided in the preoperative assessment of PAF in ano using MRI. It would also help decrease complications and unnecessary surgeries. Keywords: Magnetic Resonance Imaging and Perianal Fistula, perianal sinus, horseshoeing

Role of MR Fistulography Combined with Diffusion-Weighted Magnetic Resonance Imaging in Evaluation of Perianal Fistula

Role of MR Fistulography Combined with Diffusion-Weighted Magnetic Resonance Imaging in Evaluation of Perianal Fistula

Magnetic resonance imaging for fistulography in perianal fistula: clinicoradiological correlation

Background: This article aims to review the role of magnetic resonance imaging (MRI) fistulography in evaluation of perianal fistula along with its concordance with clinical examination and impact on surgical intervention.Methods: A retrospective study of 61 patients who underwent surgery for anal fistula in RMLIMS collected from database from January 1, 2017 to September, 2021Results: The study showed a significant MRI contribution to clinical evaluation in 65.6%. MRI provided significant information for complex fistu­las than for simple fistulas (45% vs. 14.6%, p=0.01). Proportion of patients with sig­nificant MRI contribution increased with in­creasing Parks grade (grade 1, 8.3%; grade 2, 52.2%, p=0.001). The concordance between St. James Hos­pital grade and Parks classification was 0.768 (Kappa coefficient, p<0.00).Conclusions: Therefore, we propose inclusion of MRI in the preoperative surgical assessment of anal fistulas when recurrent, complex, high grade, or when the external opening is located more than 2 cm from the anal canal.

Liver Acquisition with Volume Acceleration versus T2 fat suppressed MRI sequences in the evaluation of perianal fistula

Back groundPerianal fistula is an abnormal communication between the anal canal and the outer perineal skin. It is a disease of young adults, being more common in males.MRI is a noninvasive, well-tolerated imaging modality with high resolution of the soft tissues. It is considered the imaging modality of choice for the initial evaluation and follow-up of perianal fistulas as it is more tolerated and less embarrassing for the patient than other imaging techniques.ObjectivesTo compare MR sequences fat-suppressed (FS) T2-weighted imaging and Liver Acquisition with Volume Acceleration (LAVA) for better visualization and assessment of the perianal fistulas and sphincters.Patients and methodsThis was a retrospective study done in the period between January 2018 and January 2020 on 100 patients. The patients' age ranged from 15 to 67 years, with a mean age of 35.45 ± 12.35 years. All patients had previously undergone MRI pelvis with intravenous contrast. We considered the operative results as the reference standard.ResultsThis study included 36 (36.0%) females and 64 (64.0%) males. LAVA sequence was better than T2 FS MRI sequence for the detection of the internal opening of the fistulous tract as well as secondary fistulous tracts with perfect interobserver agreement (P < 0.001). Both LAVA and T2 FS MRI sequences have the same significance for the detection of the abscesses, horseshoe, and supralevator extension of the fistula, with perfect interobserver agreement between both observers and between them and surgery.ConclusionAdding LAVA sequence to the protocol of MRI in the evaluation of perianal fistula helps to give better details as compared with T2 FS sequence as regarding the internal opening and the secondary tracts of the fistulous tract, but they have the same results regarding the sensitivity to detect abscesses, horseshoe, and supralevator extension of the perianal fistula.

The Role of Diagnostic Medical Imaging Techniques in the Evaluation of Perianal Fistula: A Review

The fistula in ano or perianal fistula is one of the common fistulae noted in routine surgical and clinical practice. It has the tendency to reoccur even after surgery, which is due to missed pathological tract or tissue during surgical exploration. An adequate pre-surgical mapping is a necessity for giving an excellent surgical outcome and choosing an appropriate surgical technique for treating various fistulas.

Knowledge of Diagnostic and Therapeutic Aspects of IBD Among Nurses Working in Digestive Endoscopy: A Nationwide Italian Survey.

The importance of inflammatory bowel disease (IBD) dedicated nurses in endoscopy services is poorly explored. Non-IBD healthcare professionals who work in endoscopy units may underestimate the discomfort and the secondary psychological distress that endoscopic procedures cause in IBD patients. We performed a nationwide survey to evaluate the level of knowledge of nurses working in endoscopy facilities throughout Italy related to IBD patients' needs undergoing endoscopic procedures. A non-validate 45 items questionnaire divided into six sections was assembled by a group of experts and supervised by nurses and IBD-physicians as part of the board of IGIBD, ANOTE-ANIGEA and AGGEI. The questionnaire was sent to 397 nurses of which 335 (84.4%) responded to the questionnaire. The median level of knowledge registered was 29 ± 12, corresponding to a medium level of knowledge based on the scores described in the method section. One hundred eighty-three nurses (54.6%) reported a high score, 113 (33.7%) a medium score, and 39 (11.6%) a low score. The majority of nurses worked in high volume endoscopy centers, where the 48% were educated in IBD management. A Low level of knowledge was recorded regarding disease severity definition, bowel preparation strategies in severe colitis and evaluation of perianal fistula. This nationwide survey clearly shows that there is a need for endoscopic nurses to acquire specific knowledge in the IBD field. Dedicated pathways for IBD management in endoscopy, continuous educational programs for nurses and further studies to improve nurse education are needed.

Evaluation of perianal fistulas with magnetic resonance imaging: Significance of T2-weighted BLADE sequence in disease diagnosis

Introduction: Anatomical details of perianal fistulas can be revealed more clearly by T2-weighted (T2-W) periodically rotated overlapping parallel lines with enhanced reconstruction (BLADE)sequence during magnetic resonance imaging (MRI). This study aimed to compare the efficacy of the T2-W BLADE sequence and the T2-W turbo spin-echo (TSE) sequence in diagnosing perianal fistula, as well as to compare the findings with the results obtained using the dynamic contrast-enhanced (DCE) T1-weighted (T1-W) sequence during routine pelvic MRI examination.&#x0D; Methods: Ninety patients (M/F: 67/23) who had undergone pelvic MRI examination (1.5Tesla) for the prediagnosis of perianal fistula were included in this prospective study.&#x0D; In addition to our routine pelvic MRI protocol, T2-W BLADE sequence imaging and T2-W TSE sequence imaging in the axial, sagittal, and coronal planes were performed. Using a three-stage scoring system, two radiologists independently compared the T2-W BLADE and T2-W TSE sequences with each other and then with the DCE T1-W sequence in terms of perianal fistula imaging. Statistical analysis was performed using a sample t-test and the Cronbach’s α test.&#x0D; Results: Compared with the T2-W TSE sequence, the T2-W BLADE sequence was associated with fewer ghosting artifacts, higher overall image quality, and with clearer visualization of the anatomical details of the perianal fistula (p &lt; 0.05). Images with high anatomic details and contrast resolution were obtained using the T2-W BLADE sequence similar to those obtained using the DCE T1-W sequence (p &lt; 0.05).&#x0D; Conclusion: On the basis of the reduced imaging time and on the higher image resolution, T2-W images can be obtained with the BLADE technique for the diagnosis of perianal fistula.

Pre-Operative MRI in evaluation of Perianal fistulas

Background: Perianal fistula is a common and often an extremely distressing disorder. MRI is a preferred modality for the preoperative assessment of perianal fistulas.&#x0D; Aims and Objective: To evaluate the accuracy and predictive values of pre-operative MRI in diagnosing severity of perianal fistulas and the conditions associated with it like internal anal opening, secondary tract, abscess and supralevator extension.&#x0D; Materials and Methods: In this study, 44 patients with clinically suspected perianal fistulas underwent MRI for the evaluation of severity and presence of the associated conditions. St James’s University Hospital Classification was used to grade the perianal fistula. Pre-operative MRI grading was compared with the surgical findings in the 26 operated patients.&#x0D; Results: Out of 44 clinically suspected perianal fistulas, 41 (93%) were diagnosed as perianal fistulas by MRI. The most common type was grade 1 seen in 12(27.3%) patients followed by grade 4 fistula seen in 10(22.7%) patients. All 26 patients evaluated by surgical findings for severity of perianal fistulas were found to be graded in identical grades by pre-operative MRI. MRI was 100% sensitive in picking up all five grades.&#x0D; Conclusion: MRI helps in the accurate delineation of fistulous tract, identification of secondary tract and abscess.

Best non-contrast magnetic resonance imaging sequence and role of intravenous contrast administration in evaluation of perianal fistula with surgical correlation.

To evaluate the best non-contrast magnetic resonance imaging (MRI) sequence and role of intravenous contrast administration in preoperative characterization and classification of perianal fistulae, keeping surgery as gold standard. This prospective study comprised of forty-five consecutive patients with actively draining external perianal opening. MRI was performed on a 1.5T scanner using non-contrast and contrast enhanced sequences in multiple planes. St. James's University Hospital MRI based classification system was used to classify the fistulae into five grades. Taking surgery as gold standard, association between surgical and MRI findings was statistically analysed. Of the 45 patients recruited, forty were deemed eligible for inclusion. Mean age was 39.7 ± 11.7years with male preponderance (M: F = 8:1). Commonest type was Grade 1 (40%). The best sequences in terms of overall accuracy were axial & coronal planes of contrast enhanced fat suppressed (FS) T1W turbo spin echo (TSE) (95.7%) followed by FS T2W TSE (94.1%) while sagittal T2W TSE sequence with or without fat suppression had the lowest accuracy (90.13%). The difference in overall diagnostic accuracy of FS T2W TSE and contrast enhanced FS T1W TSE sequence for evaluating perianal fistula was not statistically significant (p = 0.52). However, contrast study had a better accuracy in detecting internal openings and secondary tract of recurrent/ post-operative cases. Best non-contrast MRI sequence is FS T2W TSE (axial and coronal). Non-contrast MRI is equally efficient to contrast study while evaluating primary/previously unoperated cases thereby eliminating the role of contrast in such cases. However, intravenous contrast should be administered for evaluating post-operative cases with recurrence.

Perianal fistula mapping at 3 T: volumetric versus conventional MRI sequences

To evaluate volumetric contrast-enhanced three-dimensional T1-weighted (CE 3D T1) turbo spin-echo (TSE) with variable flip angle (SPACE), CE 3D T1 volumetric interpolated breath-hold examination (VIBE) sequences with conventional CE-two-dimensional (2D)-T1 and 2D-T2-weighted imaging (WI) sequences in assessing perianal fistulas. Twenty-three patients with perianal fistula were included in this prospective study and underwent pelvic magnetic resonance imaging (MRI) at 3 T including fat-supressed CE 3D T1 SPACE, CE 3D T1 VIBE, axial and coronal 2D-T1WI together with 2D-T2WI sequences in the axial and coronal planes. Acquisition times were recorded. Performance of each sequence was evaluated in terms of image quality, presence of artefacts, lesion conspicuity, fistula type, presence of abscess, visibility of internal orifice, and number of internal orifices. Results were compared with post-surgical findings defined as the reference standard. Both CE 3D T1 VIBE and CE 3D T1 SPACE were the best sequences to determine fistula type and in terms of image quality, artefacts, and determining locations of internal orifices. The number of internal orifices was detected correctly in 23 (100%) patients for CE 3D T1 SPACE and CE 3D T1 VIBE sequences, in 17 (73.9%) patients on CE-T1WI, and in seven (30.4%) patients on 2D-T2WI. Lesion conspicuity was higher for CE 3D T1 SPACE and CE 3D T1 VIBE sequences compared to the 2D sequences (p<0.05). The overall acquisition time for each 3D sequence was shorter compared to the 2D sequences combined. CE 3D T1 SPACE and CE 3D T1 VIBE sequences may outperform conventional 2D sequences in the evaluation of perianal fistulas in terms of visibility and number of internal orifices with a shorter scanning time.

Diagnostic Accuracy of Short Tau Inversion Recovery as a Limited Protocol for Diagnosing Perianal Fistula.

IntroductionPerianal fistula refers to abnormal communication between perianal skin and anal canal. Magnetic resonance imaging (MRI) and endoanal ultrasound have been used in the evaluation of perianal fistula. Endoanal ultrasound is a cost-effective but operator-dependent technique. MRI provides accurate details regarding anal canal anatomy and effectively identifies the fistulae. For evidence-based care, a cost-effective and an accurate imaging modality is required in a developing country. Therefore, the aim of this study was to determine the diagnostic accuracy of short tau inversion recovery (STIR) as a limited protocol MRI pelvis in diagnosing perianal fistula taking surgical findings as the gold standard.Materials and methodsA retrospective review of MRI pelvis from 1st February 2018 to 1st July 2018 was undertaken. Patients of any age or gender suspected to have perianal fistula were included. One radiologist interpreted the complete MRI pelvis and the other radiologist only viewed axial and coronal STIR sequences as a limited protocol. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of axial and coronal STIR sequence were calculated taking surgical findings as the gold standard.ResultsIn total, 150 patients were included in this study. The mean age of the patients was 43.20 ± 13.75 years. In total, 122 (81.3%) were males and 28 (18.7%) were females. Using STIR as a limited protocol, fistulae were found in 125 (83.3%) patients, whereas on surgery, the fistulae were found in 119 (79.3%) patients. Sensitivity, specificity, PPV, NPV, and diagnostic accuracy of STIR as limited protocol MRI pelvis in diagnosing perianal fistulae was found to be 96.6%, 67.7%, 92.0%, 84.0%, and 90.6%, respectively, taking surgical findings as the gold standard.ConclusionSTIR has high sensitivity and diagnostic accuracy in diagnosing in the perianal fistula. Using STIR as a limited protocol in a developing country can help improving patient care by accurately diagnosing perianal fistulae. Moreover, it is recommended that further studies for identifying internal opening on STIR should also be carried out to improve patient care.

THE VALUE OF MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF PERI-ANAL FISTULA

Background: Perianal fistula accounts for 0.01% of general population and is frequently managed inadequately resulting in a significant morbidity. Magnetic resonance imaging (MRI) plays an essential role in the preoperative assessment of the disease, therefore improving post-operative surgical outcome. Objective: To study the role of MRI in the evaluation of perianal fistula and to show the value of using contrast enhanced MR study in the determination of the precise tract pathway, extensions and other associated pathologies. Methods: A cross sectional analytic study was conducted on a total of 32 patients with perianal fistulas in the MRI Department of Al-Imamein Al-Kadhimein Medical City, Baghdad, Iraq during the period from November 2015 to December 2016. Patients underwent MRI examination using axial and coronal T2 weighted images with and without fat suppression and T1 fat suppressed sequences before and after contrast administration. The type of fistula, location of the internal opening, associated abscesses and/or sinus tracts and horseshoe extension were evaluated using different MR sequences. Results: The most common type of fistula encountered was the inter-sphincteric type, which was seen in 21 patients (66%), of those patients 16 fistulas (50%) were grade I and 5 fistulas (16%) were grade II. Trans-sphincteric fistulas were seen in 9 patients (28%), 2 of them (6%) were grade III and 7 fistulas (22%) were grade IV. Two patients (6%) had extra-sphincteric type. T2 weighted TSE, T2 TSE with fat suppression and T1 weighted fat suppressed post contrast sequences all show significant correlation with surgical results (with p-value less than 0.05) and the highest significance was obtained by the post contrast sequence (p-value of 0.00001). The highest accuracy in the diagnosis of fistula in ano was with the use of T1 enhanced fat suppressed sequence (98.8%) followed by 87% for the T2 fat suppression sequence and only 57% for the T2 weighted TSE sequence. Conclusion: MRI is an essential, noninvasive tool in the preoperative assessment of perianal fistulous tracks, with the axial and coronal post contrast fat suppression T1 providing the highest accuracy and clinical significance with surgical data and therefore giving a highly promising decrement in the incidence of post-operative complications. Keywords: MRI, perianal fistula Citation: Jawad AM, kadhim MA, Al-Jobouri ZK, Hussain MAA. The value of magnetic resonance imaging in the evaluation of peri-anal fistula. Iraqi JMS. 2018; 16(2): 166-176. doi: 10.22578/IJMS.16.2.8

ACCURACY OF TRANSPERINEAL ULTRASOUND RELATIVE TO MAGNETIC RESONANCE IMAGING IN EVALUATION OF PERIANAL FISTULAS

Background&#x0D; Ano-rectal fistula is a chronic inflammation of perianal tissues affecting 1/10.000 individuals. Traditionally, treatment is surgical with the possibility of recurrence reaching up to a quarter of cases, therefore preoperative appropriate evaluations and imaging are necessary to decrease recurrence rate. &#x0D; Objectives &#x0D; Determining accuracy of transperineal ultrasound relative to magnetic resonance imaging in evaluation of perianal fistulas. &#x0D; Methods&#x0D; A prospective study was conducted on 51 patients with clinically diagnosed perianal fistula. Transperineal ultrasound (TPUS) and magnetic resonance imaging (MRI) were done for all patients. The following variables were recorded by each of the tests and the results were compared one to one: Firstly the number of the tracts, their relation to the anal sphincters. Secndly the number of internal openings, their sites and distances from the anal verge. Thirdly any associated findings, including perianal abscess, extension (branching) or local inflammatory phlegmons. Descriptive statistics were used. P-values ≤ 0.05 were considered statistically significant.&#x0D; Results&#x0D; Relative to the MRI, the accuracy of TPUS in detection of fistula tract was 96%. Finding of at least one relation of the tract to the anal sphincter was 86.7%, detection of internal opening was 82%, and localization of the internal opening was 82% with comparable result in measuring their distance from the anal verge (P value = 0.15). Lastly the overall accuracy of TPUS to find at least one associated finding was 92%. Among detected associated findings, TPUS was able to accurately classify them with no significant difference between TPUS and MRI (P-Value &gt; 0.05). Three superficial fistula tracts were detected by TPUS and proved by surgical operation while they were undetectable by MRI.&#x0D; Conclusion&#x0D; TPUS is an accurate imaging investigation in the evaluation of perianal fistula and its results was comparable to those of MRI in preoperative assessment of perianal fistula diseases.

MR imaging of perianal fistulas in Crohn's disease: sensitivity and specificity of STIR sequences.

Although some studies proved the role of STIR sequences in the evaluation of perianal fistulas in Crohn's Disease (CD), contrast medium is still injected in many institutions since there is not a validated reference MR protocol. Our purpose was to evaluate the role of the STIR sequence in the detection and characterization of perianal fistulae comparing it to the post-contrast T1 sequence and correlating it with rectal examination under anesthesia. We retrospectively reviewed all clinical records of 31 CD patients, suspected of having perianal fistulas, who had been submitted to an MR study before and after contrast medium injection and surgical exploration under anesthesia within the same month. Perianal fistulas were classified according to the Parks' criteria. Finally, comparison between STIR and post-contrast T1-weighted fat saturated sequences was done. 29 fistulas were detected in 25 patients who underwent an MR study. There was no significant difference between MR imaging and exploration under anesthesia. For the detection of perianal fistulas of any type, there was a perfect statistical agreement between gadolinium-enhanced and STIR sequences (kappa value=1). STIR sequences represent a valid alternative to the T1-weighted sequences acquired after the injection of contrast medium, allowing the identification of the primary fistula, any secondary ramification, and complications of the disease.

PERIANAL FISTULA

MRI is increasingly used nowadays in the evaluation and management of PerianalFistula. Objectives: To assess the role of MRI in the detection and classification of PerianalFistula and correlation of preoperative MRI findings with the findings on surgery. Study Design:Prospective study. Setting: Department of Radiology King Khalid Civilian Hospital TabukKingdom of Saudi Arabia. Study Period: Two years between February 2013 and February 2015.Material and Methods: 60 patients were referred from surgical department for evaluation ofPerianal fistula by MRI during the above mentioned period. MRI was performed in 48 Patients.(42 males and 6 Females) using variety of MRI sequences. Fistulas were classified according toSJUH (St James’s University Hospital classification MR imaging based grading system) and MRIfindings of individual MRI sequence used were correlated with operative findings. Results: Mostcommon fistula was Grade 1 (37.5%).In majority of the cases internal opening was found at 6 Oclock position. Post intravenous contrast enhanced Axial and coronal oblique (CE FST1WFSE)Fat suppressed T1 weighted Fast spin echo and Axial and coronal Fat suppressed T2W FSEsequence (FST2WFSE) showed the highest Accuracies 98.13% and 97.06% respectively indiagnosis of anorectal fistulae. Conclusion: MRI should be used as a first line imaging modalityin the preoperative assessment of Perianal fistula. Findings on Axial and coronal oblique CEFST1WFSE, axial and coronal oblique FST2WFSE showed the excellent agreement with thesurgical findings. By using MRI as the first line imaging modality in the evaluation of PerianalFistula one can percept best possible surgical management resulting in prevention of residual/recurrence disease and complications such as fecal incontinence.

Ultrasonography Accuracy for Perianal Fistula Anatomy

Background Endorectal ultrasonography is a diagnostic modality for evaluation of perianal pathologies and suitable surgical planning, especially in perianal fistula, due to its close relation to the anal sphincter complex. Detection of anatomical location of fistula tract and abscess is critical to select the best procedure. Objectives This study tries to demonstrate the accuracy of endorectal ultrasonography in mixed group of patients in diagnosing perianal fistula during two years, retrospectively. Patients and Methods After Ethics Committee approval, all endorectal ultrasonography reports of all patients with perianal fistula referred to Shiraz Endorectal Ultrasonography Clinic of Shiraz colorectal research center between 2010 and 2012 were gathered. All endorectal ultrasonographies in this center was perform by a colorectal surgeon with BK Medical Class I type B Ultrasonography scanner with 12 MHz probe. Results Finally, 183 cases of perianal fistula were enrolled in the study. Operation notes were evaluated and the type of fistula was compared with ultrasound findings. This study showed that endorectal ultrasonography has adequate accuracy with 97.92% sensitivity and acceptable 89.53% specificity in diagnosis of perianal fistula. Compared with other reports, it seems that endorectal ultrasonography is an acceptable diagnostic tool for detecting perianal fistula compared with other diagnostic modalities. Conclusions Endoanal sonography would be one of the high sensitive modalities for evaluation of perianal fistula. Detection of anatomy of fistula helps surgeon to choose best method for surgery.

Imaging diagnosis of perianal fistula in Crohn disease

Anal fistula is the most common perianal lesion in Crohn disease (CD), which usually is complicated and difficult to treat, and has a high recurrence rate and serious influence on the quality of life of patients. Inaccurate or incomplete intervention may result in irreversible damage. In order to achieve the best outcome, an optimal disease assessment is crucial. Many imaging modalities are useful for the evaluation of perianal fistulas in CD, which may help confirm the diagnosis, accurately classify the disease, plan the most suitable treatment, and monitor the efficacy. Magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) and anal endosonography (AES) are considered to be the suitable options for evaluation of the initial perianal fistula, both in terms of sensitivity and specificity, while MRI is more suitable for monitoring the curative efficacy. Fistulography (by X ray or CT) is generally less applied due to inferior soft tissue performance, radiation exposure, etc. This paper reviews the various imaging modalities, analyzes their advantages and disadvantages in order to assist clinicians in selecting the most appropriate examination individually.