Preoperative MRI of perianal fistula: Is it really indispensable? Can it be deceptive? (original) (raw)
Related papers
MRI in the pre operative evaluation of perianal fistula
Journal of Postgraduate Medical Institute, 2014
Objective: To assess the diagnostic accuracy of Magnetic Resonance Imaging (MRI) in the pre operative evaluation of peri anal fistulae. Methodology: Between Decemebr 2010 and January 2013, thirty patients with clinical suspicion of peri-anal fistulae had MRI scans done for evaluation of extent of disease. Out of these 11 patients underwent surgery in our hospital and were included in the study. All patients had body-coil MR Imaging examinations including the following sequences for anatomic and pathologic information: T2 sagittal, T1, T2 and STIR axial oblique, T2 and STIR coronal oblique and post contrast T1 FAT SAT sagittal, axial oblique and coronal oblique planes. Scans were interpreted by a senior radiologist with more than 5 year experience in body MR imaging. Surgical findings were accepted as the gold standard and were recorded independently by the surgeon. MRI findings were compared with surgical findings using Park's classification. Results: The MRI findings were in accordance with surgical findings in 10 out of 11 patients regarding type and extent of fistula in ano. In one patient peroperatively diagnosed and treated fistula did not show on MRI. Statistical parameters showed that MRI has a sensitivity of 90%, specificity of 100% and diagnostic accuracy of 90% in determining type and extent of peri-anal fistula. Conclusion: MRI is an accurate and non invasive imaging modality for determining type and extent of peri-anal fistula and helps in pre operative management and surgical planning by giving correct assessment of extent of disease.
Pre-Operative MRI in evaluation of Perianal fistulas
2021
Perianal fistula is a common and often an extremely distressing disorder. MRI is a preferred modality for the preoperative assessment of perianal fistulas. 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. 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. 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. Conclusion: MRI helps in the accurate delineation of fistulous tract, identification of secondary tract and abscess.
Diagnostic Role of Mri in the Pre-Operative Evaluation of Perianal Fistula
International journal of medical science and diagnosis research, 2018
Background-Ano-rectal fistulas are chronic inflammations of perianal tissues with a connection between the skin of the perineum and the anal canal. Methods-This prospective study was conducted in 35 patients during the period of one year and patients fulfilling inclusion and exclusion criteria was included in the study and was include data collection, data organization, presentation, data analysis and data interpretation. Results-Out of 35 patients examined with MRI, classification of fistula was done according to St. James's University Hospital Classification of perianal fistula. 13 patients (37.14%) had Grade 1 fistula, 8 patients (11.14%) had Grade 2 fistula, 4 patients (11.4%) had Grade 3 fistula, 6 patients (17.14%) had Grade 4 fistula and 4 patients (11.4%) had Grade 5. Conclusion-Magnetic Resonance Imaging (MRI) was highly accurate in assessment of surgically important parameters of perianal fistulae.
Role of Mri in Perianal Fistulas- a Study of 30 Patients
Journal of Evidence Based Medicine and Healthcare
BACKGROUND We presented role of MRI in fistula-in-ano before the surgery. In our institute, we do preoperative MRI in all the patients presented with perianal discharge or external opening. MRI is very accurate for depiction of both the primary tract (sensitivity, 100%; specificity, 86%) and abscesses (sensitivity, 96%; specificity, 97%). The aim of the study is to classify the perianal fistulas according to the St. James University Hospital (SJUH) grading scheme and Park's classification and to evaluate the different characteristics of the fistula-in-ano in clinically-diagnosed cases.
Preoperative MRI of perianal fistula evaluation and its impact on surgical outcome
Egyptian Journal of Radiology and Nuclear Medicine, 2019
Background Perianal fistula (PAF) is an abnormal tract communicating an external cutaneous opening in the perianal region to the anal canal. PAF is one of the common anorectal disorders in surgical practice with high prevalence. The current study aimed to determine the ability of preoperative MRI for preoperative evaluation of perianal fistula. Results This is a retrospective evaluation of 65 patients with perianal fistula. MRI fistula imaging-related data were revised, and fistula severity was scored using criteria of both local extension of fistulas and active inflammation for a total maximum score of 22. Preoperative MRI could predict the severity of perianal disease with sensitivity, specificity, and accuracy rates of 75%, 92%, and 84.6%, respectively. Surgical findings concerning PAF severity correlated significantly with MRI findings. Diffusion-weighted magnetic resonance imaging (DW-MRI) provided high sensitivity and accuracy with 100% specificity for fistula visualization an...
2020
Introduction: MRI evaluation of perianal fistula plays a crucial role in the diagnosis, classification and surgical management of the fistulous disease. Perianal fistulisation is an unusual condition but significantly contribute to gastrointestinal morbidity. Proper technique and dedicate protocol of MRI helps in identification of detail anatomy, primary and secondary tracks, classification, complications like abscesses and hence guides the surgeons to plan an appropriate treatment strategy. Our study aims to evaluate the role of MRI in preoperative classification and its management of perianal fistula. Materials and Methods: A total of 124 patients who were diagnosed to have perianal fistula clinically and referred for MRI Imaging during the study period Jan 2019 to June 2020 included. MRI findings were reviewed, tabulated and analysed. Results: MRI fistulography prove to have a 100% detection rate of the fistulous tract, its extension and relation to internal and external sphincte...
THE PROFESSIONAL MEDICAL JOURNAL, 2017
Perianal fistula is defined as an abnormal communication channel between anal canal and perianal skin. Among all the imaging tools Magnetic resonance imaging (MRI) is of choice in the diagnosis and management of perianal fistulas. Objectives: "To determine the diagnostic accuracy of MR imaging in detection of perianal fistulas and comparing it with per operative findings". Peroperative findings are taken as gold standard. Place and Duration of Study: This study was carried out in Diagnostic Radiology, Pakistan Institute of Medical Sciences (P.I.M.S) Islamabad, over a period of nine months from 01-02-2012 to 31-10-2012. For this collaboration was made with the Department of General Surgery P.I.M.S and Department of gynecology (MCH center) PIMS and gastroenterology Department. Patients and Methods: A total of 95 patients were included in study having perianal fistulas on clinical examination. MRI was performed in the patients and T1-weighted fast spin echo (T1W FSE) images were taken before and after gadolinium injection. Fat suppressed T2-weighted fast spin echo (T2W FSE) images were obtained in all three planes including transverse, sagittal and coronal. All the scans were viewed by a single consultant radiologist to avoid observer bias. Results: Out of 95, 81 patients (85.3%) were male and 14 (14.7%) were female. Sensitivity, specificity and accuracy of magnetic resonance imaging (MRI) was 96.2%, 75.0% and 92.6%, respectively. Positive predictive value was 95.0% and negative predictive value was 80.0%. Conclusion: our study proves that among imaging modalities MRI is of choice for preoperative assessment of perianal fistulas. It provides highly accurate, noninvasive and relatively very less time consuming means of performing pre-operative evaluation, specially the complex, branching fistulas. This diagnostic accuracy not only helps in surgical cure but avoids recurrence and post-operative complications like fecal incontinence
Outcome after surgery for perianal fistula: predictive value of MR imaging
American Journal of Roentgenology, 1998
OBJECTIVE. The purposeof thisstudywasto determineif MR findingsarepredictiveof long-term outcome in a cohort of patients whose initial surgery was performed without access to the findings of MR imaging. SUBJECTS AND METHODS. Forty patientswith surgicallyprovenperianal fistulas underwent preoperative dynamic contrast-enhanced MR imaging. The MR and surgical find ings were independently recorded on an identical anatomic form. Three patients were subse quently lost to follow-up. The outcome for the remaining 37 patients was determined from surgical review, case notes, and questionnaires. Minimum follow-up period was 14 months (range, 14â€"39 months).Outcomewas determinedby one observerwho was unawareof the initial MR grading and had not been present during surgery. Outcome was considered unsatis factory if further surgery was required. RESULTS. MR imagingwasbetterthansurgical explorationin predictingoutcome(for MR imaging:positivepredictivevalue,73%; negativepredictivevalue,87%; sensitivity, 89%; and specificity, 68%; for surgical exploration: positive predictive value, 57%; negative predictive value, 64%; sensitivity, 73%; and specificity, 47%). MR classification of fistulas was signifi cantlyassociated with outcome(p = .0004), andsurgical classification wasnot significantlyas sociated with outcome (p = .22, chi-square test). Also MR grades differed significantly for patientswith satisfactory and unsatisfactoryoutcomes(p < .001, Mann-Whitney U test). CONCLUSION. MR imaging is valuablein the managementof patientswith perianal fistulas.MR imagingaccuratelyrevealssurgicalanatomyandcanbe usedto makebetterpre dictionsregardingpatientoutcomethansurgicalfindings.
Usefulness assessment of preoperative MRI fistulography in patients with perianal fistulas
PubMed, 2011
Background: Accurate preoperative assessment of the perianal fistulous tract is the main purpose of the diagnostics and to a large extend determines surgery effectiveness. One of the useful diagnostic methods in perianal fistulas is magnetic resonance imaging. The authors presented experiences in the application of MRI fistulography for evaluation of cases of perianal fistulas difficult to diagnose and treat. Material/methods: Own examination method was described; MRI fistulography findings were analyzed and compared with intraoperative conditions in 14 patients (11 men and 3 women) diagnosed in the years 2005- 2009. Eight patients had recurrent fistulas and 6 had primary fistulas. Imaging was performed with a GE SIGNA LX HS scanner with a 1.5-Tesla field strength and a dedicated surface coil placed at the level of hip joints. Contrast agent was a gadolinium-based solution. Results: Intraoperative findings were consistent with radiological descriptions of 13 MRI fistulographies. Only in one case, according to surgery findings, it was a transsphincteric fistula with an abscess in the ischioanal fossa, with an orifice in the posterior crypt; the radiologist described it as a transsphincteric, internal blind fistula. Conclusions: Due to its accuracy in the assessment of the perianal fistulous tracts in soft tissues, MRI fistulography becomes a useful and recommended diagnostic method in this pathology. It shows the location of the fistula regarding the system of anal sphincters, and identifies the internal orifice and branching of the fistula. It enables precise planning of surgical treatment. Authors suggest that this diagnostic method should be improved and applied more commonly.