Classification of anal fistulas based on magnetic resonance imaging / 中华胃肠外科杂志

OBJECTIVE@#To explore the diagnostic value of magnetic resonance imaging(MRI) in anal fistula.@*METHODS@#A total of 2160 patients were clinically diagnosed with anal fistula at the Sixth Affiliated Hospital of Sun Yat-sen University from March 2010 to September 2015. Among them, 232 cases with operative history at other hospital, 218 with Crohn's disease, 6 with rectum cancer and 8 with other disease were excluded, and 1696 patients were finally enrolled and retrospectively analyzed. The saggital FSE T2WI imaging was confirmed based on the midline of body, and then the coronal and axial scanning line were confirmed. The key point was that the coronal scanning line must parallel and the axial scanning line must be perpendicular to the major axis of anal canal. The characteristics of anal fistula were recorded, and anal fistula were classified as five types, including intersphincteric, transphincteric, suprasphincteric, extrasphincteric and superficial fistula according to the Parks classification and our experience. The distribution of internal opening was described by using lithotomy position clock method.@*RESULTS@#Of 1696 patients, 1456 were males and 240 females with median age of 26.5 (0.2 to 87.0) years. Age of 8.4% (143/1696) cases was under 20 years old, of 57.4%(973/1696) cases was between 20 to 40, of 28.4%(482/1696) cases was between 40 to 60, of 5.8%(98/1696) cases was over 60. The 1696 MR examinations included 1128 on 1.5T MR and 568 on 0.5T MR. Of all the anal fistulas was 29.0%(492) high position and 71.0%(1204) was low position. Among the 1696 patients, 1057 were intersphincteric fistulas(62.3%), 407 were transphincteric fistulas(24.0%), 68 were suprasphincteric fistulas(4.0%), 54 were extrasphincteric fistulas (3.2%), 67 were superficial fistulas(4.0%), and 43(2.5%) were difficult to classify. A total of 1996 internal openings were found and most of them were located around the dentate line of 5-7 o'clock in lithotomy position(47.7%, 952/1996).@*CONCLUSIONS@#Anal fistula mainly occur in young men, and the most common type is intersphincteric fistula. MRI can accurately classify anal fistulas and clearly demonstrate internal openings, and provide reliable evidence for clinical treatment and surgery.

The value of MRI with CUBE sequence in early evaluation of the efficacy of neoadjuvant therapy for locally advanced rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the value of MRI with CUBE sequence in early evaluation of the efficacy of neoadjuvant therapy (NAT) for locally advanced rectal cancer.</p><p><b>METHODS</b>Inclusion criteria: (1) rectal cancer proven by biopsy; (2) locally advanced rectal cancer (T3-4 or positive lymph nodes) with distance from lower edge of tumor to anal verge within 12 cm diagnosed by MRI before NAT; (3) acceptance of NAT treatment regulations and completion of NAT; (4) completion of routine MRI scan and CUBE scan before and after 2-course NAT chemotherapy (including new neoadjuvant chemotherapy and chemoradiotherapy); (5) completion of surgery 6-8 weeks after NAT; (6) exclusion of any previous NAT due to rectal malignant tumor or other tumors; (7) exclusion of poor image quality of preoperative routine MRI insufficient for rectal cancer staging or of CUBE image insufficient for tumor volume measurement. Fifty patients with advanced local rectal cancer were recruited in our hospital from February 2014 to January 2016. All the patients underwent MRI before and after 2-course neoadjuvent therapy. Tumor volume on CUBE were measured and the volume changes were calculated: volume difference= pre-treatment volume-post-treatment volume, volume change rate= (pre-treatment volume-post-treatment volume)/ pre-treatment volume. All the patients were categorized into sensitive and non-sensitive group according to postsurgical pathology. Comparisons were made between both groups before and after therapy. ROC curve was used to evaluate the value of CUBE-associated parameters in predicting the efficacy of rectal cancer.</p><p><b>RESULTS</b>Among enrolled 50 patients with rectal cancer, 31 were male and 19 were female, with mean age of 49.1 years (range 21 to 70 years). T-staging by MRI before NAT was T2N1-2 in 1 case, T3 in 43 cases, T4 in 6 cases. The number of patients after NAT from tumor regression grading (TRG) 0 to TRG3 was 14, 13, 18, 5, respectively. The sensitive group and insensitive group were 45 cases and 5 cases. Mean tumor volume before and after preoperative 2-course NAT was 18.70 (4.14 to 91.77) cmand 9.26 (1.02 to 52.58) cm, respectively, whose difference was significant (U=-5.826, P<0.001). Both measure values of overall tumor volume before and after preoperative NAT between sensitive group and insensitive group did not show significant differences(all P>0.05). While sensitivity group had significantly higher volume difference and change rate compared to insensitive group [ (11.90±10.01) cmvs. (0.65±3.93) cm, P=0.005; 0.45±0.28 vs. 0.09±0.36, P=0.010]. ROC curve revealed that the optimal cutoff value of accurate identification of patients with NAT sensitive was 1.96 cmfor volume difference with sensitivity 86.7% and specificity 80%, and 0.06 for volume change rate with sensitivity 93.3% and specificity 60%.</p><p><b>CONCLUSION</b>MRI CUBE can predict the efficacy of NAT for early rectal cancer patients accurately and sensitively through the detection of tumor volume change before and after NAT.</p>

Analysis of perianal fistulas of ileocolonic Crohn's disease by CT enterography / 中国医学影像技术

Objective To explore the relationship between ileocolonic lesions and perianal fistulas of Crohn's disease as sessed by CT enterography (CTE).Methods Totally 28 patients with initial diagnosis of active ileocolonic lesions of Crohn 's disease were collected,16 with perianal fistula and 11 without perianal fistulas.All patients underwent CTE and pelvic MRI.Total number of lesions,minimum length between every two lesions in colon wall and maximum length of colonic le sions were calculated.The rank sum test was performed respectively.Results Lesions of 14 patients (14/16,87.50％) in perianal fistulas group located in left colon or rectum,while lesions of 6 patients (6/12,50.00 ％) in non-perianal fistulas group located in left colon or rectum,the difference was statistically significant (Z=-2.135,P＜0.05).The mean number of lesions in patients with perianal fistulas was 3.06,while in patients without perianal fistulas was 2.91,there was no statistical difference (P＞0.05).The maximum length of colonic lesions in patients with perianal fistulas was (12.79± 8.30)cm,while in patients without perianal fistulas was (7.04± 3.09)cm,and there was no statistical difference(P＞ 0.05).The minimum length hetween every two lesions in patients with perianal fistulas was (5.23±2.98)cm,while in pa tients without perianal fistulas was (8.44 ± 2.87) cm,the difference was statistically significant (Z =-2.095,P＜ 0.05).Conclusion Crohn's disease complicated with perianal fistulas has relationship with lesion location and smaller length intervals between two lesions in colon wall,and has no relationship with total number of lesions and maximum length of colon lesions.

Imaging features of surgical complications of Crohn's disease / 中华消化外科杂志

Objective To investigate the imaging features of surgical complications of Crohn's disease (CD).Methods The retrospective cross-sectional study was conducted.The clinical data of 128 CD patients with surgical complications who were admitted to the Sixth Affiliated Hospital of Sun Yat-sen University from January 2014 to December 2015 were collected.All the patients underwent computed tomography enterography (CTE),magnetic resonance enterography (MRE),magnetic resonance imaging (MRI) of anal tube and X-ray examination.The patients underwent surgical therapies after examinations.Observation indicators:(1) clinical characteristics of surgical complications of CD:occurrence of surgical complications of CD,correlation between preoperative complications and Montreal types of CD,(2) diagnostic accuracy of surgical complications and perianal lesions through CTE,MRE and MRI of anal tube,(3) imaging findings of preoperative complications of CD,(4) treatment and follow-up situations.Follow-up using telephone interview and outpatient examination was performed to detect the postoperative recovery and reoperations of patients up to March 2016.Count data were represented as frequency or percentage.The correlation between preoperative complications and Montreal types of CD was represented as the odds ratio (OR) and 95％ confidence interval (CI).The features of diagnostic indexes were described as the sensitivity and specificity.Results (1) Clinical characteristics of preoperative complications of CD:all the 128 patients had preoperative complications,including 71 with anal fistula or anal fistula combined with perianal abscess,26 with intestinal fistula,24 with intestinal obstruction,23 with abdominal abscess,3 with digestive tract perforation,1 with kidney stone and 1 with hydronephrosis.Of 128 patients,12 had intestinal fistula combined with abdominal abscess,1 had intestinal fistula combined with intestinal obstruction,3 had intestinal fistula combined with abdominal abscess and intestinal obstruction,1 had intestinal fistula combined with digestive tract perforation and 1 had intestinal fistula combined with hydronephrosis.There was a correlation between lesion location of CD and type of complications.Thirty-five of 51 patients had strictures or penetrationtype lesions,with a correlation between strictures or penetration-type lesions and ileal CD [OR =6.23,95％ confidence interval (95％ CI):2.86-13.61,P ＜ 0.05].Fifty-six of 77 patients had anal fistula,showing a correlation between combined anal fistula and colonic lesions of CD (OR =6.40,95％ CI:2.92-14.01,P ＜ 0.05).(2) Diagnostic accuracy of CTE,MRE and MRI of anal tube:with intraoperative exploration findings as the standard,the sensitivity and specificity of surgical complications of CD were 84％ and 95％ through CTE or MRE,and the sensitivity and specificity of anal fistula were 100％ and 100％ through MRI of anal tube.(3) Imaging findings of surgical complications of CD.① Of 71 patients with anal fistula,65 had 2 or more internal openings or fistula tract of complex anal fistula.The internal opening was a starting point of the fistula tract,and enhanced scans of MRI displayed punctate,shredded or small round abnormal strengthening signals between under mucous membrane of the anal canal and sphincter.The tubular and striped fistula tract was horizontal or vertical distribution,with a lightly high-high signal on T2 weighted-images (WI).The results of enhanced scans of MRI showed that there was an obvious homogeneous enhancement in the fistula tract or enhancement in the fistula tract wall,and no enhancement in the cavity of fistula tract.MRI findings in 38 patients combined with perianal abscess included a obvious high-signal on T2WI,and enhanced scans of MRI showed circular enhancement and no internal enhancement.② Of 26 patients with intestinal fistula,17 had intestinal fistula,imaging findings included multiple thickened intestinal walls and more obvious enhancement compared with normal intestinal canal.There was gathering and adhesions among intestinal canals,showing mash connections and petal-like changes.Fourteen patients had enterocutaneous fistula (6 combined with intestinal fistula and 1 patient combined with intestinal fistula and intestine-bladder fistula).Four patients had intestine-bladder fistula (2 combined with intestinal fistula and 1 combined with intestinal fistula and enterocutaneous fistula).One patient had intestine-vagina fistula.The results of CTE and MRE examinations showed that thickened intestinal canals and intestinal walls in the lesions,and shadows of intestinal canals communicated with the abdominal,bladder wall and vagina,with a high signal on T2WI and enhancement of intestinal wall by enhanced scan.The partial intestinal canals were physically close to other organs,without a connection between them,and anomalous enhancement or local pneumatosis among the adjacent organs were detected.③ CTE findings of intestinal obstruction included constriction of intestinal canal combined with dilatation of proximal intestinal canal.There were 3 enhancement methods of thickened intestinal wall in 24 patients with intestine obstruction.Imaging findings of 12 patients included enhancement in the intestinal mucosa and no enhancement in the submucosa and muscularis mucosa.Imaging findings of 4 patients included enhancement of intestinal mucosa and muscularis mucosa and no enhancement in the submucosa.Imaging findings of 8 patients included homogenous and heterogeneous enhancements in the intestinal walls.④ Twentythree patients were complicated with abdominal abscess,including 15 combined with intestine fistula.The scans of CTE showed that there was a round-like or oval mass in the abdomen,with a high signal on T2WI,fluid-dominated inflammatory exudation around the mesentery,the enhancement of annular wall of mesentery and no enhancement of pus within the mesentery.⑤ Three patients were combined with digestive tract perforation,including 1 combined with intestine fistula.CTE and X-ray detections showed there was a shadow of free gas in the intestinal mesentery and under abdominal diaphragm.⑥ Two patients were combined with kidney stone and hydronephrosis.X-ray findings of kidney stone included the deposition of multiple and sharp-edged dense shadows within the renal calices.CTE findings of hydronephrosis included inflammatory thickening of ureteric wall with proximal ureter dilatation.(4) Treatment and follow-up situations:128 patients underwent successful operation and were followed up for 4-27 months.Of 10 patients undergoing reoperations due to postoperative complications,MRI detection of 7 patients with recurrence of anal fistula showed fistula tract or abscess located at the previous loci was incompletely healed or progressed,morphous and location of lesions were roughly the same as the preoperative situations.The scans of CTE in 2 patients with anastomotic stricture showed that there were the thickening of intestinal wall and obstruction and dilatation at the proximal anastomotic-site.The enhanced scan of CTE in 1 patient with anastomotic fistula showed that there were irregularly cavity-like lesion beside the metal anastomotic ring,and effusion was seen within the lesions,with an edge enhancement.The other 118 patients recovered well without intestinal fistula or intestinal obstruction on CTE or MRE examination.Conclusions Anal fistula is the most common surgical complication of CD,and intestinal fistula,intestinal obstruction and abdominal abscess are also relatively common.The early postoperative complications consist of the recurrence of anal fistula.Location of lesions in CD is associated with the type of complications.CTE or MRE and anal MRI findings have different imaging characteristics for CD combined with different complications,with a certain value in the assessment of abdominal and perianal complications.

Application of adaptive iterative dose reduction technique in CT enterography in diagnosing Crohn disease / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the application of low-dose CT enterography with adaptive iterative dose reduction(AIDR) technique in diagnosing Crohn's disease.</p><p><b>METHODS</b>Retrospective analysis was performed on 26 patients diagnosed as Crohn's disease by the multidisciplinary team in our hospital. Low-dose CT enterography with 640-slice MDCT was performed on these 26 patients using adaptive iterative dose reduction(AIDR) technique. Characteristics of Crohn's disease in CT enterography images were independently analyzed by two radiologists who were experienced in Crohn's disease with calculating the total radiation dosage.</p><p><b>RESULTS</b>The radiation dosage of 26 patients ranged from 5.58 to 12.90 [mean (9.00±2.00)] mSv, which was lower than conventional scan (around 15 mSv) known from the literatures. According to the images of CT enterography of 26 cases, bowel wall thickening with abnormal enhancement and lymphadenectasis were found in 25 cases with total 109 segmental bowel wall thickening. Among 25 thickening cases, enterostenosis was found in 16 cases, stratification enhancement in 12 cases and comb sign in 14 cases. Besides, it was found that 8 cases with hyperdense fat on the mesenteric side, 7 cases with intestinal fistula, 6 cases with abdominal cavity abscess, and 3 cases with anal fistula.</p><p><b>CONCLUSION</b>CT enterography of Crohn's disease with adaptive iterative dose reduction technique is an effective method to evaluate Crohn's disease without compromising image quality with reduced radiation dosage.</p>