Discussion on the role of goal-oriented comprehensive teaching method in the rotation of breast surgery residents / 中华医学教育探索杂志

Objective:To explore the application effect of the goal-oriented comprehensive teaching method in the rotation of breast surgery residents.Method:A total of 40 residents who rotated in the Department of Breast Surgery of Xiangya Hospital of Central South University from January 2019 to January 2020 were selected as the control group, and another 41 residents who rotated from February 2020 to February 2021 were selected as the study group. The control group adopted the traditional teaching method, while the study group adopted the goal-oriented comprehensive teaching method. The scores of theory and skill operation examination after teaching, nurses' clinical ability before and after teaching and satisfaction with teaching were compared between the two groups. SPSS 25.0 was used for independent sample t test, paired t test and chi-square test. Results:After teaching, the scores of theory and skill operation in the study group were significantly higher than those in the control group [(86.19±4.64) vs. (79.27±5.36), (89.32±5.47) vs. (84.51±6.22)], with statistical differences ( P<0.05). After teaching, the scores of clinical abilities of the two groups were higher than those before teaching ( P<0.05), and the scores of clinical abilities of the study group were higher than those in the control group, with statistical differences ( P<0.05). The satisfaction with teaching form, content, effect and comprehensive evaluation of the study group were higher than that of the control group, with statistical differences ( P<0.05). Conclusion:The application of the goal-oriented comprehensive teaching method in the teaching of rotation training of residents in the department of breast surgery can enhance their learning and mastering of theoretical knowledge, operational skills and the cultivation of clinical ability, and improve the teaching quality, with high teaching satisfaction.

The value of multi-parametric MRI radiomics in the prediction of neoadjuvant therapy for rectal mucinous adenocarcinoma / 中华放射学杂志

Objective:To investigate the application value of baseline MRI multi-parametric imaging radiomics in prediction of neoadjuvant chemoradiotherapy (NCR) efficacy of rectal mucinous adenocarcinoma (RMAC).Methods:Retrospective analysis was performed in the Sixth Affiliated Hospital of Sun Yat-sen University from August 2012 to October 2018. A total of 79 patients were included in this study, including 52 males and 27 females, aged 20-78 years (median age 52 years). According to the classification criteria of pathological regression, all patients were divided into NCR responsiveness group ( n=31) and nonresponsiveness group ( n=48). And 701 imaging features of T 2WI, diffusion weighted imaging (DWI) and enhanced T 1WI images of baseline MRI were extracted, and feature subsets were selected by repeatability analysis and feature dimensionality reduction to construct the radiomics prediction model. The tumor features from baseline MRI between the NCR responsiveness group and the nonresponsiveness group were compared, and the features of P<0.05 were combined with the radiomics to construct a model. Using pathology as the gold standard, the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficiency of the prediction model, and the area under the curve (AUC), 95% confidence interval, sensitivity and specificity were calculated, and the DeLong test was used to compare the diagnostic efficacy of different prediction models. Results:By comparing the conventional tumor imaging characteristics of the NCR responsiveness group and the nonresponsiveness group, the differences in lymph node stage and mucinous nodule status between the two groups were statistically significant (χ2 =6.040, 5.870, P<0.05). The AUC of ROC curves based on T 2WI, DWI, and enhanced T 1WI radiomics were 0.816, 0.821, and 0.819, respectively, which were higher than those of conventional tumor characteristics (lymph node staging, mucinous nodule status) (AUC=0.607), and the differences were statistically significant ( Z=-2.391, -2.580 and -2.717, P<0.05). Among the joint prediction models of T 2WI, DWI and contrast-enhanced T 1WI radiomics and conventional tumor features, the DWI combined model had the largest AUC (0.843), and there was no statistically significant difference between the three combined models (all P>0.05). Conclusion:The baseline T 2WI, DWI, and contrast-enhanced T 1WI radiomics model can be used to predict the NCR efficacy of RMAC, which is better than the predictive efficacy of conventional features, and the combination with conventional features can further improve the predictive efficacy.

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.

Endorectal ultrasound in evaluation on mesorectal fascia invasion in preoperative rectal cancer / 中国医学影像技术

Objective To evaluate the value of endorectal ultrasonography (ERUS) in assessment of mesorectal fascia (MRF) invasion in rectal cancer.Methods Data of 44 patients who accepted preoperative ERUS and total mesorectal excision surgery within a week were retrospective analyzed.There were 18 patients who accepted preoperative neoadjuvant chemotherapy and 26 patients didn't acceped.Taking the pathological diagnosis of circumferential resection margin (CRM) as the gold standard,the diagnostic efficiency of ERUS for the MRF invasion in rectal cancer was evaluated.Results The final pathological T staging was T1 in 2 cases,T2 in 17 cases and T3 in 25 cases.There were 2 cases of CRM positive results,and 42 cases of CRM negative results.With regard to the location of tumor,there were 16 cases located in low,and 28 cases in mid rectum.There were 26 cases located in anterior or antero-lateral wall of rectum,13 cases in posterior or postero-lateral wall,and 5 cases with a circle of rectum.The diagnostic accuracy were 83.33 ％ (15/18) and 92.31％ (24/26) for cases of accepting and not accepting the preoperative neoadjuvant chemotherapy;80.77％ (21/26) for cases located in anterior or antero-lateral wall,and 100％ (13/13) for cases located in posterior or postero-lateral wall;75.00％ (12/16)and 96.43 ％ (27/28) for low position and mid position tumors.The total diagnostic accuracy was 88.64％ (39/44).Conclusion ERUS can be an effective method in preoperative assessment of the MRF invasion in rectal cancer.

Evaluation of three-dimensional CT reconstruction on the anatomic variation of inferior mesenteric artery and left colic artery / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To demonstrate the clinical applicability of three-dimensional CT angiography by evaluating the anatomic features and variation of inferior mesenteric artery(IMA) and left colic artery(LCA) in order to provide reference to vessel ligation strategy in laparoscopic rectal cancer surgery.</p><p><b>METHODS</b>Clinical and image data of 123 patients receiving abdominal multislice CT at The Sixth Affiliated Hospital from 2014 to 2015 were retrospectively analyzed. The images were 3D-reconstructed with computer 3D CT angiography and arterial enhancement phase images were chosen for analysis. Linear distances from IMA root to abdominal aortic bifurcation and from LCA at IMA root level to IMA root were measured. Branch types of IMA, coursing pattern of LCA, and association between LCA and inferior mesenteric vein (IMV) site were summarized.</p><p><b>RESULTS</b>Of 123 cases, 80 were males and 43 were females, mean age was (46.8±16.6) years, body weight was (57.7±10.4) kg, and BMI was (21.3±3.6) kg/m. The average distance from IMA root to abdominal aortic bifurcation was (42.5±7.9) mm, and this distance was closely associated with body weight (OR=4.771, 95%CI: 1.398 to 16.283, P=0.013). Longer distance tended to appear in the heavier patients. LCA and sigmoid artery (SA) originating from same single IMA was found in 61(49.6%) cases; LCA and SA forking at same point in 35(28.5%) cases; LCA and SA coursing together and forking afterwards in 24(19.5%) cases, and LCA disappearing in 3(2.4%) cases. In 71(57.7%) patients, LCA ascended medial to the lateral border of left kidney, while in 16(13.0%) patients, LCA arranged below the inferior border of left kidney. When the LCA site was higher and the distance from LCA to IMA root was closer [distance from LCA to IMA root level was (24.2±9.9) mm, (30.0±15.2) mm and (66.6±12.3) mm, F=83.2, P<0.001]. At the level of IMA root, LCA located medial to IMV in 21(17.1%) cases, located just lateral to IMV in 54(43.9%) cases, and located lateral and ascended far away from IMV in 48(39.0%) cases.</p><p><b>CONCLUSION</b>3D-CT angiography is non-invasive, efficient and accurate in evaluating coursing features and variation of IMA and its branches, which can provide important reference to the surgeons, promising laparoscopic surgery smooth and safe.</p>

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.

Influences of inferior mesenteric artery types and Riolan artery arcade absence on the incidence of anastomotic leakage after laparoscopic resection of rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the influences of inferior mesenteric artery (IMA) types and Riolan artery arcade absence on the incidence of anastomotic leakage(AL) after laparoscopic resection of rectal cancer.</p><p><b>METHODS</b>Clinical data of 116 local advanced rectal cancer patients who underwent laparoscopic resection in The Sixth Affiliated Hospital of Sun Yat-sen University from January 2012 to December 2014 were analyzed retrospectively. IMA and Riolan artery arcade were examined by preoperative computed tomography angiography (CTA) reconstruction. The influences of IMA type, Riolan artery arcade absence and ligation site (high or low) on AL were analyzed by Logistic regression.</p><p><b>RESULTS</b>The proportion of IMA types(I(-IIII() was 57.8%(67/116), 10.3%(12/116), 31.0%(36/116) and 0.9%(1/116), respectively. Riolan artery arcade absence was found in 60.3%(70/116). Eight (6.9%) patients suffered from AL. IMA type III( had significantly higher AL incidence as compared to other IMA types [19.4%(7/36) vs. 1.2%(1/80), P=0.001]. Meanwhile, patients with Riolan artery arcade absence also had significantly higher AL incidence[11.4%(8/70) vs. 0.0%(0/46), P=0.030]. However, the difference in AL incidence between high and Low IMA ligation was not statistically significant [8.0%(7/87) vs. 3.4%(1/29), P=0.531]. Seven of these 8 AL patients were found in IMA type III( with Riolan artery arcade absence and high ligation. Multivariate analysis showed that IMA type III( (P=0.001) and Riolan artery arcade absence (P=0.002) were independent risk factors of AL.</p><p><b>CONCLUSIONS</b>IMA type III( with Riolan artery arcade absence increases AL incidence significantly in laparoscopic resection of rectal cancer. IMA type and Riolan aretry arcade absence or not contribute to the selection of IMA ligation site in the operation. For the colorectal cancer patients with IMA type III( and Riolan artery arcade absence, selective low IMA ligation with root lymph node dissection should be recommended.</p>

Pay attention to the imaging diagnosis of complex anal fistula / 中华胃肠外科杂志

The diagnosis and treatment of complex anal fistula has been a significant challenge. Unwise incision and excessive exploration will lead to the secondary branch, sinus and perforation. A simple fistula may become a surgical problem and result in disastrous consequences. Preoperative accurate diagnosis of anal fistula, including in the internal opening, primary track and location of the fistula, extensions and abscess, is important for anal fistula treatment. In the diagnosis of anal fistula, imaging examination, especially MRI plays a crucial role. Localization and demarcation of anal fistula and the relationship with sphincter are important. MRI has been an indispensable confirmatory imaging examination.

The impact of heart rate on image quality and radiation dose of coronary angiography using 640-slice dynamic volume CT / 实用放射学杂志

Objective To analyze retrospectively the impact of different heart rates on image quality and radiation dose of coronary angiography using 640-slice dynamic volume CT.Methods A total of 461 patients with suspected coronary artery disease or referred to health check underwent coronary angiography with 640-slice dynamic volume CT.Two groups were created according to their heart rates:Group A had heart rate < 65 beats per minute (n=337)and Group B had heart rate between 65 to 122 beats per minute (n=124).Image quality was assessed by analyzing the 1 5 segments of the main coronary branches using 3-grade scale (grade I-good,grade Ⅱ-acceptable,grade Ⅲ-poor).Effective radiation dose was also evaluated.Results Patients in both A group and B group performed successful CT coronary angiography with a total of 6 91 5 coronary segments.Among them,coronary segments that could be evaluated reliably accounted for 94.5% (6 535/6 91 5)while 5.5% (380/6 91 5)were too small (≤1.5 mm)to be assessed. For the image quality,Group A and Group B had grade I in 90.5% (305/337)vs 74.2% (92 /124),grade Ⅱ in 9.5% (32/337)vs 21.0% (26 / 124)and grade Ⅲ in 0 % (0 / 337 )vs 4.8% (6 / 124),respectively.Image quality was significantly different be-tween Group A and Group B (P <0.001).In addition,32 patients (9.5%)in Group A had slight cardiac motion artifacts but with-out affecting image quality,whereas 26 patients (21.0%)in Group B had higher degree of cardiac motion artifacts thus graded as grade Ⅱ.Stair-step artifacts were not found in all patients.The effective radiation dose was higher in Group B than in Group A by 32.05%(7.91±0.34 mSv vs 5.99±0.17 mSv).Conclusion Coronary angiography using 640-slice dynamic volume CT can guarantee excellent image quality when heart rate < 65 beats per minute.Although the image quality would decrease in some extent it is still diagnostic when heart rate is between 65 to 122(include 65 and 122)beats per minute.

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>

Imaging diagnosis of perianal fistula in Crohn disease / 中华胃肠外科杂志

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.

Magnetic resonance imaging of T2 mapping in rabbit lumbar intervertebral disc / 中国组织工程研究

BACKGROUND:The magnetic resonance molecular imaging used in the research of lumbar disc degeneration includes T2 mapping and T1ρtechnologies at present. OBJECTIVE:To evaluate the feasibility of 1.5 T MR equipment on T2 mapping of New Zealand white rabbits lumbar disc. METHODS:T2 mapping images of New Zealand white rabbit lumbar discs were obtained on 1.5 T MR equipment. The regions of interest T2 values of lumbar discs were measured with post-processing workstation. RESULTS AND CONCLUSION:Sagittal and coronal T2 maps of 3-month rabbit discs were obtained satisfactorily on 1.5 T MR equipment. The regions of interest T2 values of nucleus pulposus in L 4/5 , L 5/6 and L 6/7 discs were (104.6±14.0) ms, (109.1±13.8) ms and (109.5±15.1) ms respectively at Pfirrmann regions of interest T2 values of anterior annulus fibrosus in L 4/5 , L 5/6 and L 6/7 discs were (82.1±9.5) ms, (80.4± 11.2) ms and (79.9±10.6) ms respectively, and T2 values of posterior annulus fibrosus in L 4/5 , L 5/6 and L 6/7 discs were (85.8±11.9) ms, (85.1±12.1) ms and (85.3±9.3) ms respectively. There were no significant differences in T2 values of nucleus pulposus, anterior annulus fibrosus and posterior annulus fibrosus in L 4/5 , L 5/6 and L 6/7 discs at PfirrmannⅠP>g 0ra.0d5e).( However, the T2 values of nucleus pulposus were higher than those of annulus fibrosus in the same discs (P0.05). The T2 values of rabbit lumbar discs obtained on 1.5 T MR equipment can be used for quantitative assessment of intervertebral disc signal.

Protective effect of PNS in spinal cord hemisection injury and its cPLA2 related mechanism / 中国医师杂志

Objective To investigate the protective effect and associated mechanism of PNS in spinal cord hemisection injury.Methods fifty-five adult SD rats were randomly divided into three groups,sham group(n =5),spinal cord injury group(n =25),PNS group(n =25).The rats were evaluated in behavioral test with BBB score,pathology and immunohistochemistry at 1 d,3d,7d,14d,21d after the procedures.Results Motor recovery was significantly better in PNS group than the spinal cord injury group at 3d,7d,14d and 21d.Nissl staining showed less neuron necrosis and more integrated neural cells in morphology.cPLA2 expression was inhabited in PNS group,and less number of positive cells were found in the group.Conclusion PNS can inhibit the expression of cPLA2 after spinal cord injury,which may be one of the mechanisms of its effect on promoting motor recovery.

Three-dimensional spin-lattice relaxation time in the rotating frame imaging and quantitation of articular cartilage at 7.0 T MR / 中华放射学杂志

Objectlve To demonstrate the feasibility of three-dimensional(3D)spin-lattice relaxation time in the rotating frame(T1ρ)-weighted imaging of porcine patellar cartilage in vitro at 7.0 T and the measurement of T1ρ of agarose phantom and patellar cartilage.Methods All the MR Imaging experiments were performed on a 7.0 T Varian scanner using a 6.0-cm-diameter quadrature birdcage RF coil tuned to 300 MHz.A 3D spin-echo sequence with a self.compensating spin-lock pulse cluster was used to acquire 3D-T1ρ-weighted images.The time of spin-locking(TSL)was from 0 to 50 ms with an interval of 10 ms.Spin-lock power wag 440 Hz.3D-T1ρweighted imaging was done three times for 6 phantoms (concentration 1%t0 6%),as well as once for 8 porcine patellar cartilages in order to assess the reproducibility of this technique.Signal-to-noise ratio(SNR)was measured on the acquired images of both phantoms and patellar cartilages,which were tested for significance using Two-way ANOVA.The images were processed on Vnmr J workstation using home-built processing software to construct 3 D T1ρ maps.T1ρ values were calculated within manually drawn regions-of-interest(ROI),and differences between groups were tested for significance using analysis of variance(One-way ANOVA).Results T1ρ -weighted images with a shorter TSL had a higher SNR value,which measured between 48±8 and 95±8 in the global cartilage.Cartilage images had a higher SNR(TSL＜30 ms)compared to agarose phantoms and a lower SNR(TSL ＞30 ms)only compared to l%agarose phantorm T1ρ relaxation times in agarose phantoms increased as agarose concentrations decreased in global regions.The CV of T1ρ in agarose phantoms was less than 10%.Global and regional analyses of patellar cartilage T1ρ were 68.9±6.3 ms,80.7±12.8 ms,65.7±7.0 ms,82.4±7.7 ms,and 69.7±6.4 ms in the global cartilage,the superficial layer,the transitional layer,the deep layer,and the calcified layer,respectively.T1ρ in the superficial and deep layer was significantly higher than in the transitional,calcified layer and global cartilage(F=6.436,P＜0.05).Conclusions The present study demonstrates the feasibihty of 3D-T1ρ-weighted imaging of porcine patellar cartilage at 7.0 T with hish image quality.T1ρ maps can be used to quantify the laminar structures in 3D-T1ρ-weighted images of articular cartilage,which pave the way to evaluate early osteoarthritis and cartilage regeneration.