Preoperative computed tomography enterography-based radiomics signature: A potential predictor of postoperative anastomotic recurrence in patients with Crohn's disease.

BACKGROUND: More than half of patients with Crohn's disease (CD) require at least one surgery for symptom management; however, approximately half of the patients may experience postoperative anastomotic recurrence (PAR). OBJECTIVES: This study aims to develop and validate a preoperative computed tomography enterography (CTE)-based radiomics signature to predict early PAR in CD. DESIGN: A total of 186 patients with CD (training cohort, n = 134; test cohort, n = 52) who underwent preoperative CTE and surgery between January 2014 and June 2020 were included in this retrospective multi-centre study. METHODS: 106 radiomic features were initially extracted from intestinal lesions and peri-intestinal mesenteric fat, respectively; significant radiomic features were selected from them and then used to develop intestinal or mesenteric radiomics signatures, using the least absolute shrinkage and selection operator and a Cox regression model. A radiomics-based nomogram incorporating these signatures with clinical-radiological factors was created for comparison with a model based on clinical-radiological features alone. RESULTS: 68 of 134 patients in training cohort and 16 of 52 patients in test cohort suffered from PAR. The intestinal radiomic signature (hazard ratio [HR]: 2.17; 95% confidence interval [CI]: 1.32-3.58; P = 0.002) and mesenteric radiomic signature (HR: 2.19; 95% CI: 1.14-4.19; P = 0.018) were independent risk factors for PAR in the training cohort as per a multivariate analysis. The radiomics-based nomogram (C-index: 0.710; 95% CI: 0.672-0.748) yielded superior predictive performance than the clinical-radiological model (C-index, 0.607; 95% CI: 0.582-0.632) in the test cohort. Decision curve analysis demonstrated that the radiomics-based nomogram outperformed the clinical-radiological model in terms of clinical usefulness. CONCLUSIONS: Preoperative mesenteric and intestinal CTE radiomics signatures are potential non-invasive predictors of PAR in postoperative patients with CD.

Hepatic mosaic enhancement pattern correlates with increased inflammatory activity and adverse therapeutic outcomes in patients with Crohn's disease.

PURPOSE: This study aimed to evaluate the role of hepatic mosaic enhancement pattern (HMEP) on computed tomography images in the disease activity and therapeutic outcome of Crohn's Disease (CD). METHODS: Twenty-five CD patients with HMEP comprised the HMEP group, and 25 CD patients without HMEP, who had a similar onset age, sex, and disease course with those in the HMEP group, comprised the non-HMEP group. No underlying liver/biliary disease was observed in any of the patients. Clinical characteristics, laboratory test results, Lémann index, and CD endoscopic index of severity (CDEIS) were compared between the groups using the Student t-, Mann-Whitney U, Chi square, or Fisher's exact tests. Patients received top-down, step-up, or traditional treatment during the follow-up period. After the 1-year follow-up, therapeutic outcomes (active inflammation [CDEIS > 3.5 if the endoscopic data were available, or C-reactive protein level > 5 mg/L if the endoscopic data were unavailable] or remission) were evaluated. RESULTS: The occurrence rate of fistulas/abscesses was higher in the HMEP group (84%, 21/25) than in the non-HMEP group (48%, 12/25) with no statistical significance (P = 0.056). The HMEP group showed a higher C-reactive protein level (P = 0.001), erythrocyte sedimentation rate (P = 0.013), and blood platelet count (P = 0.005). There was no significant difference in therapeutic strategies between the groups (P = 0.509). The HMEP group showed a significantly lower remission ratio after anti-inflammatory treatment than the non-HMEP group (P = 0.045). CONCLUSIONS: HMEP was correlated with increased inflammatory activity and adverse therapeutic outcomes in CD. This finding provided insights regarding novel markers of CD diagnosis and treatment.

Degree of Creeping Fat Assessed by Computed Tomography Enterography is Associated with Intestinal Fibrotic Stricture in Patients with Crohn's Disease: A Potentially Novel Mesenteric Creeping Fat Index.

BACKGROUND AND AIMS: Emerging evidence points to a link between creeping fat and the pathogenesis of Crohn's disease [CD]. Non-invasive assessment of the severity of creeping fat on cross-sectional imaging modality has seldom been investigated. This study aimed to develop and characterize a novel mesenteric creeping fat index [MCFI] based on computed tomography [CT] in CD patients. METHODS: MCFI was developed based on vascular findings on CT in a retrospective cohort [n = 91] and validated in a prospective cohort [n = 30]. The severity of creeping fat was graded based on the extent to which mesenteric fat extended around the intestinal circumference using the vessels in the fat as a marker. The accuracy of MCFI was assessed by comparing it with the degree of creeping fat observed in surgical specimens. The relationship between MCFI and fibrostenosis was characterized by determining if these correlated. The accuracy of MCFI was compared with other radiographic indices [i.e. visceral to subcutaneous fat area ratio and fibrofatty proliferation score]. RESULTS: In the retrospective cohort, MCFI had moderate accuracy in differentiating moderate-severe from mild fibrostenosis (area under the receiver operating characteristic [ROC] curve [AUC] = 0.799; p = 0.000). ROC analysis in the retrospective cohort identified a threshold MCFI of > 3 which accurately differentiated fibrostenosis severity in the prospective cohort [AUC = 0.756; p = 0.018]. An excellent correlation was shown between MCFI and the extent of fat wrapping in specimens in the prospective cohort [r = 0.840, p = 0.000]. Neither visceral to subcutaneous fat area ratio nor fibrofatty proliferation score correlated well with the degree of intestinal fibrosis. CONCLUSIONS: MCFI can accurately characterize the extent of mesenteric fat wrapping in surgical specimens. It may become another non-invasive measure of CD fibrostenosis.

A novel identification system combining diffusion kurtosis imaging with conventional magnetic resonance imaging to assess intestinal strictures in patients with Crohn's disease.

PURPOSE: To determine the utility of diffusion kurtosis imaging (DKI) for assessing bowel fibrosis and to establish a new magnetic resonance imaging (MRI)-based classification based on DKI and conventional MRI parameters for characterizing intestinal strictures in Crohn's disease (CD) using the histological evaluation of resected intestine samples as the reference standard. METHODS: Thirty-one patients with CD undergoing preoperative conventional MRI and diffusion-weighted imaging (DWI) (b values = 0-2000 s/mm2) were consecutively enrolled. We classified the mural T2-weighted signal intensity and arterial-phase enhancement patterns on conventional MRI. We also measured DWI-derived apparent diffusion coefficients (ADCs) and DKI-derived apparent diffusion for non-Gaussian distribution (Dapp) and apparent diffusional kurtosis (Kapp). A new MRI-based classification was established to characterize intestinal strictures in CD. Its performance was validated in nine additional patients with CD. RESULTS: Histological inflammation grades were significantly correlated to T2-weighted signal intensity (r = 0.477; P < 0.001) and ADC (r = - 0.226; P = 0.044). Histological fibrosis grades were moderately correlated to Kapp (r = 0.604, P < 0.001); they were also correlated to Dapp (r = - 0.491; P < 0.001) and ADC (r = - 0.270; P = 0.015). T2-weighted signal intensity could differentiate between no-to-mild and moderate-to-severe bowel inflammation (sensitivity, 0.970; specificity, 0.479). Kapp could differentiate between no-to-mild and moderate-to-severe bowel fibrosis (sensitivity, 0.959; specificity, 0.781). The agreement between the new MRI-based classification and the histological classification was moderate in the test (κ = 0.507; P < 0.001) and validation (κ = 0.530; P < 0.001) sets. CONCLUSIONS: DKI can be used to assess bowel fibrosis. The new MRI-based classification can help to distinguish between fibrotic and inflammatory intestinal strictures in patients with CD.

Magnetisation transfer imaging adds information to conventional MRIs to differentiate inflammatory from fibrotic components of small intestinal strictures in Crohn's disease.

OBJECTIVES: Identifying inflammation- or fibrosis-predominant strictures in Crohn's disease (CD) is crucial for treatment strategies. We evaluated the additive value of magnetisation transfer (MT) to conventional MRI for differentiating CD strictures using surgical histopathology as a reference standard. METHODS: Twenty-eight consecutive CD patients who underwent MRI preoperatively were recruited. MRI parameters included T2-weighted imaging (T2WI) hyperintensity, bowel wall thickness, enhancement pattern changes over time, enhancement pattern and gain ratio in dynamic contrast-enhanced phases, and MT ratio. Correlation analysis was performed using Spearman's rank test. Receiver operating characteristic curve analysis and Cohen's κ were used. A model with combined MRI variables characterising intestinal strictures was proposed and validated in 14 additional CD patients. RESULTS: Significant correlations with histological inflammation scores were shown for wall thickness (r = 0.361, p = 0.001) and T2WI hyperintensity (r = 0.396, p < 0.001), whereas histological fibrosis scores were significantly correlated with MT ratio (r = 0.681, p < 0.001) and wall thickness (r = 0.461, p < 0.001). T2WI hyperintensity could differentiate mild from moderate-to-severe inflammation with a sensitivity of 0.871 and a specificity of 0.800. MT ratio could discriminate mild from moderate-to-severe fibrosis with a sensitivity and a specificity of 0.913 and 0.923, respectively. Combining MT ratio and T2WI hyperintensity, the MRI classification moderately agreed with the pathological stricture classification (p < 0.01, κ = 0.549). In the validation set, the diagnostic accuracy of T2WI hyperintensity and MT ratio were 86% and 89%, with good agreement between MRI and histopathological classification (p < 0.01, κ = 0.665). CONCLUSIONS: MT ratio combined with conventional MRI improves the differentiation of fibrotic from inflammatory components of small-bowel strictures in CD patients. KEY POINTS: • MT ratio from magnetisation transfer imaging combined with T2WI from conventional MRI can simultaneously characterise bowel fibrosis and inflammation in adult Crohn's disease.

A novel collagen area fraction index to quantitatively assess bowel fibrosis in patients with Crohn's disease.

BACKGROUND: A validated histopathological tool to precisely evaluate bowel fibrosis in patients with Crohn's disease is lacking. We attempted to establish a new index to quantify the severity of bowel fibrosis in patients with Crohn's disease-associated fibrostenosis. METHODS: We analyzed the histopathological data of 31 patients with Crohn's disease strictures undergoing surgical resection. The most representative sections of resected strictured segments were stained with Masson trichrome to manifest bowel fibrosis. The collagen area fraction and histological fibrosis score were simultaneously calculated for the same section to evaluate the severity of bowel fibrosis. RESULTS: Collagen area fraction strongly correlated with histological fibrosis scores (r = 0.733, P < 0.001). It showed a stronger correlation (r = 0.561, P < 0.001) with the degree of bowel strictures than the histological fibrosis score did (r = 0.468, P < 0.001). It was also shown to be more accurate for diagnosing Crohn's disease strictures (area under the receiver operating characteristic curve = 0.815, P < 0.001) compared with the histological fibrosis score (area under the curve = 0.771, P < 0.001). High repeatability was observed for the collagen area fraction, with an intraclass correlation coefficient of 0.915 (P < 0.001). CONCLUSIONS: Collagen area fraction is a simple and reliable index to quantify the severity of bowel fibrosis in patients with Crohn's disease-associated fibrostenosis.

Ability of DWI to characterize bowel fibrosis depends on the degree of bowel inflammation.

OBJECTIVES: Although diffusion-weighted imaging (DWI) is reported to be accurate in detecting bowel inflammation in Crohn's disease (CD), its ability to assess bowel fibrosis remains unclear. This study assessed the role of DWI in the characterization of bowel fibrosis using surgical histopathology as the reference standard. METHODS: Abdominal DWI was performed before elective surgery in 30 consecutive patients with CD. The apparent diffusion coefficients (ADCs) in pathologic bowel walls were calculated. Region-by-region correlations between DWI and the surgical specimens were performed to determine the histologic degrees of bowel fibrosis and inflammation. RESULTS: ADCs correlated negatively with bowel inflammation (r = - 0.499, p < 0.001) and fibrosis (r = - 0.464, p < 0.001) in 90 specimens; the ADCs in regions of nonfibrosis and mild fibrosis were significantly higher than those in regions of moderate-severe fibrosis (p = 0.008). However, there was a significant correlation between the ADCs and bowel fibrosis (r = - 0.641, p = 0.001) in mildly inflamed segments but not in moderately (r = - 0.274, p = 0.255) or severely (r = - 0.225, p = 0.120) inflamed segments. In the mildly inflamed segments, the ADCs had good accuracy with an area under the receiver-operating characteristic curve of 0.867 (p = 0.004) for distinguishing nonfibrosis and mild fibrosis from moderate-severe fibrosis. CONCLUSIONS: ADC can be used to assess bowel inflammation in patients with CD. However, it only enables the accurate detection of the degree of bowel fibrosis in mildly inflamed bowel walls. Therefore, caution is advised when using ADC to predict the degree of intestinal fibrosis. KEY POINTS: • Diffusion-weighted imaging was used to assess bowel inflammation in patients with Crohn's disease. • The ability of diffusion-weighted imaging to evaluate bowel fibrosis decreased with increasing bowel inflammation. • Diffusion-weighted imaging enabled accurate detection of the degree of fibrosis only in mildly inflamed bowel walls.

IVIM with fractional perfusion as a novel biomarker for detecting and grading intestinal fibrosis in Crohn's disease.

OBJECTIVES: Intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (MRI) provides information on both perfusion and diffusion and has been used to evaluate Crohn's disease (CD) activity and fibrosis in children; however, there are no reports on its use in adults. We aimed to determine its value for detecting and grading intestinal fibrosis in adults with CD compared with contrast-enhanced imaging and traditional diffusion-weighted imaging using surgical histopathology as a reference standard. METHODS: Twenty-four adults with CD underwent preoperative IVIM, traditional diffusion-weighted, and contrast-enhanced imaging. Region-by-region correlations between MRI findings and histologic findings of the surgical specimens were performed. Imaging parameters including fractional perfusion, perfusion coefficient, and diffusion coefficient for IVIM and apparent diffusion coefficient value for traditional diffusion-weighted imaging and contrast-enhanced parameter of 95 bowel lesions were measured. Intestinal fibrosis was histologically scored from 0 to 3. RESULTS: The fractional perfusion (r = - 0.629, p < 0.001) and apparent diffusion coefficient values (r = - 0.495, p < 0.001) were significantly correlated with fibrosis scores. Fractional perfusion decreased following increases in fibrosis severity from mild, to moderate, to severe (p < 0.001). The area under the receiver operating characteristic curve for distinguishing moderate-severe from mild fibrosis was 0.876 (p < 0.001) for fractional perfusion, followed by 0.802 for apparent diffusion coefficient value (p < 0.001). Perfusion coefficient, diffusion coefficient, and contrast-enhanced parameter were uncorrelated with histological fibrosis. CONCLUSIONS: IVIM diffusion-weighted magnetic resonance imaging outperforms traditional diffusion-weighted and contrast-enhanced imaging in grading bowel fibrosis, and fractional perfusion may be a promising biomarker for fibrosis severity in adults with CD. KEY POINTS: • Intravoxel incoherent motion diffusion-weighted MRI outperforms contrast-enhanced imaging and traditional diffusion-weighted MRI for detecting and grading intestinal fibrosis in adult Crohn's disease. • The parameter fractional perfusion, a promising biomarker for fibrosis severity, may be beneficial for treatment planning and monitoring of bowel fibrosis in adult Crohn's disease. • Perfusion coefficient, diffusion coefficient, and the percentage of enhancement gain between 70 s and 7 min were uncorrelated with histological fibrosis.

Heat shock protein family A member 6 combined with clinical characteristics for the differential diagnosis of intestinal Behçet's disease.

OBJECTIVE: To investigate the role of heat shock protein family A member 6 (HSPA6) expression alone and in combination with clinical characteristics in distinguishing intestinal Behçet's disease (BD) from Crohn's disease (CD) with ileocolonic involvement. METHODS: Patients diagnosed with either intestinal BD or CD were enrolled. Their clinical characteristics, disease activity, laboratory test results including hypersensitive C-reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR), endoscopic, pathological and radiological features were retrospectively analyzed. Enzyme-linked immunosorbent assay was applied to measure serum HSPA6 levels. RESULTS: Among intestinal BD patients, abdominal pain and diarrhea were the leading gastrointestinal symptoms. Submucosal lymphocyte infiltration was the most common pathological finding. Computed tomography enterography features involved number of segments of less than 4 and bowel wall thickening. Independent factors were round/ellipsoid intestinal ulcer (P < 0.001), number of ulcers ≤5 (P = 0.050), elevated ulcer margin (P = 0.019), absence of aphthous ulcer (P = 0.005), bowel wall thickening >13 mm (P < 0.001) and serum HSPA6 level >3.725 ng/mL (P = 0.008) for the differential diagnosis between intestinal BD and CD. Serum HSPA6 expression was significantly elevated in intestinal BD (0.72 ± 0.39 ng/mL) compared with CD (0.50 ± 0.24 ng/mL, P = 0.000) and healthy controls (0.38 ± 0.37 ng/mL, P = 0.000). CONCLUSION: HSPA6 in combination with clinical, radiological and pathological characteristics is useful in distinguishing intestinal BD from CD with ileocolonic involvement.

T2* Mapping to characterize intestinal fibrosis in crohn's disease.

BACKGROUND: Assessing bowel fibrosis in patients with Crohn's disease (CD) has important therapeutic implications. PURPOSE: To determine the utility of T2* mapping versus that of contrast enhanced (CE) imaging in grading intestinal fibrosis in patients with CD using surgical pathology as the reference standard. STUDY TYPE: Prospective. SPECIMENS: 102 specimens from 27 patients with CD. FIELD STRENGTH/SEQUENCE: 3.0T; T2WI; T1WI; T2*WI. ASSESSMENT: The T2*WI values of the bowel wall targeted for resection were measured by two radiologists by drawing regions of interest on the thickened bowel wall. The resected bowel specimens with pathological fibrosis and type I collagen were classified into four severity grades (0-3) by a pathologist using a semi-quantitative scoring system. STATISTICAL TESTS: The differences in the T2*WI values among the different histological grades were analyzed using one-way analysis of variance or the Kruskal-Wallis test, and their correlations were analyzed. The ability of the T2*WI values to discriminate between various degrees of fibrosis was assessed using a receiver operating characteristic (ROC) curve. RESULTS: Significant differences were observed in the T2* values of mild (23.56 ± 1.60 ms), moderate (16.19 ± 0.55 ms), and severe (13.59 ± 0.53 ms) fibrosis types (F = 35.84; P < 0.001). T2* values were moderately associated with histological fibrosis (r = -0.627; P < 0.001) and type I collagen scores (r = -0.588; P < 0.001). T2* values were highly accurate, with an area under the ROC curve (AUC) of 0.951 (P < 0.001) for differentiating moderate-to-severe fibrosis from nonfibrosis and mild fibrosis, followed by an AUC of 0.508 for the percentage of enhancement gain (P = 0.908). A threshold T2* value of 18.06 ms was recommended for diagnosing moderate-to-severe fibrosis with 94.7% sensitivity and 78.3% specificity. DATA CONCLUSION: MRI T2* mapping outperforms CE parameters in distinction of various degrees of bowel fibrosis in CD. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

Characterization of Degree of Intestinal Fibrosis in Patients with Crohn Disease by Using Magnetization Transfer MR Imaging.

Purpose To evaluate the role of magnetization transfer (MT) magnetic resonance (MR) imaging for the characterization of intestinal fibrosis compared with contrast material-enhanced and diffusion-weighted MR imaging and its capability for differentiating fibrotic from inflammatory strictures in humans with Crohn disease (CD) by using surgical histopathologic analysis as the reference standard. Materials and Methods Institutional review board approval and informed consent were obtained for this prospective study. Abdominal MT imaging, contrast-enhanced imaging, and diffusion-weighted imaging of 31 consecutive patients with CD were analyzed before elective surgery. The bowel wall MT ratio normalized to skeletal muscle, the apparent diffusion coefficient (ADC), and the percentage of enhancement gain were calculated; region-by-region correlations with the surgical specimen were performed to determine the histologic degree of fibrosis and inflammation. The performance of MT imaging was validated in five new patients. One-way analysis of variance test, Spearman rank correlation, and receiver operating characteristic curve were used for statistical analysis. Results Normalized MT ratios strongly correlated with fibrosis scores (r = 0.769; P = .000) but did not correlate with inflammation scores (r = -0.034; P = .740). Significant differences (F = 49.002; P = .000) in normalized MT ratios were found among nonfibrotic, mildly, moderately, and severely fibrotic walls. The normalized MT ratios of mixed fibrotic and inflammatory bowel walls were significantly higher than those of bowel walls with only inflammation present (t = -8.52; P = .000). A high accuracy of normalized MT ratios was shown with an area under the receiver operating characteristic curve (AUC) of 0.919 (P = .000) for differentiating moderately to severely fibrotic bowel walls from nonfibrotic and mildly fibrotic bowel walls, followed by ADC (AUC, 0.747; P = .001) and the percentage of enhancement gain (AUC, 0.592; P = .209). The sensitivity, specificity, and AUC of MT imaging for diagnosing moderate to severe fibrosis in the validation data set were 80% (12 of 15), 100% (three of three), and 0.9 (P = .033), respectively. Conclusion MT imaging outperforms ADC and contrast-enhanced imaging in detecting and distinguishing varying degrees of bowel fibrosis with or without coexisting inflammation. MT imaging could potentially be used as a method to differentiate fibrotic from inflammatory intestinal strictures in patients with CD. © RSNA, 2018 Online supplemental material is available for this article.

Diffusion kurtosis MRI versus conventional diffusion-weighted imaging for evaluating inflammatory activity in Crohn's disease.

PURPOSE: To assess the efficacy of diffusion kurtosis imaging (DKI) and to compare DKI-derived parameters with that of conventional diffusion-weighted imaging (DWI) for grading the inflammatory activity of Crohn's disease (CD). MATERIALS AND METHODS: In all, 38 patients with CD underwent 3T magnetic resonance enterography (MRE) with DKI (b values of 0-2000 s/mm2 ). The inflammatory activity of the bowel segments was graded by magnetic resonance index of activity (MaRIA) as inactive (<7), mild (≥7 and <11), or moderate-severe (≥11). Apparent diffusion for non-Gaussian distribution (Dapp ) and apparent kurtosis coefficient (Kapp ) on DKI as well as apparent diffusion coefficient (ADC) on DWI were compared. RESULTS: In all, 86 bowel segments including inactive (20), mild (19), and moderate-severe (47) CD were analyzed. The differences in Kapp , Dapp , and ADC among inactive, mild, and moderate-severe CD were significant (all P < 0.05). Kapp (r = 0.862), Dapp (r = -0.755), and ADC (r = -0.713) correlated well with MaRIA in all segments. Stronger correlation with MaRIA in moderate-severe CD was found for Kapp (r = 0.647) than that of Dapp (r = -0.414) and ADC (r = -0.580). Receiver operating characteristic (ROC) curve analysis showed high accuracy of Kapp , Dapp , and ADC for differentiating active from inactive CD (AUC: 0.953 for Kapp , 0.944 for Dapp , 0.907 for ADC) as well as differentiating inactive-mild from moderate-severe CD (AUC: 0.946 for Kapp , 0.887 for Dapp , 0.846 for ADC). The threshold Kapp of 0.731 allowed differentiation of active from inactive CD with 89.4% sensitivity and 95% specificity. CONCLUSION: DKI of CD is clinically feasible and might be superior to conventional DWI for grading the inflammatory activity of CD. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:702-709.

Diffusion-weighted MRI Enables to Accurately Grade Inflammatory Activity in Patients of Ileocolonic Crohn's Disease: Results from an Observational Study.

BACKGROUND: Diffusion-weighted imaging (DWI) is a novel technique to evaluate bowel inflammation in Crohn's disease (CD). It remains unclear whether DWI could differentiate grades of inflammation activity and add to the accuracy of conventional magnetic resonance enterography (MRE) in defining disease activity. We aimed to assess the accuracy of DWI for evaluating ileocolonic CD inflammation compared with conventional MRE, using ileocolonoscopy as reference standard. METHODS: This was an observational study of CD patients who underwent both ileocolonoscopy and MRE with DWI. The conventional MRE and DWI findings of the ileocolon were scored from 0 to 3. The respective segment endoscopic disease activity was scored by simplified endoscopic score for Crohn's disease (SES-CD) and was graded as inactive (0-2), mild (3-6) or moderate-severe (≥7). RESULTS: One hundred eighty-five bowel segments from 43 consecutive CD patients were evaluated and included inactive (n = 86), mild (n = 72), and moderate-severe (n = 27) ileo-colonic segments. The area under the receiver operating characteristics curve (AUC) of 0.973 for apparent diffusion coefficient (ADC) to differentiate active from inactive CD was significantly higher than those of conventional MRE parameters (AUC between 0.840 and 0.940). Higher accuracy of ADC (AUC = 0.919) for differentiating inactive-mild from moderate-severe CD was also shown compared with that of conventional MRE parameters (AUC between 0.868 and 0.915). ADC values demonstrated strongest correlation with SES-CD (r = -0.880) comparing to DWI SI and conventional MRE parameters (r between 0.787 and 0.867). CONCLUSIONS: DWI enables to accurately grade inflammatory activity in patients of ileocolonic CD and may be better suited than conventional MRE for monitoring the activity of CD.

Assessment of Activity of Crohn Disease by Diffusion-Weighted Magnetic Resonance Imaging.

To assess the diagnostic efficacy of diffusion-weighted MR imaging (DWI) for evaluating inflammatory activity in patients with Crohn's disease (CD). A total of 47 CD patients underwent MR enterography (MRE) and DWI using 3 b values of 50, 400, and 800 s/mm. Apparent diffusion coefficients (ADCs) of inflamed and normal bowel wall were calculated. The conventional MRE findings and DWI signal intensities were qualitatively scored from 0 to 3. The correlation between Crohn disease activity index (CDAI) and both ADCs and magnetic resonance imaging scores was analyzed. Receiver-operating characteristic curve analysis was used to determine the diagnostic accuracy of CD activity. Of the 47 patients, 25 were active CD (CDAI≥150) and 22 were inactive (CDAI<150). Diffusion-weighted MR imaging and MRE + DWI scores of active CD were significantly higher than that of inactive CD (both P < 0.001). Apparent diffusion coefficients in inflamed segments of active CD were lower than that of inactive CD (P < 0.001). The DWI scores (r = 0.74, P < 0.001), ADCs (r = -0.71, P < 0.001), MRE scores (r = 0.54, P < 0.001), and MRE + DWI scores (r = 0.66, P < 0.001) were all correlated with CDAI. The areas under the receiver-operating characteristics curves for ADCs, DWI scores, MRE scores, and MRE + DWI scores ranged from 0.83 to 0.98. The threshold ADC value of 1.17 × 10 mm/s allowed differentiation of active from inactive CD with 100% sensitivity and 88% specificity. Diffusion-weighted MR imaging and ADC correlated with CD activity, and had excellent diagnostic accuracy for differentiating active from inactive CD.

Diagnostic and post-treatment CT appearance of biopsy proven mixed Cryptococcus and Candida cholangitis.

Cryptococcus neoformans and Candida are common opportunistic pathogens of human. There is very limited literature on Cryptococcus neoformans cholangitis or Candida cholangitis in immunocompetent patient while mixed Cryptococcus neoformans and Candida cholangitis has not been reported in the literature ever before. We hereby report the imaging findings of a case of mixed Cryptococcus neoformans and Candida cholangitis in an immunocompetent boy. The CT features included nodules in the cystic duct and common bile duct, dilatation of the intra- and extrahepatic bile ducts with mural thickening, irregular hypodense mass-like lesion extending along the bile ducts from the liver hilum to the periphery which was confirmed by the presence of enlarged and confluent lymph nodes. CT characteristics can contribute to timely diagnosis and treatment of this disease.

[Value of computed tomography features for prognosis evaluation of gastrointestinal stromal tumor].

OBJECTIVE: To analyze the association between CT features and survival rate of GIST, and to elucidate the significance of CT features for prognosis. METHODS: Clinical data of 38 patients with pathologically and immunohistochemically proven GISTs, including 11 patients at high biological risk, 13 at moderate risk, 10 at low risk and 4 at very low risk. Patients who underwent CT examination for primary tumors were included. Association between CT features and survival rate was examined. RESULTS: The mean follow-up period of 38 cases was 42.6 months and the 3-year survival rate was 86.8%. Univariate analysis revealed that tumor growth pattern, diameter, lobulated shape, irregular margin, necrosis, ulceration, adjacent invasion, and liver metastasis were associated factors of 3-year survival rate. Circumference invasion and hepatic metastases predicted poor 3-year survival rate (P<0.05). Calcification and intensity were not associated with prognosis (P>0.05). CONCLUSIONS: CT can demonstrate the tumor growth pattern, size, shape, boundary, density, necrosis, hemorrhage, calcification, ulcer, enhance features and metastasis. CT can play an important role in estimating the survival rate of GIST.

Multidetector computed tomography (MDCT) manifestations of the normal duodenal papilla.

OBJECTIVE: This study aimed to investigate Multidetector Computed Tomography (MDCT) manifestations of the normal duodenal papilla, thereby improving the knowledge on the CT manifestations of the normal anatomy of the duodenal papilla. METHODS: A retrospective study was conducted by reviewing the CT results of 70 normal duodenal papilla cases examined by 64-MDCT. The analysis particularly focused on the position, size, morphology, and enhancement pattern of the duodenal papilla, as well as the ampulla of Vater. RESULTS: In axial images, the average base diameter of the duodenal papilla was (7.3 ± 1.4)mm, whereas the average height was (6.5 ± 1.8)mm. Majority of the duodenal papilla (52.9%, 37/70) showed a round shape. In most cases (97.1%, 68/70), the duodenal papilla were located at the middle and lower third of the descending duodenum. In 84.3% of the cases (59/70), the arterial phase enhanced CT scan images were optimal for the visualization of the papilla. The "target sign" could be clearly identified from arterial phase images in 71.4% (50/70) of the cases. In 72.9% (51/70) of the cases, the ampulla of Vater had a common channel (Y type). CONCLUSION: 64-MDCT can clearly visualize the normal anatomy of the duodenal papilla and surrounding structures, thereby providing valuable information for the diagnosis and treatment of diseases in this region.

[Assessment of 64-slice spiral computed tomography angiography with image fusion for perigastric arteries anatomy].

OBJECTIVE: To evaluate the efficacy and clinical significance of 64-multislice spiral computed tomography angiography(MSCTA) with image fusion for the anatomy of perigastric arteries. METHODS: A total of 53 patients underwent abdominal 64-MSCTA, among whom 26 patients with gastric cancer underwent gastrectomy. Using volume rendering techniques, computed tomography angiography(CTA) of perigastric arteries and the stomach were reconstructed respectively, and then the images were fused together. The branching pattern of the celiac trunk and the origins and courses along the stomach of the 10 perigastric arteries were assessed. The accuracy, sensitivity, and specificity of 64-MSCTA were determined based on intraoperative findings. RESULTS: CTA clearly showed the celiac trunk. The most common branching pattern of the celiac trunk was Michels type I( in 46 patients(86.8%). The anatomy of perigastric arteries and stomach could be clearly demonstrated from any angle according to image fusion. The left gastric artery and the right gastroepiploic artery were shown in 100%, the left gastroepiploic artery 94.3%(50/53), the right gastric artery 83.0%(44/53), short gastric artery 58.5%(31/53), posterior gastric artery 49.1%(26/53), the replaced left hepatic artery 15.1%(8/53). The accessory left hepatic artery, accessory left gastric artery and replaced right hepatic artery were all identified in 7.5%(4/53) patients. The accuracy of preoperative CTA in term of correctly identifying perigastric arteries ranged from 84.6% to 100%, the sensitivity 82.6% to 100%, and the specificity was 100% for all the perigastric arteries. CONCLUSIONS: 64-MSCTA can clearly reveal individual perigastric arteries. The anatomy of the stomach and perigastric arteries can be shown in vivo by fused image, and can provide guidance for gastrectomy.

[Pilot study on MRI of human colon adenocarcinoma cells labeled with superparamagnetic iron oxide in vitro].

OBJECTIVE: To study the feasibility of MRI of human colon adenocarcinoma cell line (Lovo) labeled with superparamagnetic iron oxide(SPIO) nanoparticles in vitro. METHODS: Lovo cells (5 × 10(5) and 1 × 10(6)) were cultured in medium containing different SPIO nanoparticles (50 microl and 500 microl). Transmission electron microscopy was used to observe cellular ultrastructure and to determine the uptake and distribution of particles in Lovo cells at 1-, 3-, 6-hours. MRI of Lovo cells was performed with T1WI, T2WI sequences. Unlabeled cells were used as controls. RESULTS: Uptake of SPIO nanoparticles occurred within 6 hours. On T1 weighted imaging, there was no significant difference in signal intensity between the experimental groups and the control group. On T2 weighted imaging, there was no significant difference in signal intensity between the experimental groups and the control group after culture of 1 h. Signal intensity began to decrease in 1 × 10(6) Lovo cells labeled with 500 microl SPIO nanoparticle after 3 hours culture. Signal intensity decreased in all the experimental groups after 6 hours culture. CONCLUSION: Human colon adenocarcinoma cell line (Lovo) can be labeled with SPIO nanoparticles, and the labeled cells can be imaged with MRI equipment.