ObjectiveTo explore the value of magnetic resonance diffusion weighted imaging (DWI) in preoperative Bismuth-Corlette classification of hilar cholangiocarcinoma (HCCA). MethodsA total of 53 HCCA patients confirmed by postoperative pathology were retrospectively included. The accuracy of two sequence combinations, namely dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) + magnetic resonance cholangiopancreatography (MRCP) and DCE-MRI + MRCP + DWI, in evaluating the longitudinally involved bile duct segments and Bismuth-Corlette classification of HCCA was compared. Additionally, the correlation between apparent diffusion coefficient (ADC) values and tumor Bismuth-Corlette classification as well as degree of differentiation was analyzed. ResultsThere were 318 bile duct segments in 53 HCCA patients. The accuracy rate of DCE-MRI + MRCP was 93.7% (298/318), the sensitivity was 91.5% (161/176), and the specificity was 96.5% (137/142); The accuracy rate of DCE-MRI + MRCP + DWI was 96.5% (307/318), the sensitivity was 96.0% (169/176), and the specificity was 97.2% (138/142). The accuracy of DCE-MRI + MRCP + DWI was higher than that of DCE-MRI + MRCP, with a statistically significant difference (χ2=275.902, P<0.001). Receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve (AUC) of DCE-MRI + MRCP + DWI was 0.966 [95%CI (0.940, 0.983), P＜0.000 1], and its diagnostic efficacy was superior to that of DCE-MRI + MRCP [AUC=0.940, 95%CI (0.908, 0.963), P＜0.000 1]. The DeLong test indicated a statistically significant difference in AUC between the two sequences (Z=2.633, P=0.008 5). The accuracy rates of preoperative Bismuth-Corlette classification of HCCA evaluated by DCE-MRI + MRCP and DCE-MRI + MRCP + DWI were 86.8% (46/53) and 94.3% (50/53), respectively. After adding the DWI sequence, the consistency between Bismuth-Corlette classification results and surgical pathological classification results (Kappa=0.922, P<0.001) was higher than that of DCE-MRI + MRCP sequence (Kappa=0.820, P<0.001), with a statistically significant difference (χ2=160.370, P<0.001). In addition, the ADC value of HCCA was negatively correlated with tumordegree of differentiation (rs=–0.524, P<0.001), but had no significant correlation with its Bismuth-Corlette classification (rs=–0.058, P=0.682). ConclusionsDCE-MRI + MRCP + DWI sequence can effectively improve the accuracy in preoperative evaluation of the involvement of bile duct segments and Bismuth-Corlette classification of HCCA, which provides guidance for precise preoperative surgical planning in clinical practice. In addition, the ADC value can provide additional information required for non-invasive preoperative prediction of the prognosis of HCCA patients.
Objective To conclude the CT manifestations and pathological features of low-grade appendiceal mucinous neoplasms. Methods We reviewed the clinical and CT findings of 24 patients with low-grade appendiceal mucinous neoplasms, who were confirmed by pathology within 1 month after CT examination in SichuanProvincial People’s Hospital from January 2018 to December 2020. The distribution, morphological characteristics, cyst wall and internal characteristics, CT value and enhancement characteristics of tumors were be detected in detail. Results ① Distribution: of the 24 patients, 22 patients located in the appendix area of the right lower quadrant, 2 patients located in the right middle abdomen, and 2 patients located in the pelvic cavity. ② Morphological characteristics: of the 24 patients, 15 patients manifested as tubular, 3 patients manifested as ellipsoidal, 5 patients manifested as saccular, and 1 patient manifested as irregular shape. The average length of tumors was about 6.4 cm (4.2–12.0 cm), and the average short diameter of tumors was about 2.2 cm (0.8–5.0 cm). The short diameter of 17 patients were more than 1.5 cm. ③ The cyst wall and internal characteristics: all the 24 patients demonstrated as cystic mass, 6 patients had evenly thin and smooth cyst wall, and other 18 patients had uneven cyst wall. Of all the patients,8 patients had arc-shaped, punctate or eggshell-like calcification. ④ The CT value and enhancement characteristics: 24 patients examined by plain CT scan, 22 patients showed uniform low density (the CT value were 7–25 HU), 2 patients contained some slightly high density, 16 patients examined by enhanced CT, the cyst wall, separation, or mural nodules of 8 patients were slightly or moderately enhanced. ⑤ Pathological results: of all the gross specimens, 15 patients showed tubular dilation, 9 patients showed partial or complete dilation as cystic mass. All the 24 patients had gelatinous or mucinous contents. Microscopically, all the patients showed low-grade mucinous epithelial hyperplasia, submucosa, and mucosal muscle atrophy, accompanied by fibrosis or calcification. Conclusion Low-grade appendiceal mucinous neoplasms show some specific CT manifestations, recognize these features can improve the accuracy of preoperative CT.