Objective To investigate MRI features of metanephric adenoma(MA). Methods The retrospective analysis was performed on 6 adult patients that were scanned by regular, DWI and dynamic-enhancement MRI two weeks before surgery and diagnosed with MA pathologically after surgery. MRI features of lesions were observed. The signal intensities of lesions and contralateral normal renal cortex and medulla were respectively measured in plain scan, cortex, parenchyma and delayed phase. The enhancement magnitudes were calculated and the ADC values of lesions were measured. The differences of the signal intensity and enhancement magnitude were assessed by paired-sample t test among renal cotex, medulla and lesions. Results All lesions in MA were single and solid masses. Four cases occurred in the right kidney and two cases in the left kidney. The maximum diameters of the lesions ranged from 21 to 79 mm and the mean value was(41 ± 20)mm. Five cases were round or oval, while one case was irregular. The signal intensity in five cases was slightly lower in T2WI than the renal parenchyma, while one case was slightly higher than the renal parenchyma. The hyperintentsity of DWI and hypointensity of ADC were seen in all cases. The mean ADC value was(0.759 ± 0.211) × 10-3mm2/s. Hemorrhage were seen in two cases. Necrosis was present in one case and the capsules were seen in two cases. No scar, fat and swollen lymph nodes was seen in all cases . There was no statistical significance of the signal intensity between lesions measure in the plain scan and normal renal parenchyma(P>0.05). After adminstrating contrast materials, all lesions shown persistently mild to moderate enhancement . The siganl intensities of lesions measured in three phases after enhancement were signifcantly lower than those of the renal cortex(P<0.05). No significant differences of the signal intensity measured in cortex and medulla phase between lesions and normal renal medulla was present(P>0.05). But the signal intensities of leisons in delayed phases were significantly lower than thoseof renal medulla(P<0.05). Except from the difference of enhanced magnitude in cortex phase between lesions and normal medulla, significant differences were present between leisons and normal renal parenchyma(P<0.05). Conclusion MRI manifestations of MA show certain distinction, including, dominantly solid lesions, relatively lower signal intensity of lesions than that of renal cortex, slowly persistent enhancement, high signal on DWI and low signal on ADC.

Objective:To explore the value of a nomogram model based on the CT enterography (CTE) signs for prediction of intestinal penetrating lesions in patients with Crohn disease (CD).Methods:The clinical and CTE data of CD patients who underwent at least two CTE examinations from January 2010 to June 2020 in the First Affiliated Hospital of Sun Yat-sen University were retrospectively collected. A total of 112 patients were enrolled, and according to whether there was intestinal wall penetration in the last CTE observation were divided into non-penetration group (84 cases) and penetration group (28 cases). First, the clinical and CTE data for the first examination was analyzed by using univariate and multivariate Cox proportional hazards regression to screen out high-risk factors that could effectively predict intestinal wall penetrating lesions in CD patients and established a nomogram model. Then the change trend of CTE data (ΔCTE) between the first and last clinical and CTE signs was analyzed by using univariate and multivariate Cox proportional hazards regression, and built a nomogram model to sort out ΔCTE that may accompany the development of penetrating lesions in CD patients. The Harrell concordance index was used to evaluate the discriminative ability of the nomogram model.Results:In the first time clinical and CTE signs, multivariate Cox proportional hazards regression results showed that numbers of diseased bowel segments (HR=0.686, 95%CI 0.475-0.991, P=0.045) and the shortest diameter of the largest lymph node (HR=0.751, 95%CI 0.593-0.949, P=0.017) were independent protection factors for penetrating lesions, and rough bowel wall surface (HR=5.626, 95%CI 2.466-12.839, P<0.001) was an independent risk factor for penetrating lesions. The specificity and sensitivity of the nomogram model to predict non-penetration lesions were 82.1% and 59.5% respectively, and the Harrell concordance index was 0.810 (95%CI 0.732-0.888). In the ΔCTE signs, multivariate Cox proportional hazards regression showed that Δrough bowel wall surface (always rough bowel wall surface HR=12.344, 95%CI 2.042-74.625, P=0.006; slide bowel wall surface becomes rough bowel wall surface HR=28.720, 95%CI 4.580-180.112, P<0.001) and Δthe shortest diameter of the largest lymph node (HR=1.534, 95%CI 1.091-2.157, P=0.014) were independent risk factors for penetrating lesions. The specificity and sensitivity of the nomogram model were 89.3% and 79.2% respectively, and the Harrell concordance index was 0.876 (95%CI 0.818-0.934). Conclusion:The nomogram based on CTE signs of numbers of diseased bowel segments, the shortest diameter of the largest lymph node and rough bowel wall surface and ΔCTE can effectively predict the intestinal wall penetrating lesions of CD patients.