Objective To discuss the value of Valsalva experiment combined with improved MRI tilt tomography applying on the pharyngeal ostium of eustachian tube opening function of patients with nasopharyngeal carcinoma.Methods 1 7 cases with patholog-ically proved NPC underwent conventional MRI plain and enhanced scan.In the eustachian tube area oblique transection T2 WI and T1 WI scanning was done before and after the Valsalva experiment.The invasion of eustachian tube and its surrounding structures was analyzed and the eustachian tube function was evaluated.Results Valsalva experiments combined with improved MRI trans-verse oblique scan could clearly display the whole structure of the eustachian tube and surrounding tissue invasion compared with conventional scanning MR scan.And it could better evaluate the eustachian tube opening function for patients suffered nasopharynge-al carcinoma.Conclusion Valsalva experiments with improved MRI oblique transverse imaging could achieve individualized scan of the eustachian tube,and could be used for evaluating the pharyngeal opening function of eustachian tube in patients with nasopharyn-geal carcinoma.

Objective To observe the value of spectral CT for predicting regional lymph node metastasis of colorectal cancer(CRC).Methods Totally 73 patients with CRC confirmed by postoperative pathology were retrospectively enrolled and divided into positive group(n=29)and negative group(n=44)based on the presence or absence of regional lymph node metastasis.The lymph node short diameter,CT value of 120 kV conventional image(CT value120 kV),CT values of 40 keV and 70 keV virtual single energy images(CT value40 keV and CT value70keV),iodine density(ID),effective atomic number(Zeff)and spectral curve slope(λHU).The above parameters and clinical indicators were compared between groups.After excluding those with variance inflation factor greater than 10,model 1 was constructed based on carbohydrate antigen 19-9(CA19-9)and carcinoembryonic antigen(CEA),model 2 based on conventional CT parameters(lymph node short diameter,CT value120 kV),model 3 based on spectral CT parameters(CT value70 keV,ID,Zeff,λHU),and model 4 based on conventional CT parameters and spectral CT parameters.The efficacy of 4 models for predicting regional lymph node metastasis of CRC were analyzed.Results Significant differences in patients'gender,carbohydrate antigen 19-9(CA1 9-9),carcinoembryonic antigen(CEA),lymph node short diameter,CT value120 kV,CT value40 keV,CT value70 keV,ID,Zeff and λHU were found between 2 groups(all P＜0.05).The area under the curve(AUC)of model 1-4 for predicting regional lymph node metastasis of CRC was 0.734,0.752,0.996 and 0.995,respectively,and significant differences were found between model 1 and 3,model 1 and 4,model 2 and 3,as well as model 2 and 4(all P＜0.001).Conclusion Enhanced venous phase spectral CT could effectively predict regional lymph node metastasis of CRC.