Objective To investigate the application value of quantitative analysis of the energy spectrum CT in the diagnosis and differential diagnosis of pulmonary mucinous adenocarcinoma and non-mucinous adenocarcinoma.Methods A retrospective analysis was conducted on the energy spectrum CT parameters of 12 cases of pulmonary mucinous adenocarcinoma and 24 cases of non-mucinous adenocarcinoma confirmed by surgery and pathology.Results There were significant differences between pulmonary mucinous adenocarcinoma and non-mucinous adenocarcinoma in 40-60 keV in plain scan,50-100 keV in arterial phase,40-140 keV CT value in venous phase and delayed phase,effective atomic number in plain scan,iodine concentration in venous phase and delayed phase(P<0.05).Conclusion The analysis of parameters of energy spectrum CT can be used for qualitative diagnosis and differential diagnosis of pulmonary mucinous adenocarcinoma and non-mucinous adenocarcinoma.

Objective:To investigate the computed tomography(CT)and magnetic resonance imaging(MRI)features of retroperitoneal ded-ifferentiated liposarcoma(DDL),and improve the understanding of DDL and the accuracy of preoperative diagnosis.Methods:Clinical and imaging features of 25 patients with retroperitoneal DDL from Tianjin Medical University Cancer Institute&Hospital,confirmed by patho-logy from January 2012 to June 2022,were retrospectively analyzed.Results:Among 25 cases of retroperitoneal DDL,19 and 6 had single and multiple tumors,respectively and 10 and 15 were oval and irregular shaped tumors,respectively.Most lesions had unclear boundaries,with 15 cases invading the surrounding tissues and organs.Small vessel shadows were visible in 15 cases,while calcifications or ossifications were observed in 7 cases,and cystic necrosis was observed in only 3 cases.Enhanced scanning exhibits a centripetal and progressive con-tinuous augmentation characteristic defined as"slow in and slow out."According to its manifestations in CT and MRI,it can be divided into two types:type I(soft tissue mass type),where the tumor has a soft tissue component with no fat content(14 cases);and type Ⅱ(fat con-taining),where the tumors exhibit both soft tissue and adipose components,most of which are clearly defined and rarely present in a mosa-ic shape.In abnormal fat areas,cord-like fibrous septa can be seen.Among them,the intratumoral fat composition<50%was Ⅱa type(10 cases).Intratumor fat composition≥50%was type Ⅱb(1 case).Conclusions:Combined with imaging classification,a comprehensive ana-lysis of the CT and MRI imaging characteristics of retroperitoneal DDL is of great value for its preoperative qualitative diagnosis.