ABSTRACT
ObjectiveTo study the imaging characteristics of SPN of adenocarcinoma (ASPNs) on 18F-FDG PET/CT.MethodsThe morphological and metabolic features of 35 ASPNs on FDG PET/CT were retrospectively reviewed.SUVmax (SUV) was measured and ΔSUVmax was calculated according to ΔSUVmax =(SUVmax on delay imaging - SUVmax on early imaging)/SUVmax on early imaging × 100％.Statistical analysis was performed by software SPSS 11.5 using t-test,analysis of variance and Fisher exact test.Results( 1 ) Fifteen ASPNs (42.86％,15/35) presented as nodular pattern on FDG PET imaging,while 20 (57.14％,20/35) as lamellar,cloudy or ill-defined patterns.The SUVmax of these ASPNs followed a descending order of nodular,lamellar,cloudy and ill:defined on both early and delay imaging (F =30.696 and 24.758,both P＜0.001).(2)There were 54.29％ (19/35) ASPNs with SUVmax ≥2.5 and 45.71％ (16/35) ASPNs with SUVmax ＜2.5.(3) Of 35 ASPNs,24(68.57％ ) were solid nodules and 11(31.43％) were ground glass nodules with SUVmax =4.54 ±2.69 and 1.30±0.87,respectively (t =-5.234,P ＜O.001 ).(4) The SUVmax of ASPNs on delay FDG imaging (4.22 ±3.52) was significantly higher than that on early imaging (3.49 ±2.72) (t =-4.021,P ＜0.001 ).However,SUVmax was dependent on SUVmax on the early imaging:when SUVmax ≥2.5,ΔSUVmax was positive in 94.74％ (18/19) of ASPNs; while SUVmax ＜2.5,ΔSUVmax was positive in 56.25％ (9/16) of ASPNs (P =0.013).(5) Of 31 ASPNs with cell differentiation data,there were 10/17 well-differentiated ASPNs and 13/14 poorly-differentiated ASPNs with positive ΔSUVmax ( P =0.045 ).The average SUVmax of well-differentiated ASPNs was significantly lower than that of poorly-differentiated ASPNs ( 1.70 ± 1.51 vs 4.91 ± 2.69,t =- 3.951,P ＜ 0.001 ).Conclusions The morphological and metabolic features of ASPNs are diversified.It is common for ASPN to present with SUVmax ＜ 2.5.ΔSUVmax may be helpful for differentiating malignant from benign SPNs.
ABSTRACT
Objective To evaluate the CT findings of lymphofollicular thymic hyperplasia in adult myasthenia gravis (MG).Methods The CT findings of thymus area of 134 adult patients with lymphofolficular thymic hyperplasia in MG were reviewed,all of them with surgically and histologically proven diagnosis,and compared with the CT findings of 165 normal subjects.Results In the group of patient,CT showed enlargement of thymus in 31 patients,5 patients had nodule or mass(＜3 cm);thus 36 cases(26.9%)can confirmed diagnose by CT with thymic hyperplasia.CT showed 2 masses(＞3 em) and 9 patients(6.7%)had normal size thymus with soft-tissue density,it can considered with thymic hyperplasia.The spotty or streak shadow showed in other patients,though it could not be certain diagnosed as thymic hyperplasia,but could not be except it.The thymus area tissue complete replacement by fatty density were not found in patient group.The CT findings of patients had marked difference when compared with group of normal subjects(P＜0.01),except the spotty or streak shadows.Conclusion CT scan is an important method in diagnosing thymic lymphofollicular hyperplasia of MG in adult.