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
<p><b>BACKGROUND</b>Previous studies have compared single-photon emission computed tomography (SPECT) and electron beam computed tomography (EBCT) in detection of coronary artery disease (CAD) in patients with myocardial infarction (MI). The purpose of this study was to compare SPECT with EBCT in detection of CAD in patients with no MI.</p><p><b>METHODS</b>One hundred and forty-seven patients with suspected CAD underwent stress-rest (99)mTc-methoxyisobutylisonitrile ((99)mTc-MIBI) myocardial SPECT, cardiac EBCT and coronary angiography (CAG) within one month. Of them, 73 patients (aged 52.6 +/- 10.6 years old) with no history of MI were included in this study. Coronary artery calcium (CAC) was defined as a CT value >or= 130 HU within the boundary of coronary artery on EBCT.</p><p><b>RESULTS</b>There were 35 and 38 patients with or without CAD according to CAG. Ninety-six percent of the patients with abnormal SPECT and CAC had a coronary arteries stenosis >or= 50%, and 90.9% patients with normal SPECT and EBCT showed no CAD. The sensitivity of SPECT and EBCT in detection of CAD was comparable, and the specificity of SPECT (92.1%) was significantly higher than that of EBCT (55.3%) (P < 0.005). For the detection of individual coronary artery stenosis, both sensitivity and specificity of SPECT (75.0% and 93.7%) were significantly higher than those of EBCT (53.3% and 76.7%) (P < 0.025 and P < 0.005, respectively). In patients without chest pain, the sensitivity and specificity of SPECT (76.9% and 91.4%) were significantly higher than those of EBCT (23.1% and 69.0%) in detection of a coronary artery stenosis of >or= 50% (P < 0.01 and P < 0.005, respectively). However, in patients with chest pain, both sensitivity and specificity of SPECT were comparable to those of EBCT. In patients <or= 45 years old, the sensitivity of SPECT (77.8%) was significantly higher than that of EBCT (27.8%) in assessing a coronary artery stenosis of >or= 50% (P < 0.005), and the specificity of SPECT was comparable to that of EBCT. In patients > 45 years old, the specificity of SPECT (94.3%) was significantly higher than that of EBCT (70.5%) (P < 0.005), and the sensitivity of SPECT was comparable to that of EBCT.</p><p><b>CONCLUSION</b>(99)mTc-MIBI myocardial perfusion SPECT has higher accuracy than that of EBCT in detection of CAD in patients without MI.</p>