Objective To evaluate the correlations between CT features and histopathologic subtypes of lung adenocarcinomas presenting as pure ground-glass nodules (pGGN) of 1 cm or less in maximal diameter. Methods CT appearances, pathology and clinical data of 95 patients (97 lesions) who underwent curative resection of lung adenocarcinomas presenting as pGGN≤1 cm in diameter from March 2011 to February 2015 were retrospectively analyzed. Of the 97 lung adenocarcinomas, there were 19 atypical adenomatous hyperplasia (AAH) (19.6%), 31 adenocarcinoma in situ (AIS) (31.9%), 19 minimally invasive adenocarcinoma (MIA) (19.6%) and 28 invasive pulmonary adenocarcinoma (IPA) (28.9%). Fifty (51.5%) were preinvasive (AAH+AIS) and 47 (48.5%) were invasive (MIA+IPA). Lesion size and density were compared among pathologic subtypes using analysis of variance (ANOVA). Lesion size were compared between preinvasive and invasive lesions using 2?independent samples t?test. Lesion location, presence of bubble?like sign, air bronchogram, vessel changes, margin, and tumor?lung interface were compared among histopathologic subtypes using chi?square test. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the cut-off point of size in discriminating preinvasive lesions from invasive lesions. Results Of the 97 lesions, there were no statistically significant differences among histopathologic subtypes in terms of lesion density, presence of bubble?like sign, air?bronchogram, and margin (P>0.05). Mean size of AAH, AIS, MIA and IPA was (0.72 ± 0.19), (0.82 ± 0.14), (0.84 ± 0.11) and (0.85 ± 0.16) cm respectively. There were statistically significant differences among histopathologic subtypes in terms of lesion size (F=3.16, P=0.028). The vessel changes occurred in 2 of AAH, 11 of AIS, 10 of MIA and 17 of IPA. There were statistically significant differences among histopathologic subtypes in terms of vessel changes (χ2=13.22, P=0.004). Lesions with clear tumor?lung interface were in 10 of AAH, 24 of AIS, 17 of MIA, and 26 of IPA. There were statistically significant differences among histopathologic subtypes in terms of tumor?lung interface (χ2=12.67, P=0.005). The optimal cutoff value of lesion size for differentiating preinvasive lesions from invasive lesions was 0.82 cm (sensitivity, 61.7%;specificity, 62.0%). Conclusion Lesion size, vessel changes, and lung?tumor interface may indicate the invasiveness of lung adenocarcinoma presenting as pGGNs of≤1 cm in diameter.

Objective To determine the correlation between coronary artery calcium score (CACS) and carotid calcification, and their risk factors. Methods 162 cases underwent coronary and carotid pre-contrast CT scan with dual-source CT scanner within 2 weeks. The reconstructed parameters were the same. The calcifications of coronary and carotid arteriae were quantified by calculating the Agatston score. The main risk factors such as age, sex, hypertension, total cholesterol, low-density-lipoprotein cholesterol (LDL), high-density-lipoprotein cholesterol (HDL), diabetes, smoking and coronary heart disease history were recorded. The CACS and carotid calcium scores were comparatively analyzed using Spearman's correlative analysis. The relativity between the risk factors and CACS scores, carotid calcium scores. Results In 162 subjects, there was positive relativity between CACS and carotid cal-cium score(r=0.690, P<0.01). Logistic regression analysis showed that CACS were of relativity with age, diabetes, total cholesterol and LDL cholesterol,otherwise, carotid calcium scores only with age and diabetes. Conclusion There is significant correlation be-tween CACS and carotid calcium score, but their risk factors are not same.

Objective To evaluate the effect of quick injection combining with slow infusion of Gd-DTPA on T1 relaxation of the blood. Methods Fifteen volunteers were recruited for coronary MRA study using a navigator-gated 3D-FIESTA sequence. Coronary MRA were acquired on the same segments two times at 5 minutes and 15 minutes after Gd-DTPA administration. Contrast agent was injected biphasically with 10 ml at a flow rate of 1.5 ml/s and 20 ml at 0. 05 ml/s to prolong the T1 relaxation effect. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated pre- and post-contrast MRA. Image quality was compared using t-test. Results The SNR and CNR at 5 minutes after contrast injection (35.37 ±6. 84 and 21.57 ± 6. 08 ) were significantly higher than that of pre-contrast MRA ( 27.38 ± 6. 24 and 13.19 ±6. 50). The SNR at 15 minutes after contrast injection (33. 81 ±9. 43) was higher than that of precontrast MRA, but there was no statistically difference(t = 1. 885 ,P =0. 074). The CNR at 15 minutes after contrast injection (21.20 ± 7.65) was significantly higher than that of pre-contrast MRA. The SNR and CNR at 15 minutes after contrast injection were no significant different compared with those at 5 minutes after contrast injection. Conclusion T1-shorting effect in the blood can be prolonged by quick injection combining with slow infusion of Gd-DTPA ,which meet with the need of multiple scans of coronary MRA.

Objective To illustrate the thoracic CT findings of Behcet disease and to assess the CT diagnostic role in patients with Behcet disease. Methods Thoracic CT images and medical records were retrospectively reviewed in 13 patients with thoracic Behcet disease. The diagnosis was based on the criteria set by the international study group for Behcet disease. Results Of 13 patients, subpleural patchy consolidations were showed in 3, bilateral diffuse ground glass opacities in 3, left low lobe collapse with a right small nodule in 1, subpleural solitary pulmonary nodule in 1, bilateral pleural effusion in 2 ,mediastinal lymphoadenopathy in 2, diffuse bilateral miliary lung nodules in 1 during treatment. Thoracic vascular involvement was presented in 8 patients, two with superior vena cava thrombosis, one with left subclavicle artery aneurysm, one with left low pulmonary artery aneurysm and mural thrombosis, one with bilateral low pulmonary arteries and left basilar artery aneurysm, three with right pulmonary artery thrombosis in which there were two with left pulmonary artery occlusion and one with left basilar artery branch aneurysm. Conclusions Thoracic CT findings of Behcet disease are variable and nonspecific. Contrast-enhanced CT scan can be helpful by showing thrombosis of the superior vena cava and pulmonary artery as well aneurysm of the pulmonary artery.

Objective To analyze the rationality of 16 or more multi-slice helical CT (MSCT) utilization for solitary pulmonary nodule (SPN) (<3 cm). Methods One hundred and fifty consultant cases with SPN from 133 different hospitals, examined with 16 or more MSCT, were selected in this study. The reconstructed slice thickness of routine CT scan, thin slice reconstruction thickness, 2D or 3D reconstruction, window wide and level setting, contrast enhancement effect were recorded from consultant films. Thoracic CT scan criteria for SPN were proposed according to the scan guidelines at Stanford University and PubMed articles. The rationality of 16 or more MSCT utilization in other hospitals for SPN was analyzed by two radiologists compared with scan criteria. The diagnostic accuracy in other hospitals was evaluated according to the pathologic and treatment results in our hospital. Results Sixteen-MSCT was performed in 92 cases, 64-MSCT in 54 cases and 40-MSCT in 4 cases. In routine thoracic CT scan, 9--10 mm reconstructed slice thickness was selected in 59 cases, 7--8 mm thickness in 12 cases and 5 mmthickness in 79 cases. Consecutive thin slice thickness (<3 mm) was used for SPN only in 46 cases. OnlyMPR and VR were filmed in 9 cases without thin slice reconstructed axial images. :53 cases (35.3%) were rescanned in our hospital due to the unsatisfied image quality. Of 150 cases, 78 cases had pathologic or treatment results in our hospital and 22 cases (14.7%) were proved to be misdiagnosed in other hospitals, and only 2 cases were misdiagnosed in our hospital. Conclusion There are many irrationalities of 16 or more MSCT utilization in our country which influence the diagnostic accuracy of SPN, Unified thoracic CT scan criteria in our country are needed.

Objective To get a MR imaging protocol for coronary arterial wall in vitro. Methods MR examinations were performed in 10 fresh porcine hearts. Three dimensional fast imaging employing steady state acquisition (3D FIESTA) was used to delineate left anterior descending artery (LAD), while 2D spin-echo T1W was performed with 8-channel head surface coil, temporomandibular surface coil and knee coil with the same parameters. T1WI was obtained with 384×256 and 512×512 in matrix using temporomandibular surface coil, and then T1WI, PDW and T2WI with fat saturation were obtained with different NEX using temporomandibular surface coil after injecting Resovist in LAD. Signal of the LAD wall, lumen, fat tissue adjacent to LAD, myocardium of anterior part of interventricular septum and noise were respectively measured. Signal-to-noise ratio (SNR) of image, contrast to noise ratio (CNR) between the wall and lumen (CNR1), CNR between the wall and surrounding fatty tissue (CNR2) were calculated. Results The SNR and CNR1, CNR2 of SE T1WI with temporomandibular coil were higher than those with 8-channel head surface coil and knee coil. SNR and CNR1, CNR2 of SE T1WI with 384×256 matrix were higher than those with 512×512 matrix. SNR and CNR1, CNR2 using 3 NEX were the highest. Conclusion Good SNR and CNR of porcine coronary wall can be achieved using temporomandibular surface coil, 384×256 in matrix and NEX of 3.

Objeetive To analyze the attenuation differences of left yentricular myocardium on 64-slice CT coronary artery angiography in adults.Methods of 1130 consecutive patients,119 patients (65 males,54 females,ranged from 27 to 83 years with mean age of 52 years)with no stenosis or stenosis less than 25% in the left anterior descending arteries were enrolled.The standard axial image with 3mm slice thickness just below the aorta valve was selected for measttrement.The regions of interest(0.1 cm× 0.1 cm)in posterior interventricular septum(septal P),anterior interventricular septum(septal A),apex,anterior free wall and posterior free wall of the left ventricle were selected within the myocardium and the mean CT value wag measured.A paired Student t test was used for the comparison of CT values in different areas,P value under 0.05 was considered statistically significant.Results The megn attenuafion of the apical region(69.9±15.5)HU was lower than that of septal A(91.9±15.1)HU(t=11.060,P＜0.01)and anterior free wall(79.7±16.9)HU(t=4.639,P＜0.01),the mean attenuation in septal(93.8±14.8)HU and posterior free wall(88.0±14.3)HU showed relatively higher values.The myocardial intensity attenuation presented as a U-shape in the left ventricular myoeardium. Conclusions The mean attenuation in the left ventrieular myoeardium demonstrates as U-shape during the coronary artery angiography examination in normal adults.This can be helpful for iudging the extent of myocardial infarctiotr.

0.05); mean transit time was significantly lower but permeability surface area product higher than benign nodules (P 0.05). ③If the mean transit time ≤ 7 s was selected as cut-off value for malignant lesion, the sensitivity was 68.97%, specificity was 66.67%, accuracy was 68.49%, positive predict value was 88.89%, and negative predict value was 35.71%. When permeability surface area product ≥ 0.20 was selected as the cut-off value for malignant lesion, the sensitivity, specificity, accuracy, positive predict value, and negative predict value were 86.21%, 53.33%, 79.45%, 87.72%, and 50.0%, respectively. CONCLUSION: CT perfusion imaging is a valuable method for assessing the physiological state of solitary pulmonary nodules.

Objective To compare 16-slice multi-detector spiral computed tomography (MDCT) and breathhold 3D magnetic resonance (MR) coronary angiography in the visualization of coronary arteries and the accuracy of detecting significant (＞ 50%) coronary stenoses in patients with suspected coronary artery disease. Methods Forty patients were examined by 16-slice CT (GE, Lightspeedl6)and MR (GE,Twinspeed) within 3 days; 31 of them underwent conventional coronary angiography (CAG) within 2 weeks after CT and MR scan. CT was performed with 16× 1.25 mm detector collimation, 0.5 s rotation time and images were reconstructed at 60%-75% of the cardiac cycle. MR was performed with breath hold 3D FIESTA (TR4.0 ms, TE1.7 ms, flip angle 65, slice thickness 3 mm, FOV 280 mm, matrix 256× 192). Mean heart rate was 63 ± 5.8 bpm and β-blocker was used in 24 patients. MR and CT image quality was evaluated in 9 coronary segments (RCA1, RCA2, RCA3, LM, LAD1, LAD2, LAD3, LCX1, LCX2) using a four-point grading scale.Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for detection of significant stenosis using CAG as the gold standard. Results 16-slice CT showed higher image quality in most coronary segments except RCA2.Forty-three segments were diagnosed as significant stenosis by CAG, 36 and 27 of these were correctly detected by CT and MR respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of 16-slice CT and MR for detecting significant stenosis were 83 %, 84 %, 49 %, 97 % and 63 %, 90 %, 55 %, 93 %, respectively. Conclusion Sixteen-slice CT showed higher image quality in most coronary segments excepted for middle RCA. 16-slice CT had higher sensitivity than MR for detection of coronary significant stenosis, whereas MR had higher specificity than CT. Both CT and MR showed high negative predictive value,which is useful for excluding coronary stenosis in symptomatic patients.

Objective To prospectively evaluate the diagnostic ability of the lesions′ morphology, signal intensity time course, and early phase enhancement rate in dynamic MRI of the breast. Methods Forty cases with breast lesions were examined with a new Efgre 3D dynamic MR imaging series. Time signal intensity curves of the lesions were obtained and classified according to their shapes as monophasic, biphasic, or washout. Early phase enhancement rates of the lesions were calculated. The diagnostic indices were got by lesions′ morphology criterion, the time signal intensity curves criterion, and the enhancement rate criterion. Results There were 23 malignant and 18 benign lesions. The distribution of curve types for malignant lesions was monophasic (5%), biphasic (18%), and washout (77%). The distribution of curve types for benign lesions was monophasic (72%), biphasic (11%), and washout (17%). The distribution proved significantly difference (? 2=20.68, P