Objective To report the CT app earances in SARS (severe acute respiratory syndrome). Methods Nine chest CT scanning examinations were performed in 6 cases of SARS that were verified by the clinic. CT films were acquired with standard pulmonary window, mediastinal window, and wide window, respectively.CT imaging appearances were summarized. Results In 5 of the 6 cases, multi-lobar or multi-segmental consolidations of bilateral lungs were detected. There was no distribution tendency for any specific pulmonary lobes or segments. The big consolidation and small multiple consolidations existed simultaneously. The big range of consolidation manifested as the bilateral or unilateral pulmonary segment consolidation that distributing along the bronchi tree. There was the air bronchogram in the consolidation. Each consolidation expanded along the pulmonary segment and mixed together to form a pulmonary segment consolidation, or even a whole pulmonary lobe consolidation. The foci that crossed the interlobar fissure were not observed. The small foci manifested as the bilateral multiple oval foci, which distributed along the lung markings. The big consolidation could appear as homogeneous densification, ground-glass appearance, or honeycomb consolidation. The ground-glass appearance could appear in cases of first visiting and in cases of recovery period. The pleural thickened was common and hydrothorax was rare. The mediastinal lymph node enlargement was not observed. Conclusion The limited SARS cases show a tendency that the pathological changes disseminate along broncho-alveolar system when SARS is developing.

Objective To assess the displaying of the cystic artery and the cystic duct in calculus cholecystitis patients using MSCT.Methods One hundred and three patients with calculus cholecystitis (the experimental group)and 71 patients with non-gallbladder disease (the control group)performed the cystic artery and the cystic duct imaging using MSCT.The data in two groups were recorded and statistical analyzed.Results (1)The display rate of the cystic duct were 93.2% (96/103)in the experimental group and 100% (71/71)in the control group with the significant difference between the two groups (P <0.05).7 cases whose cystic ducts could not displayed in the experimental group were all the acute cholecystitis,and the display rate of the cystic duct in the acute cholecystitis was 77.4%(24/31).The display rate of the cystic artery were 100% in both the experimental and control group.(2)The variation rate of the cystic duct running were 10.4% (10/96)in the experimental group and 18.3% (13/71 )in the control group with no significant difference between the groups (P >0.05).The variation rate of the cystic artery running were 13.5% (13/96)in the experimental group and 1 5.5% (1 1/71)in the control group.There was no significant difference between the groups (P >0.05).Conclusion The cystic duct and the cystic artery could be evaluted well in calculus cholecystitis using CT.The displaying of the cystic duct is relatively poor in acute cholecystitis.

Objective To investigate the diagnosis of intracranial artery fenestration and its other vascular anomalies with CT angiography ( CTA ) . Methods The image data of 653 patients examined with head CTA and 39 patients diagnosed as intracranial artery fenestration in Zhongshan Hospital Affiliated to Sun Yat-sen University from January 2013 to January 2014 were analyzed retrospectively. The incidence, location,morphology of intracranial artery fenestration, and other vascular anomalies were analyzed. Results (1) In 653 patients,39 (5. 97%) with 41 artery fenestrations were detected. The detection rates of basilar artery fenestration was 3. 37% (n=22),vertebral artery fenestration was 0. 31% (n=2),anterior cerebral artery fenestration was 1. 22% (n =8),anterior communicating artery fenestration was 0. 61%(n=4),and middle cerebral artery fenestration was 0. 76% (n=5),respectively. The post-circulation fenestration was mainly convex lens type (66. 67%,n =17),the anterior-circulation fenestration was mainly fissure type (76. 47%,n=24),and there was significant difference (χ2=7. 411,P<0. 05). (2) In the 39 patients,22 complicated other vascular anomalies. Most of them were unilateral or bilateral fetal-type posterior cerebral arteries (n=10),and followed by aneurysms (n=5). The locations of 5 aneurysms were far from the fenestration,3 located in the communicating segment of internal carotid artery,1 in the top of basilar artery,and 1 in the M2 segment of bilateral middle cerebral arteries. Conclusion CTA can intuitively and clearly reveal the intracranial artery fenestration and other vascular anomalies. But there is no significant correlation between arterial fenestration and vascular anomalies.

0.05).(2) The volume range of 25 hepatocellular tumors was 395.16～2747.7 ml using diameter measurement and 203.10～1463.19 ml using MSCT 3D measurement before the operation.There was significant difference of the data in these two groups using t-test (t=7.689, P

Objective To compare the image quality and patient radiation dose of coronary computed tomography angiography (CCTA) received by prospectively-gated step-and-shoot (SAS) technique with those obtained by retrospectively-gated spiral (RGS) technique on a 256-slice CT scanner. Methods A total of 200 patients were enrolled in this study. One hundred patients underwent CCTA with SAS mode were subdivided into two groups: ( 1 ) 50 patients with an average heart rate (HR) ≤70 bpm were scanned with a data acquisition time window centered at the 75％ of the R-R cycle ( group A) and (2) 50 patients with HR ＞ 70 bpm were scanned with the data acquisition time window centered at the 45％ of the R-R cycle, including a phase tolerance of ±％ (group B). Other 100 patients underwent CCTA with RGS mode and ECG-based tube current modulation were also subdivided into two groups: (3) 50 patients with HR ≤70 bpm were scanned with cardiac dose right set to phase of 75％ (group C) and (4) 50 patients with HR ＞ 70 bpm were scanned with cardiac ose Rdight set to phases of 45％ and 75％ (group D). All patients were grouped in randomized order. The image quality of CCTA were evaluated using a rank scale from 1 to 4 ( 1 : excellent ; 4 : non-assessable ) .Radiation dose of the four groups received was also estimated. The image quality between groups was compared by Mann-Whitney U test.The radiation dose between groups was compared by t test. For the 100 patients received by prospective ECG-gated CCTA, the receiver operating characteristic curve (ROC) was used to analyze the CCTA image quality and average heart rate to determine the uppercutoff of HR for obtaining diagnostic coronary images with SAS mode. A spearman correlation analysis was also performed to analyze the correlation of HR and image quality in patients underwent CCTA with SAS mode.Results Of 2338 coronary artery segments, excellent or good image quality( score of 1 or 2) was achieved in 96. 5％ (585 of 606) in group A, 77.7％ (445 of 573 ) in B,96. 1％ (548 of 570) in C, and 85. 7％ (505/589) in D, with no significant difference for A vs C(Z ＝- 1. 351 ,P ＞0. 05) and with significant differenceS for B vs D (Z＝ -2. 236,P ＜0. 05). Linear correlation analysis indicated a significant degradation of image quality with the increase of heart rate using SAS mode (Spearman correlation, r ＝ 0. 577, P ＜0. 01 ). ROC analysis established an upper HR threshold of 78 bpm for obtaining diagnostic image quality using SAS mode( AUC ＝ 0. 827, P ＜ 0. 05 ). The average radiation dose in group A [ ( 2. 6 ± 0. 5 ) mSv]reduced 75 ％ comparing with that in group C [ ( 10. 6 ± 2. 3 ) mSy], and the average radiation dose in group B [ ( 4.0 ± 0. 7 ) mSy]reduced 69％ comparing with that in group D [ ( 13.0 ± 1. 4) mSv]. ConclusionUsing SAS mode to perform low-dose CCTA with 256-slice helical CT could keep the image quality and reduce radiation dose significantly. Our preliminary experience suggests a good promise of this technique which could be applied to a wider group of patients such as with higher heart rates.

Objective To investigate image quality and radiation dose of prospective ECG-gated coronary combined with carotid and cerebrovascular angiography and compare it with common coronary CTA and carotid-cerebrovascular CTA at a 256-slice spiral CT.Methods Fifty-seven patients were included in the study.The data was analyzed retrospectively and divided into 3 groups.Group 1 underwent coronary combined with carotid CTA ( n =17 ),which included a wide range of prospective ECG-gated coronary,carotid and cerebral vascular one-stop angiography.Group 2 underwent coronary CTA ( n =20),which was routine prospective ECG-gated coronary angiography.Group 3 underwent routine carotid and cerebrovascular CTA (n =20).Mean CT image attenuation and image noise were measured in the ascending aorta root,proximal parts of the bilateral common carotid artery and vertebral artery,and in the internal carotid artery at sellae level in the axial plane.Coronary artery image quality was rated using a four-point ordinal scale and carotid cerebral vascular image quality was rated using a three-point ordinal scale.Radiation dose were calculated.Mean CT image attenuation,image noise and radiation dose were compared among the 3 groups using t test.Using Mann-Whitney U,the coronary artery imaging quality was compared between group 1 and 2,and image quality of cerebral vessels was compared between group 1 and 3.Results Mean CT image attenuation [ (427 ±50) HU in group 1 and (426 ±86) HU in group 2] and image noise of the ascending aorta root [ (30 ± 9) HU in group 1 and (31 ± 9) HU in group 2 ] showed no statistical difference between group 1 and 2 (t =0.058,-0.325,P ＞0.05).There were no non-diagnosis coronary segments in group 1 and 2.And coronary segments with excellent or good image quality reached 98.1％ (202/206) in group 1 and 99.6％ ( 244/245 ) in group 2.It showed no significant difference between group 1 and 2 ( Z =-0.572,P ＞ 0.05 ).There were significant differences of mean CT image attenuation in the common carotid artery between group 1 [ ( 474 ± 70 ) HU ] and group 3 [ ( 348 ± 81 ) HU ],and in the vertebral artery between group 1 [(447 ±83)HU] and group 3 [(328 +66) HU] (t =5.043,4.869,P＜0.05).However,there was no significant difference of mean CT image attenuation in the internal carotid artery [ (370 ± 92) HU in group 1 and ( 367 ± 97 ) HU in group 3 ] ( t =0.111,P ＞ 0.05 ).There was a significant difference of image quality scores of carotid and cerebrovascular arteries between group 1 and 3 (Z =- 3.306,P ＜ 0.05 ).Effective radiation dose of groups 1,2,3 were ( 7.0 ± 0.8 ),( 3.1 ± 0.4 ) and (5.0 ± 0.3) mSv respectively.Conclusion The prospective ECG-gated coronary combined with carotid and cerebrovascular angiography is able to obtain diagnostic image quality of coronary,carotid and cerebral vascular at the 256-slice spiral CT.It is a simple,fast,noninvasive way to assess coronary and carotid cerebrovascular arteries,with advantages of less contrast medium and low radiation dose.

Objective To investigate the CT findings of histocyticnecrotizing lymphadenitis(HNL)in the neck.Methods CT data of 10 patients with pathologically confirmed HNL in the neck were retrospectively analyzed,7 males and 3 females,aged from 4 to 75 years old(median age 26 years old).Nine patients had plain CT scans and 5 of them had contrast scans.One case had only contrast CT scan.Results Totally,127 lymph nodes were identified in the neck,mainly located in the area of Ⅱ,Ⅲ,Ⅳ and Ⅴ.The maximum diameter of the involved lymph nodes ranged from 0.5-3.6 cm,1.3 cm in average.One hundred and eight lymph nodes were homogeneous and 8 were heterogeneous in plain CT images.Seventy nine lymph nodes had homogeneous enhancement and 27 had heterogeneous enhancement One hundred and ten lymph nodes had unclear margins and the surrounding fat was blurred.Conclusion CT findings of HNL of the neck are variable and non-specific.Clinical findings and laboratory examination may be helpful for the diagnosis and differential diagnosis.