ABSTRACT
Objective To evaluate the application of prospective ECG-gated dual source CT (DSCT) in patients with acute chest pain, and compare it's image quality and radiation dose with those of retrospective ECG-gated spiral scan. Methods Thirty consecutive patients (Group A, average HR ≥85 bpm) with acute chest pain were scanned with prospective ECG-gated scan and another 30 consecutive patients (Group B, average HR ≥85 bpm)were analyzed by retrospective ECG-gated scan. Tube voltage and tube current were adapted by the BMI of patients. MPR, MIP, CPR and VR were used to display pulmonary arteries (PA), thoracic aorta and coronary arteries (CA). Image quality as well as radiation dose were assessed in 2 groups. Qualitative image quality was compared with chi-square test between the two groups,while quantitative image quality [the image noise ( IN ), signal-to-noise ratio ( SNR ) and contrast-to-noise ratio(CNR)] and radiation dose were evaluated with x2 test and Student's t test. Results The proportion of valid coronary segments for diagnosis were 379/385 ( 98. 44% ) and 390/396 ( 98.48% ) respectively in Group A and Group B with no significant difference(x2 =0. 002,P =0. 961 ). The IN [( 16. 23 ±5.75)vs ( 16. 31 ±3. 32) HU] ,SNR (26. 85 ±9. 94 vs 24. 78 ±9. 91 ) and CNR (20. 99 ±9. 31 vs 18. 65 ±8. 72)showed no significant differences between 2 groups ( t = 0. 069,0. 908 and 1. 224, P ＞ 0. 05, respectively).The ED was on average ( 8. 37 ± 2. 69 ) mSv in Group A, whereas on average ( 20. 05 ± 5.52 ) mSv in Group B. There was a statistical difference between 2 groups ( t = 9. 401, P = 0. 000). Conclusion Low dose prospective ECG-gated DSCT angiography can show similar image quality as retrospective ECG-gated spiral scan with radiation dose.
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Objective To assess the role and its tecnhique superiority of 64-slice spiral CT angiography(CTA) in lower limb arterial diseases.Methods MSCT studies in 33 cases suspected diseases of lower limb arteries was performed,the helical scans covered the extent of renal artery to the artery of the lower extremity.3D reconstruction of vessel was done in Wizard workstation.The manifestations of MSCTA were compared with that of conventional angiography . Results Of the 693 segments of arteria , 683 were assessable on both DSA and CTA.Using the DSA images as the standard reference,the sensitivity,specificity and accuracy of CTA were 97.6%(95% CI,94.9%~100.7%),98.9%(95% CI,98.0%~99.8%),98.7%(95% CI,97.9%~99.5%)in detecting the segments occluded . With the regard the detection of segments that had more than moderate stenosis , the sensitivity , specificity and accuracy of MIP were 98.9% ( 95% CI , 97.4%~100.4%),99.4%( 95% CI, 98.7%~100.1%) and 99.3%(95% CI, 92.4%~99.9%).Conclusion In assessment of diseases of lower limb arteries with 64-slice spiral CT angiography is equal to DSA basically, it is a highly accurate and non-invasive angiography in diagnosing arterial diseases of the lower extremities.
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Objective To explore the imaging diagnostic value of primary ureter carcinoma.Methods Intravenous or retrograde pyelography was performed in 21 cases.Ultrasound(US)examination was performed in 25 cases.CT scan was performed in 14 cases.Results The manifestations of the intravenous and retrograde pyelography of the ureter carcinoma were irregular filling defect. The US revealed the various sized, irregular solid node , the tumor protruding into the bladder cavity. The CT displayed as various sized , different density , irregular soft mass . Conclusion The intravenous and retrograde pyelography combine with US , CT , the diagnostic level of ureter carcinoma can be increased .
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Objective To improve the applied value of Multi-slice CT (MSCT) in the diagnosis and treatment of the colonic tumours.Methods MSCT axial images reconstruction 4-D,MIP and CT virtual colonoscopy (CTVC) in 30 patients with colonic tumours proved histologically were analysed and compared these results with that of barium enema and colon endoscopy.Results The diagnostic correctly rate in this group was 100% by MSCT,while the diagnostic rate by CTVE and colon endoscopy was basicly identical.Conclusion MSCT is recommended for the diagnosis and treatment of the colonic tumour.