Radiological features of dual-energy CT lung perfusion imaging in patients with acute pulmonary embolism: comparison with CT pulmonary angiography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the relationship of the perfusion defects in the dual-energy CT lung perfusion image and the filling defects in the CT pulmonary angiography (CTPA) in patients with acute pulmonary embolism.</p><p><b>METHODS</b>The clinical data of 22 patients with acute pulmonary embolism were retrospectively analyzed. All of them underwent contrast CT scan in two phases using dual-energy CT: the first is pulmonary artery phase, and the second was performed immediately after the first phase using dual-energy scan covered the whole lung. Perfusion defects in the lung perfusion images were compared with the filling defects in the CTPA.</p><p><b>RESULTS</b>Complete filling defects of segmental and subsegmental pulmonary arteries mostly showed correspondence perfusion defects in the CT perfusion map, accounting for 83% and 62% respectively. However, when there were partial or central filling defects, most of them were partial perfusion defects or normal in the CT perfusion map. Three segmental perfusion defects were depicted without the visualization of endoluminal thrombi within the corresponding arteries.</p><p><b>CONCLUSIONS</b>The perfusion defects in the CT lung perfusion image are not completely corresponding to the filling defects in the CTPA. The combination of CTPA and CT lung perfusion map will offer more information for the acute pulmonary embolism.</p>

Dual-energy CT angiography for evaluation of internal carotid artery stenosis and occlusion / 中国医学科学院学报

<p><b>OBJECTIVE</b>To compare the feasibility of bone and calcified plaque subtracted dual-energy CT angiography (CTA) with time of flight magnetic resonance angiography (TOF MRA) in evaluation of internal carotid artery atherosclerosis.</p><p><b>METHODS</b>Totally 32 patients received a dual-energy CTA scan, along with a cerebral TOF MRA scan before or after CTA examination from one day to one month. Dual-energy software was used for bone and calcified plaque subtraction. Five anatomical segments were described for each internal carotid artery according to Fischer (1938). Ratings were based on a 1-4 scale for the dual-energy CTA maximum intensity projection (MIP) image: 1 not diagnostic, 2 partially diagnostic, 3 diagnostic, and 4 excellent. Lesions were categorized as mild (0-29%), moderate (30%-69%), severe (70%-99%), or occluded (no flow detected). Stenosis of internal carotid artery was evaluated based on post-subtracted CTA images and TOF MRA images.</p><p><b>RESULTS</b>In 320 arterial segments, 99% of arterial segments were > or = 3 score. Grading of stenosis on dual-energy CTA agreed with grading of stenoses on MRA images in 98% of arteries. In the mild and occlusion group, the agreement was 100% respectively. In the moderate and severe group, dual-energy CTA showed more severe stenosis than MRA in 7 vessels and there was significant difference between the results from the two different modalities (Z = -3.071, P = 0.002).</p><p><b>CONCLUSION</b>Dual-energy CTA can be used to assess the stenosis of internal arteries around skull base, but may exaggerate the severe stenosis of cerebral arteries compared with TOF MRA.</p>

Perfusion characteristics of renal tumor and volume of normal kidney before and after arterial embolization on 64-slice spiral CT / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the perfusion characteristics and compare the volume of normal kidney and serum creatinine (Scr) before and after arterial embolization on 64-slice spiral CT.</p><p><b>METHODS</b>Totally 21 patients with renal tumor were enrolled. Sixty-four slice spiral CT was used for renal perfusion scan before and after patients underwent tumor arterial embolization. Perfusion characteristics, including blood flow, blood volume, and permeability of renal mass parenchyma and renal cortex in normal kidneys were calculated and the volume of normal kidneys was measured. The values of Scr in all patients were recorded. The perfusion characteristics, the volume of normal kidneys and the level of Scr before and after embolization were compared.</p><p><b>RESULTS</b>Renal clear cell carcinoma was pathologically confirmed in all patients. After having supply blood arterial embolization of renal tumor, perfusion characteristics of tumor parenchyma significantly decreased, perfusion characteristics of renal cortex in normal kidney significantly increased, and the volume of normal kidneys was significantly enlarged (P < 0.01); however, the values of Scr in all patients were not significantly different (P > 0.05).</p><p><b>CONCLUSIONS</b>The perfusion characteristics and volume of kidney may reflect the effects of renal arterial embolization on renal function. Perfusion imaging with multi-slice spiral CT is potentially useful in the evaluation of renal pathophysiological characteristics.</p>

Perfusion characteristics of normal renal cortex with 64-slice spiral CT / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate perfusion characteristics of normal renal cortex with 64-slice spiral CT and to investigate the correlation between perfusion parameters and gender, age, and serum creatinine (Scr).</p><p><b>METHODS</b>In total 71 healthy subjects, the kidney non-enhanced imaging and perfusion imaging with 64-slice spiral CT were performed. Perfusion parameters of renal cortex including blood flow (BF), blood volume (BV), and permeability (PM) were calculated with Siemens Body PCT (VB20B) software. The differences of BF, BV and PM in different age and gender people were compared by one-way ANOVA. The correlation between age and perfusion parameters, Scr, and PM were analyzed.</p><p><b>RESULTS</b>Technical failures were experienced in 3 (3/71, 4.2%) subjects. Perfusion values of normal renal cortex in male, female, and all subjects were obtained separately. Male subjects (n = 56): BF = (229.8 +/- 49.9) ml/(100 ml x min), BV = (398.2 +/- 59.5) 1000:1, PM = (213.5 +/- 54.0) 0.5 ml/(100 ml x min); female subjects (n = 52): BF = (230.0 +/- 56.1) ml/(100 ml x min) BV = (358.1 +/- 49.7) 1000:1, PM = (186.2 +/- 32.1) 0.5 ml/(100 ml x min); all subjects (n = 108): BF = (229.9 +/- 52.7) ml/(100 ml x min), BV = (378.9 +/- 58.4) 1000:1, PM = (200.4 +/- 46.7) 0.5 ml/(100 ml x min). There was no significant difference in BF (F = 0.367, P = 0.547), BV (F = 3.088, P = 2.762), and PM (F = 3.308, P = 0.074) between male and female. In male, female, and all subjects, BF were all negatively correlated with age (r = -0.484, r = -0.429, r = -0.425; P < 0.01), while there was no correlation between BV (r = -0.152, r = -0.243, r = -0.043, P > 0.05) and PM (r = 0.053, r = 0.123, r = 0.172, P > 0.05) and age. There was no correlation between PM and Scr (r = 0.064, P > 0.05).</p><p><b>CONCLUSION</b>The measurement of normal renal cortical perfusion characteristics with 64-slice spiral CT is feasible and can be used for the quantitative evaluation of the physiological functions of normal renal cortex.</p>

Spectrum of functioning islet cell tumor on multislice computed tomography: experience on 70 patients / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To review experience in preoperative detection of islet cell tumors using multislice computed tomography (MSCT) and summarize various imaging features of functioning islet cell tumors on enhanced MSCT.</p><p><b>METHODS</b>Seventy patients with clinical or pathological diagnosis of functioning pancreatic islet cell tumor between October 2003 and February 2007 were included in this retrospective study. Seventy-four enhanced MSCT scans in these patients were identified. All MSCT scans were interpreted by two experienced radiologists by consensus interpretation. Surgery and pathology reports were used to confirm the diagnosis, localization, and size of tumors.</p><p><b>RESULTS</b>Totally, 73 functioning islet cell tumors including 65 benign insulinomas, 2 benign glucagonomas, 3 malignant insulinomas, and 3 malignant glucagonomas were pathologically diagnosed. Tumors in only two cases were not found by MSCT. In 67 benign lesions, 32 showed typical enhancement style, 21 showed prolonged enhancement in portal venous phase, 4 showed delayed enhancement, 4 had iso-dense enhancement with normal pancreatic parenchyma, 2 had no enhancement at all in arterial phase and portal venous phase, and 4 had inhomogeneous enhancement with necrosis or cyst-formation. Patchy or spotty calcifications were found in 3 of the 67 tumors. In 6 malignant islet cell tumors, vessel invasion (2/6) and bowel invasion (1/6) were seen. Different enhancement patterns were shown. All hepatic metastases showed hyper-enhancement during their arterial phase.</p><p><b>CONCLUSIONS</b>Pancreatic islet cell tumor may display a wide spectrum of presentations in MSCT. Tumors with unusual appearances often present as diagnostic challenges. Non-contrast and post-contrast multiphase scans are recommended for the localization of functioning islet cell tumors.</p>

Perfusion characteristics of renal mass with 64-slice spiral computed tomography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the perfusion characteristics of renal mass parenchyma on 64-slice spiral computed tomography (CT).</p><p><b>METHODS</b>Totally 91 patients with renal mass were enrolled. Sixty-four slice spiral CT was used for renal perfusion scan that began with a contrast bolus injection of 50 ml (370 mgI/ml) at a rate of 5 ml/s. Perfusion characteristics, including blood flow (BF), blood volume (BV), and permeability (PM) of renal mass parenchyma and renal cortex in affected and normal kidneys were calculated from Siemens Body PCT (VB20B) software, and the perfusion characteristics among renal mass parenchyma and renal cortex in affected and normal kidneys were compared.</p><p><b>RESULTS</b>Renal clear cell carcinoma (RC-CC), renal pelvic transitional cell carcinoma (RPTCC), and renal angiomyolipoma (RAML) was pathologically confirmed in 40, 21, and 16 patients, respectively, while the remaining 14 patients were diagnosed as with renal simple cyst (RSC). Technical failure was experienced in 1 (1.1% ) patient. Perfusion parameters of tumor parenchyma were measured as follow: RCCC, BF (93.7 +/- 20.2) ml x (100 ml)(-1) x min(-1), BV (182.0 +/- 46.6) 1000:1, PM (115.7 +/-30.2) 0.5 ml x (100 ml)(01) x min(-1); RPTCC, BF (48.0 +/- 21.2) ml x (100 ml)(-1) x min(-1), BV (82.4 +/- 29.7) 1000:1, PM (65.7 +/- 17.2) 0.5 ml (100 ml)(-1) x min(-1); RAML, BF (52.6 +/- 18.5) ml x (100 ml)(-1) x min(-1), BV (110.1 +/- 45.9) 1000:1, PM (60.1 +/- 23.0) 0.5 ml x (100 ml)(-1) x min-1; RSC, BF (7.0 +/- 6.5) ml x (100 ml)(-1) min(-1), BV (16.2 +/- 9.7) 1000:1, PM (12.0 +/- 7.2) 0.5 ml x (100 ml) (-1) x min(-1). In all pathological groups, perfusion pa- rameters showed significant differences (P <0 . 1) between mass parenchyma and renal cortex in affected kidney, while there were no significant differences (P > 0. 5) in perfusion characteristics between renal cortex in affected and normal kidneys. Aslo, the perfusion characteristics were significantly different between parenchyma D in any two kinds of renal masses (P <0 . 5) except for RPTCC and RAML (P > 0. 5). C ONCLUSIONS: fDif-rent pathological types of renal mass have different perfusion characteristics. Perfusion imaging with multislice CT is potentially useful in the differential diagnosis of renal mass.</p>

Coronary angiography with dual source computed tomography: initial experience / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To explore the scan technique and image quality of coronary angiography with dual source computed tomography (CT) without oral metoprolol preparation.</p><p><b>METHODS</b>Plain and enhanced dual source CT coronary angiography without oral metoprolol preparation was prospectively performed in 600 patients. Calcium scoring with plain scan images as well as multi-planar reconstruction (MPR), maximum intensity projection (MIP), and volume rendering technique (VRT) reconstruction with enhanced scan images were performed in all cases. The scan technique and post-reconstruction experience was summarized. The image quality was classified as 1 to 4 points, and coronary segments classified according to the American Heart Association standards were evaluated.</p><p><b>RESULTS</b>The average calcium score of the 600 cases was 213.6 +/- 298.7 (0-3,216.5). The average heart rate of the enhanced scan was 82.1 +/- 16.2 (47-139) bpm. The post-reconstruction methods with which coronary segments could be shown as best as possible consisted of single phase reconstruction method, two or more phases supplemented method, and electrocardiogram editing method. Altogether 8,457 coronary segments were evaluated, among which 97.2% were evaluated as point 1, 1.7% point 2, 0.5% point 3, and 0.6% point 4. The coronary segments in 261 cases were completely normal, while 360 segments were diagnosed with < 50% stenosis and 625 segments with > or = 50% stenosis.</p><p><b>CONCLUSIONS</b>Excellent coronary artery image can be obtained with dual source CT in patients with any heart rate without oral metoprolol preparation. Heart rate is not a major source of the artifact, coronary segments can be well shown with single or multiple-phase reconstruction method.</p>

Retrospective analysis of magnetic resonance myocardial delayed enhancement / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To explore the imaging and related clinical characteristics of magnetic resonance (MR) delayed enhancement in patients with ischemic or nonischemic heart disease.</p><p><b>METHODS</b>Thirty-two cases who underwent MR myocardial cine and delayed enhancement imaging from January 2004 to October 2006 were retrospectively analyzed. The cine sequence imaging included the four-chamber view and the left ventricular short axis view. The delayed enhancement imaging was taken 10 minutes after the infusion of gadolinium from the antecubital vein with a segmented inversion-recovery-prepared T1-weighted fast gradient echo sequence. Patients underwent coronary computed tomography angiography (CTA) two weeks before or after the MR imaging examination. Combined with clinical history, the clinical and MR imaging characteristics of the patients who had delayed enhancement were analyzed.</p><p><b>RESULTS</b>MR delayed enhancement could be found in 16 cases. Among them, 12 cases had ischemic heart disease. Their coronary CTA showed one to three vessel diseases. The delayed enhancement was transmural or subendocardium, and the area of delayed enhancement corresponded well with one or more coronary arteries which had severe stenosis or occlusion. Four cases had nonischemic heart diseases. One case was dilated cardiomyopathy, with diffuse small midwall spots in delayed enhancemen and only 30% stenosis of the anterior descending coronary artery in coronary CTA. One case was hypertrophic cardiomyopathy, with delayed enhancement of strip- and patch-shaped at midwall of the hypertrophic myocardium. One case was restrictive cardiomyopathy, and the delayed enhancement was located in the area of subendocardium of both the right and left ventricles. Coronary CTA of these two cases were normal. The other case was a mass of the lateral wall of the left ventricle, and the delayed enhancement with a clumpy shape was located in the lateral wall of the left ventricle.</p><p><b>CONCLUSIONS</b>MR myocardial delayed enhancement is not a specific sign of myocardial infarction of ischemic heart disease. Nonischemic heart diseases including all kinds of primary cardiomyopathy and some other diseases affecting myocardium can also cause delayed enhancement, but their characteristics are different. The differentiation of the etiology of the nonischemic heart disease with delayed enhancement relies upon the intimate connection with clinical history and the cine sequence MR images.</p>

CT perfusion in evaluation of cerebral hemodynamics in carotid artery stenosis / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the clinical value of multi-slice spiral CT (MSCT) perfusion technique in evaluation of cerebral hemodynamics in patients with severe carotid stenooclusive lesions.</p><p><b>METHODS</b>Twenty-three patients with severe carotid stenosis were enrolled for evaluation of cerebral hemodynamics, including 12 patients with carotid occlusion and 11 with severe carotid stenosis (> 70%). Among them, 16 patients had multiple arterial diseases, including contralateral carotid stenosis, vertebral arteries stenosis, and cerebral arteries stenosis or occlusion. All patients received CT perfusion examination. Ten normal persons received CT perfusion were regarded as the control group.</p><p><b>RESULTS</b>Cerebral perfusion was bilaterally symmetrical in 10 normal persons. While in the patients group, cerebral hemodynamic impairments ipsilateral to the stenosis side were found by CT perfusion in 17 patients, including an delay of time to peak (TTP) (17 patients), increase of cerebral blood volume (CBV) (7 patients), and decrease of cerebral blood flow (CBF) (4 patients). No significant difference was found between occlusion group (n = 8) and stenosis group (n = 9) (P = 0.640), but incidences of hemodynamic impairment were significantly higher in multiple arterial diseases group (n = 14) than single arterial disease group (n = 3) (P = 0.045).</p><p><b>CONCLUSION</b>CT perfusion technique can sensitively reveal the cerebral hemodynamic impairments in patients with severe carotid stenooclusive diseases, and therefore valuable for clinical application.</p>

Diagnosis of Takayasu's arteritis affecting carotid arteries with multi-slice spiral CT / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore changes in the carotid arteries in Tarkayasu arteritis (TA) with computed tomographic angiography (CTA).</p><p><b>METHODS</b>The common carotid artery intima-medial thickness (CCA-IMT) in 20 common carotid arteries (CCAs) in 10 controls and 40 CCAs in 20 patients with TA were analyzed and compared.</p><p><b>RESULTS</b>Contrast-enhanced CT scanning combined with the application of 3D reconstruction clearly showed the carotid vascular luminal abnormalities, such as stenosis, occlusion, dilation, and aneurysm formation. CCA-IMT increased in all the patients with TA affecting carotid arteries. CCA-IMT was significantly larger in the patients than in controls [(0.36 +/- 0.13) cm vs. (0.03 +/- 0.02) cm, P < 0.05] , and was significantly larger in patients with active diseases than in those without active diseases [(0.44 +/- 0.09) cm vs. (0.24 +/- 0.10) cm, P < 0.05].</p><p><b>CONCLUSION</b>CCA-IMT increases in TA affecting carotid arteries, especially in active diseases.</p>

Comparison of coronary artery bypass graft imaging between 64-slice and 16-slice spiral CT / 中国医学科学院学报

<p><b>OBJECTIVE</b>To compare the coronary artery bypass graft (CABG) imaging between 16-slice spiral CT and 64-slice spiral CT.</p><p><b>METHODS</b>Totally 27 patients with CABG received multi-slice spiral CT imaging and the results were retrospectively analyzed. Among them, 8 patients received 16-slice spiral CT scanning, 19 patients received 64-slice spiral CT scanning.</p><p><b>RESULTS</b>The evaluability rates of 64-slice spiral CT in evaluating the proximal anastomosis, bypass graft, distal anastomosis, and distal blood vessel were 100%, 100%, 90.2%, and 93.9%, respectively, while those of 16-slice spiral CT were 92.3%, 95.2%, 90.0%, and 90.0%, respectively. The patency rates of the above four aspects of 64-slice spiral CT were 66.7%, 70.0%, 71.7%, and 70.0%, respectively, while those of 16-slice spiral CT were 83.3%, 85.0%, 83.3%, and 88.9% .</p><p><b>CONCLUSIONS</b>64-slice spiral CT is superior to 16-slice spiral CT in CABG imaging. It can be used as a non-invasive tool for the post-operative follow-up of CABG.</p>

Comparison of coronary angiography between 64-slice and 16-slice spiral CT / 中国医学科学院学报

<p><b>OBJECTIVE</b>To compare the image quality and visibility of arteries of 64-slice spiral coronary CT angiography (CTA) with those of 16-slice spiral coronary CTA, and to evaluate the diagnostic accuracy of 64-slice spiral CT for the assessment of coronary artery stenosis.</p><p><b>METHODS</b>Totally 100 patients (Group A) with suspected coronary artery diseases (CAD) were examined by 64-slice spiral CT, 48 of whom also underwent conventional coronary angiography (CAG). Another 100 patients (Group B) with suspected CAD were studied by 16-slice spiral CT. Patients with a heart rate above 70 bpm received oral beta-blockers before the scan. Data were retrospectively analyzed and reviewed by two observers. Image quality was assessed by using a 3-point grading scale from excellent (1) to non-assessable (3) and the rate of displayed coronary branches was calculated. The left main artery (LM), left anterior descending artery (LAD), circumflex artery (CX), and right coronary artery (RCA) were screened for the presence of over 50% stenosis.</p><p><b>RESULTS</b>The mean heart rates of two groups showed no significant difference [(61 +/- 8) bpm vs. (61 +/- 7) bpm, P > 0.05]. The mean scan time of Group A was significantly shorter than that of Group B [(11.9 +/- 0.9) s vs. (22.2 +/- 1.1) s, P < 0.01]. In the evaluation of image quality, better results were obtained in Group A than in Group B (1.20 +/- 0.47 vs. 1.37 +/- 0. 63, P < 0.05). The visibility of proximal arteries was similar between two groups, while the visibility of some distal arteries and small branches was found higher in Group A than in Group B (LAD distal 92% vs. 48%, CX distal 98% vs. 89%, the first obtuse marginal (OMI) 93% vs. 84%, cone branch (CB) 86% vs. 71%, P < 0.05). Compared with CAG, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 64-slice spiral coronary CTA to identify over 50% stenosis were 94.9% (56/59), 93.2% (124/133), 86.2% (56/65), and 97.6% (124/127), respectively.</p><p><b>CONCLUSIONS</b>With higher temporal and spatial resolution, 64-slice spiral CT provides improved image quality and visibility of small branches as compared with 16-slice spiral CT. 64-slice spiral coronary CTA allows reliable non-invasive diagnosis of obvious coronary artery stenosis.</p>

Assessment of coronary stent lumen visibility and patency by 64-slice spiral CT angiography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the clinical value of assessment of coronary stent patency by 64-slice spiral CT coronary angiography.</p><p><b>METHODS</b>Totally 29 patients (59 stents) were investigated using a retrospective ECG-gated enhanced scan by 64-slice spiral CT at a mean interval of (28.4 +/- 21.2) months after coronary stent implantation. Axial multi-planar reconstruction (MPR) of the stents and curved-planar reconstruction (CPR) through the stents were evaluated for image quality on a 5-point scale (1 = excellent, 5 = uninterpretable) and lumen diameter. Stent lumen diameter was compared with the vessel diameter proximal of the stents to assess the in-stent lumen visibility. Conventional coronary angiography was performed in 5 patients, and 9 stents were evaluated.</p><p><b>RESULTS</b>The image quality was good to excellent on average (scores: 1.94 +/- 0.84), depending on heart rate, breath movement, and stent location. Stent lumen was visible, on average a percentage off (76.1 +/- 11.1)% of the lumen diameter. All the 9 stents were correctly detected as being patent, which was confirmed by conventional coronary angiography.</p><p><b>CONCLUSION</b>64-slice spiral CT is a useful tool to assess the coronary stent patency.</p>

Assessment of global left ventricular function with multi-slice spiral computed tomography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the value of multi-slice spiral computed tomography (MSCT) in the determination of global left ventricular function.</p><p><b>METHODS</b>Twenty-nine patients with confirmed or suspected coronary heart diseases were imaged with a contrast-enhanced retrospective electrocardiogram (ECG) -gated technique on a 64-slice spiral CT scanner. The data sets were reconstructed at both end-diastolic and end-systolic phases in order to measure left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular stroke volume (LVSV), and left ventricular ejection fraction (LVEF). The results were compared with corresponding values obtained from conventional left ventriculography (LVG).</p><p><b>RESULTS</b>LVEDV, LVESV, LVSV, and LVEF obtained with 64-slice spiral CT were significantly correlated with the LVG data (r = 0. 887-0.956, P < 0.001). According to the Bland-Altman approach, the mean differences for LVEDV, LVESV, LVSV, and LVEF were -2.3 ml, 4.1 ml, -6.4 ml, and - 3.5%, respectively. The limits of agreement for LVEDV, LVESV, LVSV, and LVEF were -27.2-22.4 ml, -10.2-18.4 ml, -26.4-13.6 ml, and -9.8%-3.0%, respectively.</p><p><b>CONCLUSION</b>MSCT has clinically acceptable agreement with LVG for the quantification of global left ventricular function.</p>

Application of multi-slice spiral CT in the diagnosis of pulmonary hypertension / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the utility of multi-slice spiral CT in the diagnosis of pulmonary hypertension.</p><p><b>METHODS</b>The clinical and multi-slice spiral CT data of 22 patients with pulmonary hypertension were retrospectively analyzed. The diagnoses included chronic thromboembolic pulmonary hypertension (CTEPH) (n = 9), primary pulmonary hypertension (PPH) (n = 7), connective tissue diseases (n = 2), portal-pulmonary hypertension (n = 2), eosinophilia-myalgia syndrome (n = 1), and fibrosing mediastinitis (n = 1). Lung parenchyma, such as ground-glass opacity, mosaic attenuation and septal thickness, mediastinum, pulmonary vascular, right ventricular enlargement and interventricular septum displacement were evaluated on CT.</p><p><b>RESULTS</b>CT pulmonary angiography (CTPA) accurately diagnosed 95% of pulmonary hypertension and the signs of right ventricular dysfunction. Pulmonary embolism was found in 9 patients. The incidence of mosaic attenuation was significantly higher in CTECH than in PPH (P = 0.034).</p><p><b>CONCLUSION</b>CTPA can accurately diagnose pulmonary hypertension and thereby provide useful information for the etiological diagnosis.</p>

Perfusion characteristics of normal pancreas and insulinoma on multi-slice spiral CT / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the perfusion characteristics of normal pancreas and insulinoma on multi-slice spiral CT (MSCT).</p><p><b>METHODS</b>Totally 21 subjects with suspected insulinoma were enrolled. Sixteen-slice spiral CT was used for perfusion scan following a standard contrast-enhanced scan. The surgical and pathological outcomes were collected for comparison. Perfusion characteristics, including blood flow (BF), patlak blood volume (pBV), time to peak (TTP), permeability, and peak enhancement (PE) of insulinomas and normal pancreas parenchyma were analyzed based on the MSCT data sets subsequently.</p><p><b>RESULTS</b>Benign insulinoma was pathologically confirmed in 12 out of the 21 subjects, while the remaining 9 subjects were normal. Technical failures were experienced in 2 (9.5%) subjects. In both normal and tumor-suffered subjects (n = 19), perfusion parameters of normal pancreatic parachyma were measured as follows: BF (p) = 104. 9 +/- 28.9, pBV (p) = 166.4 +/- 41.8, TrP (p) = 133.3 +/- 24.4, Permeability (p) = 81.3 +/- 24.4, and peak enhancement (p) = 121.3 +/- 31.1. In subjects with insulinoma (n = 11), perfusion parameters of tumor tissue were measured as follows: F (i) = 206.5 +/- 42.2, BV (i) = 315.9 +/- 79.0, TFP (i) = 123.2 +/- 18.8, Permeability (i) = 102.5 +/- 54. 8, and peak enhancement (i) = 221.3 +/- 48.5. Results of F, BV, and peak enhancement in these two kinds of tissue showed significant differences (P < 0.01), while there were no significant difference (P > 0.05) in TTP and permeability between normal pancreatic parenchyma and insulinoma.</p><p><b>CONCLUSIONS</b>Benign insulinoma has perfusion characteristics of increased blood flow and blood volume, but its TTP is consistent with normal pancreas and has normal permeability. MSCT allows further understanding of the blood flow of the normal pancreas and its benign tumor insulinoma.</p>

Non cholangio-contrast cholangiopancreatography using multi-slice spiral CT / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the feasibility of multi-slice spiral CT (MSCT) for cholangiopancreatography without cholangio-contrast.</p><p><b>METHODS</b>Ten patients without any digestion system diseases and 24 patients with suspected pancreatic malignancy received the 16-slice spiral CT multi-phased contrast-enhanced scanning. The images of patients without any digestion system diseases and cancer-suffered patients were curved reformatted (CR) technique to perform the structure of pancreatic duct, common bile duct, and ampulla. The cholangiopancreatical systems of the cancer suffered patient were reconstructed through volume rendering technique (VRT), minimum intensity projection (MinIP), and indirect minimum intensity projection (IMinIP). The results of patients without any digestion system diseases in curved multiplanar reconstruction were analyzed; meanwhile display rates of the pancreatic duct, common bile duct, and ampulla were evaluated.</p><p><b>RESULTS</b>of the four different cholangiopancreatographies were compared.</p><p><b>RESULTS</b>The display rate of pancreatic duct in the CR images was 90.0 (9/10) with an average diameter of (2.63 +/- 0.51) mm. Sub-pancreatic duct could be seen in 88.9% (8/9) of them. The display rate of common bile duct in the CR images was 100% (10/10) with an average diameter of (7.45 +/- 1.12) mm. The display rate of ampulla was 60.0 (6/10), which was affected by the filling status of duodenum. The cholangiopancreatography using CR, VRT, MinIP, and IMinIP for patients with pancreatic cancer reveal the whole pancreatic and common bile duct, and the modality of distal obstructed bile duct. The result showed that IminIP got the best outcome (98.6%), while VRT got the worst (68.1%).</p><p><b>CONCLUSION</b>The negative CT cholangiopancreatography is a simple and non-invasive examination. It reflects both the 3-dimensional cholangio-pancreatic anatomical structure and its adjacent condition. It has curtain clinical application values, especially for patients with obstructed duct system.</p>

Techniques and clinical applications of 16 multislice helical CT in colonic diseases / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the techniques and clinical applications of 16 multislice helical CT in colonic lesions.</p><p><b>METHODS</b>Eighty-one patients including 54 colorectal carcinomas, 5 adenomas, 1 non-Hodgkin's lymphoma, 6 inflammatory bowel diseases, and other 15 cases underwent volume scanning using 16 multislice helical CT. Four types of reconstruction included multiple planar reconstruction, shaded surface display, raysum, and CT virtual colonoscopy.</p><p><b>RESULTS</b>Complete colon could be shown in all patients. The lesions' morphology, number, size, location, intestinal cavity, pericolonic changes, and other abdominal organs were satisfactorily shown by CT.</p><p><b>CONCLUSIONS</b>Sixteen multislice helical CT colonography is a valuable imaging technique for detecting colonic diseases. It is effective in diagnosis and treatment planning. It can display the portions of colon that is inaccessible at colonoscopy.</p>

Non-invasive imaging of coronary artery with 16-slice spiral computed tomography / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the value of 16-slice spiral CT in the demonstration of coronary artery and in the diagnose of coronary artery stenosis.</p><p><b>METHODS</b>Plain and enhanced CT scans were performed with a 16-slice CT scanner (Sensation 16, Siemens, Germany) in 230 patients with suspected coronary heart disease (CHD). Parameters of the plain scan were: 120 kV, 133 mA, slice collimation 16 mm x 1.5 mm, rotation time 0.42 seconds, increment 1.5 mm, and slice width 3 mm. Parameters of the enhanced scan were: 120 kV, 500 mA, slice collimation 16 mm x 0.75 mm, rotation time 0.42 seconds, increment 0.5 mm, and slice width 1 mm. Enhanced CT scan was performed with a rapid intravenous injection of 100 mL iothalamate meglumine (Ultravist) (370 mgI/mL) or Omnipaque (350 mgI/mL) and 30 mL 0.9% NaCl chaser bolus at a flow rate of 3.5 mL/s. Calcium scoring with plain scan images and two and three dimensional reconstruction with enhanced scan images were made in all cases, among which 30 cases underwent conventional coronary angiography. Demonstration of coronary arteries and their stenosis were evaluated and the factors that might influence the image quality were analyzed.</p><p><b>RESULTS</b>Coronary calcium scores were calculated and coronary artery was demonstrated in our study. In the evaluation of image quality with volume rendering technique (VRT) images, 78.3% of the images were of the first class, 12.2% the second class, and 9.6% the third class. Multi-planar reconstruction (MPR) and maximal intensity projection (MIP) were better than VRT in the demonstration of small branches. The image quality was related to the heart rate, with or without arrhythmia, and breath-hold ability of patients. Comparative study of the stenosis of coronary arteries in 30 cases showed that the sensitivity and specificity of 16-slice coronary CT angiography (CTA) to diagnose significant stenosis were 95.8% and 94.8% respectively.</p><p><b>CONCLUSION</b>As a non-invasive and quick method, 16-slice coronary CTA is sensitive and specific to diagnose the stenosis of coronary arteries and can be used as a screening method in the diagnosis of CHD.</p>

Coronary artery imaging with dual-source CT:initial experience / 中华放射学杂志

Objective To explore the scan technique and image quality of coronary artery imaging with dual-source CT without oral Betaloc preparation.Methods Plain and enhanced dual-source CT coronary artery imaging without oral Betaloc preparation was performed in 215 patients with clinically suspected coronary heart disease or early-stage coronary lesions.Calcium scoring with plain scan images and multi-planar reconstruction(MPR),maximum intensity projection(MIP)and volume rendering technique (VRT)reconstruction with enhanced scan images were made in all cases.The scan technique and post reconstruction experience was summarized.The image quality was classified as three grades,and coronary segments classified according to AHA standards were evaluated.Results The median of calcium score of the 215 cases was 82.2(2.3—1827.9).The average heart rate of the enhanced scan was(80.6?15.3) (57—139)bpm.The post reconstruction methods with which coronary segments could be shown as best as possible consisted of(1)multiphases screening methods,(2)bi-phase or multiple-phase complement method,and(3)premature beat removing or arrhythmia shifting method.Altogether 3026 coronary segments were evaluated,among them 97.5% were evaluated as grade 1 image quality,2.0% were evaluated as grade 2 and 0.5% were evaluated as grade 3.The coronary segments in 91 cases were completely normal, while 112 segments with