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[Application of Low Concentration Contrast Agent Combined Double Low Dose in CT Pulmonary Angiography for Pulmonary Embolism].
Li, L, Zhao, F, Pu, YM, Zhang, K, Pu, J, Li, YM, Peng, WL, Zhang, JG, Xia, CC, Li, ZL
Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition. 2018;(2):239-242
Abstract
OBJECTIVE To investigate the feasibility of low concentration contrast agent combined double low dose in CT pulmonary angiography. METHODS 60 patients with clinically suspected pulmonary embolism examed by CT pulmonary angiography (CTPA) were divided into two groups (experimental group: n=30,80 kV, 15 mL,320 mg I/mL;control group: n=30,120 kV,50 mL,370 mg I/mL). The average CT value of main right and left pulmonary arteries,lobar arteries was calculated. Imaging post processing techniques included curved plannar reconstruction (CPR),volume rendering (VR) and maximal intensity projection (MIP). The artifact of the remaining contract in the superior vena cava and overall quality of the image were observed and analyzed by two senior doctors who were double blinded. RESULTS All patients in two groups completed CTPA successfully. The image qualities of two groupssatisfy clinical diagnostic requirements and no difference of the image qualities was observed between two groups (P>0.05). The evaluation of venous pollution in experimental group was better than that of control group (P<0.01).No difference of CT values were observed between two groups [experimental group (423.2±89.4) HU,control group (465.7±85.6) HU](P>0.05). The SNR and CNR in experimental group were lower than those in control group (P<0.01 both).The CT dose index volume (CTDIvol),dose-length product (DLP) and size-specific dose estimates (SSDE) in experimental group were significantly lower than those incontrol group (P<0.01 all). CONCLUSION The low concentration contrast agent combined double low dose in CT pulmonary angiography satisfies clinical diagnostic requirements. It has good clinical value for it could reduce venous pollution,iodine contrast agent and radiation exposure.
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MDCT angiography of the pulmonary arteries: intravascular contrast enhancement does not depend on iodine concentration when injecting equal amounts of iodine at standardized iodine delivery rates.
Keil, S, Plumhans, C, Behrendt, FF, Das, M, Stanzel, S, Mühlenbruch, G, Seidensticker, P, Knackstedt, C, Mahnken, AH, Günther, RW, et al
European radiology. 2008;(8):1690-5
Abstract
To compare the impact of iodine concentration using two different contrast materials (CM) at standardized iodine delivery rate (IDR) and overall iodine load in 16-multidetector-row-CT-angiography (MDCTA) of the pulmonary arteries of 192 patients with known or suspected pulmonary embolism. One hundred three patients (group A) received 148 ml of a CM containing 300 mg iodine/ml (Ultravist 300, BayerScheringPharma) at a flow rate of 4.9 ml/s. Eighty-nine patients (group B) received 120 ml of a CM with a concentration of 370 mg iodine/ml (Ultravist 370) at a flow rate of 4.0 ml/s, resulting in a standardized IDR (approximately 1.5 gI/s) and the same overall amount of iodine (44.4 g). Both CM injections were followed by a saline chaser. Mean density values were determined in the pulmonary trunk, the ascending and the descending aorta, respectively. Applying repeated-measures ANOVA, no statistically significant differences between both MDCTA protocols were found (p = 0.5790): the mean density in the pulmonary trunk was 355 +/- 116 Hounsfield Units (group A) and 358 +/- 115 (group B). The corresponding values for the ascending and descending aorta were 295 +/- 79 (group A) and 284 +/- 65 (group B) as well as 272 +/- 71 and 262 +/- 70. In conclusion, the use of standardized IDR and overall iodine load provides comparable intravascular CM density in pulmonary 16-MDCTA for delivering contrast materials with different iodine concentrations.
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Tomographic imaging in the diagnosis of pulmonary embolism: a comparison between V/Q lung scintigraphy in SPECT technique and multislice spiral CT.
Reinartz, P, Wildberger, JE, Schaefer, W, Nowak, B, Mahnken, AH, Buell, U
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2004;(9):1501-8
Abstract
UNLABELLED Although ventilation/perfusion (V/Q) lung scintigraphy is a well-accepted and frequently performed procedure in the diagnosis of pulmonary embolism, there is growing controversy about its relevance, particularly due to the increasing competition between scintigraphy and CT. Even though comparative studies between both modalities have already been performed, their results were highly inconsistent. Remarkably, in most of those studies, conventional planar perfusion scans were compared with tomographic images acquired using state-of-the-art CT scanners-a study design that cannot give impartial results. Hence, the aim of our study was a balanced comparison between V/Q lung scintigraphy and CT angiography using advanced imaging techniques for both modalities. METHODS A total of 83 patients with suspected pulmonary embolism were examined using V/Q lung scintigraphy in SPECT technique as well as 4-slice spiral CT. Ventilation scans were done using an ultrafine aerosol. Additionally, planar images in 8 views were extracted from the V/Q SPECT datasets. Two experienced referees assessed each of the 3 modalities. The final diagnosis was made at a consensus meeting while taking into account all of the imaging modalities, laboratory tests, clinical data, and evaluation of a follow-up period. RESULTS In the course of the consensus conference, pulmonary embolism was diagnosed in 37 of the 83 patients (44.6%). Compared with planar scintigraphy, SPECT raised the number of detectable defects at the segmental level by 12.8% (+11 defects; P = 0.401) and at the subsegmental level by 82.6% (+57 defects; P < 0.01). The sensitivity/specificity/accuracy of planar V/Q scintigraphy and V/Q SPECT was 0.76/0.85/0.81 and 0.97/0.91/0.94, respectively, compared with 0.86/0.98/0.93 for multislice CT. CONCLUSION SPECT and ultrafine aerosols are technical advancements that can substantially improve lung scintigraphy. Using advanced imaging techniques, V/Q scintigraphy and multislice spiral CT both yield an excellent and, in all aspects, comparable diagnostic accuracy, with CT leading in specificity while SPECT shows a superior sensitivity. Even though planar lung scintigraphy yields satisfactory results for a nontomographic modality, it does not compare with tomographic imaging.
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Effect of orally active prostacyclin analogue on survival in patients with chronic thromboembolic pulmonary hypertension without major vessel obstruction.
Ono, F, Nagaya, N, Okumura, H, Shimizu, Y, Kyotani, S, Nakanishi, N, Miyatake, K
Chest. 2003;(5):1583-8
Abstract
OBJECTIVES This study investigated whether treatment with beraprost sodium (BPS), an orally active prostacyclin analog, improves hemodynamics and survival in patients with peripheral-vessel chronic thromboembolic pulmonary hypertension (CTEPH), for which there is no surgical option. BACKGROUND Oral administration of BPS has been shown to improve the hemodynamics and prognosis in patients with primary pulmonary hypertension; however, whether BPS has beneficial effects in CTEPH remains unknown. METHODS Forty-three patients with peripheral-vessel CTEPH were classified into two groups: patients treated with BPS (BPS group, n = 20) and those without BPS (conventional group, n = 23). Baseline demographic and hemodynamic data did not significantly differ between the two groups. RESULTS BPS therapy improved New York Heart Association functional class in 10 patients (50%) and significantly decreased total pulmonary resistance from 18 +/- 6 to 15 +/- 8 Wood units (p < 0.05) [mean +/- SD]. Sixteen patients died of cardiopulmonary causes in the conventional group during a mean follow-up period of 58 +/- 45 months. In contrast, only three patients died of cardiopulmonary causes in the BPS group during a mean follow-up period of 44 +/- 30 months. The absence of BPS therapy, elevated total pulmonary resistance, heart rate, and age were independently related to the mortality by Cox proportional hazard analysis. The 1-year, 3-year, and 5-year survival rates for the BPS group were 100%, 85%, and 76%, respectively, compared to 87%, 60%, and 46% in the conventional group. CONCLUSIONS This preliminary study suggests that oral administration of BPS may improve hemodynamics and survival in patients with peripheral-vessel CTEPH, for which there is no surgical option.