51
|
Zhao Y, Wu Y, Zuo Z, Suo H, Zhao S, Zhang H. CT pulmonary angiography using different noise index values with an iterative reconstruction algorithm and dual energy CT imaging using different body mass indices: Image quality and radiation dose. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2017; 25:79-91. [PMID: 27802249 DOI: 10.3233/xst-160608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To investigate the differences in imaging quality and radiation dose in CT pulmonary angiography (CTPA) by using fast-kV switching dual energy CT imaging and 3D Smart mA modulation at different body mass indices (BMIs) and at different noise index (NI) values with an adaptive statistical iterative reconstruction (ASIR) algorithm. METHODS Four hundred patients who underwent CTPA were equally divided into two groups: A (18.5 kg/m2 ≦ BMI <24.9 kg/m2) and B (24.9 kg/m2 ≦ BMI ≦ 4.9 kg/m2). The groups were randomly subdivided into four subgroups (n = 50): A1-A4 and B1-B4. The patients in subgroups A1 and B1 underwent fast-kV switching dual energy CT imaging. The other patients underwent 3D Smart mA modulation with the ASIR algorithm at NI values 26, 36, and 46 for A2/B2, A3/B3, and A4/B4, respectively. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of all images were calculated after CTPA. Images were then subjectively evaluated using a 5-point scale. The volume CT dose index and dose-length product (DLP) were recorded and their means calculated. The DLP was converted to the effective dose (ED). RESULTS In group A, the SNR, CNR, and subjective image scores showed no statistical differences (P > 0.05). The ED in subgroup A4 was 67.12% and 31.53% lower than that in A1 and A2, respectively. In group B, the variables showed no significant differences between the subgroups B3, B1, and B2 (P > 0.05). The ED in subgroup B3 was 50.12% and 35.95% lower than that in B1 and B2, respectively. CONCLUSIONS Setting different NI values according to BMIs and applying the ASIR algorithm can more effectively reduce the radiation dose in CTPA than in fast-kV switching dual energy CT, while maintaining image quality. Imaging may be performed at NI = 46 in patients with lower BMI (group A) and at NI = 36 in patients with higher BMI (group B).
Collapse
Affiliation(s)
- Yongxia Zhao
- The Affiliated Hospital of Hebei University, Baoding, China
| | - Yanmin Wu
- The Affiliated Hospital of Hebei University, Baoding, China
| | - Ziwei Zuo
- The Affiliated Hospital of Hebei University, Baoding, China
| | - Hongna Suo
- Medicine School of Hebei University, Baoding, China
| | - Sisi Zhao
- The Affiliated Hospital of Hebei University, Baoding, China
| | - Haisong Zhang
- The Affiliated Hospital of Hebei University, Baoding, China
| |
Collapse
|
52
|
Tilve-Gómez A, Rodríguez-Fernández P, Trillo-Fandiño L, Plasencia-Martínez JM. Imaging techniques used in the diagnostic workup of acute venous thromboembolic disease. RADIOLOGIA 2016; 59:329-342. [PMID: 27986265 DOI: 10.1016/j.rx.2016.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 09/09/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022]
Abstract
Early diagnosis is one of the most important factors affecting the prognosis of pulmonary embolism (PE); however, the clinical presentation of PE is often very unspecific and it can simulate other diseases. For these reasons, imaging tests, especially computed tomography angiography (CTA) of the pulmonary arteries, have become the keystone in the diagnostic workup of PE. The wide availability and high diagnostic performance of pulmonary CTA has led to an increase in the number of examinations done and a consequent increase in the population's exposure to radiation and iodinated contrast material. Thus, other techniques such as scintigraphy and venous ultrasonography of the lower limbs, although less accurate, continue to be used in certain circumstances, and optimized protocols have been developed for CTA to reduce the dose of radiation (by decreasing the kilovoltage) and the dose of contrast agents. We describe the technical characteristics and interpretation of the findings for each imaging technique used to diagnose PE and discuss their advantages and limitations; this knowledge will help the best technique to be chosen for each case. Finally, we comment on some data about the increased use of CTA, its clinical repercussions, its "overuse", and doubts about its cost-effectiveness.
Collapse
Affiliation(s)
- A Tilve-Gómez
- Servicio de Radiodiagnóstico, IISGS, XXIV, Hospital Álvaro Cunqueiro, Vigo (Pontevedra), España.
| | - P Rodríguez-Fernández
- Servicio de Radiodiagnóstico, IISGS, XXIV, Hospital Álvaro Cunqueiro, Vigo (Pontevedra), España
| | - L Trillo-Fandiño
- Servicio de Radiodiagnóstico, IISGS, XXIV, Hospital Álvaro Cunqueiro, Vigo (Pontevedra), España
| | - J M Plasencia-Martínez
- Servicio de Radiodiagnóstico, Hospital General Universitario José María Morales Meseguer, Murcia, España
| |
Collapse
|
53
|
Zhao YX, Zuo ZW, Suo HN, Wang JN, Chang J. CT Pulmonary Angiography Using Automatic Tube Current Modulation Combination with Different Noise Index with Iterative Reconstruction Algorithm in Different Body Mass Index: Image Quality and Radiation Dose. Acad Radiol 2016; 23:1513-1520. [PMID: 27717760 DOI: 10.1016/j.acra.2016.07.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/20/2016] [Accepted: 07/01/2016] [Indexed: 10/20/2022]
Abstract
RATIONALE AND OBJECTIVES This study aimed to determine the appropriate body mass index (BMI)-dependent noise index (NI) setting in computed tomography pulmonary angiography (CTPA) with automatic tube current modulation with adaptive statistical iterative reconstruction (ASiR). MATERIALS AND METHODS A total of 480 patients who had a CTPA were divided into group A (18.5 kg/m2 ≤ BMI < 25 kg/m2), group B (25 kg/m2 ≤ BMI < 30 kg/m2), and group C (BMI ≥ 30 kg/m2), according to their BMI values; each group had 160 patients. The three groups were further randomly divided into four subgroups: A1, A2, A3, A4; B1, B2, B3, B4; and C1, C2, C3, C4, with corresponding NI values of 26, 36, 40, and 46, respectively. All images were restructured with the ASiR algorithm, and the images with the lowest NI (26 Hounsfield units) in each group were used as reference standard. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for the pulmonary artery of each group were calculated. Subjective image quality was evaluated using a five-score method by two independent radiologists. The CT dose index of volume and dose-length product were recorded and were converted to effective dose (ED). SNR and CNR in the group A, B, and C subgroups were compared to repeated measures analysis of variance, and the subjective score, Volumetric CT dose index of volume, dose-length product, and ED were compared to one-way analysis of variance. RESULTS For groups A and B, the SNR, CNR, and subjective scores of the images in their subgroups showed no statistical differences (P >.05). The ED in subgroups A4 and B4 was significantly lower than that in subgroups A1 (by 33.24%) and B1 (by 34.47%) (P <.01). For group C, there was no significant difference in the SNR, CNR, and the subjective image scores between subgroups C3 and C1 (P >.05). The ED in subgroup C3 was significantly lower than the ED in subgroup C1 (by 47.75%) (P <.01) CONCLUSIONS: Patient BMI-dependent NI settings that are higher than the recommended value may be used in CTPA with automatic tube current modulation and ASiR to effectively reduce radiation dose while maintaining diagnostic image quality.
Collapse
|
54
|
State-of-the-Art Pulmonary CT Angiography for Acute Pulmonary Embolism. AJR Am J Roentgenol 2016; 208:495-504. [PMID: 27897042 DOI: 10.2214/ajr.16.17202] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Pulmonary CT angiography (CTA) is the imaging modality of choice in suspected acute pulmonary embolism (PE). Current pulmonary CTA techniques involve ever lower doses of contrast medium and radiation along with advanced postprocessing applications to enhance image quality, diagnostic accuracy, and provide added value in patient management. The objective of this article is to summarize these current developments and discuss the appropriate use of state-of-the-art pulmonary CTA. CONCLUSION Pulmonary CTA is well established as a fast and reliable means of excluding or diagnosing PE. Continued developments in CT system hardware and postprocessing techniques will allow incremental reductions in radiation and contrast material requirements while improving image quality. Advances in risk stratification and prognostication from pulmonary CTA examinations should further refine its clinical value while minimizing the potential harm from overutilization and overdiagnosis.
Collapse
|
55
|
Mitchell DP, Rowan M, Loughman E, Ridge CA, MacMahon PJ. Contrast monitoring techniques in CT pulmonary angiography: An important and underappreciated contributor to breast dose. Eur J Radiol 2016; 86:184-189. [PMID: 28027745 DOI: 10.1016/j.ejrad.2016.11.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 09/28/2016] [Accepted: 11/06/2016] [Indexed: 01/21/2023]
Abstract
OBJECTIVE The aims of our study were to evaluate the contribution of contrast-monitoring techniques to breast dose in pregnant and non-pregnant women, and to investigate the effect of a reduced peak kilovoltage (kV) monitoring scan protocol on breast dose and Computed Tomography Pulmonary Angiography (CTPA) diagnostic quality. MATERIALS AND METHODS Single center retrospective study of 221 female patients undergoing a reduced kV 80kV contrast-monitoring CTPA protocol compared to 281 patients using the conventional 120kV contrast-monitoring protocol (Siemens Somatom Definition AS+). 99 pregnant patients analyzed separately. ImPACT dosimetry software was used to calculate dose. Group subsets were evaluated to assess CTPA diagnostic quality. RESULTS The contrast-monitoring component of a CTPA study constituted 27% of the overall breast dose when using a standard 120kV protocol compared to only 7% of the overall breast dose in the 80kV study group. The dose to the breast from the contrast-monitoring component alone was reduced by 79% in the non-pregnant patients (0.36mGy±0.37 versus 1.7mGy±1.02; p<0.001), and by 88% in the pregnant population (0.25mGy±0.67 versus 2.24mGy±1.61; p<0.001). There was no statistical difference in CTPA diagnostic quality or timing. CONCLUSION Despite a short scan length and relatively small DLP, contrast-monitoring techniques (test-bolus or bolus-tracked) set at 120kV can account for 27% of the overall breast dose accrued from a CTPA study. By decreasing the kilovoltage of the contrast-monitoring component, a significant reduction in breast dose for pregnant and non-pregnant female patients can be achieved without affecting CTPA quality or timing.
Collapse
Affiliation(s)
- D P Mitchell
- Department of Radiology, Whitty Building, North Circular Road, Mater Misericordiae University Hospital, Dublin 7, Ireland.
| | - M Rowan
- Department of Radiology, Whitty Building, North Circular Road, Mater Misericordiae University Hospital, Dublin 7, Ireland.
| | - E Loughman
- Department of Radiology, Whitty Building, North Circular Road, Mater Misericordiae University Hospital, Dublin 7, Ireland.
| | - C A Ridge
- Department of Radiology, Whitty Building, North Circular Road, Mater Misericordiae University Hospital, Dublin 7, Ireland.
| | - P J MacMahon
- Department of Radiology, Whitty Building, North Circular Road, Mater Misericordiae University Hospital, Dublin 7, Ireland.
| |
Collapse
|
56
|
Rui X, Jin Y, FitzGerald PF, Wu M, Alessio AM, Kinahan PE, De Man B. Fast analytical approach of application specific dose efficient spectrum selection for diagnostic CT imaging and PET attenuation correction. Phys Med Biol 2016; 61:7787-7811. [PMID: 27754977 DOI: 10.1088/0031-9155/61/21/7787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Computed tomography (CT) has been used for a variety of applications, two of which include diagnostic imaging and attenuation correction for PET or SPECT imaging. Ideally, the x-ray tube spectrum should be optimized for the specific application to minimize the patient radiation dose while still providing the necessary information. In this study, we proposed a projection-based analytic approach for the analysis of contrast, noise, and bias. Dose normalized contrast to noise ratio (CNRD), inverse noise normalized by dose (IND) and bias are used as evaluation metrics to determine the optimal x-ray spectrum. Our simulation investigated the dose efficiency of the x-ray spectrum ranging from 40 kVp to 200 kVp. Water cylinders with diameters of 15 cm, 24 cm, and 35 cm were used in the simulation to cover a variety of patient sizes. The effects of electronic noise and pre-patient copper filtration were also evaluated. A customized 24 cm CTDI-like phantom with 13 mm diameter inserts filled with iodine (10 mg ml-1), tantalum (10 mg ml-1), water, and PMMA was measured with both standard (1.5 mGy) and ultra-low (0.2 mGy) dose to verify the simulation results at tube voltages of 80, 100, 120, and 140 kVp. For contrast-enhanced diagnostic imaging, the simulation results indicated that for high dose without filtration, the optimal kVp for water contrast is approximately 100 kVp for a 15 cm water cylinder. However, the 60 kVp spectrum produces the highest CNRD for bone and iodine. The optimal kVp for tantalum has two selections: approximately 50 and 100 kVp. The kVp that maximizes CNRD increases when the object size increases. The trend in the CTDI phantom measurements agrees with the simulation results, which also agrees with previous studies. Copper filtration improved the dose efficiency for water and tantalum, but reduced the iodine and bone dose efficiency in a clinically-relevant range (70-140 kVp). Our study also shows that for CT-based attenuation correction applications for PET or SPECT, a higher-kVp spectrum with copper filtration is preferable. This method is developed based on filter back projection and does not require image reconstruction or Monte Carlo dose estimates; thus, it could potentially be used for patient-specific and task-based on-the-fly protocol optimization.
Collapse
Affiliation(s)
- Xue Rui
- Image Reconstruction Laboratory, GE Global Research Center, Niskayuna, NY, USA
| | | | | | | | | | | | | |
Collapse
|
57
|
Strategies to Lessen the Radiation Risk from CT: A Multination Perspective. CURRENT RADIOLOGY REPORTS 2016. [DOI: 10.1007/s40134-016-0186-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
58
|
Scout-Based Automated Tube Potential Selection Technique (kV Assist) in Enhanced Chest Computed Tomography: Effects on Radiation Exposure and Image Quality. J Comput Assist Tomogr 2016; 41:442-445. [PMID: 27759600 DOI: 10.1097/rct.0000000000000523] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE The aim of our study was to assess radiation dose reduction and image quality for enhanced chest CT examinations with a scout-based automated tube potential selection technique (kV Assist) compared with a standard 120-kV protocol. METHODS Prospective study of enhanced chest CT examinations was performed in 100 consecutive patients with kV Assist and in 100 consecutive patients with conventional 120-kV protocol on a multislice CT (Discovery CT750 HD). The body mass index, CT dose index volume, and dose length product were recorded from the examination protocol. Image noise and CT value was measured on region of interest, signal-to-noise ratio, and contrast-to-noise ratio was calculated. The subjective image quality was assessed by two radiologists blinded to the respective protocol with the use of a 3-grade scale (3, superior quality; 2, moderate quality; 1, inferior quality). RESULTS With kV Assist, the percentages of patients being scanned using 80, 100, and 120 kV were 12.0%, 80.0%, and 8.0%, respectively. The kilovolt setting was related with body mass index (r = 0.565, P = 0.000). Compared with the conventional 120 kV protocol, kV Assist allowed for an overall average decrease of 30.6% in CT dose index volume (kV Assist, 11.05 ± 4.78 mGy; 120 kV, 15.92 ± 6.89 mGy) (P < 0.001) and 32.3% in dose length product (kV Assist, 386.41 ± 184.02 mGy cm; 120 kV, 571.14 ± 286.68 mGy cm) (P < 0.001). In the kV Assist, mean attenuation of regions of interest inside the aorta was significantly higher than that in 120-kV protocols (kV Assist, 310.27 ± 73.70 HU; 120 kV, 239.44 ± 47.65 HU) (P < 0.001), resulting in increased contrast-to-noise ratio (kV Assist, 26.69 ± 7.78; 120 kV, 21.38 ± 6.05) (P < 0.001). There was no significant difference in subjective image quality scores between the 2 groups. CONCLUSIONS The use of attenuation-based kV Assist technique enables significant dose reduction in enhanced chest CT scan while improving arterial enhancement and preserving image quality at adequate levels.
Collapse
|
59
|
Spinal dual-energy computed tomography: improved visualisation of spinal tumorous growth with a noise-optimised advanced monoenergetic post-processing algorithm. Neuroradiology 2016; 58:1093-1102. [DOI: 10.1007/s00234-016-1733-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/19/2016] [Indexed: 01/14/2023]
|
60
|
Brix G, Lechel U, Sudarski S, Trumm C, Henzler T. Spectral optimization of iodine-enhanced CT: Quantifying the effect of tube voltage on image quality and radiation exposure determined at an anthropomorphic phantom. Phys Med 2016; 32:999-1006. [PMID: 27484397 DOI: 10.1016/j.ejmp.2016.07.618] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/14/2016] [Accepted: 07/25/2016] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To provide an experimental basis for spectral optimization of iodine-enhanced CT by a quantitative analysis of image quality and radiation dose characteristics consistently measured for a large variety of scan settings at an anthropomorphic phantom. METHODS CT imaging and thermoluminescent dosimetry were performed at an anthropomorphic whole-body phantom with iodine inserts for different tube voltages (U, 70-140kV) and current-time products (Q, 60-300mAs). For all U-Q combinations, the iodine contrast (C), the noise level (N) and, from these, the contrast-to-noise ratio (CNR) of reconstructed CT images were determined and parameterized as a function of U, Q or the measured absorbed dose (D). Finally, two characteristic curves were derived that give the relative increase of CNR at constant D and the relative decrease of D at constant CNR when lowering U. RESULTS Lowering U affects the measured CNR only slightly but markedly reduces D. For example, reducing U from 120kV to 70kV increases the CNR at constant D by a factor of nearly 1.8 or, alternatively, reduces D at constant CNR by a factor of nearly 5. CONCLUSION Spectral optimization by lowering U is an effective approach to attain the necessary CNR for a specific diagnostic task at hand while at the same time reducing radiation exposure as far as practically achievable. The characteristic curves derived in this study from extensive measurements at a reference 'person' can support CT users in an easy-to-use manner to select an appropriate voltage for various clinical scenarios.
Collapse
Affiliation(s)
- Gunnar Brix
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleissheim, Germany.
| | - Ursula Lechel
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleissheim, Germany
| | - Sonja Sudarski
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
| | - Christoph Trumm
- Department of Clinical Radiology, Grosshadern Clinic, Hospital of the Ludwig-Maximilians University, Munich, Germany
| | - Thomas Henzler
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
| |
Collapse
|
61
|
Manual adjustment of tube voltage from 120 to 100 kVp during abdominal CT in patients with body weights ≤75 kg: assessment of image quality and radiation dose in a prospective, randomised trial. Clin Radiol 2016; 71:615.e1-6. [DOI: 10.1016/j.crad.2016.02.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/05/2016] [Accepted: 02/14/2016] [Indexed: 11/22/2022]
|
62
|
Mourits M, Nijhof W, van Leuken M, Jager G, Rutten M. Reducing contrast medium volume and tube voltage in CT angiography of the pulmonary artery. Clin Radiol 2016; 71:615.e7-615.e13. [DOI: 10.1016/j.crad.2016.03.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 01/27/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
|
63
|
How Much Is the Dose Varying between Follow-Up CT-Examinations Performed on the Same Scanner with the Same Imaging Protocol? PLoS One 2016; 11:e0152961. [PMID: 27050659 PMCID: PMC4822887 DOI: 10.1371/journal.pone.0152961] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 03/22/2016] [Indexed: 12/12/2022] Open
Abstract
Purpose To investigate the dose variation between follow-up CT examinations, when a patient is examined several times on the same scanner with the identical scan protocol which comprised automated exposure control. Material and Methods This retrospective study was approved by the local ethics committee. The volume computed tomography dose index (CTDIvol) and the dose-length-product (DLP) were recorded for 60 cancer patients (29 male, 31 female, mean age 60.1 years), who received 3 follow-up CT examinations each composed of a non-enhanced scan of the liver (LI-CT) and a contrast-enhanced scan of chest (CH-CT) and abdomen (AB-CT). Each examination was performed on the same scanner (Siemens Definition FLASH) equipped with automated exposure control (CARE Dose 4D and CARE KV) using the identical scan protocol. Results The median percentage difference in DLP between follow-up examinations was 9.6% for CH-CT, 10.3% for LI-CT, and 10.1% for AB-CT; the median percentage difference in CTDIvol 8.3% for CH-CT, 7.4% for LI-CT and 7.7% for AB-CT (p<0.0001 for all values). The maximum difference in DLP between follow-up examinations was 67.5% for CH-CT, 50.8% for LI-CT and 74.3% for AB-CT; the maximum difference in CTDIvol 62.9% for CH-CT, 47.2% for LI-CT, and 49% for AB-CT. Conclusion A significant variance in the radiation dose occurs between follow-up CT examinations when the same CT scanner and the identical imaging protocol are used in combination with automated exposure control.
Collapse
|
64
|
Trad HS, Boasquevisque GS, Giacometti TR, Trad CY, Zoghbi Neto OS, Trad CS. Pulmonary 64-MDCT angiography with 50 mL of iodinated contrast material in an unselected patient population: a feasible protocol. Radiol Bras 2016; 49:75-8. [PMID: 27141128 PMCID: PMC4851474 DOI: 10.1590/0100-3984.2014.0115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Objective To propose a protocol for pulmonary angiography using 64-slice multidetector
computed tomography (64-MDCT) with 50 mL of iodinated contrast material, in
an unselected patient population, as well as to evaluate vascular
enhancement and image quality. Materials and Methods We evaluated 29 patients (22-86 years of age). The body mass index ranged
from 19.0 kg/m2 to 41.8 kg/m2. Patients underwent
pulmonary CT angiography in a 64-MDCT scanner, receiving 50 mL of iodinated
contrast material via venous access at a rate of 4.5 mL/s. Bolus tracking
was applied in the superior vena cava. Two experienced radiologists assessed
image quality and vascular enhancement. Results The mean density was 382 Hounsfield units (HU) for the pulmonary trunk; 379
and 377 HU for the right and left main pulmonary arteries, respectively; and
346 and 364 HU for the right and left inferior pulmonary arteries,
respectively. In all patients, subsegmental arteries were analyzed. There
were streak artifacts from contrast material in the superior vena cava in
all patients. However, those artifacts did not impair the image
analysis. Conclusion Our findings suggest that pulmonary angiography using 64-MDCT with 50 mL of
iodinated contrast can produce high quality images in unselected patient
populations.
Collapse
|
65
|
Ma CL, Chen XX, Lei YX, Zhang XR, Jia YJ, Tian X, Tian Q. Clinical value of dual-energy spectral imaging with adaptive statistical iterative reconstruction for reducing contrast medium dose in CT portal venography: in comparison with standard 120-kVp imaging protocol. Br J Radiol 2016; 89:20151022. [PMID: 27031376 DOI: 10.1259/bjr.20151022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate the clinical value of dual-energy spectral CT with adaptive statistical iterative reconstruction (ASiR) for reducing contrast medium dose in CT portal venography (CTPV). METHODS This prospective study was institutional review board-approved, and written informed consent was obtained from all patients. 50 patients undergoing abdominal CT were randomized to 2 groups: Group A (n = 25), using spectral CT and 350 mgI kg(-1) contrast injection protocol; Group B (n = 25), using standard 120 kVp and 500 mgI kg(-1) contrast. Spectral CT images at 60 keV and standard 120-kVp images were both reconstructed with 50% ASiR. CT number and contrast-to-noise ratio (CNR) for intrahepatic and extrahepatic portal veins were measured. The maximum intensity projection (MIP) and volume-rendering (VR) images were used for subjective evaluation. These two kinds of results were statistically analyzed. RESULTS CNR values for the intrahepatic portal vein of the 60-keV spectral images (4.2 ± 1.1) were higher than those of 120-kVp images (3.0 ± 2.1) (p = 0.03) and were the same for the extrahepatic portal vein (5.9 ± 1.4 vs 5.9 ± 1.6, p = 0.90). The portal vein and left and right branches in the 60-keV spectral images had higher CT number and lower standard deviation than the 120-kVp images (p < 0.05). Radiation dose (dose-length product and effective dose) and subjective image quality were similar for the two groups, while the spectral CT group required 25% less iodine dose (23.1 ± 3.2 g vs 30.5 ± 5.0 g). CONCLUSION The 60-keV spectral CT images with ASiR allow 25% reduction in the iodine dose while providing better or equal image quality as the standard 120-kVp images in portal venography with comparable radiation dose. ADVANCES IN KNOWLEDGE Compared with conventional 120-kVp CT, the use of 60-keV spectral CT images provides 25% contrast dose reduction with similar image quality in CTPV. Compared with conventional 120-kVp CT, the use of 60-keV spectral CT images with ASiR algorithm improves CNR values for the intrahepatic portal vein.
Collapse
Affiliation(s)
- Chun-Ling Ma
- Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China
| | - Xiao-Xia Chen
- Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China
| | - Yu-Xin Lei
- Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China
| | - Xi-Rong Zhang
- Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China
| | - Yong-Jun Jia
- Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China
| | - Xin Tian
- Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China
| | - Qian Tian
- Department of Radiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, People's Republic of China
| |
Collapse
|
66
|
Loizou L, Albiin N, Leidner B, Axelsson E, Fischer MA, Grigoriadis A, Del Chiaro M, Segersvärd R, Verbeke C, Sundin A, Kartalis N. Multidetector CT of pancreatic ductal adenocarcinoma: Effect of tube voltage and iodine load on tumour conspicuity and image quality. Eur Radiol 2016; 26:4021-4029. [PMID: 26965503 DOI: 10.1007/s00330-016-4273-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 02/03/2016] [Accepted: 02/04/2016] [Indexed: 12/11/2022]
Abstract
OBJECTIVES To compare a low-tube-voltage with or without high-iodine-load multidetector CT (MDCT) protocol with a normal-tube-voltage, normal-iodine-load (standard) protocol in patients with pancreatic ductal adenocarcinoma (PDAC) with respect to tumour conspicuity and image quality. METHODS Thirty consecutive patients (mean age: 66 years, men/women: 14/16) preoperatively underwent triple-phase 64-channel MDCT examinations twice according to: (i) 120-kV standard protocol (PS; 0.75 g iodine (I)/kg body weight, n = 30) and (ii) 80-kV protocol A (PA; 0.75 g I/kg, n = 14) or protocol B (PB; 1 g I/kg, n = 16). Two independent readers evaluated tumour delineation and image quality blindly for all protocols. A third reader estimated the pancreas-to-tumour contrast-to-noise ratio (CNR). Statistical analysis was performed with the Chi-square test. RESULTS Tumour delineation was significantly better in PB and PA compared with PS (P = 0.02). The evaluation of image quality was similar for the three protocols (all, P > 0.05). The highest CNR was observed with PB and was significantly better compared to PA (P = 0.02) and PS (P = 0.0002). CONCLUSION In patients with PDAC, a low-tube-voltage, high-iodine-load protocol improves tumour delineation and CNR leading to higher tumour conspicuity compared to standard protocol MDCT. KEY POINTS • Low-tube-voltage high-iodine-load MDCT improves pancreatic cancer conspicuity compared to a standard protocol. • The pancreas-to-tumour attenuation difference increases significantly by reducing the tube voltage. • The radiation exposure dose decreases by reducing the tube voltage.
Collapse
Affiliation(s)
- L Loizou
- Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 14186, Stockholm, Sweden. .,Department of Radiology, C1-46 Karolinska University Hospital Huddinge, 14186, Stockholm, Sweden.
| | - N Albiin
- Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 14186, Stockholm, Sweden.,Department of Radiology, Ersta Hospital, 11691, Stockholm, Sweden
| | - B Leidner
- Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 14186, Stockholm, Sweden.,Department of Radiology, C1-46 Karolinska University Hospital Huddinge, 14186, Stockholm, Sweden
| | - E Axelsson
- Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 14186, Stockholm, Sweden.,Department of Radiology, C1-46 Karolinska University Hospital Huddinge, 14186, Stockholm, Sweden
| | - M A Fischer
- Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 14186, Stockholm, Sweden.,Department of Radiology, C1-46 Karolinska University Hospital Huddinge, 14186, Stockholm, Sweden
| | - A Grigoriadis
- Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 14186, Stockholm, Sweden.,Department of Radiology, C1-46 Karolinska University Hospital Huddinge, 14186, Stockholm, Sweden
| | - M Del Chiaro
- Division of Surgery, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet and Center for Digestive Diseases, Karolinska University Hospital Huddinge, 14186, Stockholm, Sweden
| | - R Segersvärd
- Division of Surgery, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet and Center for Digestive Diseases, Karolinska University Hospital Huddinge, 14186, Stockholm, Sweden
| | - C Verbeke
- Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet and Karolinska University Hospital Huddinge, 14186, Stockholm, Sweden
| | - A Sundin
- Department of Surgical Sciences, Division of Radiology, Uppsala University and Department of Radiology, Uppsala University Hospital, 751 85, Uppsala, Sweden
| | - N Kartalis
- Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 14186, Stockholm, Sweden.,Department of Radiology, C1-46 Karolinska University Hospital Huddinge, 14186, Stockholm, Sweden
| |
Collapse
|
67
|
Moradi M, Monfared LJ. Qualitative evaluation of pulmonary CT angiography findings in pregnant and postpartum women with suspected pulmonary thromboembolism. JOURNAL OF RESEARCH IN MEDICAL SCIENCES 2016; 20:1088-93. [PMID: 26941814 PMCID: PMC4755097 DOI: 10.4103/1735-1995.172834] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Background: Considering the importance of using more appropriate imaging technique for accurate diagnosis of pulmonary thromboembolism (PTE) with less side effects, we aimed to evaluate the quality of pulmonary 64-multidetector computed tomographic (MDCT) angiography in pregnant and postpartum women with suspected PTE in Isfahan. Materials and Methods: In this descriptive study, radiological findings of pregnant and postpartum women with suspected PTE who underwent pulmonary 64-MDCT angiography were evaluated. Prevalence of PTE in pregnant and postpartum women, mean of pulmonary arteries density for right and left pulmonary arteries, and their lobar and segmental branches, diagnostic quality of the pulmonary arteries density and their scoring, frequency of diagnostic and nondiagnostic images, mean of radiation dose and mean of bolus time, and the correlation between the quality of the vascular density with the peak density of the pulmonary artery were determined. Results: In this study, 44 pregnant and postpartum women with suspected PTE were selected. The overall prevalence of PTE was 9.1% (4/44). PTE was diagnosed in 1 (3.7%) pregnant and 3 (17.5%) postpartum women (P = 0.14). Mean density of pulmonary trunk was 278.81± 108.16 Hounsfield unit (HU) and 308.41 ± 59.30 HU in pregnant and postpartum women, respectively. Mean of bolus timing, kilovoltage peak (kVp), tube current, and dose length product (DLP) were 12.53 ± 2.36 s, 105.22± 45.71 milliamperage (MA), 382.9 ± 173.5 MA, and 317.98 ± 78.92 mGy/cm, respectively. The rate of nondiagnostic images was 4.5%. Conclusion: Our findings indicated that pulmonary 64-MDCT angiography is an appropriate imaging method for diagnosing PTE in pregnant and postpartum women with suspected PTE. It seems that, using fast CT systems (64-MDCT), in accordance with high flow rate, high contrast medium concentration and low kVp could explain the obtained appropriate quality of images more efficiently than computed tomographic pulmonary angiography (CTPA).
Collapse
Affiliation(s)
- Maryam Moradi
- Department of Radiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Leyla Jalali Monfared
- Department of Radiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
68
|
Thacker PG, Lee EY. Advances in Multidetector CT Diagnosis of Pediatric Pulmonary Thromboembolism. Korean J Radiol 2016; 17:198-208. [PMID: 26957904 PMCID: PMC4781758 DOI: 10.3348/kjr.2016.17.2.198] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/18/2015] [Indexed: 11/19/2022] Open
Abstract
Although pediatric pulmonary thromboembolism is historically believed to be rare with relatively little information available in the medical literature regarding its imaging evaluation, it is more common than previously thought. Thus, it is imperative for radiologists to be aware of the most recent advances in its imaging information, particularly multidetector computed tomography (MDCT), the imaging modality of choice in the pediatric population. The overarching goal of this article is to review the most recent updates on MDCT diagnosis of pediatric pulmonary thromboembolism.
Collapse
Affiliation(s)
- Paul G Thacker
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Edward Y Lee
- Division of Thoracic Imaging, Department of Radiology and Medicine, Pulmonary Division Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
69
|
Synergistic Radiation Dose Reduction by Combining Automatic Tube Voltage Selection and Iterative Reconstruction. J Thorac Imaging 2016; 31:111-8. [DOI: 10.1097/rti.0000000000000196] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
70
|
Sabel BO, Buric K, Karara N, Thierfelder KM, Dinkel J, Sommer WH, Meinel FG. High-Pitch CT Pulmonary Angiography in Third Generation Dual-Source CT: Image Quality in an Unselected Patient Population. PLoS One 2016; 11:e0146949. [PMID: 26872262 PMCID: PMC4752234 DOI: 10.1371/journal.pone.0146949] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/22/2015] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES To investigate the feasibility of high-pitch CT pulmonary angiography (CTPA) in 3rd generation dual-source CT (DSCT) in unselected patients. METHODS Forty-seven patients with suspected pulmonary embolism underwent high-pitch CTPA on a 3rd generation dual-source CT scanner. CT dose index (CTDIvol) and dose length product (DLP) were obtained. Objective image quality was analyzed by calculating signal-to-noise-ratio (SNR) and contrast-to-noise ratio (CNR). Subjective image quality on the central, lobar, segmental and subsegmental level was rated by two experienced radiologists. RESULTS Median CTDI was 8.1 mGy and median DLP was 274 mGy*cm. Median SNR was 32.9 in the central and 31.9 in the segmental pulmonary arteries. CNR was 29.2 in the central and 28.2 in the segmental pulmonary arteries. Median image quality was "excellent" in central and lobar arteries and "good" in subsegmental arteries according to both readers. Segmental arteries varied between "excellent" and "good". Image quality was non-diagnostic in one case (2%), beginning in the lobar arteries. Thirteen patients (28%) showed minor motion artifacts. CONCLUSIONS In third-generation dual-source CT, high-pitch CTPA is feasible for unselected patients. It yields excellent image quality with minimal motion artifacts. However, compared to standard-pitch cohorts, no distinct decrease in radiation dose was observed.
Collapse
Affiliation(s)
- Bastian O. Sabel
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Kristijan Buric
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Nora Karara
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Kolja M. Thierfelder
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Julien Dinkel
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Wieland H. Sommer
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Felix G. Meinel
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| |
Collapse
|
71
|
Hendriks BMF, Kok M, Mihl C, Bekkers SCAM, Wildberger JE, Das M. Individually tailored contrast enhancement in CT pulmonary angiography. Br J Radiol 2016; 89:20150850. [PMID: 26689096 DOI: 10.1259/bjr.20150850] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE The purpose was to evaluate individually shaped contrast media (CM) delivery in CT pulmonary angiography (CTPA) for suspected pulmonary embolism (PE). METHODS 100 consecutive emergency patients with clinical suspicion of PE were evaluated. High-pitch CTPA was performed on a second-generation dual-source CT using the following parameters: 100 kV, 200-250 mAsref, rotation time 0.28 s, 128 × 0.6 mm col. and image reconstruction 1.0/0.8 mm (B30f). Group 1 (n = 50) then received a fixed CM bolus (300 = mgI ml(-1), volume = 90 ml and flow rate = 6 ml s(-1)); Group 2 (n = 50) received a body weight-adapted CM bolus determined by dedicated contrast injection software. For analysis, groups were further subdivided into low-weight (40-75 kg) and high-weight (76-117 kg) groups. Technical image quality was graded using a four-point Likert scale (1 = non-diagnostic; 2 = diagnostic; 3 = good and 4 = excellent image quality) at the level of the pulmonary trunk and pulmonary arteries. Objective image quality analysis was performed by measuring contrast enhancement in Hounsfield units (HU) at the same levels. Attenuation levels > 180 HU were considered diagnostic. RESULTS All examinations were graded as diagnostic at each level. The individual minimum pulmonary attenuation was 184 and 270 HU for Group 1 and 2, respectively. Mean attenuation was as follows: Group 1: 475 ± 105 HU (40-75 kg) and 402 ± 115 HU (76-117 kg), p < 0.03. Group 2: 424 ± 76 HU (40-75 kg) and 418 ± 100 HU (76-117 kg), p = 0.8. For Group 2, CM volumes were: 55 ± 5 ml (40-75 kg) and 66 ± 5 ml (76-117 kg), leading to 16-51% CM reduction. CONCLUSION Even under emergency conditions, individualized CM protocols can provide diagnostic and robust image quality in CTPA for PE with a substantial reduction of CM volume for lower weight patients, compared with a fixed CM protocol. ADVANCES IN KNOWLEDGE CM volume can substantially be reduced by using individualized CM protocols in CT angiography for PE without compromising the diagnostic image quality.
Collapse
Affiliation(s)
- Babs M F Hendriks
- 1 Departments of Radiology, Maastricht University Medical Center, Maastricht, Netherlands.,2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands
| | - Madeleine Kok
- 1 Departments of Radiology, Maastricht University Medical Center, Maastricht, Netherlands.,2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands
| | - Casper Mihl
- 1 Departments of Radiology, Maastricht University Medical Center, Maastricht, Netherlands.,2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands
| | - Sebastiaan C A M Bekkers
- 2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands.,3 Departments of Cardiology, Maastricht University Medical Center, Maastricht, Netherlands
| | - Joachim E Wildberger
- 1 Departments of Radiology, Maastricht University Medical Center, Maastricht, Netherlands.,2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands
| | - Marco Das
- 1 Departments of Radiology, Maastricht University Medical Center, Maastricht, Netherlands.,2 CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, Netherlands
| |
Collapse
|
72
|
Hinrichs JB, von Falck C, Hoeper MM, Olsson KM, Wacker FK, Meyer BC, Renne J. Pulmonary Artery Imaging in Patients with Chronic Thromboembolic Pulmonary Hypertension: Comparison of Cone-Beam CT and 64-Row Multidetector CT. J Vasc Interv Radiol 2016; 27:361-8.e2. [PMID: 26803575 DOI: 10.1016/j.jvir.2015.11.046] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 11/16/2015] [Accepted: 11/19/2015] [Indexed: 12/30/2022] Open
Abstract
PURPOSE To compare the depiction of pulmonary arteries in pulmonary arterial catheter-based contrast-enhanced cone-beam CT with peripheral intravenous contrast-enhanced multidetector CT in patients with suspected chronic thromboembolic pulmonary hypertension. MATERIAL AND METHODS In 20 patients (15 men and 5 women, 63.4 y ± 16.3), cone-beam CT using a catheter placed in the main pulmonary artery and 64-row multidetector CT using an appropriate venous access were performed. Contrast enhancement was measured in the main pulmonary artery, the right and left pulmonary arteries, and the left atrium. The amount of peripheral vessel conspicuity adjacent to the pleural surface (distance from vessel-to pleura) was measured. Two readers (R1, R2) independently evaluated the pulmonary arteries for image quality and pathologic findings in both modalities. RESULTS Contrast density was higher in the main pulmonary artery and right and left pulmonary arteries (P < .002) and lower in the left atrium (P = .001) on cone-beam CT. The smallest distance between clearly delineated vessels and the pleura was significantly lower on cone-beam CT images (P < .0001). Interobserver agreement was good for cone-beam CT (κ = 0.79) and multidetector CT (κ = 0.78), whereas intermodality agreement was moderate (R1, κ = 0.60; R2, κ = 0.59). Both readers detected more weblike stenoses with cone-beam CT (76; 22%) compared with multidetector CT (25; 7%). CONCLUSIONS Cone-beam CT shows improved contrast between pulmonary arteries and the left atrium and allows a more detailed depiction of the pulmonary arteries.
Collapse
Affiliation(s)
- Jan B Hinrichs
- Department of Diagnostic and Interventional Radiology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany.
| | - Christian von Falck
- Department of Diagnostic and Interventional Radiology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Marius M Hoeper
- Clinic for Pneumology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Karen M Olsson
- Clinic for Pneumology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Frank K Wacker
- Department of Diagnostic and Interventional Radiology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Bernhard C Meyer
- Department of Diagnostic and Interventional Radiology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Julius Renne
- Department of Diagnostic and Interventional Radiology, Member of the German Center for Lung Research, Hannover Medical School, Hannover, Germany
| |
Collapse
|
73
|
A Comparison of the Image Quality and Radiation Dose Using 100-kVp Combination of Different Noise Index and 120-kVp in Computed Tomography Pulmonary Angiography. J Comput Assist Tomogr 2016; 40:784-90. [DOI: 10.1097/rct.0000000000000488] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
74
|
Kim JH, Choo KS, Moon TY, Lee JW, Jeon UB, Kim TU, Hwang JY, Yun MJ, Jeong DW, Lim SJ. Comparison of the image qualities of filtered back-projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction for CT venography at 80 kVp. Eur Radiol 2015; 26:2055-63. [PMID: 26486938 DOI: 10.1007/s00330-015-4060-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 09/28/2015] [Accepted: 10/06/2015] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the subjective and objective qualities of computed tomography (CT) venography images at 80 kVp using model-based iterative reconstruction (MBIR) and to compare these with those of filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR) using the same CT data sets. MATERIALS AND METHODS Forty-four patients (mean age: 56.1 ± 18.1) who underwent 80 kVp CT venography (CTV) for the evaluation of deep vein thrombosis (DVT) during 4 months were enrolled in this retrospective study. The same raw data were reconstructed using FBP, ASIR, and MBIR. Objective and subjective image analysis were performed at the inferior vena cava (IVC), femoral vein, and popliteal vein. RESULTS The mean CNR of MBIR was significantly greater than those of FBP and ASIR and images reconstructed using MBIR had significantly lower objective image noise (p < .001). Subjective image quality and confidence of detecting DVT by MBIR group were significantly greater than those of FBP and ASIR (p < .005), and MBIR had the lowest score for subjective image noise (p < .001). CONCLUSION CTV at 80 kVp with MBIR was superior to FBP and ASIR regarding subjective and objective image qualities. KEY POINTS • MBIR provides superior image quality compared with FBP and ASIR • CTV at 80kVp with MBIR improves diagnostic confidence in diagnosing DVT • CTV at 80kVp with MBIR presents better image quality with low radiation.
Collapse
Affiliation(s)
- Jin Hyeok Kim
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Ki Seok Choo
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea.
| | - Tae Yong Moon
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Jun Woo Lee
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Ung Bae Jeon
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Tae Un Kim
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Jae Yeon Hwang
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Myeong-Ja Yun
- Department of Preventive and Occupational Medicine, School of Medicine, Pusan National University, Pusan, Korea
| | - Dong Wook Jeong
- Department of Family Medicine, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Soo Jin Lim
- Department of Cardiology, Kimhae Jungang Hospital, Gyeongsangnam-do, Korea
| |
Collapse
|
75
|
Gill MK, Vijayananthan A, Kumar G, Jayarani K, Ng KH, Sun Z. Use of 100 kV versus 120 kV in computed tomography pulmonary angiography in the detection of pulmonary embolism: effect on radiation dose and image quality. Quant Imaging Med Surg 2015; 5:524-33. [PMID: 26435916 DOI: 10.3978/j.issn.2223-4292.2015.04.04] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To determine the effective radiation dose and image quality resulting from 100 versus 120 kilovoltage (kV) protocols among patients referred for computed tomography pulmonary angiography (CTPA). METHODS Sixty-six patients with clinical suspicion of pulmonary embolism (PE) were prospectively enrolled. Two CTPA protocols (group A: n=33, 100 kV/115 mAs; group B: n=33, 120 kV/90 mAs) were compared. Two experienced radiologists assessed image quality in terms of diagnostic performance and effect of artefacts. Image quality parameters [CT attenuation, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR)] and effective radiation dose between the two protocols were compared. RESULTS The contrast enhancement in central and peripheral pulmonary arteries was significantly higher in group A than in group B (P<0.001) with the identical SNR (P=0.26), whereas the CNR was significantly higher in group A than in group B (P<0.001). The effective radiation dose for the 100 and 120 kV scans was 3.2 and 6.8 mSv, respectively. CONCLUSIONS Reducing the tube voltage from 120 to 100 kV in CTPA allows a significant reduction of radiation dose without significant loss of diagnostic image quality.
Collapse
Affiliation(s)
- Maninderpal Kaur Gill
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia ; 2 University of Malaya Research Imaging Centre (UMRIC), University of Malaya, Kuala Lumpur, Malaysia ; 3 Department of Medical Radiation Sciences, Faculty of Science and Engineering, Curtin University, Perth, Western Australia, Australia
| | - Anushya Vijayananthan
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia ; 2 University of Malaya Research Imaging Centre (UMRIC), University of Malaya, Kuala Lumpur, Malaysia ; 3 Department of Medical Radiation Sciences, Faculty of Science and Engineering, Curtin University, Perth, Western Australia, Australia
| | - Gnana Kumar
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia ; 2 University of Malaya Research Imaging Centre (UMRIC), University of Malaya, Kuala Lumpur, Malaysia ; 3 Department of Medical Radiation Sciences, Faculty of Science and Engineering, Curtin University, Perth, Western Australia, Australia
| | - Kasthoori Jayarani
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia ; 2 University of Malaya Research Imaging Centre (UMRIC), University of Malaya, Kuala Lumpur, Malaysia ; 3 Department of Medical Radiation Sciences, Faculty of Science and Engineering, Curtin University, Perth, Western Australia, Australia
| | - Kwan-Hoong Ng
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia ; 2 University of Malaya Research Imaging Centre (UMRIC), University of Malaya, Kuala Lumpur, Malaysia ; 3 Department of Medical Radiation Sciences, Faculty of Science and Engineering, Curtin University, Perth, Western Australia, Australia
| | - Zhonghua Sun
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia ; 2 University of Malaya Research Imaging Centre (UMRIC), University of Malaya, Kuala Lumpur, Malaysia ; 3 Department of Medical Radiation Sciences, Faculty of Science and Engineering, Curtin University, Perth, Western Australia, Australia
| |
Collapse
|
76
|
70 kVp computed tomography pulmonary angiography: potential for reduction of iodine load and radiation dose. J Thorac Imaging 2015; 30:69-76. [PMID: 25423130 DOI: 10.1097/rti.0000000000000124] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The purpose of the study was to evaluate 70 kVp dual-source computed tomography pulmonary angiography (CTPA) with reduced iodine load in comparison with single-source 70 and 100 kVp CTPA with standard iodine load regarding image quality and radiation dose. MATERIALS AND METHODS Three groups with 40 consecutive patients each underwent either standard single-source 100 kVp (120 mAs; group A), single-source 70 kVp (208 mAs; group B), or dual-source 70 kVp CTPA (416 mAs; group C). A volume of 70 mL of contrast material with 400 mg I/mL (groups A, B) or 300 mg I/mL (group C) was administered. Chest diameter, dose-length product, intravascular signal attenuation, image noise, signal to noise ratio (SNR), and contrast to noise ratio (CNR) were compared. Two observers rated subjective image quality regarding intravascular enhancement and image noise using 5-point scales. RESULTS Chest diameter and age were similar (P ≥ 0.28) for all groups. Compared with group A, the average dose-length product was 59% lower in group B (67.3 ± 11.8 vs. 164.7 ± 50.6 mGy cm, P<0.001) and similar between groups A and C (167.7 ± 41.2 mGy cm, P = 0.39). Average SNR and CNR were significantly higher for group C (21.5 ± 4.7 and 19.0 ± 4.5, respectively) compared with groups A (18.3 ± 3.5 and 15.8 ± 3.4, respectively) and B (17.3 ± 5.8 and 15.6 ± 5.5, respectively; all Ps ≤ 0.001). Subjective image quality ratings regarding enhancement and noise were highest for group C (1.73 ± 0.62 and 2.03 ± 0.66, respectively). CONCLUSIONS Compared with standard 100 kVp CTPA, single-source 70 kVp CTPA allows for significant radiation dose savings with comparable SNR and CNR, whereas dual-source 70 kVp CTPA results in a superior objective image quality albeit a reduction of iodine concentration.
Collapse
|
77
|
Albrecht MH, Scholtz JE, Hüsers K, Beeres M, Bucher AM, Kaup M, Martin SS, Fischer S, Bodelle B, Bauer RW, Lehnert T, Vogl TJ, Wichmann JL. Advanced image-based virtual monoenergetic dual-energy CT angiography of the abdomen: optimization of kiloelectron volt settings to improve image contrast. Eur Radiol 2015; 26:1863-70. [PMID: 26334508 DOI: 10.1007/s00330-015-3970-2] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 08/03/2015] [Accepted: 08/06/2015] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To compare quantitative image quality parameters in abdominal dual-energy computed tomography angiography (DE-CTA) using an advanced image-based (Mono+) reconstruction algorithm for virtual monoenergetic imaging and standard DE-CTA. METHODS Fifty-five patients (36 men; mean age, 64.2 ± 12.7 years) who underwent abdominal DE-CTA were retrospectively included. Mono + images were reconstructed at 40, 50, 60, 70, 80, 90 and 100 keV levels and as standard linearly blended M_0.6 images (60 % 100 kV, 40 % 140 kV). The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) of the common hepatic (CHA), splenic (SA), superior mesenteric (SMA) and left renal arteries (LRA) were objectively measured. RESULTS Mono+ DE-CTA series showed a statistically superior CNR for 40, 50, 60, 70 and 80 keV (P < 0.031) compared to M_0.6 images for all investigated arteries except SMA at 80 keV (P = 0.08). CNR at 40 keV revealed a mean relative increase of 287.7 % compared to linearly blended images among all assessed arteries (P < 0.001). SNR of Mono+ images was consistently significantly higher at 40, 50, 60 and 70 keV compared to M_0.6 for CHA and SA (P < 0.009). CONCLUSIONS Compared to linearly blended images, Mono+ reconstructions at low keV levels of abdominal DE-CTA datasets significantly improve quantitative image quality. KEY POINTS • Mono+ combines increased attenuation with reduced image noise compared to standard DE-CTA. • Mono+ shows superior contrast-to-noise ratios at low keV compared to linearly-blended images. • Contrast-to-noise ratio in monoenergetic DE-CTA peaks at 40 keV. • Mono+ reconstructions significantly improve quantitative image quality at low keV levels.
Collapse
Affiliation(s)
- Moritz H Albrecht
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany.
| | - Jan-Erik Scholtz
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Kristina Hüsers
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Martin Beeres
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Andreas M Bucher
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Moritz Kaup
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Simon S Martin
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Sebastian Fischer
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Boris Bodelle
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Ralf W Bauer
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Thomas Lehnert
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Thomas J Vogl
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Julian L Wichmann
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| |
Collapse
|
78
|
Evaluation of a high iodine delivery rate in combination with low tube current for dose reduction in pulmonary computed tomography angiography. J Thorac Imaging 2015; 29:293-7. [PMID: 25100138 DOI: 10.1097/rti.0000000000000099] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The present study evaluates the combination of a high iodine delivery rate with a low tube current-time product for pulmonary computed tomography angiography (CTA). MATERIALS AND METHODS One-hundred nineteen consecutive patients undergoing pulmonary CTA for suspected pulmonary embolism were included and imaged on a 128-row computed tomography scanner at 100 kVp using highly concentrated contrast material (85 mL Iomeprol; 400 mg iodine/mL). The protocol entailed a flow rate of 5 mL/s and 90 mAs for group A, 3.5 mL/s and 135 mAs for group B, 5 mL/s and 135 mAs for group C, and 3.5 mL/s and 90 mAs for group D. Signal-to-noise ratio and contrast-to-noise ratio (CNR) were determined for the pulmonary artery. Subjective image quality (IQ) was rated on a 5-point scale (1=nondiagnostic IQ to 5=excellent IQ). RESULTS CNR did not differ significantly between groups A (43.7±27.7), B (34.5±17.9), and C (38.9±13.8), as well as between groups B and D (29.9±11.2). CNR was higher in groups A and C than in group D (P<0.02). Subjective IQ was higher in group A than in groups B and D (P<0.05). Subjective IQ was significantly higher in group A compared with group D (P=0.026) and in group C compared with group D (P=0.007). CONCLUSIONS A high iodine delivery rate permits dose reduction in pulmonary CTA and can be recommended in patients with suspected pulmonary embolism.
Collapse
|
79
|
Breast Dose Reduction Options During Thoracic CT: Influence of Breast Thickness. AJR Am J Roentgenol 2015; 204:W421-8. [DOI: 10.2214/ajr.14.13255] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
80
|
Zhang C, Yu Y, Zhang Z, Wang Q, Zheng L, Feng Y, Zhou Z, Zhang G, Li K. Imaging quality evaluation of low tube voltage coronary CT angiography using low concentration contrast medium. PLoS One 2015; 10:e0120539. [PMID: 25811785 PMCID: PMC4374912 DOI: 10.1371/journal.pone.0120539] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 01/23/2015] [Indexed: 12/28/2022] Open
Abstract
PURPOSE To compare the image quality of prospectively ECG-gated low voltage coronary computed tomography angiography (CTA) with an administration of low concentration contrast medium. METHOD AND MATERIALS A total of 101 patients, each with a heart rate below 65 beats per minute (BPM), underwent a prospectively ECG-gated axial scan in CT coronary angiography on a 64-slice CT scanner. All patients were allocated in three groups (group A: n=31, 80 kVp, 300 mgI/ml; group B: n=34, 100 kVp, 300 mgI/ml; group C: n=36, 120 kVp, 370 mgI/ml). The CT attenuation values of aortic root (AR), left main coronary artery (LMA), right main coronary artery (RMA) and chest subcutaneous fat tissue were measured. The contrast-to-noise ratio (CNR) of AR, LMA and RMA were calculated according to the formulas below. The values of computed tomography dose index (CTDI) and dose-length product (DLP) were recorded. Image quality was assessed on a 5-point scale. The results were compared using the one-way ANOVA and rank sum tests. RESULTS The values of CNR and SNR for vessels in group A and group B were not significantly different from group C (each p > 0.05). The effective radiation dose in group A (1.51 ± 0.70 mSv) and group B (2.59 ± 1.24 mSv) were both lower than group C (4.92 ± 2.82 mSv) (each p < 0.05). There was no significant difference among the image quality scores of group A (4.10 ± 0.41), group B (3.90 ± 0.48) and group C (4.04 ± 0.36) (each P > 0.05). CONCLUSION Low tube voltage coronary CT angiography using low concentration contrast medium does not affect the imaging quality for assessing the coronary arteries compared with high voltage coronary CT angiography using high concentration contrast medium. Meanwhile low concentration contrast medium allowed 47-69% of radiation dose reduction.
Collapse
Affiliation(s)
- Chengzhong Zhang
- Department of Radiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China
| | - Yuejun Yu
- Department of Interventional Radiology, Weifang People's Hospital, Weifang, Shandong, People’s Republic of China
| | - Zaixian Zhang
- Department of Radiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China
| | - Qingguo Wang
- Department of Radiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China
| | - Linfeng Zheng
- Department of Radiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China
| | - Yan Feng
- Department of Radiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China
| | - Zhiguo Zhou
- Department of Radiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China
| | - Guixiang Zhang
- Department of Radiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China
| | - Kangan Li
- Department of Radiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China
| |
Collapse
|
81
|
Zhang LJ, Lu GM, Meinel FG, McQuiston AD, Ravenel JG, Schoepf UJ. Computed tomography of acute pulmonary embolism: state-of-the-art. Eur Radiol 2015; 25:2547-57. [DOI: 10.1007/s00330-015-3679-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 02/17/2015] [Indexed: 12/13/2022]
|
82
|
Bilbey N, Blanke P, Leipsic J. Dual-Energy CT of the Heart: Current State and Future Prospects. CURRENT RADIOLOGY REPORTS 2015. [DOI: 10.1007/s40134-015-0089-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
83
|
Palacio D, Benveniste MF, Betancourt-Cuellar SL, Gladish GW. Multidetector computed tomography pulmonary angiography pitfalls in the evaluation of pulmonary embolism with emphasis in technique. Semin Roentgenol 2015; 50:217-25. [PMID: 26002242 DOI: 10.1053/j.ro.2015.01.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Diana Palacio
- Department of Medical Imaging, The University of Arizona College of Medicine, Tucson, Arizona USA; Department of Radiology, University of Texas MD Anderson Cancer Center, Houston, TX.
| | - Marcelo F Benveniste
- Department of Radiology, University of Texas MD Anderson Cancer Center, Houston, TX
| | | | - Gregory W Gladish
- Department of Radiology, University of Texas MD Anderson Cancer Center, Houston, TX
| |
Collapse
|
84
|
Pontana F, Henry S, Duhamel A, Faivre JB, Tacelli N, Pagniez J, Remy J, Remy-Jardin M. Impact of iterative reconstruction on the diagnosis of acute pulmonary embolism (PE) on reduced-dose chest CT angiograms. Eur Radiol 2015; 25:1182-9. [PMID: 25636413 DOI: 10.1007/s00330-014-3393-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 07/21/2014] [Accepted: 08/08/2014] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate the impact of iterative reconstruction on the detectability of clots. METHODS AND MATERIALS Fifty-three patients were enrolled in a study comparing reduced-dose and full-dose images, available from the same dual-source data set. From each acquisition, three series of images were generated: (1) full-dose images (from both tubes), reconstructed with filtered back projection (FBP) (group 1; standard of reference), (2) reduced-dose images (from tube A only; 60 % dose reduction) reconstructed with FBP (group 2) and iterative reconstruction (SAFIRE) (group 3). RESULTS In group 1 (mean DLP: 264.6 mGy.cm), (1) PE was diagnosed in 8 patients (15 %) with 82 clots in the central (n = 5), segmental (n = 39) and subsegmental (n = 38) arteries and (2) mean level of noise was 30.56 ± 5.07. In group 2 (mean DLP: 105.8 mGy.cm), a significant increase in noise (44.56 ± 6.24; p < 0.0001) (1) hampered detection of PE in one patient and (2) altered detection of peripheral clots (12 false-negative and 2 false-positive results). In group 3, image noise was not significantly different from that in group 1 (p = 0.1525; effect size: 0.2683), with a similar detection of PE compared to group 1 (p = 1). CONCLUSION Reconstruction of reduced-dose images (60 % dose reduction) with SAFIRE provided image quality and diagnostic value comparable to those of full-dose FBP images. KEY POINTS • Iterative reconstruction does not alter the detection of endoluminal clots. • Iterative reconstruction allows dose reduction in the context of acute PE. • Iterative reconstruction allows radiologists to approach the prospects of submilliSievert CT.
Collapse
Affiliation(s)
- François Pontana
- Department of Thoracic Imaging, Hospital Calmette (EA 2694), CHRU et Université de Lille 2 Nord de France, 59000, Lille, France
| | | | | | | | | | | | | | | |
Collapse
|
85
|
Okada M, Kunihiro Y, Nakashima Y, Nomura T, Kudomi S, Yonezawa T, Suga K, Matsunaga N. Added value of lung perfused blood volume images using dual-energy CT for assessment of acute pulmonary embolism. Eur J Radiol 2015; 84:172-177. [DOI: 10.1016/j.ejrad.2014.09.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/29/2014] [Accepted: 09/11/2014] [Indexed: 12/01/2022]
|
86
|
Cho ES, Chung TS, Ahn SJ, Chong K, Baek JH, Suh SH. Cerebral computed tomography angiography using a 70 kVp protocol: improved vascular enhancement with a reduced volume of contrast medium and radiation dose. Eur Radiol 2014; 25:1421-30. [PMID: 25510446 DOI: 10.1007/s00330-014-3540-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/29/2014] [Accepted: 11/21/2014] [Indexed: 01/28/2023]
Affiliation(s)
- Eun-Suk Cho
- Department of Radiology, Yonsei University College of Medicine, Gangnam Severance Hospital, 211 Eonjuro, Gangnam-gu, Seoul, 135-720, Korea
| | | | | | | | | | | |
Collapse
|
87
|
Sabarudin A, Yusof MZ, Mohamad M, Sun Z. Radiation dose associated with cerebral CT angiography and CT perfusion: an experimental phantom study. RADIATION PROTECTION DOSIMETRY 2014; 162:316-321. [PMID: 24255172 DOI: 10.1093/rpd/nct280] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A study on the radiation dose associated with cerebral CT angiography (CTA) and CT perfusion (CTP) was conducted on an anthropomorphic phantom with the aim of estimating the effective dose (E) and entrance skin dose (ESD) in the eyes and thyroid gland during different CTA and CTP protocols. The E was calculated to be 0.61 and 0.28 mSv in CTA with 100 and 80 kV(p), respectively. In contrast, CTP resulted in an estimated E of 2.74 and 2.07 mSv corresponding to 40 and 30 s protocols, respectively. The eyes received a higher ESD than the thyroid gland in all of these protocols. The results of this study indicate that combining both CTA and CTP procedures are not recommended in the stroke evaluation due to high radiation dose. Application of modified techniques in CTA (80 kV(p)) and CTP (30 s) is highly recommended in clinical practice for further radiation dose reduction.
Collapse
Affiliation(s)
- Akmal Sabarudin
- Diagnostic Imaging and Radiotherapy Program, School of Diagnostic and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Mohd Zaki Yusof
- Diagnostic Imaging and Radiotherapy Program, School of Diagnostic and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Mazlyfarina Mohamad
- Diagnostic Imaging and Radiotherapy Program, School of Diagnostic and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Zhonghua Sun
- Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University, GPO Box U1987 Perth, WA 6845, Australia
| |
Collapse
|
88
|
Megyeri B, Christe A, Schindera ST, Horkay E, Sikula J, Cullmann JL, Kollar J, Heverhagen JT, Szucs-Farkas Z. Diagnostic confidence and image quality of CT pulmonary angiography at 100 kVp in overweight and obese patients. Clin Radiol 2014; 70:54-61. [PMID: 25459197 DOI: 10.1016/j.crad.2014.09.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 09/13/2014] [Accepted: 09/17/2014] [Indexed: 11/15/2022]
Abstract
AIM To compare image quality and diagnostic confidence of 100 kVp CT pulmonary angiography (CTPA) in patients with body weights (BWs) below and above 100kg. MATERIALS AND METHODS The present retrospective study comprised 216 patients (BWs of 75-99kg, 114 patients; 100-125kg, 88 patients; >125kg, 14 patients), who received 100 kVp CTPA to exclude pulmonary embolism. The attenuation was measured and the contrast-to-noise ratio (CNR) was calculated in the pulmonary trunk. Size-specific dose estimates (SSDEs) were evaluated. Three blinded radiologists rated subjective image quality and diagnostic confidence. Results between the BW groups and between three body mass index (BMI) groups (BMI <25kg/m(2), BMI = 25-29.9kg/m(2), and BMI ≥30kg/m(2), i.e., normal weight, overweight, and obese patients) were compared using the Kruskal-Wallis test. RESULTS Vessel attenuation was higher and SDDE was lower in the 75-99kg group than at higher BWs (p-values between <0.001 and 0.03), with no difference between the 100-125 and >125kg groups (p = 0.892 and 1). Subjective image quality and diagnostic confidence were not different among the BW groups (p = 0.225 and 1). CNR was lower (p < 0.006) in obese patients than in normal weight or overweight subjects. Diagnostic confidence was not different in the BMI groups (p = 0.105). CONCLUSION CTPA at 100 kVp tube voltage can be used in patients weighing up to 125kg with no significant deterioration of subjective image quality and confidence. The applicability of 100 kVp in the 125-150kg BW range needs further testing in larger collectives.
Collapse
Affiliation(s)
- B Megyeri
- Department of Anaesthesiology and Intensive Care, University of Debrecen, Clinical Centre, Nagyerdei krt. 98, Debrecen, H-4012, Hungary
| | - A Christe
- University Institute of Diagnostic, Interventional and Paediatric Radiology, Inselspital, University Hospital Bern, Freiburgstrasse 10, Berne, CH-3010, Switzerland
| | - S T Schindera
- Department of Radiology, University Hospital Basel, Petersgraben 4, Basel, CH-4031, Switzerland
| | - E Horkay
- Department of Radiology, University of Debrecen, Clinical Centre, Nagyerdei krt. 98, Debrecen, H-4012, Hungary
| | - J Sikula
- Department of Radiology, University of Debrecen, Clinical Centre, Nagyerdei krt. 98, Debrecen, H-4012, Hungary
| | - J L Cullmann
- University Institute of Diagnostic, Interventional and Paediatric Radiology, Inselspital, University Hospital Bern, Freiburgstrasse 10, Berne, CH-3010, Switzerland
| | - J Kollar
- Department of Radiology, University of Debrecen, Clinical Centre, Nagyerdei krt. 98, Debrecen, H-4012, Hungary
| | - J T Heverhagen
- University Institute of Diagnostic, Interventional and Paediatric Radiology, Inselspital, University Hospital Bern, Freiburgstrasse 10, Berne, CH-3010, Switzerland
| | - Z Szucs-Farkas
- University Institute of Diagnostic, Interventional and Paediatric Radiology, Inselspital, University Hospital Bern, Freiburgstrasse 10, Berne, CH-3010, Switzerland; Institute of Radiology, Hospital Centre of Biel, Vogelsang 84, Biel/Bienne, CH-2501, Switzerland.
| |
Collapse
|
89
|
Salgado RA, Leipsic JA, Shivalkar B, Ardies L, Van Herck PL, Op de Beeck BJ, Vrints C, Rodrigus I, Parizel PM, Bosmans J. Preprocedural CT Evaluation of Transcatheter Aortic Valve Replacement: What the Radiologist Needs to Know. Radiographics 2014; 34:1491-514. [DOI: 10.1148/rg.346125076] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
90
|
Renne J, Falck CV, Ringe KI, Raatschen HJ, Wacker F, Shin HO. CT angiography for pulmonary embolism detection: the effect of breathing on pulmonary artery enhancement using a 64-row detector system. Acta Radiol 2014; 55:932-7. [PMID: 24103917 DOI: 10.1177/0284185113507712] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Computed tomography pulmonary angiography (CTPA) is used most often in routine clinical practice for the assessment of a suspected pulmonary embolism. The diagnostic accuracy relies on sufficient contrast enhancement. PURPOSE To evaluate whether image acquisition during shallow breathing can improve the image quality in patients with insufficient contrast enhancement during breath-hold examinations. MATERIAL AND METHODS A total of 2786 CT pulmonary angiographies, acquired on a 64-row CT during deep-inspiration breath-hold, were reviewed. Twenty-four examinations were considered non-diagnostic due to poor contrast enhancement in the pulmonary arteries (PA), although they showed preserved vascular enhancement of the superior vena cava (SVC) and the ascending aorta (AO). Eleven flawed CTPA examinations, including severe breathing artifacts and incorrect triggering were excluded. In 13 of the remaining patients, the examination was repeated during shallow breathing. Vascular contrast enhancement was compared between both scans by measuring the relative enhancement within the SVC, the main PA, and the AO. Image quality was scored by two, clinically experienced radiologists. The values are given as median and [25th;75th] quartile. RESULTS There was a significant difference in the CT values for the PA between the repeated scans (P = 0.0002, Wilcoxon test), and with the CTPA in deep-inspiration showing a median enhancement of 97 HU (59-173), compared with 303 HU (239-385) in the CTPA acquired during free breathing. The differences for both the AO (P = 0.54) and the SVC (P = 0.78) were not significant. Scoring for the attenuation quality rose significantly (P = 0.0002) and no severe motion artifacts were detected on either scans. CONCLUSION If there is insufficient pulmonary artery enhancement during CTPA, attenuation of the pulmonary arteries can be improved by acquisition during shallow breathing and is without significant loss of the overall diagnostic image quality.
Collapse
Affiliation(s)
- Julius Renne
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Christian von Falck
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Kristina Imeen Ringe
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Hans-Jürgen Raatschen
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Frank Wacker
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Hoen-Oh Shin
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| |
Collapse
|
91
|
Laqmani A, Regier M, Veldhoen S, Backhaus A, Wassenberg F, Sehner S, Groth M, Nagel HD, Adam G, Henes FO. Improved image quality and low radiation dose with hybrid iterative reconstruction with 80kV CT pulmonary angiography. Eur J Radiol 2014; 83:1962-9. [DOI: 10.1016/j.ejrad.2014.06.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/18/2014] [Accepted: 06/20/2014] [Indexed: 11/27/2022]
|
92
|
Lu GM, Luo S, Meinel FG, McQuiston AD, Zhou CS, Kong X, Zhao YE, Zheng L, Schoepf UJ, Zhang LJ. High-pitch computed tomography pulmonary angiography with iterative reconstruction at 80 kVp and 20 mL contrast agent volume. Eur Radiol 2014; 24:3260-8. [PMID: 25100336 DOI: 10.1007/s00330-014-3365-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 05/12/2014] [Accepted: 07/21/2014] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To evaluate the image quality, radiation dose and diagnostic accuracy of 80kVp, high-pitch CT pulmonary angiography (CTPA) with iterative reconstruction using 20 ml of contrast agent. METHODS One hundred patients with suspected pulmonary embolism (PE) were randomly divided into two groups (n = 50 each; group A, 100 kVp, 1.2 pitch, 60 ml of contrast medium and filtered back projection algorithm; group B, 80 kVp, 2.2 pitch, 20 ml of contrast medium and sinogram affirmed iterative reconstruction). Image quality, diagnostic accuracy and radiation dose were evaluated and compared. RESULTS Mean CT numbers of pulmonary arteries in group B were higher than those in group A (all P < 0.001). Contrast-to-noise ratio and signal-to-noise ratio of group B were higher than those of group A (both P < 0.001). There was no significant difference in subjective image quality scores between two groups (P = 0.807). The interobserver agreement was excellent (k = 0.836). There was no significant difference in diagnostic accuracy between the two groups (P > 0.05). Compared with group A, radiation dose of group B was reduced by 50.3% (P < 0.001). CONCLUSIONS High-pitch CTPA at 80 kVp can obtain sufficient image quality in normal-weight individuals with 20 ml of contrast agent and half the radiation dose of a conventional CTPA protocol. KEY POINTS CTPA is feasible at 80 kVp using only 20 ml of contrast agent. High-pitch CTPA at 80 kVp has an effective dose under 1 mSv. This CTPA protocol can obtain sufficient image quality in normal-weight individuals.
Collapse
Affiliation(s)
- Guang Ming Lu
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, 210002, China,
| | | | | | | | | | | | | | | | | | | |
Collapse
|
93
|
Kumamaru KK, Rybicki FJ, Madan R, Gill R, Wake N, Hunsaker AR. Incidental findings detection using low tube potential for CT pulmonary angiography. Int J Cardiovasc Imaging 2014; 30:1579-88. [DOI: 10.1007/s10554-014-0484-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 06/30/2014] [Indexed: 10/25/2022]
|
94
|
Kubo T, Ohno Y, Kauczor HU, Hatabu H. Radiation dose reduction in chest CT--review of available options. Eur J Radiol 2014; 83:1953-61. [PMID: 25066756 DOI: 10.1016/j.ejrad.2014.06.033] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 06/24/2014] [Accepted: 06/30/2014] [Indexed: 10/25/2022]
Abstract
Computed tomography currently accounts for the majority of radiation exposure related to medical imaging. Although technological improvement of CT scanners has reduced the radiation dose of individual examinations, the benefit was overshadowed by the rapid increase in the number of CT examinations. Radiation exposure from CT examination should be kept as low as reasonably possible for patient safety. Measures to avoid inappropriate CT examinations are needed. Principles and information on radiation dose reduction in chest CT are reviewed in this article. The reduction of tube current and tube potential are the mainstays of dose reduction methods. Study results indicate that routine protocols with reduced tube current are feasible with diagnostic results comparable to conventional standard dose protocols. Tube current adjustment is facilitated by the advent of automatic tube current modulation systems by setting the appropriate image quality level for the purpose of the examination. Tube potential reduction is an effective method for CT pulmonary angiography. Tube potential reduction often requires higher tube current for satisfactory image quality, but may still contribute to significant radiation dose reduction. Use of lower tube potential also has considerable advantage for smaller patients. Improvement in image production, especially the introduction of iterative reconstruction methods, is expected to lower radiation dose significantly. Radiation dose reduction in CT is a multifaceted issue. Understanding these aspects leads to an optimal solution for various indications of chest CT.
Collapse
Affiliation(s)
- Takeshi Kubo
- Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
| | - Yoshiharu Ohno
- Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
| | - Hans Ulrich Kauczor
- Diagnostic and Interventional Radiology, University Clinic Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg, Germany.
| | - Hiroto Hatabu
- Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, United States.
| |
Collapse
|
95
|
McLaughlin PD, Liang T, Homiedan M, Louis LJ, O'Connell TW, Krzymyk K, Nicolaou S, Mayo JR. High pitch, low voltage dual source CT pulmonary angiography: assessment of image quality and diagnostic acceptability with hybrid iterative reconstruction. Emerg Radiol 2014; 22:117-23. [PMID: 24993583 DOI: 10.1007/s10140-014-1230-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 04/23/2014] [Indexed: 12/20/2022]
Abstract
Increased use of CT Pulmonary angiography in suspected pulmonary embolism (PE) has driven research to minimize radiation dose while maintaining image quality and diagnostic accuracy. Following institutional review board approval, we performed a retrospective comparison study in patients with suspected PE. Patients were scanned using an ultra high pitch dual source technique (pitch = 2.6) using 120 kV (SVCTPA) (n = 54) or 100 kV (RV-CTPA) (n = 52). SV-CTPA images were reconstructed using filtered back projection (SV-wFBP) and RV-CTPA images were reconstructed using both FBP (RV-wFBP) and Iterative Reconstruction (RV-IR). Comparison of radiation dose, diagnostic ability, subjective image noise, quality, and sharpness, diagnostic agreement, signal to noise (SNR) and contrast to noise ratios (CNR) were performed. Mean effective dose was 2.56 ± 0.19 mSv for the RV protocol compared to 5.36 ± 0.60 mSv for the SV. The RV-CTPA protocol resulted in a mean DLP reduction of 52 % and mean CTDI reduction of 51 %. Pulmonary artery SNR and CNR were significantly higher on RV-IR images than SV-wFBP (p = 0.007, p = 0.003). Mean subjective image noise, quality and sharpness scores did not differ significantly between the SV-wFBP and RVIR images (p > 0.05). Subjective quality scores were significantly better for the RV-IR group compared to the RV-wFBP group (p < 0.001). Agreement between readers for presence or absence of pulmonary emboli on RV-IR images was almost perfect (κ = 0.891, p < 0.001). Iterative reconstruction complements ultra high pitch dual source CTPA examinations acquired using a reduced voltage resulting in higher mean pulmonary artery SNR and CNR when compared to both RV-wFBP and SV-CTPA.
Collapse
Affiliation(s)
- Patrick D McLaughlin
- Department of Radiology, Vancouver General Hospital, Vancouver, BC, Canada, V5Z 1M9,
| | | | | | | | | | | | | | | |
Collapse
|
96
|
Zizka J, Ryska P, Stepanovska J, Poulova Z, Klzo L, Grepl J, Cermakova E. Iterative reconstruction of pulmonary MDCT angiography: Effects on image quality, effective dose and estimated organ dose to the breast. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2014; 158:259-64. [DOI: 10.5507/bp.2013.059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Accepted: 07/25/2013] [Indexed: 11/23/2022] Open
|
97
|
Raju R, Thompson AG, Lee K, Precious B, Yang TH, Berger A, Taylor C, Heilbron B, Nguyen G, Earls J, Min J, Carrascosa P, Murphy D, Hague C, Leipsic JA. Reduced iodine load with CT coronary angiography using dual-energy imaging: a prospective randomized trial compared with standard coronary CT angiography. J Cardiovasc Comput Tomogr 2014; 8:282-8. [PMID: 25151920 DOI: 10.1016/j.jcct.2014.06.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 05/27/2014] [Accepted: 06/08/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND There is concern regarding the administration of iodinated contrast to patients with impaired renal function because of the increased risk of contrast-induced nephropathy. OBJECTIVE Evaluate image quality and feasibility of a protocol with a reduced volume of iodinated contrast and utilization of dual-energy coronary CT angiography (DECT) vs a standard iodinated contrast volume coronary CT angiography protocol (SCCTA). METHODS A total of 102 consecutive patients were randomized to SCCTA (n = 53) or DECT with rapid kVp switching (n = 49). Eighty milliliters and 35 mL of iodinated contrast were administered in the SCCTA and DECT cohorts, respectively. Two readers measured signal and noise in the coronary arteries; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. A 5-point signal/noise Likert scale was used to evaluate image quality; scores of <3 were nondiagnostic. Agreement was assessed through kappa analyses. RESULTS Demographics and radiation dose were not significantly different; there was no difference in CNR between both cohorts (P = .95). A significant difference in SNR between the groups (P = .02) lost significance (P = .13) when adjusted for body mass index. The median Likert score was inferior for DECT for reader 1 (3.6 ± 0.6 vs 4.3 ± 0.6; P < .001) but not reader 2 (4.1 ± 0.6 vs 4.3 ± 0.5; P = .06). Agreement in diagnostic interpretability in the DECT and SCCTA groups was 91% (95% confidence interval, 86%-100%) and 96% (95% confidence interval, 90%-100%), respectively. CONCLUSION DECT resulted in inferior image quality scores but demonstrated comparable SNR, CNR, and rate of diagnostic interpretability without a radiation dose penalty while allowing for >50% reduction in contrast volume compared with SCCTA.
Collapse
Affiliation(s)
- Rekha Raju
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | - Angus G Thompson
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | - Kristy Lee
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | - Bruce Precious
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | - Tae-Hyun Yang
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | - Adam Berger
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | - Carolyn Taylor
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | - Brett Heilbron
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | - Giang Nguyen
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | | | - James Min
- New York Presbyterian/Weil Cornell Medical College, New York, NY, USA
| | - Patricia Carrascosa
- Department of Radiology, Buenos Aires University School of Medicine, Buenos Aires, Argentina
| | - Darra Murphy
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | - Cameron Hague
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada
| | - Jonathon A Leipsic
- Department of Radiology and Division of Cardiology, St Paul's Hospital, 1081 Burrard Street, Vancouver V6Z 1Y6, BC, Canada.
| |
Collapse
|
98
|
Szucs-Farkas Z, Megyeri B, Christe A, Vock P, Heverhagen JT, Schindera ST. Prospective randomised comparison of diagnostic confidence and image quality with normal-dose and low-dose CT pulmonary angiography at various body weights. Eur Radiol 2014; 24:1868-77. [DOI: 10.1007/s00330-014-3208-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/14/2014] [Accepted: 04/28/2014] [Indexed: 01/23/2023]
|
99
|
Abstract
OBJECTIVE Recent technologic advances in MDCT have led to the introduction of dual-energy CT (DECT). The basic principle of DECT is to acquire images at two different energy levels simultaneously and to use the attenuation differences at these different energy levels for deriving additional information, such as virtual monochromatic images, artifact suppression, and material composition of various tissues. CONCLUSION A variety of image reconstruction and postprocessing techniques are available for better demonstration and characterization of pathologic abnormalities. DECT can provide both anatomic and functional information of different organ systems. This article focuses on the main applications of DECT in emergency radiology.
Collapse
|
100
|
Schneider D, Apfaltrer P, Sudarski S, Nance JW, Haubenreisser H, Fink C, Schoenberg SO, Henzler T. Optimization of kiloelectron volt settings in cerebral and cervical dual-energy CT angiography determined with virtual monoenergetic imaging. Acad Radiol 2014; 21:431-6. [PMID: 24594412 DOI: 10.1016/j.acra.2013.12.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 12/14/2013] [Accepted: 12/15/2013] [Indexed: 10/25/2022]
Abstract
RATIONALE AND OBJECTIVES Dual-energy computed tomography (DECT) offers various fields of application, especially in angiography using virtual monoenergetic imaging. The aim of this study was to evaluate objective image quality indices of calculated low-kiloelectron volt monoenergetic DECT angiographic cervical and cerebral data sets compared to virtual 120-kV polyenergetic images. MATERIALS AND METHODS Forty-one patients (21 men, mean age 58 ± 14) who underwent DECT angiography of the cervical (n = 7) or cerebral vessels (n = 34) were retrospectively included in this study. Data acquired with the 80 and 140 kVp tube using dual-source CT technology were subsequently used to calculate low-kiloelectron volt monoenergetic image data sets ranging from 120 to 40 keV (at 10-keV intervals per patient). Vessel and soft tissue attenuation and image noise were measured in various regions of interest, and contrast-to-noise ratio (CNR) was subsequently calculated. Differences in image attenuation and CNR were compared between the different monoenergetic data sets and virtual 120-kV polyenergetic images. RESULTS For cervical angiography, 60-keV monoenergetic data sets resulted in the greatest improvements in vessel attenuation and CNR compared to virtual 120-kV polyenergetic data sets (+40%, +16%; all P < .01). Also for cerebral vessel assessment, 60-keV monoenergetic data sets provided the greatest improvement in vessel attenuation and CNR (+40%, +9%; all P < .01) compared to virtual 120-kV polyenergetic data sets. CONCLUSIONS 60-keV monoenergetic image data significantly improve vessel attenuation and CNR of cervical and cerebral DECT angiographic studies. Future studies have to evaluate whether the technique can lead to an increased diagnostic accuracy or should be used for dose reduction of iodinated contrast material.
Collapse
|