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Lin CS, Peng BR, Ma HB, Chen KL, Lin TH, Pan LK, Lin YH. Inverse Problem Algorithm-Based Time-Resolved Imaging of Head and Neck Computed Tomography Angiography Contrast Kinetics with Clinical Testification. Diagnostics (Basel) 2023; 13:3354. [PMID: 37958250 PMCID: PMC10649766 DOI: 10.3390/diagnostics13213354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/18/2023] [Accepted: 10/28/2023] [Indexed: 11/15/2023] Open
Abstract
This study mitigated the challenge of head and neck CT angiography by IPA-based time-resolved imaging of contrast kinetics. To this end, 627 cerebral hemorrhage patients with dizziness, brain aneurysm, stroke, or hemorrhagic stroke diagnosis were randomly categorized into three groups, namely, the original dataset (450), verification group (112), and in vivo testified group (65), in the Affiliated BenQ Hospital of Nanjing Medical University. In the first stage, seven risk factors were assigned: age, CTA tube voltage, body surface area, heart rate per minute, cardiac output blood per minute, the actual injected amount of contrast media, and CTA delayed trigger timing. The expectation value of the semi-empirical formula was the CTA number of the patient's left artery (LA). Accordingly, 29 items of the first-order nonlinear equation were calculated via the inverse problem analysis (IPA) technique run in the STATISTICA 7.0 program, yielding a loss function and variance of 3.1837 and 0.8892, respectively. A dimensionless AT was proposed to imply the coincidence, with a lower AT indicating a smaller deviation between theoretical and practical values. The derived formula was confirmed for the verification group of 112 patients, reaching high coincidence, with average ATavg and standard deviation values of 3.57% and 3.06%, respectively. In the second stage, the formula was refined to find the optimal amount of contrast media for the CTA number of LA approaching 400. Finally, the above procedure was applied to head and neck CTA images of the third group of 65 patients, reaching an average CTA number of LA of 407.8 ± 16.2 and finding no significant fluctuations.
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Affiliation(s)
- Chih-Sheng Lin
- Department of Radiology, BenQ Medical Center, Affiliated BenQ Hospital of Nanjing Medical University, Nanjing 211166, China; (C.-S.L.); (H.-B.M.)
| | - Bing-Ru Peng
- Department of Medical Imaging and Radiological Science, Central Taiwan University of Science and Technology, Takun, Taichung 406, Taiwan; (B.-R.P.); (T.-H.L.); (L.-K.P.)
| | - Hong-Bing Ma
- Department of Radiology, BenQ Medical Center, Affiliated BenQ Hospital of Nanjing Medical University, Nanjing 211166, China; (C.-S.L.); (H.-B.M.)
| | - Ke-Lin Chen
- Department of Radiology, First Affiliated Hospital of Ningbo University, Ningbo 315012, China;
| | - Tsung-Han Lin
- Department of Medical Imaging and Radiological Science, Central Taiwan University of Science and Technology, Takun, Taichung 406, Taiwan; (B.-R.P.); (T.-H.L.); (L.-K.P.)
- Department of Traditional Chinese Medicine, Taichung Armed Forces General Hospital, Taichung 411, Taiwan
| | - Lung-Kwang Pan
- Department of Medical Imaging and Radiological Science, Central Taiwan University of Science and Technology, Takun, Taichung 406, Taiwan; (B.-R.P.); (T.-H.L.); (L.-K.P.)
| | - Ya-Hui Lin
- Department of Medical Imaging and Radiological Science, Central Taiwan University of Science and Technology, Takun, Taichung 406, Taiwan; (B.-R.P.); (T.-H.L.); (L.-K.P.)
- Department of Clinical Pharmacy, Taichung Armed Forces General Hospital, Taichung 411, Taiwan
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Experimental Insight into the Hemodynamics and Perfusion of Radiological Contrast in Patent and Non-patent Aortic Dissection Models. Cardiovasc Eng Technol 2019; 10:314-328. [PMID: 30805874 DOI: 10.1007/s13239-019-00407-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 02/09/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE In a curved vessel such as the aortic arch, the velocity profile closer to the aortic root is normally skewed towards the inner curvature wall, while further downstream along the curve, the velocity profile becomes skewed towards the outer wall. In an aortic dissection (AD) disease, blood velocities in the true lumen (TL) and false lumen (FL) are hypothesized to depend on the proximity of the entry tear to the root of aortic arch. Faster velocity in the FL can lead to higher hemodynamic loading, and pose tearing risk. Furthermore, the luminal velocities control the perfusion rate of radiological contrast media during diagnostic imaging. The objective in this study is to investigate the effect of AD disease morphology and configuration on the blood velocity field in the TL and FL, and on the relative perfusion of radiological enhancement agents through the dissection. METHODS Eight in vitro models were studied, including patent and non-patent FL configurations. Particle image velocimetry (PIV) was used to quantify the AD velocity field, while laser-induced fluorescence (LIF) was implemented to visualize dynamical flow phenomena and to quantify the perfusion of injected dye, in mimicry of contrast-enhanced computed tomography (CT). RESULTS The location of the proximal entry tear along the aortic arch in a patent FL had a dramatic impact on whether the blood velocity was higher in the TL or FL. The luminal velocities were dependent on the entry/reentry tear size combination, with the smaller tear (whether distal or proximal) setting the upper limit on the maximal flow velocity in the FL. Upon merging near the distal reentry tear, the TL/FL velocity differential gave rise to the roll up and shedding of shear layer vortices that convected downstream in close proximity to the wall of the non-dissected aorta. In a non-patent FL, the flow velocity was practically null with all the blood passing through the TL. LIF imaging showed much slower perfusion of contrast dye in the FL compared to the TL. In a patent FL, however, dye had a comparable perfusion rate appearing around the same time as in the TL. CONCLUSIONS Blood velocities in the TL and FL were highly sensitive to the exact dissection configuration. Geometric case A1R, which had its proximal entry tear located further downstream along the aortic arch, and had its entry and reentry tears sufficiently sized, exhibited the highest FL flow velocity among the tested models, and it was also higher than in the TL, which suggest that this configuration had elevated hemodynamic loading and risk for tearing. In contrast-enhanced diagnostic imaging, a time-delayed acquisition protocol is recommended to improve the detection of suspected cases with a non-patent FL.
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Zein-El-Dine S, Bou Akl I, Mohamad M, Chmaisse A, Chahwan S, Asmar K, El-Merhi F, Saade C. Split-bolus contrast injection protocol enhances the visualization of the thoracic vasculature and reduced radiation dose during chest CT. Br J Radiol 2018; 91:20180509. [PMID: 30160182 DOI: 10.1259/bjr.20180509] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE To investigate the visualization of mediastinal lymph nodes during thoracic CT employing a multiphasic contrast media (CM) protocol. METHODS Institutional review board approved retrospective study consisting of 300 patients with known chest malignancy. Patients were allocated to one of two CM protocols: Protocol A, consisted of dual bolus (Phase 1:100 ml CM followed by 100 ml saline chaser) i.v. injected at 2.5 ml s-1; Protocol B employed 100 ml of CM using a multiphasic injection protocol (Phase 1 and 2:60 ml contrast and saline, followed by Phase 3 and 4:40 ml contrast and saline injected at 2.5 ml s-1) with a fixed scan delay of 70 s for each acquisition. Attenuation profiles of the thoracic arteries and veins were calculated as well as the arterio-venous contrast ratios (AVCR). Receiver operating characteristic (ROC), visual grading characteristic (VGC), and Cohen's kappa analysis were assessed. RESULTS Arterial opacification was up to 24% (p < 0.032) higher in protocol B than A, whereas, in the veins it was significantly lower in protocol B than A, with a maximum reduction of up to 84% (p < 0.0001). There was no statistical significance between the central and peripheral pulmonary arteries [>263 Hounsfield units (HU)] in each protocol. Protocol B, demonstrated significant improvement in AVCR at various anatomical sites (p < 0.002). Radiation dose was significantly reduced in protocol B compared to A (p < 0.004). Both ROC and VGC demonstrated significantly higher Az score for protocol B compared to A (p < 0.0001) with an increased inter reader agreement from poor to excellent. CONCLUSION Employing a multiphasic CM protocol significantly improves opacification of the thoracic vasculature and visualization of mediastinal lymph nodes during thoracic CT. ADVANCES IN KNOWLEDGE Uniform opacification between thoracic arteries and veins increases the delineation between vasculature and lymph nodes, reduces radiation dose when employing a multiphase contrast media injection protocol.
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Affiliation(s)
- Salah Zein-El-Dine
- 1 Respiratory Medicine Department, American University of Beirut Medical Center , Beirut , Lebanon
| | - Imad Bou Akl
- 1 Respiratory Medicine Department, American University of Beirut Medical Center , Beirut , Lebanon
| | - Maha Mohamad
- 2 Diagnostic Radiology Department, University of Beirut Medical Center , Beirut , Lebanon
| | - Ahmad Chmaisse
- 2 Diagnostic Radiology Department, University of Beirut Medical Center , Beirut , Lebanon
| | - Stephanie Chahwan
- 2 Diagnostic Radiology Department, University of Beirut Medical Center , Beirut , Lebanon
| | - Karl Asmar
- 2 Diagnostic Radiology Department, University of Beirut Medical Center , Beirut , Lebanon
| | - Fadi El-Merhi
- 2 Diagnostic Radiology Department, University of Beirut Medical Center , Beirut , Lebanon
| | - Charbel Saade
- 3 Faculty of Health Sciences, Medical Imaging Sciences, American University of Beirut , Beirut , Lebanon
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Saade C, El-Merhi F, El-Ashkar B, Mohamad M, Haydar A, Abchee A. Synchronisation between contrast media administration and caudocranial scan direction increases visualisation of altered coronary artery blood flow in patients presenting with dual left anterior descending coronary artery. BJR Case Rep 2017; 3:20150500. [PMID: 30363277 PMCID: PMC6159239 DOI: 10.1259/bjrcr.20150500] [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] [Received: 12/10/2015] [Revised: 10/12/2016] [Accepted: 10/27/2016] [Indexed: 11/23/2022] Open
Abstract
Coronary CT angiography (CCTA) has the advantage over invasive coronary angiography in that its non-invasive nature and minimal risk on patients. CCTA enables accurate assessment of the entire heart, coronary artery system and thorax, displaying three-dimensional information about the spatial relations of the anomalous vessels and surrounding intraluminal and extraluminal anatomy, and thereby contributing clinically important prognostic information. Dual left anterior descending (LAD) coronary artery consists of of two LAD arteries within the anterior interventricular sulcus (AIVS). Type 4 is infrequently reported subtype and differs from the others, with a long LAD originating from the right coronary artery (Mercado, A., Johnson Jr, G., Calver, D., & Sokol, R. J. (1989). Cocaine, pregnancy, and postpartum intracerebral hemorrhage. Obstetrics & Gynecology, 73(3, Part 2), 467-468. and the short LAD originating from the left main coronary artery. However, the radiological features between the short LAD and septal coronary arteries remain a controversy, with the latter being determined by CCTA. We present a case report based on short LAD terminating proximally in the AIVS and the long LAD originating from the RCA and terminating into the distal AIVS with the later having a long septal travelling parallel to the long LAD.
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Affiliation(s)
- Charbel Saade
- Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut, Lebanon
| | - Fadi El-Merhi
- Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut, Lebanon
| | - Bassam El-Ashkar
- Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut, Lebanon
| | - Maha Mohamad
- Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut, Lebanon
| | - Ali Haydar
- Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut, Lebanon
| | - Antione Abchee
- Department of Cardiology, American University of Beirut Medical Center, Beirut, Lebanon
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Saade C, Al-Fout G, Mayat A, Brennan PC, Hui F, Maroun G, Kikano RN, Naffaa L. Increased image quality and reduced radiation dose and contrast media volume: a holistic approach to intracranial CTA. Clin Radiol 2017; 72:797.e11-797.e16. [PMID: 28477959 DOI: 10.1016/j.crad.2017.03.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 02/17/2017] [Accepted: 03/29/2017] [Indexed: 11/28/2022]
Abstract
AIM To investigate the dose-length product (DLP) during intracranial computed tomography angiography (CTA) using a patient-specific contrast formula. MATERIALS AND METHODS Intracranial CTA was performed on 120 patients using 64-channel CT. Patients were subjected in equal numbers to one of two acquisitions/contrast medium protocols. Protocol A, consisted of 80 ml contrast medium and protocol B, involved a novel contrast medium formula. In each protocol, contrast medium and saline were injected at a flow rate of 4.5 ml/s. The DLP and contrast volume (CV) were measured between each protocol and the data obtained were compared using two-tailed independent t-test. RESULTS Mean arterial vessel attenuation was up to 56% (p<0.01) higher using protocol B compared with A. In the venous system, the mean vessel attenuation was significantly lower in protocol B than A with a maximum reduction of 93% (p<0.001). The mean CV was significantly lower in protocol B (53±10 ml) compared to A (80±1 ml, p<0.001). The scan time was equal in each protocol (B, 4.22±1.2 seconds; A, 4.01±1.3 seconds). A significant reduction in mean DLP was demonstrated in protocol B (3.99±0.22 mSv) compared to A (4.74±0.22 mSv; p=0.02). CONCLUSION A significant reduction in CV and DLP during intracranial CTA can be achieved when employing a patient-specific contrast medium formula.
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Affiliation(s)
- C Saade
- Department of Radiology, American University of Beirut, Beirut, Lebanon; Discipline of Medical Radiation Sciences, The University of Sydney, Australia
| | - G Al-Fout
- Department of Radiology, American University of Beirut, Beirut, Lebanon
| | - A Mayat
- Department of Radiology, Campbelltown Public Hospital, Sydney, Australia
| | - P C Brennan
- Discipline of Medical Radiation Sciences, The University of Sydney, Australia
| | - F Hui
- Department of Diagnostic Radiology, The Johns Hopkins Hospital, Baltimore, USA
| | - G Maroun
- Department of Radiology, American University of Beirut, Beirut, Lebanon
| | - R N Kikano
- Department of Diagnostic Radiology, Lebanese American University, Beirut, Lebanon
| | - L Naffaa
- Department of Radiology, American University of Beirut, Beirut, Lebanon.
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256 Slice Multi-detector Computed Tomography Thoracic Aorta Computed Tomography Angiography: Improved Luminal Opacification Using a Patient-Specific Contrast Protocol and Caudocranial Scan Acquisition. J Comput Assist Tomogr 2016; 40:964-970. [PMID: 27755255 DOI: 10.1097/rct.0000000000000456] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
CLINICAL RELEVANCE STATEMENT Caudocranial scan direction and contrast injection timing based on measured patient vessel dynamics can significantly improve arterial and aneurysmal opacification and reduce both contrast and radiation dose in the assessment of thoracic aortic aneurysms (TAA) using helical thoracic computed tomography angiography (CTA). OBJECTIVES To investigate opacification of the thoracic aorta and TAA using a caudocranial scan direction and a patient-specific contrast protocol. MATERIALS AND METHODS Thoracic aortic CTA was performed in 160 consecutive patients with suspected TAA using a 256-slice computed tomography scanner and a dual barrel contrast injector. Patients were subjected in equal numbers to one of two contrast protocols. Patient age and sex were equally distributed across both groups. Protocol A, the department's standard protocol, consisted of a craniocaudal scan direction with 100 mL of contrast, intravenously injected at a flow rate of 4.5 mL/s. Protocol B involved a caudocranial scan direction and a novel contrast formula based on patient cardiovascular dynamics, followed by 100 mL of saline at 4.5 mL/s. Each scan acquisition comprised of 120 kVp, 200 mA with modulation, temporal resolution 0.27 seconds, and pitch 0.889:1. The dose length product was measured between each protocol and data generated were compared using Mann-Whitney U nonparametric statistics. Receiver operating characteristic analysis, visual grading characteristic (VGC), and κ analyses were performed. RESULTS Mean opacification in the thoracic aorta and aneurysm measured was 24 % and 55%, respectively. The mean contrast volume was significantly lower in protocol B (73 ± 10 mL) compared with A (100 ± 1 mL) (P<0.001). The contrast-to-noise ratio demonstrated significant differences between the protocols (protocol A, 18.2 ± 12.9; protocol B, 29.7 ± 0.61; P < 0.003). Mean effective dose in protocol B (2.6 ± 0.4 mSv) was reduced by 19% compared with A (3.2 ± 0.8 mSv) (P < 0.004). Aneurysmal detectability demonstrated significant increases by receiver operating characteristic and visual grading characteristic analysis for protocol B compared with A (P < 0.02), and reader agreement increased from poor to excellent. CONCLUSIONS Significant increase in the visualization of TAAs following a caudocranial scan direction during helical thoracic CTA can be achieved using low-contrast volume based on patient-specific contrast formula.
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Saade C, Deeb IA, Mohamad M, Al-Mohiy H, El-Merhi F. Contrast medium administration and image acquisition parameters in renal CT angiography: what radiologists need to know. Diagn Interv Radiol 2016; 22:116-24. [PMID: 26728701 PMCID: PMC4790062 DOI: 10.5152/dir.2015.15219] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 07/06/2015] [Accepted: 07/20/2015] [Indexed: 12/12/2022]
Abstract
Over the last decade, exponential advances in computed tomography (CT) technology have resulted in improved spatial and temporal resolution. Faster image acquisition enabled renal CT angiography to become a viable and effective noninvasive alternative in diagnosing renal vascular pathologies. However, with these advances, new challenges in contrast media administration have emerged. Poor synchronization between scanner and contrast media administration have reduced the consistency in image quality with poor spatial and contrast resolution. Comprehensive understanding of contrast media dynamics is essential in the design and implementation of contrast administration and image acquisition protocols. This review includes an overview of the parameters affecting renal artery opacification and current protocol strategies to achieve optimal image quality during renal CT angiography with iodinated contrast media, with current safety issues highlighted.
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Affiliation(s)
- Charbel Saade
- From the Department of Radiology (C.S., I.A.D., M.M., F.E.M. ), American University of Beirut, Beirut, Lebanon; the Department of Radiology (H.A.M.), King Khalid University, Abha, Saudi Arabia
| | - Ibrahim Alsheikh Deeb
- From the Department of Radiology (C.S., I.A.D., M.M., F.E.M. ), American University of Beirut, Beirut, Lebanon; the Department of Radiology (H.A.M.), King Khalid University, Abha, Saudi Arabia
| | - Maha Mohamad
- From the Department of Radiology (C.S., I.A.D., M.M., F.E.M. ), American University of Beirut, Beirut, Lebanon; the Department of Radiology (H.A.M.), King Khalid University, Abha, Saudi Arabia
| | - Hussain Al-Mohiy
- From the Department of Radiology (C.S., I.A.D., M.M., F.E.M. ), American University of Beirut, Beirut, Lebanon; the Department of Radiology (H.A.M.), King Khalid University, Abha, Saudi Arabia
| | - Fadi El-Merhi
- From the Department of Radiology (C.S., I.A.D., M.M., F.E.M. ), American University of Beirut, Beirut, Lebanon; the Department of Radiology (H.A.M.), King Khalid University, Abha, Saudi Arabia
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Giant aneurysm of the right internal carotid artery in an 8-month-old child presenting with a persistent red eye. Radiography (Lond) 2016. [DOI: 10.1016/j.radi.2015.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Exponentially Decelerated Contrast Media Injection Rate Combined With a Novel Patient-Specific Contrast Formula Reduces Contrast Volume Administration and Radiation Dose During Computed Tomography Pulmonary Angiography. J Comput Assist Tomogr 2016; 40:370-4. [DOI: 10.1097/rct.0000000000000371] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Saade C, El-Merhi F, Mayat A, Brennan PC, Yousem D. Comparison of Standard and Quadruple-Phase Contrast Material Injection for Artifacts, Image Quality, and Radiation Dose in the Evaluation of Head and Neck Cancer Metastases. Radiology 2015; 279:571-7. [PMID: 26624972 DOI: 10.1148/radiol.2015150511] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To investigate opacification of head and neck vasculature during computed tomography (CT) of supraclavicular lymph nodes with a quadruple-phase contrast media and saline dual-injection protocol. MATERIALS AND METHODS This retrospective study was institutional review board approved. In 180 consecutive patients, routine head and neck CT was performed with one of two protocols: protocol A, craniocaudal scan direction with 100 mL of contrast material injected intravenously as a single bolus; or protocol B, 100 mL of contrast material injected in four phases (phases 1-2, 60 mL of contrast material and saline injected at 2.5 mL/sec; phases 3-4, 40 mL of contrast material and saline injected at 2.5 mL/sec); both protocols had a fixed scan delay of 70 seconds. Attenuation of supraclavicular arteries and veins was measured with arteriovenous contrast ratio (AVCR) and contrast-to-noise ratio (CNR). Effective dose was calculated. Data were compared with the two-sample t test. Receiver operating characteristic (ROC) and visual grading characteristic analyses were performed. RESULTS Arterial attenuation was up to 20% higher (P < .05) after protocol B (mean ± standard deviation, 234.5 HU ± 33.2) than protocol A (160.0 HU ± 29.5). Venous system attenuation was significantly lower in protocol B (164.0 HU ± 17.0) than in protocol A (664.0 HU ± 12.0), with up to a 75% reduction (P < .0001). Protocol B generated significant (P < .0001) improvements in AVCR at multiple anatomic sites. At all anatomic levels, mean CNR with protocol B (34.4 HU ± 9.0) was significantly higher than that with protocol A (14.5 HU ± 14.0) (P < .0313). Effective dose was significantly reduced with protocol B (2.6 mSv ± 0.4 vs 3.2 mSv ± 0.8 with protocol A; P < .0041). ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (P < .0022), with interreader agreement increasing from poor to excellent in lymph node visualization. CONCLUSION Significant improvement in lymph node visualization at the cervicothoracic junction is achieved with a quadruple-phase contrast media injection protocol.
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Affiliation(s)
- Charbel Saade
- From the Department of Diagnostic Radiology, American University of Beirut Medical Center, PO Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon (C.S., F.E.); Department of Radiology, Campbelltown Public Hospital, Campbelltown, NSW, Australia (A.M.); Discipline of Medical Radiation Sciences, University of Sydney, Lidcombe, NSW, Australia (P.C.B.); and Department of Diagnostic Radiology, Johns Hopkins Hospital, Baltimore, Md (D.Y.)
| | - Fadi El-Merhi
- From the Department of Diagnostic Radiology, American University of Beirut Medical Center, PO Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon (C.S., F.E.); Department of Radiology, Campbelltown Public Hospital, Campbelltown, NSW, Australia (A.M.); Discipline of Medical Radiation Sciences, University of Sydney, Lidcombe, NSW, Australia (P.C.B.); and Department of Diagnostic Radiology, Johns Hopkins Hospital, Baltimore, Md (D.Y.)
| | - Ahmad Mayat
- From the Department of Diagnostic Radiology, American University of Beirut Medical Center, PO Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon (C.S., F.E.); Department of Radiology, Campbelltown Public Hospital, Campbelltown, NSW, Australia (A.M.); Discipline of Medical Radiation Sciences, University of Sydney, Lidcombe, NSW, Australia (P.C.B.); and Department of Diagnostic Radiology, Johns Hopkins Hospital, Baltimore, Md (D.Y.)
| | - Patrick C Brennan
- From the Department of Diagnostic Radiology, American University of Beirut Medical Center, PO Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon (C.S., F.E.); Department of Radiology, Campbelltown Public Hospital, Campbelltown, NSW, Australia (A.M.); Discipline of Medical Radiation Sciences, University of Sydney, Lidcombe, NSW, Australia (P.C.B.); and Department of Diagnostic Radiology, Johns Hopkins Hospital, Baltimore, Md (D.Y.)
| | - David Yousem
- From the Department of Diagnostic Radiology, American University of Beirut Medical Center, PO Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon (C.S., F.E.); Department of Radiology, Campbelltown Public Hospital, Campbelltown, NSW, Australia (A.M.); Discipline of Medical Radiation Sciences, University of Sydney, Lidcombe, NSW, Australia (P.C.B.); and Department of Diagnostic Radiology, Johns Hopkins Hospital, Baltimore, Md (D.Y.)
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Synchronization of contrast media administration with retrograde blood flow in patients with hypoplastic ascending aorta. Diagn Interv Imaging 2015; 97:265-8. [PMID: 26342530 DOI: 10.1016/j.diii.2015.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 07/04/2015] [Accepted: 07/27/2015] [Indexed: 11/20/2022]
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Evaluation of A New Bolus Tracking–Based Algorithm for Predicting A Patient-Specific Time of Arterial Peak Enhancement in Computed Tomography Angiography. Invest Radiol 2015; 50:531-8. [DOI: 10.1097/rli.0000000000000160] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Quantitative Evaluation of the Performance of a New Test Bolus–Based Computed Tomographic Angiography Contrast-Enhancement–Prediction Algorithm. Invest Radiol 2015; 50:1-8. [DOI: 10.1097/rli.0000000000000088] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Dendumrongsup T, Plumb AA, Halligan S, Fanshawe TR, Altman DG, Mallett S. Multi-reader multi-case studies using the area under the receiver operator characteristic curve as a measure of diagnostic accuracy: systematic review with a focus on quality of data reporting. PLoS One 2014; 9:e116018. [PMID: 25541977 PMCID: PMC4277459 DOI: 10.1371/journal.pone.0116018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 12/02/2014] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION We examined the design, analysis and reporting in multi-reader multi-case (MRMC) research studies using the area under the receiver-operating curve (ROC AUC) as a measure of diagnostic performance. METHODS We performed a systematic literature review from 2005 to 2013 inclusive to identify a minimum 50 studies. Articles of diagnostic test accuracy in humans were identified via their citation of key methodological articles dealing with MRMC ROC AUC. Two researchers in consensus then extracted information from primary articles relating to study characteristics and design, methods for reporting study outcomes, model fitting, model assumptions, presentation of results, and interpretation of findings. Results were summarized and presented with a descriptive analysis. RESULTS Sixty-four full papers were retrieved from 475 identified citations and ultimately 49 articles describing 51 studies were reviewed and extracted. Radiological imaging was the index test in all. Most studies focused on lesion detection vs. characterization and used less than 10 readers. Only 6 (12%) studies trained readers in advance to use the confidence scale used to build the ROC curve. Overall, description of confidence scores, the ROC curve and its analysis was often incomplete. For example, 21 (41%) studies presented no ROC curve and only 3 (6%) described the distribution of confidence scores. Of 30 studies presenting curves, only 4 (13%) presented the data points underlying the curve, thereby allowing assessment of extrapolation. The mean change in AUC was 0.05 (-0.05 to 0.28). Non-significant change in AUC was attributed to underpowering rather than the diagnostic test failing to improve diagnostic accuracy. CONCLUSIONS Data reporting in MRMC studies using ROC AUC as an outcome measure is frequently incomplete, hampering understanding of methods and the reliability of results and study conclusions. Authors using this analysis should be encouraged to provide a full description of their methods and results.
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Affiliation(s)
| | - Andrew A. Plumb
- Centre for Medical Imaging, University College London, London, United Kingdom
| | - Steve Halligan
- Centre for Medical Imaging, University College London, London, United Kingdom
| | - Thomas R. Fanshawe
- Nuffield Department of Primary Care Health Sciences, Oxford University, Oxford, United Kingdom
| | - Douglas G. Altman
- Centre for Statistics in Medicine, Wolfson College, Oxford University, Oxford, United Kingdom
| | - Susan Mallett
- Nuffield Department of Primary Care Health Sciences, Oxford University, Oxford, United Kingdom
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Saade C, Bourne R, El-Merhi F, Somanathan A, Chakraborty D, Brennan P. An optimised patient-specific approach to administration of contrast agent for CT pulmonary angiography. Eur Radiol 2013; 23:3205-12. [DOI: 10.1007/s00330-013-2919-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Revised: 04/27/2013] [Accepted: 04/30/2013] [Indexed: 11/29/2022]
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