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Chakravarti S, Uyeda JW. Expanding Role of Dual-Energy CT for Genitourinary Tract Assessment in the Emergency Department, From the AJR Special Series on Emergency Radiology. AJR Am J Roentgenol 2023; 221:720-730. [PMID: 37073900 DOI: 10.2214/ajr.22.27864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
Among explored applications of dual-energy CT (DECT) in the abdomen and pelvis, the genitourinary (GU) tract represents an area where accumulated evidence has established the role of DECT to provide useful information that may change management. This review discusses established applications of DECT for GU tract assessment in the emergency department (ED) setting, including characterization of renal stones, evaluation of traumatic injuries and hemorrhage, and characterization of incidental renal and adrenal findings. Use of DECT for such applications can reduce the need for additional multiphase CT or MRI examinations and reduce follow-up imaging recommendations. Emerging applications are also highlighted, including use of low-energy virtual monoenergetic images (VMIs) to improve image quality and potentially reduce contrast media doses and use of high-energy VMIs to mitigate renal mass pseudoenhancement. Finally, implementation of DECT into busy ED radiology practices is presented, weighing the trade-off of additional image acquisition, processing time, and interpretation time against potential additional useful clinical information. Automatic generation of DECT-derived images with direct PACS transfer can facilitate radiologists' adoption of DECT in busy ED environments and minimize impact on interpretation times. Using the described approaches, radiologists can apply DECT technology to improve the quality and efficiency of care in the ED.
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Affiliation(s)
| | - Jennifer W Uyeda
- Department of Emergency Radiology, Brigham and Women's Hospital/Harvard Medical School, 75 Francis St, Boston, MA 02115
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2
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Ananthakrishnan L, Kulkarni N, Toshav A. Dual-Energy Computed Tomography: Integration Into Clinical Practice and Cost Considerations. Radiol Clin North Am 2023; 61:963-971. [PMID: 37758363 DOI: 10.1016/j.rcl.2023.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Optimization of dual-energy CT (DECT) workflow is critical for successful integration of DECT into practice. Patient selection strategies differ by scanner type and may be based on patient size, exam indication, or both. All stakeholders involved in patient scheduling and scan acquisition should be involved in patient triage to DECT. Automation of DECT postprocessing frees up technologist and radiologist time, but care must be taken to avoid sending unnecessary reconstructions to PACS. DECT use in the Emergency Department aids in incidentaloma characterization and improves reader diagnostic confidence, and results in quantifiable cost savings by eliminating the need for follow-up exams.
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Affiliation(s)
- Lakshmi Ananthakrishnan
- Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
| | - Naveen Kulkarni
- Department of Radiology, Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, WI 53226, USA
| | - Aran Toshav
- Department of Radiology, Southeast Louisiana Veterans Healthcare System, LSUHSC, New Orleans, LA 70119, USA
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3
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Virarkar MK, Mileto A, Vulasala SSR, Ananthakrishnan L, Bhosale P. Dual-Energy Computed Tomography Applications in the Genitourinary Tract. Radiol Clin North Am 2023; 61:1051-1068. [PMID: 37758356 DOI: 10.1016/j.rcl.2023.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
By virtue of material differentiation capabilities afforded through dedicated postprocessing algorithms, dual-energy CT (DECT) has been shown to provide benefit in the evaluation of various diseases. In this article, we review the diagnostic use of DECT in the assessment of genitourinary diseases, with emphasis on its role in renal stone characterization, incidental renal and adrenal lesion characterization, retroperitoneal trauma, reduction of radiation, and contrast dose and cost-effectiveness potential. We also discuss future perspectives of the DECT scanning mode, including the use of novel contrast injection strategies and photon-counting detector computed tomography.
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Affiliation(s)
- Mayur K Virarkar
- Department of Radiology, University of Florida College of Medicine, Clinical Center, C90, 2nd Floor, 655 West 8th Street, Jacksonville, FL 32209, USA
| | - Achille Mileto
- Department of Radiology, Mayo Clinic, Mayo Building West, 2nd Floor, 200 First Street SW, Rochester, MN, 55905, USA
| | - Sai Swarupa R Vulasala
- Department of radiology, University of Florida College of Medicine, Clinical Center, C90, 2nd Floor, 655 West 8th Street, Jacksonville, FL, 32209, USA.
| | - Lakshmi Ananthakrishnan
- Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Priya Bhosale
- Department of Diagnostic Radiology, Division of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 1479, Houston, TX 77030, USA
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4
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May C, Sodickson A. Leveraging Dual-Energy Computed Tomography to Improve Emergency Radiology Practice. Radiol Clin North Am 2023; 61:1085-1096. [PMID: 37758358 DOI: 10.1016/j.rcl.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Dual-energy computed tomography affords emergency radiologists with important tools to aid in the detection and discrimination of commonly encountered ED pathologies. In doing so, it can increase the speed of diagnosis and diagnostic certainty while sparing patients potentially unnecessary downsteam workups and radiation exposure. This article demonstrates these clinical benefits through a case-based approach.
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Affiliation(s)
- Craig May
- Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA.
| | - Aaron Sodickson
- Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
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Schawkat K, Krajewski KM. Insights into Renal Cell Carcinoma with Novel Imaging Approaches. Hematol Oncol Clin North Am 2023; 37:863-875. [PMID: 37302934 DOI: 10.1016/j.hoc.2023.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
This article presents a comprehensive overview of new imaging approaches and techniques for improving the assessment of renal masses and renal cell carcinoma. The Bosniak classification, version 2019, as well as the clear cell likelihood score, version 2.0, will be discussed as new imaging algorithms using established techniques. Additionally, newer modalities, such as contrast-enhanced ultrasound, dual energy computed tomography, and molecular imaging, will be discussed in conjunction with emerging radiomics and artificial intelligence techniques. Current diagnostic algorithms combined with newer approaches may be an effective way to overcome existing limitations in renal mass and RCC characterization.
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Affiliation(s)
- Khoschy Schawkat
- Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA; Harvard Medical School
| | - Katherine M Krajewski
- Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA; Harvard Medical School; Dana-Farber Cancer Institute, 440 Brookline Avenue, Building MA Floor L1 Room 04AC, Boston, MA 02215, USA.
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6
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Dual Energy-Derived Metrics for Differentiating Adrenal Adenomas From Nonadenomas on Single-Phase Contrast-Enhanced CT. AJR Am J Roentgenol 2023; 220:693-704. [PMID: 36416399 DOI: 10.2214/ajr.22.28323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND. Adrenal masses are often indeterminate on single-phase postcontrast CT. Dual-energy CT (DECT) with three-material decomposition algorithms may aid characterization. OBJECTIVE. The purpose of this study was to compare the diagnostic performance of metrics derived from portal venous phase DECT, including virtual noncontrast (VNC) attenuation, fat fraction, iodine density, and relative enhancement ratio, for characterizing adrenal masses. METHODS. This retrospective study included 128 patients (82 women, 46 men; mean age, 64.6 ± 12.7 [SD] years) who between January 2016 and December 2019 underwent portal venous phase abdominopelvic DECT that showed a total of 139 adrenal lesions with an available reference standard based on all imaging, clinical, and pathologic records (87 adenomas, 52 nonadenomas [48 metastases, two adrenal cortical carcinomas, one ganglioneuroma, one hematoma]). Two radiologists placed ROIs to determine the following characteristics of the masses: VNC attenuation, fat fraction, iodine density normalized to portal vein, and for masses with VNC greater than 10 HU, relative enhancement ratio (ratio of portal venous phase attenuation to VNC attenuation). Readers' mean measurements were used for ROC analyses, and clinically optimal thresholds were derived as thresholds yielding the highest sensitivity at 100% specificity. RESULTS. Adenomas and nonadenomas were significantly different (all p < .001) in VNC attenuation (mean ± SD, 18.5 ± 12.9 vs 34.1 ± 8.9 HU), fat fraction (mean ± SD, 24.3% ± 8.2% vs 14.2% ± 5.6%), normalized iodine density (mean ± SD, 0.34 ± 0.15 vs 0.17 ± 0.17), and relative enhancement ratio (mean ± SD, 186% ± 96% vs 58% ± 59%). AUCs for all metrics ranged from 0.81 through 0.91. The metric with highest sensitivity for adenoma at the clinically optimal threshold (i.e., 100% specificity) was fat fraction (threshold, ≥ 23.8%; sensitivity, 59% [95% CI, 48-69%]) followed by VNC attenuation (≤ 15.2 HU; sensitivity, 39% [95% CI, 29-50%]), relative enhancement ratio (≥ 214%; sensitivity, 37% [95% CI, 25-50%]), and normalized iodine density (≥ 0.90; sensitivity, 1% (95% CI, 0-60%]). VNC attenuation at the traditional true noncontrast attenuation threshold of 10 HU or lower had sensitivity of 28% (95% CI, 19-38%) and 100% specificity. Presence of fat fraction 23.8% or greater or relative enhancement ratio 214% or greater yielded sensitivity of 68% (95% CI, 57-77%) with 100% specificity. CONCLUSION. For adrenal lesions evaluated with single-phase DECT, fat fraction had higher sensitivity than VNC attenuation at both the clinically optimal threshold and the traditional threshold of 10 HU or lower. CLINICAL IMPACT. By helping to definitively diagnose adenomas, DECT-derived metrics can help avoid downstream imaging for incidental adrenal lesions.
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Toia GV, Mileto A, Wang CL, Sahani DV. Quantitative dual-energy CT techniques in the abdomen. Abdom Radiol (NY) 2022; 47:3003-3018. [PMID: 34468796 DOI: 10.1007/s00261-021-03266-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 02/06/2023]
Abstract
Advances in dual-energy CT (DECT) technology and spectral techniques are catalyzing the widespread implementation of this technology across multiple radiology subspecialties. The inclusion of energy- and material-specific datasets has ushered overall improvements in CT image contrast and noise as well as artifacts reduction, leading to considerable progress in radiologists' ability to detect and characterize pathologies in the abdomen. The scope of this article is to provide an overview of various quantitative clinical DECT applications in the abdomen and pelvis. Several of the reviewed applications have not reached mainstream clinical use and are considered investigational. Nonetheless awareness of such applications is critical to having a fully comprehensive knowledge base to DECT and fostering future clinical implementation.
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Affiliation(s)
- Giuseppe V Toia
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Mailbox 3252, Madison, WI, 53792, USA.
| | - Achille Mileto
- Department of Radiology, Mayo Clinic, 200 First Street, SW, Rochester, MN, 55905, USA
| | - Carolyn L Wang
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Dushyant V Sahani
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA, 98195, USA
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8
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Editorial Comment: Renal Lesions and Dual-Energy CT-Are We Finally Ready to Forgo True Unenhanced Images? AJR Am J Roentgenol 2022; 219:623. [PMID: 35506558 DOI: 10.2214/ajr.22.27900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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9
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Laukamp KR, Tirumani SH, Lennartz S, Hokamp NG, Gupta A, Pennig L, Persigehl T, Gilkeson R, Ramaiya N. Evaluation of equivocal small cystic pancreatic lesions with spectral-detector computed tomography. Acta Radiol 2021; 62:172-181. [PMID: 32306744 DOI: 10.1177/0284185120917119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND Evaluation of small cystic lesions of the pancreas remains a challenging task, as due to their size appearance can be rather hypodense than clearly fluid-filled. PURPOSE To evaluate whether additional information provided by novel dual-layer spectral-detector computed tomography (SDCT) imaging can improve assessment of these lesions. MATERIAL AND METHODS For this retrospective study, we reviewed reports of 1192 contrast-enhanced portal-venous phase SDCT scans of the abdomen conducted between May 2017 and January 2019. On basis of the radiological report 25 small (≤1.5 cm) cystic pancreatic lesions in 22 patients were identified, in which additional short-term follow-up imaging was recommended to confirm/clarify cystic nature. Conventional images (CI) and spectral images (SI) including virtual-monoenergetic images at 40 keV (VMI), iodine-density and iodine-overlay images were reconstructed. Two readers indicated lesion conspicuity and confidence for presence of cystic nature on three-point scales. First, solely CI were evaluated, while in a second reading after a four-week interval, the combination of CI and corresponding SI were reviewed. Quantitatively, ROI-based mean attenuation was measured in CI and VMI. RESULTS In the subjective reading, SI significantly improved lesion conspicuity (CI 2 [1-2], SI 3 [2-3], P < 0.001) and confidence regarding presence of cystic nature (CI 2 [1-2], SI 3 [3-3], P < 0.001). Inter-observer agreement depicted by intraclass correlation coefficient improved considerably from 0.51 with only CI to 0.85 when the combination with SI was used. Further, VMI displayed significantly higher signal-to-noise (CI 1.2 ± 0.8, VMI 3.2 ± 1.8, P < 0.001) and contrast-to-noise ratios (CI 2.6 ± 0.8, VMI 4.7 ± 1.9). CONCLUSION Compared to CI alone, combination with SI significantly improves visualization and confidence in evaluation of small equivocal cystic pancreatic lesions.
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Affiliation(s)
- Kai Roman Laukamp
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Sree Harsha Tirumani
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nils Große Hokamp
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Amit Gupta
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Lenhard Pennig
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Thorsten Persigehl
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Robert Gilkeson
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Nikhil Ramaiya
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
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10
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Abstract
Dual-energy CT (DECT) overcomes several limitations of conventional single-energy CT (SECT) for the evaluation of gastrointestinal diseases. This article provides an overview of practical aspects of the DECT technology and acquisition protocols, reviews existing clinical applications, discusses current challenges, and describes future directions, with a focus on gastrointestinal imaging. A head-to-head comparison of technical specifications among DECT scanner implementations is provided. Energy- and material-specific DECT image reconstructions enable retrospective (i.e., after examination acquisition) image quality adjustments that are not possible using SECT. Such adjustments may, for example, correct insufficient contrast bolus or metal artifacts, thereby potentially avoiding patient recalls. A combination of low-energy monochromatic images, iodine maps, and virtual unenhanced images can be included in protocols to improve lesion detection and disease characterization. Relevant literature is reviewed regarding use of DECT for evaluation of the liver, gallbladder, pancreas, and bowel. Challenges involving cost, workflow, body habitus, and variability in DECT measurements are considered. Artificial intelligence and machine-learning image reconstruction algorithms, PACS integration, photon-counting hardware, and novel contrast agents are expected to expand the multienergy capability of DECT and further augment its value.
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11
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Building a dual-energy CT service line in abdominal radiology. Eur Radiol 2020; 31:4330-4339. [PMID: 33210201 DOI: 10.1007/s00330-020-07441-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 10/08/2020] [Accepted: 10/23/2020] [Indexed: 10/23/2022]
Abstract
As the access of radiology practices to dual-energy CT (DECT) has increased worldwide, seamless integration into clinical workflows and optimized use of this technology are desirable. In this article, we provide basic concepts of commercially available DECT hardware implementations, discuss financial and logistical aspects, provide tips for protocol building and image routing strategies, and review radiation dose considerations to establish a DECT service line in abdominal imaging. KEY POINTS: • Tube-based and detector-based DECT implementations with varying features and strengths are available on the imaging market. • Thorough assessment of financial and logistical aspects is key to successful implementation of a DECT service line. • Optimized protocol building and image routing strategies are of critical importance for effective use and seamless inception of DECT in routine clinical workflows.
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12
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Thiravit S, Brunnquell C, Cai LM, Flemon M, Mileto A. Use of dual-energy CT for renal mass assessment. Eur Radiol 2020; 31:3721-3733. [PMID: 33210200 DOI: 10.1007/s00330-020-07426-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/11/2020] [Accepted: 10/14/2020] [Indexed: 12/22/2022]
Abstract
Although dual-energy CT (DECT) may prove useful in a variety of abdominal imaging tasks, renal mass evaluation represents the area where this technology can be most impactful in abdominal imaging compared to routinely performed contrast-enhanced-only single-energy CT exams. DECT post-processing techniques, such as creation of virtual unenhanced and iodine density images, can help in the characterization of incidentally discovered renal masses that would otherwise remain indeterminate based on post-contrast imaging only. The purpose of this article is to review the use of DECT for renal mass assessment, including its benefits and existing limitations. KEY POINTS: • If DECT is selected as the scanning mode for most common abdominal protocols, many incidentally found renal masses can be fully triaged within the same exam. • Virtual unenhanced and iodine density DECT images can provide additional information when renal masses are discovered in the post-contrast-only setting. • For renal mass evaluation, virtual unenhanced and iodine density DECT images should be interpreted side-by-side to troubleshoot pitfalls that can potentially lead to erroneous interpretation.
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Affiliation(s)
- Shanigarn Thiravit
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357115, Seattle, WA, 98195, USA.,Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Christina Brunnquell
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357115, Seattle, WA, 98195, USA
| | - Larry M Cai
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357115, Seattle, WA, 98195, USA
| | - Mena Flemon
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357115, Seattle, WA, 98195, USA
| | - Achille Mileto
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357115, Seattle, WA, 98195, USA.
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13
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Obmann MM, Cosentino A, Cyriac J, Hofmann V, Stieltjes B, Boll DT, Yeh BM, Benz MR. Quantitative enhancement thresholds and machine learning algorithms for the evaluation of renal lesions using single-phase split-filter dual-energy CT. Abdom Radiol (NY) 2020; 45:1922-1928. [PMID: 31451887 DOI: 10.1007/s00261-019-02195-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To establish thresholds for contrast enhancement-based attenuation (CM) and iodine concentration (IOD) for the quantitative evaluation of enhancement in renal lesions on single-phase split-filter dual-energy CT (tbDECT) and combine measurements in a machine learning algorithm to potentially improve performance. MATERIAL 126 patients with incidental renal cysts (both hypo- and hyperdense cysts) or high suspicion for renal cell carcinoma (312 total lesions) undergoing abdominal, portal venous phase tbDECT were initially included in this retrospective study. Gold standard was pathological confirmation or follow-up imaging (MRI or multiphasic CT). CM, IOD, and ROI size were recorded. Thresholds for CM and IOD were identified using Youden-Index of the empirical ROC curves. Decision tree (DTC) and random forest classifier (RFC) were trained. Sensitivities, specificities, and AUCs were compared using McNemar and DeLong test. RESULTS The final study cohort comprised 40 enhancing and 113 non-enhancing renal lesions. Optimal thresholds for quantitative iodine measurements and contrast enhancement-based attenuation were 1.0 ± 0.0 mg/ml and 23.6 ± 0.3 HU, respectively. Single DECT parameters (IOD, CM) showed similar overall performance with an AUC of 0.894 and 0.858 (p = 0.541) (sensitivity 90 and 80%, specificity 88 and 92%, respectively). While overall performance for the DTC (AUC 0.944) was higher than RFC (AUC 0.886), this difference (p = 0.409) and comparison to CM (p = 0.243) and IOD (p = 0.353) was not statistically significant. CONCLUSIONS Enhancement in incidental renal lesions on single-phase tbDECT can be classified with up to 87.5% sensitivity and 94.6% specificity. Algorithms combining DECT parameters did not increase overall performance.
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Affiliation(s)
- Markus M Obmann
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, University of Basel, Petersgraben 4, 4031, Basel, Switzerland.
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA.
| | - Aurelio Cosentino
- Department of Surgical Sciences, Radiology Unit, University of Turin, Turin, Italy
| | - Joshy Cyriac
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, University of Basel, Petersgraben 4, 4031, Basel, Switzerland
| | - Verena Hofmann
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, University of Basel, Petersgraben 4, 4031, Basel, Switzerland
| | - Bram Stieltjes
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, University of Basel, Petersgraben 4, 4031, Basel, Switzerland
| | - Daniel T Boll
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, University of Basel, Petersgraben 4, 4031, Basel, Switzerland
| | - Benjamin M Yeh
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA
| | - Matthias R Benz
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, University of Basel, Petersgraben 4, 4031, Basel, Switzerland.
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14
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Dual energy CT in clinical routine: how it works and how it adds value. Emerg Radiol 2020; 28:103-117. [PMID: 32483665 DOI: 10.1007/s10140-020-01785-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/04/2020] [Indexed: 02/06/2023]
Abstract
Dual energy computed tomography (DECT), also known as spectral CT, refers to advanced CT technology that separately acquires high and low energy X-ray data to enable material characterization applications for substances that exhibit different energy-dependent x-ray absorption behavior. DECT supports a variety of post-processing applications that add value in routine clinical CT imaging, including material selective and virtual non-contrast images using two- and three-material decomposition algorithms, virtual monoenergetic imaging, and other material characterization techniques. Following a review of acquisition and post-processing techniques, we present a case-based approach to highlight the added value of DECT in common clinical scenarios. These scenarios include improved lesion detection, improved lesion characterization, improved ease of interpretation, improved prognostication, inherently more robust imaging protocols to account for unexpected pathology or suboptimal contrast opacification, length of stay reduction, reduced utilization by avoiding unnecessary follow-up examinations, and radiation dose reduction. A brief discussion of post-processing workflow approaches, challenges, and solutions is also included.
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15
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Cicero G, Ascenti G, Albrecht MH, Blandino A, Cavallaro M, D'Angelo T, Carerj ML, Vogl TJ, Mazziotti S. Extra-abdominal dual-energy CT applications: a comprehensive overview. Radiol Med 2020; 125:384-397. [PMID: 31925704 DOI: 10.1007/s11547-019-01126-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 12/27/2019] [Indexed: 12/12/2022]
Abstract
Unlike conventional computed tomography, dual-energy computed tomography is a relatively novel technique that exploits ionizing radiations at different energy levels. The separate radiation sets can be achieved through different technologies, such as dual source, dual layers or rapid switching voltage. Body tissue molecules vary for their specific atomic numbers and electron density, and the interaction with different sets of radiations results in different attenuations, allowing to their final distinction. In particular, iodine recognition and quantification have led to important information about intravenous contrast medium delivery within the body. Over the years, useful post-processing algorithms have also been validated for improving tissue characterization. For instance, contrast resolution improvement and metal artifact reduction can be obtained through virtual monoenergetic images, dose reduction by virtual non-contrast reconstructions and iodine distribution highlighting through iodine overlay maps. Beyond the evaluation of the abdominal organs, dual-energy computed tomography has also been successfully employed in other anatomical districts. Although lung perfusion is one of the most investigated, this evaluation has been extended to narrowly fields of application, such as musculoskeletal, head and neck, vascular and cardiac. The potential pool of information provided by dual-energy technology is already wide and not completely explored, yet. Therefore, its performance continues to raise increasing interest from both radiologists and clinicians.
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Affiliation(s)
- Giuseppe Cicero
- Section of Radiological Sciences, Department of Biomedical Sciences and Morphological and Functional Imaging, University of Messina, Policlinico "G. Martino" Via Consolare Valeria 1, 98100, Messina, Italy.
| | - Giorgio Ascenti
- Section of Radiological Sciences, Department of Biomedical Sciences and Morphological and Functional Imaging, University of Messina, Policlinico "G. Martino" Via Consolare Valeria 1, 98100, Messina, Italy
| | - Moritz H Albrecht
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Alfredo Blandino
- Section of Radiological Sciences, Department of Biomedical Sciences and Morphological and Functional Imaging, University of Messina, Policlinico "G. Martino" Via Consolare Valeria 1, 98100, Messina, Italy
| | - Marco Cavallaro
- Section of Radiological Sciences, Department of Biomedical Sciences and Morphological and Functional Imaging, University of Messina, Policlinico "G. Martino" Via Consolare Valeria 1, 98100, Messina, Italy.,Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Tommaso D'Angelo
- Section of Radiological Sciences, Department of Biomedical Sciences and Morphological and Functional Imaging, University of Messina, Policlinico "G. Martino" Via Consolare Valeria 1, 98100, Messina, Italy
| | - Maria Ludovica Carerj
- Section of Radiological Sciences, Department of Biomedical Sciences and Morphological and Functional Imaging, University of Messina, Policlinico "G. Martino" Via Consolare Valeria 1, 98100, Messina, Italy
| | - Thomas J Vogl
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Silvio Mazziotti
- Section of Radiological Sciences, Department of Biomedical Sciences and Morphological and Functional Imaging, University of Messina, Policlinico "G. Martino" Via Consolare Valeria 1, 98100, Messina, Italy
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