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Choi ES, Kim JS, Lee JK, Lee HA, Pak S. Prospective evaluation of low-dose multiphase hepatic computed tomography for detecting and characterizing hepatocellular carcinoma in patients with chronic liver disease. BMC Med Imaging 2022; 22:219. [PMID: 36536325 PMCID: PMC9762112 DOI: 10.1186/s12880-022-00947-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Knowing the lowest acceptable radiation dose of multiphase hepatic CT may allow us to reduce the radiation dose for detecting HCC. PURPOSE To prospectively assess the image quality and diagnostic performance of low-dose and ultra-low-dose multiphase hepatic computed tomography using a dual-source CT scanner. METHODS Three reconstructed different dose scan images (standard-dose, low-dose, and ultra-low-dose) of hepatic multiphase CT were obtained from 67 patients with a dual-source CT scanner. The image quality and the diagnostic performance of the three radiation dose CT scans of the hepatic focal lesion (≥ 0.5 cm) were analyzed by two independent readers using the Liver Imaging Reporting and Data System. RESULTS Qualitative image quality and signal-to-noise ratio were significantly different among the radiation doses (p < 0.001). In total, 154 lesions comprising 32 hepatocellular carcinomas (HCC) and 122 non-HCC were included. The sensitivities of SDCT, LDCT, and ULDCT were 90.6%(29/32), 81.3%(26/32), and 56.2%(18/32), respectively. The accuracies of SDCT, LDCT, and ULDCT were 98.1%(151/154), 96.1%(148/154), and 89.6%(138/154), respectively. On per-lesion analysis, SDCT and LDCT did not show significantly different sensitivity and accuracy in diagnosing HCC (p = 0.250 and 0.250). CONCLUSIONS The diagnostic performance of dynamic hepatic LDCT with 33% reduced radiation dose in comparison to SDCT would be acceptable even though its image quality was qualitatively and quantitatively inferior. However, few HCCs could be overlooked. Therefore, with caution, radiation dose reduction by one-third could be implemented for follow-up CT scans for patients suspected of having HCC with caution and further studies are needed in the future.
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Affiliation(s)
- Eun Sun Choi
- grid.255649.90000 0001 2171 7754Department of Radiology and Medical Research Institute, College of Medicine, Ewha Womans University, Seoul, Korea
| | - Jin Sil Kim
- grid.255649.90000 0001 2171 7754Department of Radiology and Medical Research Institute, College of Medicine, Ewha Womans University, Seoul, Korea
| | - Jeong Kyong Lee
- grid.255649.90000 0001 2171 7754Department of Radiology and Medical Research Institute, College of Medicine, Ewha Womans University, Seoul, Korea
| | - Hye Ah Lee
- grid.255649.90000 0001 2171 7754Clinical Trial Center, Mokdong Hospital, Ewha Womans University, Seoul, Korea
| | - Seongyong Pak
- grid.267370.70000 0004 0533 4667Department of Biomedical Engineering, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
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2
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Alsleem H, Tajaldeen A, Almutairi A, Almohiy H, Aldaais E, Albattat R, Alsleem M, Abuelhia E, Kheiralla OAM, Alqahtani A, Alghamdi S, Aljondi R, Alharbi R. The Actual Role of Iterative Reconstruction Algorithm Methods in Several Saudi Hospitals As A Tool For Radiation Dose Minimization of Ct Scan Examinations. J Multidiscip Healthc 2022; 15:1747-1757. [PMID: 36016857 PMCID: PMC9398457 DOI: 10.2147/jmdh.s376729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/09/2022] [Indexed: 11/25/2022] Open
Abstract
Background Iterative reconstruction algorithm (IR) techniques were developed to maintain a lower radiation dose for patients as much as possible while achieving the required image quality and medical benefits. The main purpose of the current research was to assess the level and usage extent of IR techniques in computed tomographic (CT) scan exams. Also, the obligation of practitioners in several hospitals in Saudi Arabia to implement IR in CT exams was assessed. Material and Methodology The recent research was based on two studies: data collection and a survey study. Data on the CT scan examinations were retrospectively collected from CT scanners. The survey was conducted using a questionnaire to evaluate radiographers’ and radiologists’ perceptions about IR and their practices with IR techniques. The statistical analysis results were performed to measure the usage strength level of IR methods. Results and Discussions The IR strength level of 50% was selected for nearly 80% of different CT examinations and patients of different ages and weights. About 46% of the participants had not learned about IR methods during their college studies, and 54% had not received formal training in applying IR techniques. Only 32% of the participants had adequate experience with IR. Half of the participants were not involved in the updating process of the CT protocol. Conclusion The results indicate that the majority of radiographer and radiologist at four different hospitals in Saudi Arabia have no explicit or understandable knowledge of selecting IR strength levels during the CT examination of patients. There is a need for more training in IR applications for both radiologists and radiographers. Training sessions were suggested to support radiographers and radiologists to efficiently utilize IR techniques to optimize image quality. Further studies are required to adjust CT exam protocols effectively to utilize the IR technique.
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Affiliation(s)
- Haney Alsleem
- Department of Radiological Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Abdulrahman Tajaldeen
- Department of Radiological Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | | | - Hussain Almohiy
- Radiological Sciences, King Khalid University, Abha, Saudi Arabia
| | - Ebtisam Aldaais
- Department of Radiological Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Rayan Albattat
- Medical Imaging Department, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | - Mousa Alsleem
- College of Dentistry, King Faisal University, Alahsa, Saudi Arabia
| | - Elfatih Abuelhia
- Department of Radiological Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | | | - Ahmed Alqahtani
- Radiology Department, King Saud Medical City, Riyadh, Saudi Arabia
| | - Salem Alghamdi
- Department of Applied Radiologic Technology, University of Jeddah, Jeddah, Saudi Arabia
| | - Rowa Aljondi
- Department of Applied Radiologic Technology, University of Jeddah, Jeddah, Saudi Arabia
| | - Renad Alharbi
- Department of Radiology, Specialized Medical Complex, Jeddah, Saudi Arabia
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3
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Muhammad N, Karim M, Harun H, Rahman M, Azlan R, Sumardi N. The impact of tube current and iterative reconstruction algorithm on dose and image quality of infant CT head examination. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Ria F, Solomon JB, Wilson JM, Samei E. Technical Note: Validation of TG 233 phantom methodology to characterize noise and dose in patient CT data. Med Phys 2020; 47:1633-1639. [PMID: 32040862 DOI: 10.1002/mp.14089] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 01/10/2020] [Accepted: 02/05/2020] [Indexed: 01/19/2023] Open
Abstract
PURPOSE Phantoms are useful tools in diagnostic CT, but practical limitations reduce phantoms to being only a limited patient surrogate. Furthermore, a phantom with a single cross sectional area cannot be used to evaluate scanner performance in modern CT scanners that use dose reduction techniques such as automated tube current modulation (ATCM) and iterative reconstruction (IR) algorithms to adapt x-ray flux to patient size, reduce radiation dose, and achieve uniform image noise. A new multisized phantom (Mercury Phantom, MP) has been introduced, representing multiple diameters. This work aimed to ascertain if measurements from MP can predict radiation dose and image noise in clinical CT images to prospectively inform protocol design. METHODS The adult MP design included four different physical diameters (18.5, 23.0, 30.0, and 37.0 cm) representing a range of patient sizes. The study included 1457 examinations performed on two scanner models from two vendors, and two clinical protocols (abdominopelvic with and chest without contrast). Attenuating diameter, radiation dose, and noise magnitude (average pixel standard deviation in uniform image) was automatically estimated in patients and in the MP using a previously validated algorithm. An exponential fit of CTDIvol and noise as a function of size was applied to patients and MP data. Lastly, the fit equations from the phantom data were used to fit the patient data. In each patient distribution fit, the normalized root mean square error (nRMSE) values were calculated in the residuals' plots as a metric to indicate how well the phantom data can predict dose and noise in clinical operations as a function of size. RESULTS For dose across patient size distributions, the difference between nRMSE from patient fit and MP model data prediction ranged between 0.6% and 2.0% (mean 1.2%). For noise across patient size distributions, the nRMSE difference ranged between 0.1% and 4.7% (mean 1.4%). CONCLUSIONS The Mercury Phantom provided a close prediction of radiation dose and image noise in clinical patient images. By assessing dose and image quality in a phantom with multiple sizes, protocol parameters can be designed and optimized per patient size in a highly constrained setup to predict clinical scanner and ATCM system performance.
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Affiliation(s)
- Francesco Ria
- Carl E. Ravin Advanced Imaging Labs, Duke University Health System, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA.,Clinical Imaging Physics Group, Duke University Health System, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA
| | - Justin B Solomon
- Clinical Imaging Physics Group, Duke University Health System, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA.,Medical Physics Graduate Program, Duke University Health System, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA
| | - Joshua M Wilson
- Clinical Imaging Physics Group, Duke University Health System, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA.,Medical Physics Graduate Program, Duke University Health System, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA
| | - Ehsan Samei
- Carl E. Ravin Advanced Imaging Labs, Duke University Health System, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA.,Clinical Imaging Physics Group, Duke University Health System, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA.,Medical Physics Graduate Program, Duke University Health System, 2424 Erwin Road, Suite 302, Durham, NC, 27710, USA
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de Boer E, Nijholt IM, Jansen S, Edens MA, Walen S, van den Berg JWK, Boomsma MF. Optimization of pulmonary emphysema quantification on CT scans of COPD patients using hybrid iterative and post processing techniques: correlation with pulmonary function tests. Insights Imaging 2019; 10:102. [PMID: 31591646 PMCID: PMC6779684 DOI: 10.1186/s13244-019-0776-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 08/09/2019] [Indexed: 11/17/2022] Open
Abstract
Objectives The aim of this study was to assess the effect of hybrid iterative reconstruction and post processing on emphysema quantification in low-dose CT scans of COPD patients using pulmonary function tests (PFT) as a reference. Methods CT scans of 23 COPD patients diagnosed with GOLD I or higher were reconstructed with iDose4 level 1 to 7 in IntelliSpace Portal (ISP) 6 and 7. ISP7 was used with and without specific denoising filter for COPD. The extent of emphysema was measured as percentage of lung voxels with attenuation < − 950 Hounsfield units (%LAA-950). The correlation between %LAA-950 and PFT, age, BMI, pack years, and the Clinical COPD Questionnaire (CCQ) and Medical Research Council dyspnea scale (MRC) was determined. Results Denoising significantly reduced %LAA-950 as was demonstrated by lower %LAA-950 in ISP7 with denoising filter and a significant reduction in %LAA-950 with higher iDose4 levels. All PFT except forced vital capacity (FVC) were significantly inversely correlated with %LAA-950. There was a trend toward a stronger correlation at higher iDose4 levels. %LAA-950 was also significantly correlated with BMI, GOLD class, and CCQ scores. Conclusions Our study showed that hybrid iterative reconstruction and use of post processing denoising can optimize the use of emphysema quantification in CT scans as a complimentary diagnostic tool to stage COPD in addition to PFT.
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Affiliation(s)
- E de Boer
- Department of Radiology, Isala hospital, Dr. van Heesweg 2, 8025 AB, Zwolle, The Netherlands
| | - I M Nijholt
- Department of Radiology, Isala hospital, Dr. van Heesweg 2, 8025 AB, Zwolle, The Netherlands
| | - S Jansen
- Department of Radiology, Isala hospital, Dr. van Heesweg 2, 8025 AB, Zwolle, The Netherlands
| | - M A Edens
- Department of Innovation and Science, Isala hospital, Zwolle, The Netherlands
| | - S Walen
- Department of Pulmonology, Isala hospital, Zwolle, The Netherlands
| | | | - M F Boomsma
- Department of Radiology, Isala hospital, Dr. van Heesweg 2, 8025 AB, Zwolle, The Netherlands.
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6
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Smarda M, Efstathopoulos E, Mazioti A, Kordolaimi S, Ploussi A, Priftis K, Kelekis N, Alexopoulou E. High-Resolution Computed Tomography Examinations for Chronic Suppurative Lung Disease in Early Childhood: Radiation Exposure and Image Quality Evaluations with Iterative Reconstruction Algorithm Use. Can Assoc Radiol J 2016; 67:218-24. [DOI: 10.1016/j.carj.2015.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 09/05/2015] [Accepted: 10/28/2015] [Indexed: 10/21/2022] Open
Abstract
Purpose High radiosensitivity of children undergoing repetitive computed tomography examinations necessitates the use of iterative reconstruction algorithms in order to achieve a significant radiation dose reduction. The goal of this study is to compare the iDose iterative reconstruction algorithm with filtered backprojection in terms of radiation exposure and image quality in 33 chest high-resolution computed tomography examinations performed in young children with chronic bronchitis. Methods Fourteen patients were scanned using the filtered backprojection protocol while 19 patients using the iDose protocol and reduced milliampere-seconds, both on a 64-detector row computed tomography scanner. The iDose group images were reconstructed with different iDose levels (2, 4, and 6). Radiation exposure quantities were estimated, while subjective and objective image qualities were evaluated. Unpaired t tests were used for data statistical analysis. Results The iDose application allowed significant effective dose reduction (about 80%). Subjective image quality evaluation showed satisfactory results even with iDose level 2, whereas it approached excellent image with iDose level 6. Subjective image noise was comparable between the 2 groups with the use of iDose level 4, while objective noise was comparable between filtered backprojection and iterative reconstruction level 6 images. Conclusions The iDose algorithm use in pediatric chest high-resolution computed tomography reduces radiation exposure without compromising image quality. Further evaluation with iterative reconstruction algorithms is needed in order to establish high-resolution computed tomography as the gold standard low-dose method for children suffering from chronic lung diseases.
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Affiliation(s)
- Magdalini Smarda
- Radiology Department, University General Hospital ATTIKON, Chaidari, Athens, Greece
| | | | - Argyro Mazioti
- Radiology Department, University General Hospital ATTIKON, Chaidari, Athens, Greece
| | - Sofia Kordolaimi
- Radiology Department, University General Hospital ATTIKON, Chaidari, Athens, Greece
| | - Agapi Ploussi
- Radiology Department, University General Hospital ATTIKON, Chaidari, Athens, Greece
| | - Konstantinos Priftis
- Department of Pediatrics, University General Hospital ATTIKON, Chaidari, Athens, Greece
| | - Nikolaos Kelekis
- Radiology Department, University General Hospital ATTIKON, Chaidari, Athens, Greece
| | - Efthymia Alexopoulou
- Radiology Department, University General Hospital ATTIKON, Chaidari, Athens, Greece
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7
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Greenberg AM. Cone beam computed tomography scanning and diagnosis for dental implants. Oral Maxillofac Surg Clin North Am 2016; 27:185-202. [PMID: 25951956 DOI: 10.1016/j.coms.2015.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cone beam computed tomography (CBCT) has become an important new technology for oral and maxillofacial surgery practitioners. CBCT provides improved office-based diagnostic capability and applications for surgical procedures, such as CT guidance through the use of computer-generated drill guides. A thorough knowledge of the basic science of CBCT as well as the ability to interpret the images correctly and thoroughly is essential to current practice.
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Affiliation(s)
- Alex M Greenberg
- Oral and Maxillofacial Surgery, Columbia University College of Dental Medicine, 630 W. 168th Street, New York, NY 10032, USA; Private Practice Limited to Oral and Maxillofacial Surgery, 18 East 48th Street Suite 1702, New York, NY 10017, USA.
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8
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Thomas P, Hayton A, Beveridge T, Marks P, Wallace A. Evidence of dose saving in routine CT practice using iterative reconstruction derived from a national diagnostic reference level survey. Br J Radiol 2015; 88:20150380. [PMID: 26133224 DOI: 10.1259/bjr.20150380] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To assess the influence and significance of the use of iterative reconstruction (IR) algorithms on patient dose in CT in Australia. METHODS We examined survey data submitted to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) National Diagnostic Reference Level Service (NDRLS) during 2013 and 2014. We compared median survey dose metrics with categorization by scan region and use of IR. RESULTS The use of IR results in a reduction in volume CT dose index of between 17% and 44% and a reduction in dose-length product of between 14% and 34% depending on the specific scan region. The reduction was highly significant (p < 0.001, Wilcoxon rank-sum test) for all six scan regions included in the NDRLS. Overall, 69% (806/1167) of surveys included in the analysis used IR. CONCLUSION The use of IR in CT is achieving dose savings of 20-30% in routine practice in Australia. IR appears to be widely used by participants in the ARPANSA NDRLS with approximately 70% of surveys submitted employing this technique. ADVANCES IN KNOWLEDGE This study examines the impact of the use of IR on patient dose in CT on a national scale.
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Affiliation(s)
- P Thomas
- Medical Imaging Section, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, VIC, Australia
| | - A Hayton
- Medical Imaging Section, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, VIC, Australia
| | - T Beveridge
- Medical Imaging Section, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, VIC, Australia
| | - P Marks
- Medical Imaging Section, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, VIC, Australia
| | - A Wallace
- Medical Imaging Section, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, VIC, Australia
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