Diagnostic Performance of Low-Dose CT for Acute Abdominal Conditions

NCT ID: NCT05651360

Last Updated: 2023-10-17

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Total Enrollment

246 participants

Study Classification

OBSERVATIONAL

Study Start Date

2022-12-07

Study Completion Date

2023-07-10

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

The goal of this non-inferiority observational study is to assess the diagnostic performance of low-dose CT with deep learning image reconstruction (DLIR) in adult participants with acute abdominal conditions. The main research question is:

• Can low-dose CT with DLIR achieve the same diagnostic performance as standard CT for the diagnosis of acute abdominal conditions.

Participants will be examined with an additional low-dose CT directly after the standard CT. Participant will be their own controls.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Background Computed Tomography (CT) has become an essential tool in modern clinical medicine. With widespread availability, a rapid increase in the use of CT imaging has been observed over the last decades. With the associated increase in radiation exposure, the potential increased risk for radiation-induced malignancy has become a public health concern. This is especially true for CT scans of the abdomen and pelvis which currently account for 50% of the collective CT dose. As the benefit of dose reduction in general is offset by deterioration of image quality, technological advances to reduce radiation dose without compromising image quality are aspired in clinical practice.

In CT-image reconstruction, filtered back projection (FBP) has been the dominant image reconstruction technique algorithm since the early 1970s, complemented by the first commercial iterative reconstruction (IR) algorithms in 2009.

A novel deep learning image reconstruction (DLIR) algorithm received clinical approval in 2019 (TrueFidelity, GE Healthcare, Milwaukee, WI). Other vendor-specific algorithms for deep learning image reconstruction are also emerging (AiCE, Canon Medical Systems, Otawara, Japan). As explained by a technical white paper, having been trained with high-dose and low-dose FBP datasets across phantom and patient cases, the DLIR algorithm strives to suppress image noise without compromising image quality. The use of deep learning image reconstruction has demonstrated potential for improved image quality and dose reduction without shifting noise texture.

For patients with acute abdominal conditions, CT of the abdomen and pelvis is considered the best first- or second-line diagnostic approach. For these patients a fast and accurate diagnosis is of great importance to avoid treatment delay and subsequent complications such as gastrointestinal perforation in case of appendicitis or diverticulitis. On the other hand, it is also important to avoid unnecessary surgical intervention and the related complications. A possible low-dose CT protocol must therefore provide a non-inferior diagnostic performance to facilitate fast diagnosis and avoid overtreatment and inconclusive examinations.

Promising results have been reported regarding low-dose CT examinations with model-based IR and dose reduction of up to 75-80%. However, with the introduction of DLIR even further dose reduction seems feasible. Our own results from an image quality perception study with DLIR indicate that a dose reduction of up to 92.5% compared to standard CT might preserve acceptable diagnostic image quality (yet unpublished work).

On this basis, the purpose of this study is to assess the diagnostic performance of low-dose CT with DLIR for the diagnosis of acute abdominal conditions in a non-inferiority setting with a large sample size provided by two major trauma centers in northern Europe.

Aims

Primary:

To evaluate the diagnostic performance for acute abdominal conditions of contrast enhanced low-dose CT with DLIR "TrueFidelity" (TF) compared to standard full-dose CT.

Secondary:

To evaluate technical and perceived image quality (qualitatively and quantitatively).

Ethics

Approval will be obtained from the regional ethics committee and the institutions data protection officer.

Written informed consent will be obtained from all participants. This project will be in accordance with the Helsinki Declaration.

Risks Minimal risks exist due to a slight increase in radiation exposure. The additional radiation exposure of 27.5% is within the national variation of radiation exposure from CT exams performed for corresponding clinical tasks. The investigators estimated the mean additional effective dose to 1.5 mSv which corresponds to about 4 months with natural background radiation exposure in Norway (4.1 mSv/year). The additional radiation exposure translates into a theoretical excess lifetime risk of deadly radiation induced cancer between 0.004 - 0.03%. The clinical risks from this exposure are considered to be minimal/not significant.

Material and Methods The study will be registered at ClinicalTrials.gov prior to initiation. Study methods and results will be reported in agreement with the Standards for Reporting of Diagnostic Accuracy Studies (STARD) statement of 2015. It should be noted that the STARD-AI Steering Group is preparing an AI-specific extension. If these STARD-AI guidelines are published before end of study, the findings will also be reported in accordance herewith. To compensate for AI specific elements not addressed in STARD, the investigators will, when relevant, rely on the Checklist for Artificial Intelligence in Medical Imaging (CLAIM) which is modelled after the STARD guideline.

Pilot A study pilot including 10 patients divided equally between Oslo and Odense will be performed to allow for testing of study logistics and adjustments of the radiation dose level of the low-dose CT.

Examination protocol / imaging Examinations will be carried out according to local routine procedures and established CT protocols (CT scanner: GE Revolution).

In addition to the CT with standard examination protocol a low-dose CT scan will be performed, not exceeding 30% radiation dose of the standard CT. Low-dose CT images will be reconstructed with TF high. The low dose CT will be performed directly after the standard CT to avoid bias from differences in the timing of the contrast phase.

Location and local study population The study will be carried out as a multicenter study involving Oslo and Odense with prospective data collection.

The estimated total study population will be divided equally between the two Hospitals.

Image evaluation The low-dose CT will not be used for diagnostic purposes or patient treatment. Image evaluation and comparison will be conducted separated from clinical routine workflow.

All low-dose CT exams will be evaluated independently by two resident radiologists and by two experienced radiologists specialized in abdominal radiology with more than 10 years of experience in abdominal CT. The readers will be blinded for all information from previous exams, the primary CT report, any finding by the other readers, all treatment related information and for the final diagnosis.

They will have access to clinical referrals and laboratory tests performed prior to the original CT examination. Image evaluation will be performed in the radiologists' clinical environment using diagnostic monitors.

In the outcome analysis, the diagnosis for each patient from low dose CT will be compared to the original radiological diagnosis based on full dose CT.

For intra reader agreement a random selection from 10% of the cases will be presented twice to each reader.

Technical image quality is assessed by positioning regions of interest (ROI) in a homogeneous segment of the portal vein, adjacent normal liver parenchyma aorta, erector spinae muscles and in the subcutaneous fat. Contrast-to-Noise Ratio (CNR) will be calculated.

Perceived image quality will be assessed by at least two radiologists on a Likert-type scale along image quality criteria based on the European guidelines for image quality in abdominal CT.

Statistics Dedicated statistical software like Stata and SPSS will be used for analysis of study data. The alpha significance level will be set to 5% and 95% confidence intervals will be used. Kappa statistics will be used for inter and intra reader agreement. Logistic regression will be used for image quality assessment. Appropriate parametric or non-parametric tests will be used for evaluation of numeric variables. The diagnostic performance will be defined by area under the curve, sensitivity, specificity, positive and negative predictive value. Significant differences in sensitivity and specificity will be determined by McNemar's test.

Power calculation and sample size A non-inferiority study design will be used to show noninferiority regarding the diagnostic performance of the low-dose CT compared to standard CT. The investigators estimated the sensitivity of the standard CT to 90%. The prevalence of acute abdominal conditions with a visible correlate on standard CT is estimated to 70% among all referrals meeting inclusion criteria. A non-inferiority margin of 10% for sensitivity was considered as clinical acceptable i.e. the probability for positive findings on low-dose CT in case of positive standard CT was assumed to be 90%.

S\_L = Probability (positive low-dose CT \| positive standard CT)

The 0-hypothesis was defined as:

S\_L \< 90%

The alternative hypothesis was then defined as:

S\_L \> 90% To identify a one-sided 6% difference (increase) from the non-inferiority margin with a power of 80% and an alpha significance level of 5%, the investigators estimated the required patients with positive CT findings to n=116 (binominal distribution). The total number of required patients was then calculated to 116/0.7=166.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Abdominal Pain Acute Pain Acute Cholecystitis Acute Appendicitis Acute Pancreatitis

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Observational Model Type

COHORT

Study Time Perspective

PROSPECTIVE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Abdominal Pain

Participants under evaluation for an acute abdominal condition who are referred to CT of the abdomen and pelvis.

low-dose CT

Intervention Type DIAGNOSTIC_TEST

Low-dose CT scan will be performed, not exceeding 30% radiation dose of the standard CT. Low-dose CT images will be reconstructed with TrueFidelity high. The low-dose CT will be performed directly after the standard CT to avoid bias from differences in the timing of the contrast phase.

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

low-dose CT

Low-dose CT scan will be performed, not exceeding 30% radiation dose of the standard CT. Low-dose CT images will be reconstructed with TrueFidelity high. The low-dose CT will be performed directly after the standard CT to avoid bias from differences in the timing of the contrast phase.

Intervention Type DIAGNOSTIC_TEST

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Patients under evaluation for an acute abdominal condition who are referred to CT of the abdomen and pelvis.
* Age \>18 years
* The patients must be able to give their oral and written consent to study participation.

Exclusion Criteria

* Contraindications regarding contrast enhanced CT examinations like known iodinated contrast media adverse reactions or claustrophobia.
* Pregnancy.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Odense University Hospital

OTHER

Sponsor Role collaborator

Oslo University Hospital

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Anselm Schulz

MD, PhD

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Anselm Schulz, PhD

Role: PRINCIPAL_INVESTIGATOR

Oslo University Hospital

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Odense University Hospital

Odense, , Denmark

Site Status

Oslo University Hospital

Oslo, , Norway

Site Status

Countries

Review the countries where the study has at least one active or historical site.

Denmark Norway

References

Explore related publications, articles, or registry entries linked to this study.

Brenner DJ, Hall EJ. Computed tomography--an increasing source of radiation exposure. N Engl J Med. 2007 Nov 29;357(22):2277-84. doi: 10.1056/NEJMra072149. No abstract available.

Reference Type BACKGROUND
PMID: 18046031 (View on PubMed)

Novelline RA, Rhea JT, Rao PM, Stuk JL. Helical CT in emergency radiology. Radiology. 1999 Nov;213(2):321-39. doi: 10.1148/radiology.213.2.r99nv01321.

Reference Type BACKGROUND
PMID: 10551209 (View on PubMed)

OECD. Computed tomography (CT) exams. 2018.

Reference Type BACKGROUND

Berrington de Gonzalez A, Mahesh M, Kim KP, Bhargavan M, Lewis R, Mettler F, Land C. Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med. 2009 Dec 14;169(22):2071-7. doi: 10.1001/archinternmed.2009.440.

Reference Type BACKGROUND
PMID: 20008689 (View on PubMed)

Mettler FA Jr, Thomadsen BR, Bhargavan M, Gilley DB, Gray JE, Lipoti JA, McCrohan J, Yoshizumi TT, Mahesh M. Medical radiation exposure in the U.S. in 2006: preliminary results. Health Phys. 2008 Nov;95(5):502-7. doi: 10.1097/01.HP.0000326333.42287.a2.

Reference Type BACKGROUND
PMID: 18849682 (View on PubMed)

Pan X, Sidky EY, Vannier M. Why do commercial CT scanners still employ traditional, filtered back-projection for image reconstruction? Inverse Probl. 2009 Jan 1;25(12):1230009. doi: 10.1088/0266-5611/25/12/123009.

Reference Type BACKGROUND
PMID: 20376330 (View on PubMed)

Beister M, Kolditz D, Kalender WA. Iterative reconstruction methods in X-ray CT. Phys Med. 2012 Apr;28(2):94-108. doi: 10.1016/j.ejmp.2012.01.003. Epub 2012 Feb 10.

Reference Type BACKGROUND
PMID: 22316498 (View on PubMed)

Hsieh JL, E.; Nett, B.; Tang, J.; Thibault JB.; Sahney, S. A new era of image reconstruction: TrueFidelity. Technical white paper on deep learning image reconstruction. 2019.

Reference Type BACKGROUND

Akagi M, Nakamura Y, Higaki T, Narita K, Honda Y, Zhou J, Yu Z, Akino N, Awai K. Deep learning reconstruction improves image quality of abdominal ultra-high-resolution CT. Eur Radiol. 2019 Nov;29(11):6163-6171. doi: 10.1007/s00330-019-06170-3. Epub 2019 Apr 11.

Reference Type BACKGROUND
PMID: 30976831 (View on PubMed)

Jensen CT, Liu X, Tamm EP, Chandler AG, Sun J, Morani AC, Javadi S, Wagner-Bartak NA. Image Quality Assessment of Abdominal CT by Use of New Deep Learning Image Reconstruction: Initial Experience. AJR Am J Roentgenol. 2020 Jul;215(1):50-57. doi: 10.2214/AJR.19.22332. Epub 2020 Apr 14.

Reference Type BACKGROUND
PMID: 32286872 (View on PubMed)

Njolstad T, Schulz A, Godt JC, Brogger HM, Johansen CK, Andersen HK, Martinsen ACT. Improved image quality in abdominal computed tomography reconstructed with a novel Deep Learning Image Reconstruction technique - initial clinical experience. Acta Radiol Open. 2021 Apr 9;10(4):20584601211008391. doi: 10.1177/20584601211008391. eCollection 2021 Apr.

Reference Type BACKGROUND
PMID: 33889427 (View on PubMed)

Solomon J, Lyu P, Marin D, Samei E. Noise and spatial resolution properties of a commercially available deep learning-based CT reconstruction algorithm. Med Phys. 2020 Sep;47(9):3961-3971. doi: 10.1002/mp.14319. Epub 2020 Jul 6.

Reference Type BACKGROUND
PMID: 32506661 (View on PubMed)

Greffier J, Hamard A, Pereira F, Barrau C, Pasquier H, Beregi JP, Frandon J. Image quality and dose reduction opportunity of deep learning image reconstruction algorithm for CT: a phantom study. Eur Radiol. 2020 Jul;30(7):3951-3959. doi: 10.1007/s00330-020-06724-w. Epub 2020 Feb 25.

Reference Type BACKGROUND
PMID: 32100091 (View on PubMed)

Brady SL, Trout AT, Somasundaram E, Anton CG, Li Y, Dillman JR. Improving Image Quality and Reducing Radiation Dose for Pediatric CT by Using Deep Learning Reconstruction. Radiology. 2021 Jan;298(1):180-188. doi: 10.1148/radiol.2020202317. Epub 2020 Nov 17.

Reference Type BACKGROUND
PMID: 33201790 (View on PubMed)

Larson DB, Johnson LW, Schnell BM, Salisbury SR, Forman HP. National trends in CT use in the emergency department: 1995-2007. Radiology. 2011 Jan;258(1):164-73. doi: 10.1148/radiol.10100640. Epub 2010 Nov 29.

Reference Type BACKGROUND
PMID: 21115875 (View on PubMed)

Expert Panel on Gastrointestinal Imaging:; Garcia EM, Camacho MA, Karolyi DR, Kim DH, Cash BD, Chang KJ, Feig BW, Fowler KJ, Kambadakone AR, Lambert DL, Levy AD, Marin D, Moreno C, Peterson CM, Scheirey CD, Siegel A, Smith MP, Weinstein S, Carucci LR. ACR Appropriateness Criteria(R) Right Lower Quadrant Pain-Suspected Appendicitis. J Am Coll Radiol. 2018 Nov;15(11S):S373-S387. doi: 10.1016/j.jacr.2018.09.033.

Reference Type BACKGROUND
PMID: 30392606 (View on PubMed)

Expert Panel on Gastrointestinal Imaging:; Peterson CM, McNamara MM, Kamel IR, Al-Refaie WB, Arif-Tiwari H, Cash BD, Chernyak V, Goldstein A, Grajo JR, Hindman NM, Horowitz JM, Noto RB, Porter KK, Srivastava PK, Zaheer A, Carucci LR. ACR Appropriateness Criteria(R) Right Upper Quadrant Pain. J Am Coll Radiol. 2019 May;16(5S):S235-S243. doi: 10.1016/j.jacr.2019.02.013.

Reference Type BACKGROUND
PMID: 31054750 (View on PubMed)

Rud B, Vejborg TS, Rappeport ED, Reitsma JB, Wille-Jorgensen P. Computed tomography for diagnosis of acute appendicitis in adults. Cochrane Database Syst Rev. 2019 Nov 19;2019(11):CD009977. doi: 10.1002/14651858.CD009977.pub2.

Reference Type BACKGROUND
PMID: 31743429 (View on PubMed)

Kabir SA, Kabir SI, Sun R, Jafferbhoy S, Karim A. How to diagnose an acutely inflamed appendix; a systematic review of the latest evidence. Int J Surg. 2017 Apr;40:155-162. doi: 10.1016/j.ijsu.2017.03.013. Epub 2017 Mar 6.

Reference Type BACKGROUND
PMID: 28279749 (View on PubMed)

Moloney F, James K, Twomey M, Ryan D, Grey TM, Downes A, Kavanagh RG, Moore N, Murphy MJ, Bye J, Carey BW, McSweeney SE, Deasy C, Andrews E, Shanahan F, Maher MM, O'Connor OJ. Low-dose CT imaging of the acute abdomen using model-based iterative reconstruction: a prospective study. Emerg Radiol. 2019 Apr;26(2):169-177. doi: 10.1007/s10140-018-1658-z. Epub 2018 Nov 17.

Reference Type BACKGROUND
PMID: 30448900 (View on PubMed)

Poletti PA, Becker M, Becker CD, Halfon Poletti A, Rutschmann OT, Zaidi H, Perneger T, Platon A. Emergency assessment of patients with acute abdominal pain using low-dose CT with iterative reconstruction: a comparative study. Eur Radiol. 2017 Aug;27(8):3300-3309. doi: 10.1007/s00330-016-4712-9. Epub 2017 Jan 12.

Reference Type BACKGROUND
PMID: 28083698 (View on PubMed)

Widmark A. Diagnostic reference level (DRL) in Norway 2017. Results, revision:and establishment of new DRL.NRPA Report 2018:3. Norwegian Radiation Protection Authority, Østerås 2018.

Reference Type BACKGROUND

Komperød M, Rudjord AL, Skuterud L, Dyve JE. Radiation Doses from the Environment. Calculations of the Public's Exposure to Radiation from the Environment in Norway. Strålevern Rapport 2015:11 Østerås: Norwegian Radiation Protection Authority 2015.

Reference Type BACKGROUND

Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig L, Lijmer JG, Moher D, Rennie D, de Vet HC, Kressel HY, Rifai N, Golub RM, Altman DG, Hooft L, Korevaar DA, Cohen JF; STARD Group. STARD 2015: An Updated List of Essential Items for Reporting Diagnostic Accuracy Studies. Radiology. 2015 Dec;277(3):826-32. doi: 10.1148/radiol.2015151516. Epub 2015 Oct 28.

Reference Type BACKGROUND
PMID: 26509226 (View on PubMed)

Sounderajah V, Ashrafian H, Golub RM, Shetty S, De Fauw J, Hooft L, Moons K, Collins G, Moher D, Bossuyt PM, Darzi A, Karthikesalingam A, Denniston AK, Mateen BA, Ting D, Treanor D, King D, Greaves F, Godwin J, Pearson-Stuttard J, Harling L, McInnes M, Rifai N, Tomasev N, Normahani P, Whiting P, Aggarwal R, Vollmer S, Markar SR, Panch T, Liu X; STARD-AI Steering Committee. Developing a reporting guideline for artificial intelligence-centred diagnostic test accuracy studies: the STARD-AI protocol. BMJ Open. 2021 Jun 28;11(6):e047709. doi: 10.1136/bmjopen-2020-047709.

Reference Type BACKGROUND
PMID: 34183345 (View on PubMed)

Mongan J, Moy L, Kahn CE Jr. Checklist for Artificial Intelligence in Medical Imaging (CLAIM): A Guide for Authors and Reviewers. Radiol Artif Intell. 2020 Mar 25;2(2):e200029. doi: 10.1148/ryai.2020200029. eCollection 2020 Mar. No abstract available.

Reference Type BACKGROUND
PMID: 33937821 (View on PubMed)

Report EUR 16262 EN. European guidelines on quality criteria for computed tomography. 2000.

Reference Type BACKGROUND

Ahn S, Park SH, Lee KH. How to demonstrate similarity by using noninferiority and equivalence statistical testing in radiology research. Radiology. 2013 May;267(2):328-38. doi: 10.1148/radiol.12120725.

Reference Type BACKGROUND
PMID: 23610094 (View on PubMed)

Eng KA, Abadeh A, Ligocki C, Lee YK, Moineddin R, Adams-Webber T, Schuh S, Doria AS. Acute Appendicitis: A Meta-Analysis of the Diagnostic Accuracy of US, CT, and MRI as Second-Line Imaging Tests after an Initial US. Radiology. 2018 Sep;288(3):717-727. doi: 10.1148/radiol.2018180318. Epub 2018 Jun 19.

Reference Type BACKGROUND
PMID: 29916776 (View on PubMed)

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

22/11840

Identifier Type: OTHER

Identifier Source: secondary_id

468490

Identifier Type: OTHER

Identifier Source: secondary_id

PVO ref. 22/11840

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.

IA Model for Acute Appendicitis in CT
NCT06175169 RECRUITING NA
Rapid Abdominal Diagnosis With AI & Radiology
NCT07040358 ACTIVE_NOT_RECRUITING
MR Urography vs CT Urography
NCT02606513 COMPLETED NA