Defining Dosimetric Reference Levels in Computed Tomography Spectral Scanning

NCT07305103 | Active Not Recruiting

• 1 other identifier: NIMAO/2024-1/DD-01
• Study Type: observational
• Target: 9,600
• Locations: 1 country
• Sites: 1

Brief Summary

Spectral computed tomography or dual-energy CT imaging can overcome the limitations of conventional CT in differentiating between two materials with equivalent total attenuation. It can generate several types of images, such as virtual monochromatic images, which improve the contrast-to-noise ratio for low energy levels and reduce artifacts for high energy levels. It also allows for quantitative image analysis and thus better characterization of lesions and tissues through material mapping (e.g., iodinated contrast agent mapping). This technique is increasingly used in routine clinical practice thanks to improvements in image flow management and technological advances. It also involves exposing patients to ionizing radiation, as with conventional CT but, unlike conventional CT scans, for which dosimetric reference levels (RLs) are defined for the most common examinations in France (RL decree dated 2019), there are currently no dosimetric reference levels for examinations performed using this technique. Yet RLs are an important and effective tools for optimizing patient exposure to ionizing radiation. Several articles were published between 2012 and 2017 when the first dual-energy scanners arrived in clinics. However, the results presented in these studies are now far removed from recent practices, as they do not take into account the latest technological developments used in dual-energy scanners, which reduce X-ray doses. The main objective of the study is to define dosimetric reference levels for the most commonly performed spectral computed tomography examinations in France.

Conditions

Medical Imaging

Keywords

Radiation dose; Reference levels; Radiology; Spectral Computed Tomography Imaging

Outcome Measures

Primary Outcomes (38)

• Dosimetric reference levels for spectral computed tomography examinations in France: Chest CT for pulmonary embolism. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Chest CT for pulmonary embolism. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Chest CT for other indications. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Chest CT for other indications. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Coronary CT with contrast injection and retrospective gating. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Coronary CT with contrast injection and prospective gating. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Cranial CT with contrast injection. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Cranial CT with contrast injection. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Supra-aortic trunk CT. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Supra-aortic trunk CT. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Neck and ear,nose and throat sphere CT with contrast injection. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Neck and ear,nose and throat sphere CT with contrast injection. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Oncological abdomen-pelvis CT scan. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Oncological abdomen-pelvis CT scan. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Abdomen-pelvis CT scan to check for kidney stones. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Abdomen-pelvis CT scan to check for kidney stones. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Abdomen-pelvis CT scan for non-oncological purposes and to check for kidney stones. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Abdomen-pelvis CT scan for non-oncological purposes and to check for kidney stones. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Oncological chest-abdomen-pelvis CT scan. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Oncological chest-abdomen-pelvis CT scan. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Non-oncological chest-abdomen-pelvis CT scan. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Non-oncological chest-abdomen-pelvis CT scan. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Oncological chest-abdomen CT scan. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Oncological chest-abdomen CT scan. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Non-oncological chest-abdomen CT scan. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Non-oncological chest-abdomen CT scan. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Lower limb angiography. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Lower limb angiography. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Cervical spine CT scan. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Cervical spine CT scan. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Thoracic spine CT scan. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Thoracic spine CT scan. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Lumbar spine CT scan. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Lumbar spine CT scan. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Pelvis CT scan. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Pelvis CT scan. DLP

  Dose length product (DLP) expressed in mGy.cm

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Extremities CT scan. CTDIvol

  Computed tomography dose index (CTDIvol) per acquisition expressed in milligray (mGy).

  Periprocedural

• Dosimetric reference levels for spectral computed tomography examinations in France: Extremities CT scan. DLP

  Dose length product (DLP) expressed in mGy.cm will be recorded

  Periprocedural

Secondary Outcomes (183)

• Impact of the spectral acquisition/detection technique on the dose delivered to patients: Chest CT for pulmonary embolism. Acquisition type

  Periprocedural

• Impact of the spectral acquisition/detection technique on the dose delivered to patients: Chest CT for pulmonary embolism. Number of acquisitions

  Periprocedural

• Impact of the spectral acquisition/detection technique on the dose delivered to patients: Chest CT for pulmonary embolism. CTDIvol

  Periprocedural

• Impact of the spectral acquisition/detection technique on the dose delivered to patients: Chest CT for pulmonary embolism. DLP

  Periprocedural

• Impact of patients' BMI on the dose delivered to patients: Chest CT for pulmonary embolism. BMI

  Periprocedural

Study Arms (1)

Patients undergoing a maximum number of 18 spectral CT scans among the examinations mentioned below

Patients undergoing a maximum number of 18 spectral CT scans among the examinations mentioned below: 1. Chest CT for pulmonary embolism 2. Chest CT for other indications 3. Coronary CT with contrast injection and retrospective gating 4. Coronary CT with contrast injection and prospective gating 5. Cranial CT with contrast injection 6. Supra-aortic trunk CT 7. Neck and ear,nose and throat sphere CT with contrast injection 8. Oncological abdomen-pelvis CT scan 9. Abdomen-pelvis CT scan to check for kidney stones 10. Abdomen-pelvis CT scan for non-oncological purposes and to check for kidney stones 11. Oncological chest-abdomen-pelvis CT scan 12. Non-oncological chest-abdomen-pelvis CT scan 13. Oncological chest-abdomen CT scan 14. Non-oncological chest-abdomen CT scan 15. Lower limb angiography 16. Cervical spine CT scan 17. Thoracic spine CT scan 18. Lumbar spine CT scan 19. Pelvis CT scan, 20. Extremities CT scan

Radiation: Spectral ComputedTomography

Interventions

Spectral ComputedTomography RADIATION

Commonly performed spectral computed tomography examinations in France

Patients undergoing a maximum number of 18 spectral CT scans among the examinations mentioned below

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

All adult patients who underwent a spectral CT scan between January 1, 2023, and August 31, 2024, as part of their treatment.

You may qualify if:

• Adult male/female patient (≥ 18 years old)
• Body Mass Index (BMI) between 18 and 35 kg/m²
• Patients who underwent a spectral CT scan between January 1, 2023, and August 31, 2024, as part of their treatment.

You may not qualify if:

• \- Pregnant women

Sponsors & Collaborators

• Centre Hospitalier Universitaire de Saint Etienne: collaborator
• Hôpital Louis Mourier, 92700 Colombes: collaborator
• Centre Hospitalier de Valenciennes: collaborator
• Hopital Louis Pradel: collaborator
• Centre Léon Bérard, Lyon: collaborator
• University Hospital, Bordeaux: collaborator
• Centre Hospitalier Lyon Sud: collaborator
• Institut Curie: collaborator
• Amiens University Hospital: collaborator
• Poitiers University Hospital: collaborator
• Henri Mondor Hospital, Créteil: collaborator
• Saint Antoine University Hospital: collaborator
• Nord Ardennes Intercommunal Hospital: collaborator
• Centre Antoine Lacassagne, Nice: collaborator
• Hôpital Edouard Herriot (GH Centre), Lyon: collaborator
• University Hospital, Lille: collaborator
• Bichat Hospital: collaborator
• Centre Hospitalier Universitaire de Nīmes: lead
• Institut Paoli Calmettes, Marseille: collaborator
• Hôpital Necker-Enfants Malades: collaborator
• CHU Hôpital Lariboisière APHP: collaborator
• Saint-Louis Hospital, Paris, France: collaborator

Study Sites (1)

Nîmes University Hospital

Nîmes, Gard, 30029, France

Location

Related Publications (9)

• Henzler T, Fink C, Schoenberg SO, Schoepf UJ. Dual-energy CT: radiation dose aspects. AJR Am J Roentgenol. 2012 Nov;199(5 Suppl):S16-25. doi: 10.2214/AJR.12.9210.

  PMID: 23097163 BACKGROUND

• Ghasemi Shayan R, Oladghaffari M, Sajjadian F, Fazel Ghaziyani M. Image Quality and Dose Comparison of Single-Energy CT (SECT) and Dual-Energy CT (DECT). Radiol Res Pract. 2020 Apr 20;2020:1403957. doi: 10.1155/2020/1403957. eCollection 2020.

  PMID: 32373363 BACKGROUND

• Greffier J, Villani N, Defez D, Dabli D, Si-Mohamed S. Spectral CT imaging: Technical principles of dual-energy CT and multi-energy photon-counting CT. Diagn Interv Imaging. 2023 Apr;104(4):167-177. doi: 10.1016/j.diii.2022.11.003. Epub 2022 Nov 19.

  PMID: 36414506 BACKGROUND

• Dabli D, Frandon J, Belaouni A, Akessoul P, Addala T, Berny L, Beregi JP, Greffier J. Optimization of image quality and accuracy of low iodine concentration quantification as function of dose level and reconstruction algorithm for abdominal imaging using dual-source CT: A phantom study. Diagn Interv Imaging. 2022 Jan;103(1):31-40. doi: 10.1016/j.diii.2021.08.004. Epub 2021 Oct 6.

  PMID: 34625394 BACKGROUND

• Si-Mohamed SA, Boccalini S, Villien M, Yagil Y, Erhard K, Boussel L, Douek PC. First Experience With a Whole-Body Spectral Photon-Counting CT Clinical Prototype. Invest Radiol. 2023 Jul 1;58(7):459-471. doi: 10.1097/RLI.0000000000000965. Epub 2023 Feb 22.

  PMID: 36822663 BACKGROUND

• Wortman JR, Shyu JY, Dileo J, Uyeda JW, Sodickson AD. Dual-energy CT for routine imaging of the abdomen and pelvis: radiation dose and image quality. Emerg Radiol. 2020 Feb;27(1):45-50. doi: 10.1007/s10140-019-01733-9. Epub 2019 Nov 1.

  PMID: 31673838 BACKGROUND

• Noda Y, Kawai N, Kawamura T, Kobori A, Miyase R, Iwashima K, Kaga T, Miyoshi T, Hyodo F, Kato H, Matsuo M. Radiation and iodine dose reduced thoraco-abdomino-pelvic dual-energy CT at 40 keV reconstructed with deep learning image reconstruction. Br J Radiol. 2022 Jun 1;95(1134):20211163. doi: 10.1259/bjr.20211163. Epub 2022 Mar 4.

  PMID: 35230135 BACKGROUND

• Etard C, Bigand E, Salvat C, Vidal V, Beregi JP, Hornbeck A, Greffier J. Patient dose in interventional radiology: a multicentre study of the most frequent procedures in France. Eur Radiol. 2017 Oct;27(10):4281-4290. doi: 10.1007/s00330-017-4780-5. Epub 2017 Mar 13.

  PMID: 28289939 BACKGROUND

• Greffier J, Ferretti G, Rousseau J, Andreani O, Alonso E, Rauch A, Gillet R, Le Roy J, Cabrol-Faivre L, Douane F, David A, Henry S, Jacques T, Stefanovic X, Decoux E, Lafay F, Pilleul F, Couzon F, Boutet C, Woerly B, Baur P, Sans N, Faruch M, Moussier-Lherm A, Tselikas L, Jacquier A, Bigand E, Pessis E, Teriitehau C, Magnier F, Cassagnes L, Haberlay M, Boutteau D, De Kerviler E, Majorel-Gouthain C, Defez D, Vuillod A, Rouviere O, Hennequin L, Fohlen A, Alwan R, Malakhia A, Aubry S, Dohan A, Eresue-Bony M, Gautier R, Dal R, Dabli D, Hebert T, Kovacs R, Hadid-Beurrier L, Bousson V, Potel M, Barbotteau Y, Michel C, Habib-Geryes B, Andre M, Arnaud T, Bestion N, Ernst O, Monfraix S, Brillet PY, Guiu B, Boussel L, Demonchy M, Beregi JP, Frandon J. National dose reference levels in computed tomography-guided interventional procedures-a proposal. Eur Radiol. 2020 Oct;30(10):5690-5701. doi: 10.1007/s00330-020-06903-9. Epub 2020 May 2.

  PMID: 32361774 BACKGROUND

Study Officials

• Joël GREFFIER

  Nîmes University Hospital

  STUDY CHAIR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 10, 2025
• First Posted: December 26, 2025
• Study Start: September 1, 2025
• Primary Completion: December 31, 2025
• Study Completion (Estimated): June 30, 2026
• Last Updated: December 26, 2025

Record last verified: 2025-11

Locations

FR (1)