CLEAR item#16

“Imaging protocol (i.e., image acquisition and processing). Provide the imaging protocol and acquisition parameters with post-processing details. Define physical pixel and voxel dimensions. Clearly state whether single or multiple or various scanners are used, with the number of instances for each protocol. Define the timing of the phase if a contrast medium was used. State the patient preparation (drug administration, blood sugar control before the scans, etc.) if performed.” [1] (from the article by Kocak et al.; licensed under CC BY 4.0)

Reporting examples for CLEAR item#16

Example#1. “CCT images were obtained using a 512-slice scanner (Revolution CT, General Electric, Chicago, IL, USA), with prospective gating, setting the slice thickness at 0.625 mm, 120 kV, automatic mA, rotation time of 0.28 s, DFOV: 25 cm, Detector Coverage: 160 mm. All patients were subjected to administration of contrast material (Omnipaque 350 mg/mL, GE Healthcare, Chicago, IL, USA) at a rate of 5 mL/s followed by a saline chaser. The image acquisition was triggered after a threshold of 80 HU was reached in a region of interest placed in the left ventricle (bolus-tracking technique).” [2] (from the article by Cavallo et al.; licensed under CC BY 4.0)

Example#2. “Patients underwent prostate MRI on a 3 T MR750 scanner (GE Healthcare, Waukesha, WI) using a 32-channel receiver coil. Intravenous injection of hyoscine butylbromide (Buscopan, 20 mg/mL; Boehringer, Ingelheim am Rhein, Germany) was administered prior to imaging to reduce peristaltic movement, unless clinically contraindicated. Multiparametric MRI protocol included Axial T1 and multiplanar high-resolution T2-weighted 2D fast recovery FSE (field of view (FOV) 18 × 18 cm2; voxel size 0.35 × 0.35 mm2; slice thickness 3 mm; gap 0 mm). Diffusion-weighted imaging (DWI) was performed using a spin-echo echo-planar imaging pulse sequence (FOV 28 cm; slice thickness 3 mm; gap 0 mm; b-values: b-150, b-750, and b-1,400 s/mm2) and an additional small FOV (24 cm) b-2,000 s/mm2 DWI sequence; ADC maps were calculated automatically. Dynamic contrast enhancement was performed using a standard sequence (FOV 24 cm; slice thickness and gap 3 mm and 0 mm, respectively; temporal resolution 7 s) following a bolus of Gadobutrol (Gadovist, 0.1 mmol/kg; Bayer, Leverkusen, Germany) at 28 s via a power injector, at a rate of 3 mL/s (dose 0.1 mmol/kg).” [3] (from the article by Sushentsev et al.; licensed under CC BY 4.0)

Explanation and elaboration of CLEAR item#16

Developing a comprehensive imaging protocol and detailing acquisition parameters, along with post-processing steps, is crucial for ensuring the reliability and reproducibility of medical imaging studies. The imaging protocol should specify the physical pixel and voxel dimensions, delineating the spatial resolution of the images in both two and three-dimensional spaces. This information is fundamental for accurately interpreting and comparing results across radiomic studies [4, 5]. Clear documentation of the scanner specifications is imperative, indicating whether single or multiple scanners were used, with the number of instances for each protocol. For studies involving contrast agents, it is essential to specify the timing of the contrast medium phase, providing details on when the images were acquired relative to contrast administration. Patient preparation details that may influence image quality, such as antispasmodic drug administration prior to small bowel exams or blood sugar control before PET scans, should be clearly stated if relevant to the imaging modality, and are essential for standardization across studies. Both Example#1 and Example#2 nicely report the image acquisition and contrast administration details for different imaging modalities.

References

  1. Kocak B, Baessler B, Bakas S, et al (2023) CheckList for EvaluAtion of Radiomics research (CLEAR): a step-by-step reporting guideline for authors and reviewers endorsed by ESR and EuSoMII. Insights Imaging 14:75. https://doi.org/10.1186/s13244-023-01415-8
  2. Cavallo AU, Troisi J, Muscogiuri E, et al (2022) Cardiac Computed Tomography Radiomics-Based Approach for the Detection of Left Ventricular Remodeling in Patients with Arterial Hypertension. Diagnostics 12:322. https://doi.org/10.3390/diagnostics12020322
  3. Sushentsev N, Rundo L, Blyuss O, et al (2021) MRI-derived radiomics model for baseline prediction of prostate cancer progression on active surveillance. Sci Rep 11:12917. https://doi.org/10.1038/s41598-021-92341-6
  4. Papp L, Rausch I, Grahovac M, et al (2019) Optimized Feature Extraction for Radiomics Analysis of 18F-FDG PET Imaging. J Nucl Med Off Publ Soc Nucl Med 60:864–872. https://doi.org/10.2967/jnumed.118.217612
  5. Mackin D, Fave X, Zhang L, et al (2015) Measuring Computed Tomography Scanner Variability of Radiomics Features. Invest Radiol 50:757–765. https://doi.org/10.1097/RLI.0000000000000180

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