Comparative Evaluation of Contrast-Enhanced MRI and FDG-PET/CT in Spinal Pathology: Image Quality and Short-Term Renal-Hematologic Safety

This prospective comparative observational study evaluates image quality characteristics and short-term physiological effects associated with contrast-enhanced magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in patients with cervical and lumbar spinal pathologies.

A total of 120 adult participants undergo either contrast-enhanced MRI or FDG-PET/CT as part of routine clinical evaluation. Image quality is assessed using quantitative metrics, including signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), as well as qualitative Visual Grading Analysis (VGA) performed by blinded radiologists. Short-term physiological effects are evaluated using blood urea nitrogen (BUN), estimated glomerular filtration rate (eGFR), and hemoglobin measurements obtained before imaging and 48 hours after imaging.

The study aims to compare image quality characteristics and short-term physiological parameters associated with these imaging modalities and to examine the influence of age group and spinal region on imaging performance.

Study Overview

• Status: Completed
• Conditions: Short-Term Renal-Hematologic Safety; Contrast-Enhanced MRI and FDG-PET/CT; Spinal Pathology

Detailed Description

Background and Rationale

Magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) are widely used imaging modalities for the evaluation of cervical and lumbar spinal disorders. MRI primarily provides high-resolution anatomical information, whereas FDG-PET/CT provides metabolic and functional information that may assist in the assessment of inflammatory, infectious, degenerative, and neoplastic spinal conditions. Although both modalities are routinely used in clinical practice, differences in image quality characteristics and short-term physiological effects associated with imaging procedures remain areas of interest.

Study Design

This study is a prospective comparative observational study designed to evaluate image quality characteristics and short-term physiological effects associated with contrast-enhanced MRI and FDG-PET/CT in adult patients with cervical or lumbar spinal pathologies. A total of 120 participants are included, with 60 participants undergoing contrast-enhanced MRI and 60 participants undergoing FDG-PET/CT according to routine clinical indications and standard institutional workflows.

The study is non-interventional. No experimental treatments, investigational drugs, or deviations from standard clinical care are introduced. All imaging procedures are performed according to established institutional protocols and manufacturer recommendations.

Study Population

Eligible participants are adults with clinically suspected or confirmed cervical or lumbar spinal pathology requiring advanced imaging evaluation. Conditions may include degenerative, inflammatory, infectious, neoplastic, traumatic, or post-surgical spinal disorders.

Imaging Procedures

MRI examinations are performed using a 3 Tesla scanner equipped with a dedicated spinal coil. Standard spinal imaging protocols include sagittal and axial T1-weighted and T2-weighted sequences. Intravenous gadolinium-based contrast administration is performed according to institutional guidelines and standard clinical practice.

FDG-PET/CT examinations are performed following standard patient preparation procedures, including fasting requirements and blood glucose assessment. Intravenous administration of 18F-fluorodeoxyglucose (FDG) is followed by image acquisition using routine clinical PET/CT protocols. CT acquisition is used for attenuation correction and anatomical localization according to institutional practice.

Image Quality Assessment

Quantitative image quality assessment includes measurement of signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) using standardized regions of interest. Measurements are performed using predefined image analysis procedures to ensure consistency across participants.

Qualitative image quality assessment is performed using Visual Grading Analysis (VGA). Independent blinded radiologists evaluate image quality using predefined criteria related to anatomical detail, tissue contrast, lesion conspicuity, image noise, and overall diagnostic usability.

Physiological and Safety Assessments

Short-term physiological effects associated with imaging procedures are evaluated using laboratory measurements obtained before imaging and 48 hours after imaging. Laboratory assessments include blood urea nitrogen (BUN), estimated glomerular filtration rate (eGFR), and hemoglobin concentration.

Routine safety monitoring is performed according to institutional standards. Adverse events associated with contrast administration or imaging procedures are documented and managed according to standard clinical protocols.

Subgroup Analyses

Prespecified subgroup analyses evaluate image quality metrics according to spinal region (cervical versus lumbar) and age group (50 years or younger versus older than 50 years). These analyses are intended to explore potential differences in imaging performance across clinically relevant patient subgroups.

Study Objectives

The primary objectives are to compare quantitative image quality metrics between contrast-enhanced MRI and FDG-PET/CT and to evaluate qualitative image quality using blinded radiologist assessment.

Secondary objectives include assessment of short-term changes in renal and hematologic laboratory parameters following imaging procedures performed as part of routine clinical care.

Ethics

The study is conducted in accordance with applicable ethical principles, institutional policies, and approved research protocols. Institutional Review Board approval has been obtained, and informed consent procedures are implemented as required by the approved protocol and applicable regulations.

• Study Type: Observational
• Enrollment (Actual): 120

Contacts and Locations

Study Locations

• Egypt
  • Giza Governorate
    • Giza, Giza Governorate, Egypt, 43556
      • (MISR University Scientific Research Innovation Committee,

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Participants will be recruited from the general population through community outreach, advertisements, and screening visits. Individuals who meet the eligibility criteria will be invited to participate.

Description

Inclusion Criteria:

• Age 18 years or older.
• Clinically suspected or confirmed cervical or lumbar spinal pathology.
• Presence of symptoms suggestive of spinal disease, including radiculopathy, localized spinal pain, neurological deficits, or suspected metastatic involvement.
• Referred for diagnostic evaluation with contrast-enhanced MRI or FDG-PET/CT according to routine clinical indications.
• Availability of baseline clinical and laboratory data, including renal function assessment.
• Ability to provide informed consent.

Exclusion Criteria:

• Severe renal impairment (eGFR <30 mL/min/1.73 m²) or acute kidney injury.
• Known hypersensitivity to gadolinium-based contrast agents or 18F-FDG.
• Contraindications to MRI, including non-compatible metallic implants or severe claustrophobia.
• Pregnancy or breastfeeding.
• Uncontrolled diabetes mellitus (blood glucose >200 mg/dL at the time of PET/CT examination).
• Active systemic infection or inflammatory condition requiring immediate treatment.
• Inability to complete the required imaging procedures.
• Incomplete clinical, laboratory, or imaging data required for study evaluation.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
patient allocation to MRI (n=60) and FDG-PET/CT (n=60) groups with stratification by spinal re-gion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quantitative Image Quality Assessment	Secondary Outcome Measure 1 Outcome Measure: Blood Urea Nitrogen (BUN) Description: Change in serum blood urea nitrogen concentration following imaging procedures. Time Frame: Baseline (pre-imaging) and 48 hours post-imaging. Unit of Measure: mg/dL Secondary Outcome Measure 2 Outcome Measure: Estimated Glomerular Filtration Rate (eGFR) Description: Change in estimated glomerular filtration rate following imaging procedures. Time Frame: Baseline (pre-imaging) and 48 hours post-imaging. Unit of Measure: mL/min/1.73 m² Secondary Outcome Measure 3 Outcome Measure: Hemoglobin Level Description: Change in hemoglobin concentration following imaging procedures. Time Frame: Baseline (pre-imaging) and 48 hours post-imaging. Unit of Measure: g/dL Secondary Outcome Measure 4 Outcome Measure: Visual Grading Analysis (VGA) Score Description: Qualitative image quality assessment performed by blinded radiologists to evaluate anatomical clarity, lesion delineation, image contrast, and	Assessed at the imaging visit (up to 1 day).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparative Evaluation of Image Quality and Short-Term Physiological Effects of Contrast-Enhanced MRI versus FDG-PET/CT in Cervical and Lumbar Spine Pathologies	Short-term physiological effects of contrast-enhanced MRI and FDG-PET/CT, assessed via changes in renal function and hematologic parameters: Serum blood urea nitrogen (BUN) at baseline and 48 hours post-imaging Estimated glomerular filtration rate (eGFR) at baseline and 48 hours post-imaging Hemoglobin levels at baseline and 48 hours post-imaging Qualitative image evaluation, measured by Visual Grading Analysis (VGA) performed by blinded radiologists to assess anatomical clarity, lesion delineation, and overall diagnostic usability.	For image quality assessment: At the time of imaging For short-term physiological effects (BUN, eGFR, hemoglobin): Baseline (pre-imaging) and 48 hours post-imaging

Collaborators and Investigators

• Sponsor: Cairo University

Publications and helpful links

General Publications

• References 1. Altman, D.G. Practical Statistics for Medical Research (1st ed.); Chapman and Hall/CRC, 1990. 2. Andreucci, M.; Solomon, R.; Tasanarong, A. Side effects of radiographic contrast media: pathogenesis, risk factors, and pre-vention. Biomed Res Int. 2014, 2014, 741018. 3. Association, W.M. World Medical Association Declaration of Helsinki: ethical principles for medical research involving human subjects. Jama 2013, 310, 2191-4. 4. Bajwa, H.; Sritharan, T.; Botha, T.; et al. Assessment of cervical spine CT by an image quality audit using qualitative and quantitative methods. J Med Imaging Radiat Oncol. 2025, 69, 7-16. 5. Benchoufi, M.; Matzner-Lober, E.; Molinari, N.; et al. Interobserver agreement issues in radiology. Diagn Interv Imaging 2020, 101, 639-41. 6. Beyer, T.; Bailey, D.L.; Birk, U.J.; et al. Medical Physics and Imaging-A Timely Perspective. Front. Phys. 2021, 9, 634693. 7. Boellaard, R.; Delgado-Bolton, R.; Oyen, W.J.; et al. FDG PET/CT: EANM procedure guidelines for tumour imaging: version 2.0. Eur J Nucl Med Mol Imaging. 2015, 42, 328-54. 8. Boos, N.; Rieder, R.; Schade, V.; et al. The Imaging characteristics of Magnetic Resonance Imaging, Work Perception, and Psychosocial Factors in Identifying Symptomatic Disc Herniations. Spine 1995, 20. 9. Boriani, L.; Zamparini, E.; Albrizio, M.; et al. Spine Infections: The Role of Fluorodeoxyglucose Positron Emission Tomography (FDG PET) in the Context of the Actual Diagnosis Guideline. Curr Med Imaging 2022, 18, 216-30. 10. Brinjikji, W.; Luetmer, P.H.; Comstock, B.; et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR Am J Neuroradiol. 2015, 36, 811-6. 11. Brown, T.F.; Yasillo, N.J. Radiation safety considerations for PET centers. J Nucl Med Technol. 1997, 25, 98-102; quiz 4-5. 12. Burmeister, H.P.; Baltzer, P.A.; Möslein, C.; et al. Visual grading characteristics (VGC) analysis of diagnostic image quality for high resolution 3 Tesla MRI vol

Study record dates

Study Major Dates

• Study Start (Actual): April 5, 2025
• Primary Completion (Actual): November 3, 2025
• Study Completion (Actual): January 1, 2026

Study Registration Dates

• First Submitted: May 31, 2026
• First Submitted That Met QC Criteria: June 5, 2026
• First Posted (Actual): June 10, 2026

Study Record Updates

• Last Update Posted (Actual): June 10, 2026
• Last Update Submitted That Met QC Criteria: June 5, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: FDG-PET/CT; Magnetic Resonance Imaging; Image Quality; Contrast-to-Noise Ratio; Spine Imaging; Signal-to-Noise Ratio; Visual Grading Analysis
• Other Study ID Numbers: DDMFDW6dc1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No