{ "id": "ep2q0p3ge3", "slug": "pet-ct-imaging", "title": "PET/CT imaging", "updated": "2026-10-15", "topic_path": [ { "id": "life", "label": "Life and health", "api_url": "https://www.edgepedia.org/api/v1/topics/life" }, { "id": "life.health", "label": "Human health and medicine", "api_url": "https://www.edgepedia.org/api/v1/topics/life.health" }, { "id": "life.health.clinical", "label": "Clinical assessment and procedures", "api_url": "https://www.edgepedia.org/api/v1/topics/life.health.clinical" }, { "id": "life.health.clinical.clinical-imaging", "label": "Medical imaging and radiography", "api_url": "https://www.edgepedia.org/api/v1/topics/life.health.clinical.clinical-imaging" }, { "id": "life.health.clinical.clinical-imaging.nuclear-medicine-and-molecular-imaging", "label": "Nuclear medicine and molecular imaging", "api_url": "https://www.edgepedia.org/api/v1/topics/life.health.clinical.clinical-imaging.nuclear-medicine-and-molecular-imaging" } ], "geo": [ { "id": "geo.nongeo.t1946.life.health.clinical.clinical-imaging.nuclear-medicine-and-molecular-imaging", "label": "Non-geographic · 1946 to 2000: Nuclear medicine and molecular imaging", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life.health.clinical.clinical-imaging.nuclear-medicine-and-molecular-imaging", "path": [ { "id": "geo.nongeo", "label": "Non-geographic", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo" }, { "id": "geo.nongeo.t1946", "label": "Non-geographic · 1946 to 2000", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946" }, { "id": "geo.nongeo.t1946.life", "label": "Life and health", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life" }, { "id": "geo.nongeo.t1946.life.health", "label": "Human health and medicine", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life.health" }, { "id": "geo.nongeo.t1946.life.health.clinical", "label": "Clinical assessment and procedures", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life.health.clinical" }, { "id": "geo.nongeo.t1946.life.health.clinical.clinical-imaging", "label": "Medical imaging and radiography", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life.health.clinical.clinical-imaging" }, { "id": "geo.nongeo.t1946.life.health.clinical.clinical-imaging.nuclear-medicine-and-molecular-imaging", "label": "Nuclear medicine and molecular imaging", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.life.health.clinical.clinical-imaging.nuclear-medicine-and-molecular-imaging" } ] } ], "excerpt": "PET/CT imaging, also called FDG PET/CT, is a hybrid nuclear medicine examination that fuses PET metabolic activity with CT anatomy, improving cancer staging accuracy by roughly 10–15%.", "snippet": "PET/CT imaging, also called FDG PET/CT, is a hybrid nuclear medicine examination that fuses PET metabolic activity with CT anatomy, improving cancer staging accuracy by roughly 10–15%.", "node": "life.health.clinical.clinical-imaging.nuclear-medicine-and-molecular-imaging", "markdown": "# PET/CT imaging\n\nPET/CT imaging is a hybrid method that acquires a positron emission tomography (PET) scan, which maps the distribution of a radioactive tracer, and a computed tomography (CT) scan, which maps anatomy, in a single examination and fuses them into one image. The combination shows metabolic activity and its anatomical location together, which neither modality provides alone: reported staging accuracy gains over PET or CT alone average roughly 10–15% across malignancies,[1](https://www.ncbi.nlm.nih.gov/books/NBK582124/) and one review attributes an increase in PET diagnostic accuracy from 91% to 98% to the combined approach.[2](https://tech.snmjournals.org/content/33/3/156) There are now over 7,800 active PET/CT installations worldwide (2025), with North America alone accounting for more than 3,000 installations.[3](https://pubs.rsna.org/doi/10.1148/radiol.2422051113)\n\n| Key fact | Detail |\n|---|---|\n| What it measures | Tracer concentration (metabolism) from PET coincidences plus x-ray anatomy from CT, fused and quantified as SUV |\n| Core physics | Positron–electron annihilation releases two 511 keV photons ~180° apart, detected in coincidence[1](https://www.ncbi.nlm.nih.gov/books/NBK582124/) |\n| Default tracer | 18F-FDG, a glucose analog; 18F half-life 109.7 min[4](https://link.springer.com/article/10.1007/s00259-014-2961-x) |\n| Typical scan time | Whole-body examination about 30 min for a 180-cm patient[5](https://pure.rug.nl/ws/portalfiles/portal/196900429/Limitations_and_Pitfalls_of_FDG_PET_CT_in_Infection_and_Inflammation.pdf) |\n| Dose | FDG about 3–4 mSv per 185 MBq; CT component 1–20 mSv or higher[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC2791475/) |\n| Spatial resolution | About 4–6 mm for clinical systems[5](https://pure.rug.nl/ws/portalfiles/portal/196900429/Limitations_and_Pitfalls_of_FDG_PET_CT_in_Infection_and_Inflammation.pdf) |\n| Main variants | FDG, PSMA-ligand, 68Ga-DOTA-peptide, and FAPI PET/CT; PET/MRI is the nearest hybrid alternative |\n\n## How it works\n\nA positron emitted by the radionuclide travels a short distance in tissue, combines with an electron, and the pair's rest mass-energy converts into two 511 keV photons emitted in approximately opposite directions.[1](https://www.ncbi.nlm.nih.gov/books/NBK582124/) Ring detectors register paired scintillation events, and a coincidence circuit with a timing window of typically 6–12 ns assigns them to a line of response.[1](https://www.ncbi.nlm.nih.gov/books/NBK582124/)\n\nThe standard tracer, 18F-FDG, is a structural analog of 2-deoxyglucose that traces glucose metabolism. It enters cells through GLUT transporters, is phosphorylated to FDG-6-phosphate, and is trapped intracellularly because the C-2 position carrying the 18F atom lacks an oxygen atom, so further catabolism is impossible.[7](https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1616_web.pdf) FDG accumulation is proportional to glucose utilization, which is elevated in most cancers through GLUT-1 overexpression and increased hexokinase activity.[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC2791475/)\n\nThe [CT scan](https://www.edgepedia.org/ct-scan) replaces the old germanium-68 [transmission scan](https://www.edgepedia.org/transmission-scan), which was inherently slow,[8](https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2024.1373260/full) and supplies essentially noiseless attenuation correction factors while cutting whole-body scan time by at least 40%.[9](https://www.sciencedirect.com/science/article/abs/pii/S0001299803700051) Because CT measures x-ray attenuation at a mean photon energy of about 70 keV, the values must be scaled to the PET energy of 511 keV; Hounsfield numbers are calibrated to 511-keV attenuation coefficients with a scaling curve that depends on the CT tube voltage and the scanner's calibration method.[3](https://pubs.rsna.org/doi/10.1148/radiol.2422051113) • [10](https://eanm.org/wp-content/uploads/2024/06/EANM20_TechGuide_digital.pdf) Uptake is quantified as the standardized uptake value (SUV), the tissue activity concentration divided by the decay-corrected injected activity per unit of body weight; SUV normalized to lean body mass is called SUL and is the recommended FDG measure.[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC2791475/) • [4](https://link.springer.com/article/10.1007/s00259-014-2961-x)\n\n## How it is done\n\n**Preparation and injection.** The patient fasts to obtain low blood glucose and low insulinaemia; the EANM guideline requires at least 4 h of fasting,[4](https://link.springer.com/article/10.1007/s00259-014-2961-x) while the IAEA manual specifies a longer fast of 6–12 h to minimize glucose competition and myocardial uptake.[7](https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1616_web.pdf) Blood glucose is measured before administration.[4](https://link.springer.com/article/10.1007/s00259-014-2961-x) Injection and flush should be completed within one minute, with the injection time recorded.[11](https://qibawiki.rsna.org/images/7/71/UPICT_Oncologic_FDG-PETCTProtocol_Dec-2014a.pdf)\n\n**Uptake wait and acquisition.** Static images are typically acquired about 60 min after injection; a consensus target is 60 min with an acceptable window of 55–75 min.[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC2791475/) • [11](https://qibawiki.rsna.org/images/7/71/UPICT_Oncologic_FDG-PETCTProtocol_Dec-2014a.pdf) A low-dose CT (10–40 mA) is acquired for attenuation correction,[10](https://eanm.org/wp-content/uploads/2024/06/EANM20_TechGuide_digital.pdf) followed by PET emission acquisition, typically in 3D mode at 1–4 min per bed position, starting from mid-thigh and moving cranially to limit bladder misalignment.[12](https://pmc.ncbi.nlm.nih.gov/articles/PMC10027805/)\n\n**Reconstruction and review.** Emission data are corrected for normalization, dead time, random coincidences, scatter, and attenuation,[4](https://link.springer.com/article/10.1007/s00259-014-2961-x) and images should be reviewed both with and without attenuation correction, because CT–emission mismatch from movement or breathing introduces correction artifacts.[10](https://eanm.org/wp-content/uploads/2024/06/EANM20_TechGuide_digital.pdf)\n\n## Origin\n\nAn earlier dual-modality precursor came from Bruce H. Hasegawa and colleagues, who combined CT and SPECT using [high-purity germanium detectors](https://www.edgepedia.org/high-purity-germanium-detector) with x-ray CT for SPECT attenuation correction, described in *IEEE Transactions on Nuclear Science* in 1993.[13](https://doi.org/10.1109/tns.1993.8526573) • [9](https://www.sciencedirect.com/science/article/abs/pii/S0001299803700051) CT-based attenuation correction for the combined PET/CT scanner was described by P. E. Kinahan, D. W. Townsend, T. Beyer, and D. Sashin in *Medical Physics* in 1998.[14](https://doi.org/10.1118/1.598392) The first combined PET/CT prototype became operational in 1998, incorporating a spiral CT with PET detectors mounted on the rear of the rotating CT assembly.[3](https://pubs.rsna.org/doi/10.1148/radiol.2422051113) Beyer, Townsend, and colleagues then reported the combined scanner for clinical oncology in the *Journal of Nuclear Medicine* in 2000; their prototype paired a Siemens Somatom AR.SP spiral CT with a partial-ring rotating ECAT ART PET scanner, and in combined mode the CT images corrected the PET data for scatter and attenuation, yielding fully quantitative whole-body images over 100 cm in under 1 hour. The first commercial PET/CT scanners appeared in 2001,[3](https://pubs.rsna.org/doi/10.1148/radiol.2422051113) and by 2003 the technology was available from all major vendors: CTI, Siemens, GE, and Philips.[9](https://www.sciencedirect.com/science/article/abs/pii/S0001299803700051)\n\n## Variants\n\n**FDG PET/CT** remains the most widely used PET radiotracer, with oncology accounting for the majority of applications.[15](https://eanm.org/wp-content/uploads/2024/06/EANM_2011_Tech_Principles_and_Practice_of_PET-CT_Part_22.pdf)\n\n**PSMA PET/CT** targets the prostate-specific membrane antigen with ligands including [68Ga]Ga-PSMA-11, [68Ga]Ga-PSMA-I&T, [18F]F-DCFPyL, [18F]F-PSMA-1007, and [18F]F-rhPSMA-7.3; it is used for initial staging and for biochemical recurrence (rising PSA after definitive therapy) of prostate cancer.[12](https://pmc.ncbi.nlm.nih.gov/articles/PMC10027805/)\n\n**DOTA-peptide PET/CT** images somatostatin receptors in neuroendocrine tumors. First clinical results with 68Ga-DOTA-TOC in carcinoid patients were published in 2001,[15](https://eanm.org/wp-content/uploads/2024/06/EANM_2011_Tech_Principles_and_Practice_of_PET-CT_Part_22.pdf) and 68Ga-peptide PET/CT is replacing 111In-Octreoscan SPECT where PET is available. 68Ga has a 68-min half-life with 89% positron branching and is eluted from a 68Ge/68Ga generator, so no on-site cyclotron is needed.[15](https://eanm.org/wp-content/uploads/2024/06/EANM_2011_Tech_Principles_and_Practice_of_PET-CT_Part_22.pdf)\n\n**FAPI PET/CT** targets fibroblast activation protein in cancer-associated fibroblasts; quinoline-based inhibitors FAPI-02 and FAPI-04 enabled 68Ga/18F radiolabeling and high-contrast imaging.[16](https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2026.1751727/full) 68Ga-FAPI has shown uptake in 28 kinds of cancers,[1](https://www.ncbi.nlm.nih.gov/books/NBK582124/) and real-world NSCLC cohorts show enhanced nodal and osseous metastasis detection with FAPI, reclassifying cancer stage in approximately 11% of patients.[16](https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2026.1751727/full)\n\n**Total-body PET/CT** uses long-axial-field-of-view scanners; the concept was laid out by Simon R. Cherry and colleagues in the *Journal of Nuclear Medicine* in 2017.[17](https://doi.org/10.2967/jnumed.116.184028) The uEXPLORER has a 194.0 cm axial field of view covering the whole body, entered routine clinical use, and achieves about 3.0 mm spatial resolution with measured sensitivity of 174 kcps/MBq, roughly 25–31-fold higher than conventional systems.[18](https://jnm.snmjournals.org/content/jnumed/early/2020/10/02/jnumed.120.250597.full.pdf)\n\n**PET/MRI** replaces the CT component with magnetic resonance imaging; it is discussed under limitations below.\n\n## Applications\n\nAccepted FDG indications include benign versus malignant differentiation, staging, recurrence assessment, radiotherapy planning, therapy monitoring, and prognosis.[7](https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1616_web.pdf) Beyond oncology, PET is class I-recommended for defining myocardial regions that will benefit from revascularization and is considered the most sensitive and specific diagnostic tool for Alzheimer disease and frontotemporal dementia.[19](https://www.ccjm.org/content/ccjom/73/12/1075.full.pdf) In carcinoma of unknown primary, FDG-PET located the primary tumor in 25% of cases after exhaustive work-up in one prospective study.[19](https://www.ccjm.org/content/ccjom/73/12/1075.full.pdf)\n\nFor solitary pulmonary nodules, pooled FDG PET or PET/CT sensitivity and specificity are 89% and 75%, with specificity 16% lower (61% vs 77%) in regions endemic for infectious lung disease; NCCN guidelines recommend FDG PET/CT for solid nodules larger than 8 mm.[20](https://onlinelibrary.wiley.com/doi/10.1155/2020/5282698) In nodal staging, 18F-FAPI showed sensitivity/specificity/accuracy of 84%/92%/90% versus FDG's 71%/67%/69%.[16](https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2026.1751727/full)\n\n## Limitations and alternatives\n\n**False positives and physiologic uptake.** Benign FDG uptake arises from physiologic uptake, infectious and inflammatory processes, benign tumors, hyperplastic conditions, and artifacts.[21](https://gravitas.acr.org/PPTS/GetDocumentView?docId=173+&releaseId=2) In PSMA PET/CT, sympathetic ganglia such as the celiac ganglia can be misread as retroperitoneal nodal metastases, benign bone lesions can accumulate tracer, and androgen-receptor inhibition elevates PSMA expression most pronouncedly in the first weeks of ADT, mimicking progression.[12](https://pmc.ncbi.nlm.nih.gov/articles/PMC10027805/)\n\n**Metabolic and physiologic failure modes.** [Hyperglycemia](https://www.edgepedia.org/hyperglycemia) limits scanning (blood glucose below 11 mmol/L is required), insulin timing restrictions apply, and metformin causes high intestinal FDG uptake that can obscure pathology; insulin treatment diverts FDG to skeletal muscle and fat, lowering tumor uptake.[5](https://pure.rug.nl/ws/portalfiles/portal/196900429/Limitations_and_Pitfalls_of_FDG_PET_CT_in_Infection_and_Inflammation.pdf) • [7](https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1616_web.pdf) Corticosteroids significantly reduce sensitivity for inflammatory disease.[5](https://pure.rug.nl/ws/portalfiles/portal/196900429/Limitations_and_Pitfalls_of_FDG_PET_CT_in_Infection_and_Inflammation.pdf) Not all cancers are FDG-avid, including broncho-alveolar, renal, and thyroid cancers, some lymphoma subtypes, carcinoids, and most prostate carcinomas.[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC2791475/)\n\n**Resolution and CT-based attenuation correction artifacts.** With 4–6 mm resolution and the [partial volume effect](https://www.edgepedia.org/partial-volume-effect), small lesions may be missed; FDG PET sensitivity declines below 6 mm tumor diameter even in FDG-avid tumors such as melanoma.[5](https://pure.rug.nl/ws/portalfiles/portal/196900429/Limitations_and_Pitfalls_of_FDG_PET_CT_in_Infection_and_Inflammation.pdf) • [6](https://pmc.ncbi.nlm.nih.gov/articles/PMC2791475/) Metallic implants generate high CT numbers, overestimating PET activity and creating false positives, while dense implants such as hip prosthetics can instead cause photopenic cold areas.[2](https://tech.snmjournals.org/content/33/3/156) Respiratory artifacts arise because PET is acquired during free breathing while CT captures one breathing stage; breath-hold or shallow-breathing protocols only partially reduce the error, and respiratory motion causes SUV errors through blurring and attenuation-correction mismatch.[2](https://tech.snmjournals.org/content/33/3/156) • [11](https://qibawiki.rsna.org/images/7/71/UPICT_Oncologic_FDG-PETCTProtocol_Dec-2014a.pdf) Truncation artifacts occur because the CT field of view (50 cm) is smaller than the PET field of view (70 cm), underestimating SUVs in truncated regions.[2](https://tech.snmjournals.org/content/33/3/156) Low-dose, noncontrast CT is commonly used for attenuation correction, while contrast-enhanced CT may be performed when clinically indicated, following the scanner protocol and accounting for possible attenuation-correction artifacts.[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC2791475/) although contrast-enhanced CT alters SUV quantification by less than 10% on average, and a literature review finds intravenous iodine contrast provides clinical benefits without significant artifact while positive oral contrast offers no major management advantage.[4](https://link.springer.com/article/10.1007/s00259-014-2961-x) • [8](https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2024.1373260/full)\n\n**Alternatives.** In a meta-analysis of 29 studies and 1656 patients, pooled patient-level sensitivity/specificity for regional nodal metastases were 86%/86% for PET/CT versus 88%/92% for PET/MRI, and lesion-level detection of recurrence or metastases was 91%/81% versus 94%/83%.[22](https://www.ajronline.org/doi/full/10.2214/AJR.24.31519) An earlier meta-analysis by Spick and colleagues combining over 2300 patients showed equivalency of FDG PET/CT and PET/MRI in oncologic evaluation.[23](https://www.ajronline.org/doi/pdf/10.2214/AJR.18.20001?download=true) PET/MRI remains limited by cost and availability, with approximately 30 systems versus over 1600 PET/CT systems installed in the United States, and its SUVs derive from MRI-based simulated tissue attenuation maps that are less accurate than CT-derived measures.[22](https://www.ajronline.org/doi/full/10.2214/AJR.24.31519) PET/MRI's Dixon-sequence attenuation correction assigns bone as soft tissue, generally underestimating uptake in or near bone, though its routine respiratory gating gives better coregistration in upper abdominal organs than nongated PET/CT.[23](https://www.ajronline.org/doi/pdf/10.2214/AJR.18.20001?download=true)\n\n## References\n\n1. [Nuclear Medicine Computed Tomography Physics (StatPearls)](https://www.ncbi.nlm.nih.gov/books/NBK582124/)\n2. [PET/CT Imaging Artifacts | Journal of Nuclear Medicine Technology](https://tech.snmjournals.org/content/33/3/156)\n3. [PET/CT: Form and Function (Radiology)](https://pubs.rsna.org/doi/10.1148/radiol.2422051113)\n4. [FDG PET/CT: EANM procedure guidelines for tumour imaging: version 2.0](https://link.springer.com/article/10.1007/s00259-014-2961-x)\n5. [Limitations and Pitfalls of FDG-PET/CT in Infection and Inflammation](https://pure.rug.nl/ws/portalfiles/portal/196900429/Limitations_and_Pitfalls_of_FDG_PET_CT_in_Infection_and_Inflammation.pdf)\n6. [FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0](https://pmc.ncbi.nlm.nih.gov/articles/PMC2791475/)\n7. [Standard Operating Procedures for PET/CT (IAEA)](https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1616_web.pdf)\n8. [Comprehensive literature review of oral and intravenous contrast-enhanced PET/CT](https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2024.1373260/full)\n9. [PET/CT scanners: A hardware approach to image fusion (Seminars in Nuclear Medicine, 2003)](https://www.sciencedirect.com/science/article/abs/pii/S0001299803700051)\n10. [EANM Technology Guide (2024)](https://eanm.org/wp-content/uploads/2024/06/EANM20_TechGuide_digital.pdf)\n11. [FDG-PET/CT UPICT v2.0 protocol (QIBA)](https://qibawiki.rsna.org/images/7/71/UPICT_Oncologic_FDG-PETCTProtocol_Dec-2014a.pdf)\n12. [PSMA PET/CT: joint EANM procedure guideline/SNMMI procedure standard for prostate cancer imaging 2.0](https://pmc.ncbi.nlm.nih.gov/articles/PMC10027805/)\n13. [Bruce H. Hasegawa and colleagues (1993). Object-specific attenuation correction of SPECT with correlated dual-energy X-ray CT. IEEE Transactions on Nuclear Science.](https://doi.org/10.1109/tns.1993.8526573)\n14. [P. E. Kinahan and colleagues (1998). Attenuation correction for a combined 3D PET/CT scanner. Medical Physics.](https://doi.org/10.1118/1.598392)\n15. [Principles and Practice of PET/CT – Part 2 (EANM Technologist's Guide, 2011)](https://eanm.org/wp-content/uploads/2024/06/EANM_2011_Tech_Principles_and_Practice_of_PET-CT_Part_22.pdf)\n16. [The comparative diagnostic and therapeutic application value of FAPI PET/CT and 18F-FDG PET/CT in oncology](https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2026.1751727/full)\n17. [Simon R. Cherry and colleagues (2017). Total-Body PET: Maximizing Sensitivity to Create New Opportunities for Clinical Research and Patient Care. Journal of Nuclear Medicine.](https://doi.org/10.2967/jnumed.116.184028)\n18. [Performance evaluation of the uEXPLORER Total-body PET/CT scanner based on NEMA NU 2-2018](https://jnm.snmjournals.org/content/jnumed/early/2020/10/02/jnumed.120.250597.full.pdf)\n19. [PET and PET/CT imaging (Cleveland Clinic Journal of Medicine, 2006)](https://www.ccjm.org/content/ccjom/73/12/1075.full.pdf)\n20. [Diagnostic Performance of PET or PET/CT with Different Radiotracers in Patients with Suspicious Lung Cancer or Pleural Tumours](https://onlinelibrary.wiley.com/doi/10.1155/2020/5282698)\n21. [ACR–ACNM–SNMMI–SPR Practice Parameter for Performing FDG-PET/CT in Oncology (revised 2021)](https://gravitas.acr.org/PPTS/GetDocumentView?docId=173+&releaseId=2)\n22. [Head-to-Head Comparison of FDG PET/CT and FDG PET/MRI in Patients With Cancer: A Systematic Review and Meta-Analysis (AJR)](https://www.ajronline.org/doi/full/10.2214/AJR.24.31519)\n23. [Clinical PET/MRI: 2018 Update](https://www.ajronline.org/doi/pdf/10.2214/AJR.18.20001?download=true)\n\n---\n*Topic: Encyclopedia › Life and health › Human health and medicine › Clinical assessment and procedures › Medical imaging and radiography › Nuclear medicine and molecular imaging*\n\n*Initially written Sep 29, 2026 · Edited: Oct 15, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n", "same_as": [], "url": "https://www.edgepedia.org/pet-ct-imaging", "markdown_url": "https://www.edgepedia.org/pet-ct-imaging.md", "license": { "name": "Edgepedia Community License 1.0", "url": "https://www.edgepedia.org/edgepedia/license", "summary": "Free with credit, commercial use included. AI training is open to everyone. For other uses, organizations over USD 100M in revenue or 100M monthly users license separately.", "spdx": "LicenseRef-Edgepedia-Community-1.0" }, "credit": "\"PET/CT imaging\", Edgepedia (EdgeChat), https://www.edgepedia.org/pet-ct-imaging. Edgepedia Community License 1.0.", "credit_md": "\"[PET/CT imaging](https://www.edgepedia.org/pet-ct-imaging)\", Edgepedia (EdgeChat), [https://www.edgepedia.org/pet-ct-imaging](https://www.edgepedia.org/pet-ct-imaging). [Edgepedia Community License 1.0](https://www.edgepedia.org/edgepedia/license).", "credit_html": "\"PET/CT imaging\", Edgepedia (EdgeChat), https://www.edgepedia.org/pet-ct-imaging. Edgepedia Community License 1.0.", "speakable": "PET/CT imaging, also called FDG PET/CT, is a hybrid nuclear medicine examination that fuses PET metabolic activity with CT anatomy, improving cancer staging accuracy by roughly 10–15%." }