PET/CT Modality Combination

Clinical LOINC – Diagnostic ImagingPSWilson, February 14, 2013

Positron Emission Tomography

• “Is a technique that measures physiological function by looking at blood flow, metabolism, neurotransmitters, and radiolabelled drugs. PET offers quantitative analyses, allowing relative changes over time to be monitored as a disease process evolves or in response to a specific stimulus. ”

• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1126321/

Applications of PET

• Cardiology• Oncology• Neurology

Use of PET for Oncology

• Metabolism and Physiology• Staging or Restaging of Cancer (not initial dx)– Prior to Chemo, Radiation Tx, or Surgery

• Always full body• Always injection of FDG

Computerized Tomography

• Majority of imaging is Head/Torso or full body• Used as a complement to PET• May or may not have IV or Oral Contrast

PET with CT

• PET for physiology, CT for anatomy– 2 settings, different times, thus 2 reports– Problem with overlay due to repositioning

• Current is a single unit– Same setting, same position– Single report

Protocols for PET

• Head and Thorax– Head/Neck Cancer

• Whole Body– Breast– Melanoma– Sarcoma

• Mid Skull to Thigh– Everything else

Protocol for CT

• With IV Contrast– Gastrointestinal (also Oral and/or Rectal)– Neuro– Endocrine

• Without Contrast– Thyroid– Renal– Breast

• With and Without IV Contrast– Lung

LOINC Perspective

• Observation is the same whether or not the images were obtained from a single or different machines

• Rarely dictated as a separate report• Diagnosis is not pertinent (captured elsewhere

in HL7• Staging versus Re-staging (same protocol)• Separate CT report for any additional images for

diagnostic purpose

Proposed (Breast,Thyroid, Renal) LOINC_NUM COMPONENT SYSTEM

METHOD_TYP

new1Multisection + Multisection ^WO Contrast

Skull base to mid thigh PET.CT

new2Multisection + Multisection ^WO Contrast Head to diaphragm PET.CT

new3Multisection + Multisection ^WO Contrast ^patient PET.CT

new4 Multisection^WO contrast Breast.left CTnew5 Multisection^WO contrast Breast.right CT44119-6 Multisection^WO contrast Breast.bilateral CT

References

• http://www.ccsnm.org/pdfs/2010/protocols/PET-CT%20FDG%20Guidelines.pdf

• http://bjr.birjournals.org/content/80/954/437.full

• http://radiology.rsna.org/content/244/1/263.full

• http://radiographics.rsna.org/content/27/suppl_1/S215.full

• http://jnm.snmjournals.org/content/45/1_suppl/25S.full