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positron emission tomography (PET, PET scan)

Indications: 1) brain disease a) Alzheimer's disease - sensitivity > specificity - bilateral parietal hypometabolism b) frontotemporal dementia c) Huntington's disease (pathognomonic) d) seizures 2) heart disease 3) malignant neoplasm - brain neoplasm - breast cancer - cervical cancer - colorectal adenocarcinoma - esophageal cancer - lung cancer - lymphoma - melanoma - pancreatic cancer - thyroid cancer [2] Contraindications: - not useful for evaluation of kidney lesions because of the high baseline metabolic activity of the kidney [3] - not useful for preoperative staging or postoperative surveillance of colorectal cancer - not useful for staging of pancreatic cancer Procedure: - 12.5 mCi of 2-fluoro*-2-deoxy-glucose (FDG) is injected intravenously - 40 minute uptake period with patient resting quietly in a dark room. - multiple transaxial images are obtained - a rotating projectionalimage, sagittal, coronal & transverse tomographic images are generated. * F-18 - glycoprotein 2A (SV2A) PET imaging allows measurement of metabolic activity at brain synapses [5] Interpretation: - a standardized uptake value (SUV) of > 17 suggests malignant transformation Clinical significance: - in brain, generally PET scan set to focus on gray matter; - white matter appears to have little metabolism - PET scan is generally normal in a pulmonary nodule < 1 cm even if the nodule is malignant [3] Notes: The West Los Angeles VA has a Siemens ECAT-953 tomographic scanner. [2]

Specific

adenosine positron emission tomography (adenosine PET) amyloid positron emission tomography (amyloid PET) brain PET scan tau positron emission tomography (tau PET ([18F]RO948), tau PET)

General

radiography (roentgenography)

References

  1. nlmpubs.nlm.nih.gov/hstat/ahcpr/
  2. Mayo Clinic Positron emission tomography (PET) scan http://www.mayoclinic.com/health/pet-scan/MY00238
  3. Medical Knowledge Self Assessment Program (MKSAP) 16, 17, 19. American College of Physicians, Philadelphia 2012, 2015, 2021
  4. Kostakoglu L, Coleman M, Leonard JP et al PET predicts prognosis after 1 cycle of chemotherapy in aggressive lymphoma and Hodgkin's disease. J Nucl Med. 2002 Aug;43(8):1018-27. PMID: 12163626
  5. Yale University New imaging scan reveals a culprit in cognitive decline of Alzheimer's. ScienceDaily. ScienceDaily, 17 February 2022 https://www.sciencedaily.com/releases/2022/02/220217090713.htm - Mecca AP, O'Dell RS, Sharp ES et al Synaptic density and cognitive performance in Alzheimer's disease: A PET imaging study with [ 11 C]UCB-J Alzheimers Dement. 2022 Feb 17 PMID: 35174954