title: Biodistribution, dosimetry, and clinical evaluation of technetium-99m ethyl cysteinate dimer in normal subjects and in patients with chronic cerebral infarction.
abstract: Technetium-99m ethyl cysteinate dimer (ECD) has high initial cerebral uptake with slow clearance in nonhuman primates suggesting ideal characteristics for single photon emission computer tomography (SPECT) imaging. We evaluated the biodistribution, dosimetry and scintigraphic pattern of [99mTc]ECD in normal subjects and the accuracy of SPECT imaging in patients with chronic cerebral infarction. Sixteen normal subjects were injected with approximately 10 mCi of [99mTc]ECD. Anterior and posterior single-pass whole-body images were obtained at multiple times after injection. Blood clearance of the radiotracer was rapid, falling to 10.0 +/- 6.6% and 4.9 +/- 1.1% of the injected dose at 2 and 60 min, respectively. Brain uptake was 6.4 +/- 2.1% of the injected dose 5 min after injection. The critical organ was the urinary bladder. Technetium-99m ECD SPECT was performed with a rotating gamma camera in ten of the 16 normal subjects and 34 patients with clinical and CT evidence of chronic stroke. Thirty-three of the thirty-four patients had focal [99mTc]ECD abnormalities on SPECT (97.1%) based on visual inspection of the SPECT images. In summary, we obtained high quality SPECT images as a result of the optimal physical and biologic characteristics of the tracer. Technetium-99m ECD SPECT shows promise for the evaluation of patients with stroke.
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115.
authors.forename: B L
authors.initials: BL
authors.lastname: Holman
authors.forename: R S
authors.initials: RS
authors.lastname: Hellman
authors.forename: S J
authors.initials: SJ
authors.lastname: Goldsmith
authors.forename: I G
authors.initials: IG
authors.lastname: Mena
authors.forename: J
authors.initials: J
authors.lastname: Leveille
authors.forename: P G
authors.initials: PG
authors.lastname: Gherardi
authors.forename: J L
authors.initials: JL
authors.lastname: Moretti
authors.forename: A
authors.initials: A
authors.lastname: Bischof-Delaloye
authors.forename: T C
authors.initials: TC
authors.lastname: Hill
authors.forename: P M
authors.initials: PM
authors.lastname: Rigo
mesh_terms: D002544:Cerebral Infarction / Q000000981:diagnostic imaging* / Q000378:metabolism; D002908:Chronic Disease; D003545:Cysteine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D008297:Male; D015337:Multicenter Studies as Topic; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D015609:Organotechnetium Compounds; D011829:Radiation Dosage; D012016:Reference Values; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed
chemical_list: D009942:Organometallic Compounds; D015609:Organotechnetium Compounds; C059659:technetium Tc 99m bicisate; D003545:Cysteine