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At least 19 recordsLinked to original sources
PubMed1988

Single photon emission computed tomography in Alzheimer's disease. Abnormal iofetamine I 123 uptake reflects dementia severity.

To determine whether abnormalities in regional cerebral functional activity estimated by iofetamine hydrochloride I 123 and single photon emission computed tomography can be detected in mild or moderate as well as severe cases of Alzheimer's disease (AD), we performed iofetamine I 123-single photon emission computed tomography in 37 patients with probable AD (nine patients with mild, 18 patients with moderate, and ten patients with severe dementia) and nine age-matched control subjects. Iofetamine I 123 uptake was measured in right and left frontal, temporal, parietal, and occipital cortices. Mean (right and left) iofetamine I 123 activity was lowest in the parietal region of patients with AD and was significantly reduced in the other three regions compared with control subjects. Only in the parietal region was lower relative iofetamine I 123 activity associated with an impaired level of patient function and with cognitive deficit.

Aged↗
PubMed1989

Iofetamine hydrochloride I 123: a new radiopharmaceutical for cerebral perfusion imaging.

Iofetamine hydrochloride I 123 permits cerebral blood perfusion imaging with single photon emission computed tomography (SPECT). SPECT is more widely available than positron emission tomography, and complements anatomic visualization with X-ray computed tomography (CT) or magnetic resonance imaging. Iofetamine is an amphetamine analog that is rapidly taken up by the lungs, then redistributed principally to the liver and brain. The precise mechanism of localization has not been determined, but is believed to result from nonspecific receptor binding. Brain uptake peaks at 30 minutes postinjection and remains relatively constant through 60 minutes. The drug is metabolized and excreted in the urine, with negligible activity remaining at 48 hours. When compared with CT in stroke patients, visualization may be performed sooner after symptom onset and a larger zone of involvement may be evident with iofetamine. Localization of seizure foci and diagnosis of Alzheimer's disease may also be possible. As CT has revolutionized noninvasive imaging of brain anatomy, SPECT with iofetamine permits routine cerebral blood flow imaging.

Amphetamines↗
PubMed1988

Increased iofetamine I 123 brain uptake in metastatic melanoma.

Four of five patients with brain metastases from melanoma had increased lofetamine I 123 uptake in the region of the tumor deposits. A comparison group of five patients with melanoma with no clinical or radiologic evidence of brain involvement and 46 of 47 patients without malignant melanoma but with known brain tumors of other histologic types had normal or decreased iofetamine I 123 brain uptake in the region of the tumor. An exception was one patient whose metastatic small cell lung cancer to the brain showed focally increased uptake. These findings suggest that certain brain tumors such as melanoma are capable of selectively binding iofetamine I 123 because of specific chemical properties of the radiopharmaceutical. Increased uptake of iofetamine I 123 in brain lesions in a patient at risk for metastatic melanoma may be a useful aid to differential diagnosis.

Amphetamines↗
PubMed1988

In vivo chemistry of iofetamine HCl iodine-123 (IMP).

Application of chemical methods for characterizing the in vivo behavior of iofetamine HCI 123I (IMP) has shed light on the metabolism of iofetamine in animals and humans. A successful technique consists of ethyl acetate extraction of the metabolites from tissue samples acidified with perchloric acid, separation of the mixture by high performance liquid chromatography, and quantitation of the radioactive components with a sensitive scintillation detector. Metabolism of iofetamine HCI 123I proceeds sequentially from the N-isopropyl group on the amphetamine side chain. The first step, dealkylation to the primary amine p-iodoamphetamine (PIA), occurs readily in the brain, lungs, and liver; activity in the brain and lungs consists of only IMP and PIA even 24 hr after administration. The rate-limiting step appears to be deamination to give the transitory intermediate p-iodophenylacetone, which is rapidly degraded to p-iodobenzoic acid and conjugated with glycine in the liver to give the end product of metabolism, p-iodohippuric acid, which is excreted through the kidneys in the urine.

Amphetamines↗
PubMed1987

Cerebral perfusion imaging in Alzheimer's disease. Use of single photon emission computed tomography and iofetamine hydrochloride I 123.

We used single photon emission computed tomography (SPECT) to study 15 patients with Alzheimer's disease and nine controls. Iofetamine hydrochloride I 123 uptake data were recorded from the entire brain using a rotating gamma camera. Activity ratios were measured for the frontal, posterior parietal, posterior, medial, and lateral cortical temporal regions and striate cortex and were normalized by the activity in the cerebellum. Abnormalities in iofetamine hydrochloride I 123 activity were similar to the abnormalities in glucose metabolism observed with positron emission tomography. Cortical tracer activity was globally depressed in patients with Alzheimer's disease, with the greatest reduction in the posterior parietal cortex.

Aged↗
PubMed1992

Temporal lobe asymmetry with iofetamine (IMP) SPECT imaging in patients with major depression.

Single photon emission computed tomography (SPECT) brain imaging with 123I labeled iofetamine (IMP) has been used to study several neuropsychiatric disorders. However, little attention has been given to patients with major depression. In the present study IMP SPECT images were obtained on 19 depressed patients and 12 medical comparison subjects who had no focal abnormalities on MRI or CT scans. 5 mCi of 123I IMP was administered intravenously and SPECT images were obtained using a GE Starcamm 2000 SPECT system. After standard reconstruction of the images, an automated region of interest (ROI) computer program was applied to each tomographic brain image. Coronal images were then used to analyze lateralized differences in IMP activity. Measurements were made of the mean IMP activity per pixel, the maximum activity per pixel, and the ratio of the mean activity per pixel in the ROI to that of the cerebellum. On visual inspection, 12 out of 19 depressed patients (63%) and only of 12 medical comparison patients (8%) appeared to have substantially increased IMP activity in the right temporal lobe (P less than 0.005). But semi-quantitative analysis showed that while IMP activity was greater in the right than the left temporal lobe of depressed patients (P less than 0.0001), it was also present in medical comparison patients (P less than 0.01). Although there was no difference in the frequency of asymmetry between groups, it was more pronounced in depressed patients. These data suggest that asymmetric temporal lobe activity on IMP SPECT images may be of potential diagnostic utility in some patients with affective disorders.

Adult↗
PubMed1997

I-123 iofetamine single-photon computed emission tomography in rapid cycling bipolar disorder: a clinical study.

The regional distribution of I-123 iofetamine (IMP) in the brain of 12 patients with rapid cycling bipolar disorder was studied by single-photon computed emission tomography imaging. Patients who were either medication free (n = 4) or on lithium monotherapy (n = 8) were assessed serially in depressed/dysphoric, manic/hypomanic, or euthymic states. In 23 imaging studies, IMP images of the brain were taken on a GE Starcam system 20 min after injection of 3-4 mCi of I-123 labeled IMP. The I-123 IMP distribution in the anterior part of the temporal lobes was asymmetric in both depression/dysphoria and mania/hypomania but not in euthymia. Images taken sequentially on the same patient showed temporal lobe asymmetry in the pathological mood states that diminished or disappeared in the euthymic state. The observed changes most likely reflect an altered cerebral blood flow and changes in high-affinity IMP binding to amine receptors in the temporal lobes. This pilot study suggests the presence of a state-dependent temporal dysfunction in bipolar disorder.

Adult↗
PubMed1997

Correlation of functional independence measure (FIM) and SPECT Iofetamine (I-123) as a predictor of functional return in stroke.

Function following stroke is often measured using the Functional Independence Measure (FIM). Independence occurs when the patient achieves certain levels of functions. SPECT imaging assesses the regional cerebral blood flow (rCBF). Is it possible to correlate the FIM scores with SPECT imaging and predict functional return? We evaluated total of 69 stroke patients with SPECT imaging using Iofetamine (I-123). Patients were scanned within 14-21 days post-stroke. CT scans were evaluated and correlated with the SPECT images. This information was compared with the admission and discharge FIM scores. The rCBF reperfusion changes and region of stroke were evaluated and correlated with discharge functional status. The right parietal areas demonstrated a strong correlation with SPECT and FIM changes as predictors of return of functional living status (p-value = 0.0438). The right parietal area demonstrated an improvement in ambulation (p-value = 0.0578); the right brain correlated with overall improvement in FIM scores and change in SPECT imaging (p-value = 0.0833); the left brain did not exhibit significant values. Our conclusion was that there were trends seen with the predictive value of stroke recovery using SPECT imaging. The current sample number was not large enough to provide an adequate study, especially for the left brain; a larger study is needed. This information could be useful to help determine patient placement for rehabilitation.

Activities of Daily Living↗
PubMed1985

Iofetamine HCl I-123 (Iodoamphetamine) brain SPECT atlas.

SPECT brain imaging using Iofetamine HC1 I-123 (IMP) has a great potential in the evaluation of various neurologic disorders. Transverse, coronal, and sagittal sectional IMP images obtained using a single head rotating gamma camera system are correlated with corresponding normal brain slices in this atlas.

Amphetamines↗
PubMed1989

I-123 iofetamine single photon emission tomography in school-age children with difficult-to-control seizures.

Interictal I-123 iofetamine (IMP) single photon emission tomography (SPECT) was performed in 15 children with difficult-to-control partial or generalized seizures. SPECT studies were compared with magnetic resonance imaging and CT in seven patients, with magnetic resonance imaging only in five, and with CT only in three. Electroencephalography was performed on all subjects, including invasive studies in nine. SPECT was abnormal in six patients. Magnetic resonance and/or CT studies were abnormal in two of the six patients. The other four patients with abnormal SPECT imaging studies had four magnetic resonance and two CT studies that were normal. The SPECT abnormality corresponded to EEG localization in each of the six cases. Lesions localized on SPECT were in or near the temporal lobes. Five other patients with normal SPECT had well-localized abnormalities on EEG. Four magnetic resonance and five CT studies were also negative in these five cases. Four patients whose EEGs did not show adequate lateralization had four normal SPECT, two normal CT, and three normal magnetic resonance studies. In children as in adults, IMP SPECT imaging shows promise in the localization of seizure foci in or near the temporal lobes.

Adolescent↗
PubMed1992

I-123 iofetamine SPECT scan in systemic lupus erythematosus patients with cognitive and other minor neuropsychiatric symptoms: a pilot study.

Accurate diagnosis of central nervous system (CNS) lupus remains difficult, especially when the manifestations are of subtle cognitive and affective changes. This pilot study reports on the use of I-123 iofetamine single photon emission computerized tomography (SPECT) scans in 18 such patients with documented systemic lupus erythematosus. Eight of the 18 scans were abnormal (44%), four in a diffuse bi-temporo-parietal pattern previously noted only in Alzheimer's disease, and four with large focal deficits. Neither the existence of the abnormal scan nor the particular pattern of abnormality correlated with the results of other diagnostic tests. These preliminary results raise the possibility that SPECT scans may offer an additional valuable diagnostic instrument in CNS lupus, although further studies are necessary to delineate their precise role.

Adolescent↗
PubMed1990

I-123 Iofetamine SPECT scan in children with neurological disorders.

I-123 Iofetamine (IMP) single photon emission computed tomography (SPECT) imaging of the brain in 42 patients (ages 14 days to 23 years) was compared with other localizing studies in children with neurological diseases. All had an EEG and at least one imaging study of the brain (computed tomography (CT) or magnetic resonance imaging (MRI), or both). Seventy-eight percent of the patients had an EEG within 24-72 hours of the IMP-SPECT scan. Thirty-five (83%) had a history of seizures, and the remainder had other neurological conditions without a history of seizures. In most cases, a normal EEG reading with normal CT or MRI result predicted a normal SPECT study. When the EEG was abnormal the majority of the IMP-SPECT scans were abnormal and localized the abnormality to the same region. A comparison with CT and MRI showed that structural abnormalities involving the cortex were usually well demonstrated with IMP-SPECT imaging. Structural lesions confined to the white matter were generally not detectable with IMP-SPECT. In a few cases, SPECT scans revealed abnormalities in deep brain areas not identified by EEG. IMP-SPECT imaging is a valuable technique for the detection and localization of abnormal cerebral metabolic activity in children with seizure disorders. A correlation with CT or MRI is essential for proper interpretation of abnormalities detected with IMP SPECT imaging.

Adolescent↗
PubMed1990

Iofetamine I 123 single photon emission computed tomography is accurate in the diagnosis of Alzheimer's disease.

To determine the diagnostic accuracy of iofetamine hydrochloride I 123 (IMP) with single photon emission computed tomography in Alzheimer's disease, we studied 58 patients with AD and 15 age-matched healthy control subjects. We used a qualitative method to assess regional IMP uptake in the entire brain and to rate image data sets as normal or abnormal without knowledge of subjects'clinical classification. The sensitivity and specificity of IMP with single photon emission computed tomography in AD were 88% and 87%, respectively. In 15 patients with mild cognitive deficits (Blessed Dementia Scale score, less than or equal to 10), sensitivity was 80%. With the use of a semiquantitative measure of regional cortical IMP uptake, the parietal lobes were the most functionally impaired in AD and the most strongly associated with the patients' Blessed Dementia Scale scores. These results indicated that IMP with single photon emission computed tomography may be a useful adjunct in the clinical diagnosis of AD in early, mild disease.

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PubMed1988

Iofetamine HCI I-123 brain scanning in stroke: a comparison with transmission CT.

Although IMP scans fail to show fine anatomical details of the brain, because of poor resolution of a single head rotational system, adequate information is offered by the scans to localize most perfusion defects caused by stroke. The following conclusions can be drawn from our study: 1. The planar IMP brain scans processed through the computer are sensitive in the early diagnosis of acute stroke except for small and deeply localized lesions. 2. The SPECT IMP imaging is more sensitive than the planar or transmission CT scans in the early diagnosis of stroke. Semiquantitative evaluations are feasible with IMP SPECT. 3. Neither transmission CT nor IMP SPECT are sensitive in the detection of acute lacunar infarcts. 4. In acute infarction, the transmission CT is usually negative or minimally positive in the early stages, while impaired uptake of IMP occurs immediately after the onset of the stroke. In acute stroke, the extent of the perfusion defect on IMP is usually greater than the abnormality seen on the transmission CT. 5. On followup studies, IMP scans show improved perfusion reflecting physiologic changes, while transmission CT scans show further dense anatomical changes when compared to the initial studies. 6. Hyperemic changes are likely due to collateral circulation or luxury perfusion. This finding suggests that the IMP reflects local cerebral blood flow in strokes.

Adult↗
PubMed1994

Dual-isotope autoradiographic measurement of regional blood flow and benzodiazepine receptor availability following unilateral middle cerebral artery occlusion.

Single-photon emission tomography (SPET) imaging in patients with complex partial epilepsy has shown that the seizure focus is characterized by both decreased interictal blood flow and decreased uptake of the benzodiazepine (BZ) receptor tracer iodine-123 iomazenil. The purpose of this study was to examine the confounding effect of decreased flow on iomazenil uptake. The left middle cerebral artery of four rats was occluded, and the animals were simultaneously injected with 25 microCi of iodine-125 iomazenil and 500 microCi of the blood flow tracer [123I]iofetamine (N-isopropyl-p-iodoamphetamine). All rats, including two sham, were sacrificed 1 h after injection, a time when uptake of both agents is nearly maximal. Control experiments showed that arterial occlusion for 1 h did not affect the total number of BZ binding sites. Using a dual autoradiographic technique, the uptake of both [123I]iofetamine and [125I]iomazenil was measured in more than 200 regions showing variable levels of reduced flow and expressed as a percentage of the contralateral homotypic area. The straight line fit of % [125I]iomazenil (y axis) versus % [123I]iofetamine (x axis) in all 200 regions had a slope of 0.74. Insofar as the rat is an accurate model of human subjects with epilepsy, these studies suggest that decreased flow to the epileptogenic focus will linearly exacerbate the decrease in uptake secondary to neuropathologic loss of BZ receptors. Thus, for localization of seizure focus, a single SPET image of [123I]iomazenil in an epileptic patient may have greater sensitivity than a comparable blood flow image, because the former is enhanced by both decreased flow and a loss of BZ receptors.

Amphetamines↗
PubMedDate not supplied

Hemimegalencephaly: clinical, EEG, neuroimaging, and IMP-SPECT correlation.

Iofetamine-single photon emission computed tomography (IMP-SPECT) was performed on 2 girls (5 1/2 and 6 years of age) with histories of intractable seizures, developmental delay, and unilateral hemiparesis secondary to hemimegalencephaly. Electroencephalography (EEG) revealed frequent focal discharges in 1 patient, while a nearly continuous burst suppression pattern over the malformed hemisphere was recorded in the other. IMP-SPECT demonstrated a good correlation with neuroimaging studies. In spite of the different EEG patterns, which had been proposed to predict contrasting clinical outcomes, both IMP-SPECT scans disclosed a similar decrease in tracer uptake in the malformed hemisphere. These results are consistent with the pattern of decreased tracer uptake found in other interictal studies of focal seizures without cerebral malformations. In view of recent recommendations for hemispherectomy in these patients, we suggest that the IMP-SPECT scan be used to compliment EEG as a method to define the extent of abnormality which may be more relevant to long-term prognosis than EEG alone.

Amphetamines↗
PubMed1993

Metabolism in vitro of radioiodinated N-isopropyl-p-iodoamphetamine by isolated hepatocytes.

An in vitro technique for the determination of radiopharmaceutical metabolism has been developed using isolated hepatocytes. Radioiodinated N-isopropyl-p-iodoamphetamine (IMP; iofetamine, USP) was employed a model tracer in these studies because its labeled metabolites are well-characterized. Hepatocytes isolated from the rat and human produced labeled metabolites in vitro for up to 4 h in a manner similar to that reported for humans in vivo. Identical metabolites were generated by all cell types investigated, but the rate of metabolism differed (rat >> human; female > male; fresh > frozen). The utility of this methodology for the preclinical evaluation of potential radiopharmaceuticals is described.

Adult↗
PubMed1992

Cerebral perfusion in progressive supranuclear palsy.

Progressive supranuclear palsy (PSP) is a neurodegenerative disorder in which structurally preserved cerebral cortex is thought to be functionally disconnected by subcortical lesions. To assess brain functional activity in patients with PSP, we measured regional cerebral perfusion, as estimated by [123I] iofetamine (IMP) and single-photon emission computed tomography (SPECT), in 11 patients with a clinical diagnosis of PSP and 10 healthy control subjects. IMP uptake was measured in 2 basal ganglia and 24 cortical regions. Neuropsychological tests were administered to assess cognitive function. Compared to age-matched normal control subjects, relative IMP uptake was significantly reduced in PSP patients in basal ganglia (21%), superior frontal (25%), anterior parietal (19%), and inferior frontal (18%) regions. Cognitive performance was most abnormal on tests thought to be subserved predominantly by frontal lobes. Our study demonstrates that IMP-SPECT detects physiological abnormalities in the cortex that parallel behavioral impairments in PSP.

Aged↗