Incidental finding of accessory spleen on bone scintigraphy.
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Adult↗
Biomedical subjects
P Gerundini
Publications and source records attributed to P Gerundini.
99Tcm-MIBI single photon emission tomography (SPET) for detecting myocardial ischaemia and necrosis in patients with significant coronary artery disease.
The ability of 99Tcm-methoxyisobutylisonitrile (MIBI) single photon emission tomography (SPET) to detect myocardial ischaemia and necrosis was assessed in 56 patients (45 male, 11 female, aged 55 +/- 5 years), with clinically recognized ischaemic heart disease (IHD). All underwent coronary angiography (CA) and left ventriculography (LV). SPET images were obtained at rest and at peak exercise (Modified Bruce) 90 min after injection of 99Tcm-MIBI (650-850 MBq). Data were acquired in 30 min over 180 degrees (from 45 degrees RAO to 45 degrees LPO) with no correction for attenuation, using a 64 x 64 matrix. The presence of persistent (P) or reversible (R) perfusion defects (PD) was then correlated to the resting and exercise ECG and to the results of CA and LV. Of the 56 patients, 34 had reversible underperfusion (RPD), 46 persistent underperfusion (PPD) and 31 had both. The occurrence of RPD correlated well with the occurrence of exercise-induced ST segment depression and/or angina (27 patients of 34 patients, 79%) and with the presence of significant coronary artery disease (CAD) (33 of 44, 73%). In 45 of 46 patients (98%) PPD corresponded to akinetic or severely hypokinetic segments (LV) usually explored by ECG leads exhibiting diagnostic Q waves (42 of 46 patients, 91%). The scan was normal both at rest and after stress in four of 11 patients with no CAD, and in two of 45 patients with CAD. Finally, an abnormal resting scan was seen in seven of 11 patients with normal coronary arteries, of whom six had regional wall motion abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Symptom-limited exercise testing causes sustained diastolic dysfunction in patients with coronary disease and low effort tolerance.
Exercise stress testing is routinely used for the noninvasive assessment of coronary artery disease and is considered a safe procedure. However, the provocation of severe ischemia might potentially cause delayed recovery of myocardial function. To investigate the possibility that maximal exercise testing could induce prolonged impairment of left ventricular function, 15 patients with angiographically proved coronary disease and 9 age-matched control subjects with atypical chest pain and normal coronary arteries were studied. Radionuclide ventriculography was performed at rest, at peak exercise, during recovery and 2 and 7 days after exercise. Ejection fraction, peak filling and peak emptying rates and left ventricular wall motion were analyzed. All control subjects had a normal exercise test at maximal work loads and improved left ventricular function on exercise. Patients developed 1 mm ST depression at 217 +/- 161 s at a work load of 70 +/- 30 W and a rate-pressure product of 18,530 +/- 4,465 mm Hg x beats/min. Although exercise was discontinued when angina or equivalent symptoms occurred, in all patients diagnostic ST depression (greater than or equal to 1 mm) developed much earlier than symptoms. Predictably, at peak exercise patients showed a decrease in ejection fraction and peak emptying and filling rates. Ejection fraction and peak emptying rate normalized within the recovery period, whereas peak filling rate remained depressed throughout recovery (p less than 0.002) and was still reduced 2 days after exercise (p less than 0.02). In conclusion, in patients with severe impairement of coronary flow reserve, maximal exercise may cause sustained impairement of diastolic function.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Measurement by single injection of polyfructosan of glomerular filtration rate in young diabetic patients.
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Adolescent↗
Biodistribution of Tc-99m methoxy-isobutyl-isonitrile (MIBI) in humans.
Hexakis (methoxyisobutilisonitrile) technetium(I), 99mTc-MIBI, has been proposed for myocardial perfusion studies. We have evaluated the biodistribution of this new agent in normal volunteers at rest and after stress. The biodistribution of 99mTc-MIBI is characterized by rapid blood clearance and a consequently early myocardial uptake. The initial intense hepatic activity is cleared into the gallbladder at 1 h after injection, and the best target to non target ratio is observed at 60-90 min after injection. Absorbed radiation dose calculations show that the thyroid is the critical target organ (230 mRad/mCi at rest), presumably because of 99mTc-pertechnetate generated in vivo. Our results indicate that 99mTc-MIBI is a promising tracer for myocardial perfusion imaging.
Adult↗
Cationic complexes of technetium for myocardial imaging.
Over the past 15 years a major goal of research in cardiovascular nuclear medicine has been the development of 99mTc complexes that could replace 201Tl and thus enhance the utility of myocardial perfusion imaging. This paper presents an overview of the current state-of-art of the development of cationic 99mTc complexes for this purpose. Cationic 99mTc complexes that have been evaluated as myocardial perfusion imaging agents in human volunteers and/or animals are discussed and classified on the basis of the oxidation state of the technetium center.
Animals↗
Crossed aphasia: functional studies with single photon emission computerized tomography.
The correlation between clinical picture, CT scan and regional cerebral blood flow (rCBF) assessed by single photon emission computerized tomography (SPECT) was investigated in two patients with crossed aphasia. The presence and degree or right hemisphere dysfunction, beyond the areas affected by CT, closely paralleled the time course of language disturbances in both patients: transient aphasia in case 1 was associated with temporary reduction of perfusion in the right hemisphere, while in case 2 persistent aphasia and apraxia were found along with severe right hemisphere hypoperfusion three year after the onset of stroke.
Aged↗
Remote effects of subcortical cerebrovascular lesions: a SPECT cerebral perfusion study.
The remote effects of small unilateral cerebrovascular lesions confined to subcortical structures were evaluated by single photon emission computerized tomography (SPECT) and a CBF tracer, I-123 HIPDM. A CBF study was performed in 34 patients presenting with subcortical stroke either in the acute or in the chronic stages. Twenty-one of the 34 patients showed areas of cortical hypoperfusion ipsilateral to the subcortical lesion. In 14 patients, asymmetry of perfusion was also observed at the cerebellar level, perfusion being significantly reduced in the cerebellar hemisphere contralateral to the lesion. There was no correlation between the degree and extension of these remote effects and the type of stroke (ischemic or hemorrhagic), the patency of cerebral arteries, or the size and site of the lesion by transmissive computerized tomography (TCT). Subcortical hematomas showed a correlation between occurrence of remote effects and time interval from the onset of stroke, occurring more frequently in the acute phase. A correlation was observed between cortical and cerebellar remote effects and the severity of clinical presentation. The causes of remote effects are still unclear and have been extensively debated. Our data indicate that there is a relationship of remote effect to the neurological status. It is possible to show, by noninvasive, low-cost methods, remote CBF effects after stroke that may contribute to the assessment of brain functional impairment.
Acute Disease↗
Pulmonary retention of iodobenzyl-propanediamine in humans. Effect of cigarette smoking.
N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine (HIPDM), a synthetic basic compound with high affinity for lung tissue of various animal species, was labeled with 123I and injected into normal smokers (n = 9) and into asymptomatic smokers (n = 9). Time/activity curves were recorded for 90 min by gamma camera. HIPDM lung clearance was described by two exponential components. In smokers, the mean time of the first component, 10 +/- 1.4 min (mean +/- SEM), did not significantly differ from that of nonsmokers (9.7 +/- 0.9 min), whereas the mean time of the second component (12.9 +/- 0.6 h) was longer than that of nonsmokers (6.7 +/- 0.2 h). The intercept to the ordinate of the second exponential component was significantly higher in smokers (90.3 +/- 1.5%) than in nonsmokers (80.7 +/- 1.9%). Control studies in rabbits showed that, 2 min after intravenous injection, 95% of HIPDM is taken up by the lung; time/activity curves were similar to those obtained in humans. The longer pulmonary persistence of HIPDM in smokers may reflect an increased number of cellular binding sites or may be the expression of hindered HIPDM biotransformation. The rabbit can be used as a model to further investigate HIPDM kinetics in relation to lung dysfunction.
Adolescent↗
Technetium-99m HM-PAO-SPECT study of regional cerebral perfusion in early Alzheimer's disease.
Regional cerebral perfusion was evaluated by single photon emission computed tomography (SPECT) using technetium-99m hexamethylpropyleneamine oxime ([99mTc]HM-PAO) in sixteen patients with Alzheimer's disease (AD) in early clinical phase and in 16 healthy elderly controls. In all patients transmission computed tomography (TCT) and/or magnetic resonance imaging (MRI) did not show focal brain abnormalities. Relative to normal subjects, AD patients showed significant reductions in cortical/cerebellar activity ratio: cortical perfusion was globally depressed with the largest reductions in frontal and posterior temporo-parietal cortices. Asymmetries of relative perfusion between cerebral hemispheres were also demonstrated when language was affected or visuospatial functions were unevenly impaired. In patients with early AD, SPECT provides functional information to be compared with clinical and psychometric data.
Aged↗
Cerebellar diaschisis in pontine ischemia. A case report with single-photon emission computerized tomography.
Regional cerebral and cerebellar blood flows were studied by N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-[123I]iodobenzyl)-1,3- propanediamine 2 HCl (I-123 HIPDM) and single-photon emission computerized tomography (SPECT) in a patient with an ischemic lesion of the pons. An asymmetry of perfusion of the cerebellar hemispheres, normal on transmission computerized tomography scan, was demonstrated by SPECT studies in the early acute phase and confirmed 15 days after. This finding may be related to the interruption of the corticopontocerebellar pathways.
Aged↗
Cerebral hemispheric and contralateral cerebellar hypoperfusion during a transient ischemic attack.
We studied a 79-year-old woman within 3 h of the onset of a motor aphasia and a right hemiparesis. Single photon emission computed tomography (SPECT) showed a 24% decrease in the perfusion of the left middle cerebral artery territory and a 16% reduction in the perfusion of the right cerebellum. A mild naming difficulty was the neurological deficit at the end of the SPECT examination, and complete recovery was achieved within 24 h. Repeated SPECT study 10 days later was normal. This is the first report of focal hemispheric and contralateral cerebellar hypoperfusion in transient cerebral ischemia.
Aged↗
Cerebral arterial spasm after subarachnoid hemorrhage. A case report with SPECT and iodine-123 HIPDM.
Cerebral arterial spasm following subarachnoid hemorrhage can be responsible for secondary neurological deficits and can influence history, prognosis, and results of surgical treatment. The demonstration of vasospasm can be important for therapy. The use of I-123 HIPDM and SPECT in evaluating regional cerebral blood flow showed the effects on cerebral perfusion of diffuse arterial spasm in a case of subarachnoid hemorrhage and its recovery. There was a parallel with clinical neurological status.
Female↗
Long-term noninvasive single photon emission computed tomography monitoring of perfusional changes after EC-IC bypass surgery.
The rCBF was evaluated using I-123 HIPDM and single photon emission computed tomography (SPECT) on 14 patients undergoing extracranial-intracranial (EC-IC) bypass surgery because of internal carotid artery (ICA) occlusion. Before surgery, all patients showed cortical areas of hypoperfusion over the affected cerebral hemisphere. Shortly after EC-IC bypass a rCBF increase was observed in six patients. However, at the 6 and 12 month follow-ups, with angiographic control of bypass patency, rCBF studies did not show any significant rCBF change. Long-term noninvasive tomographic monitoring of perfusion changes occurring after EC-IC bypass surgery failed to show a long-lasting improvement in perfusion.
Adult↗
Crossed cerebellar diaschisis in patients with cerebral ischemia assessed by SPECT and 123I-HIPDM.
Crossed cerebellar diaschisis (CCD) was investigated in a series of 59 patients (34 completed strokes and 25 reversible ischemic attacks, RIAs) using single photon emission computerized tomography (SPECT) with 123I-HIPDM as a cerebral blood flow (CBF) indicator. CCD was present in 17 (50%) of the patients with completed stroke and in 6 (24%) of the patients with RIAs. CCD was significantly correlated to the clinical severity (p less than 0.001) and to the extension of the supratentorial lesion (p less than 0.05). However, CCD was also recorded in 3 out of 16 patients with normal neurological examination and CT scan, suggesting that a 'functional' hemispheric disturbance may be sufficient to produce a remote effect on the contralateral cerebellar hemisphere. Time elapsed between the clinical onset and SPECT study was not critical, since CCD was recorded in the acute as well as in chronic studies. Follow-up SPECT studies showed that CCD disappeared in 5 out of 18 patients after a successful extra-intracranial bypass, while a spontaneous recovery was observed in only one of 16 nonsurgical patients.
Adult↗
Development of nonreducible technetium-99m(III) cations as myocardial perfusion imaging agents: initial experience in humans.
A series of 15 nonreducible technetium-99m(III) complexes of formula tr-[99mTcL(Y)2]+ has been prepared by a general synthetic route based on reductive addition of Y to the technetium-99m (99mTc) intermediate [99mTcL(O)]+. In these complexes, selected for potential use as myocardial imaging agents, L represents one of the two tetradentate Schiff base ligands N,N'-ethylenebis(acetylacetone iminato), (en), or N,N'-propylene-1,2-bis(acetylacetone iminato), (pn), while Y represents a monodentate phosphine, phosphite or isonitrile ligand as exemplified by P(CH3)3, P(OCH3)3 and CN-C(CH3)3. Of these 15 complexes, several with octanol/saline partition coefficients in the range 0.04-20 exhibit significant myocardial uptake in rats and dogs. Of these, none exhibit detectable myocardial washout, providing strong support for the hypothesis that myocardial washout occurs only for those 99mTc(III) cations that undergo in vivo reduction to the neutral 99mTc(II) form. Evaluation of the prototypical complex tr-[99mTc(en)(P(CH3)3)2]+ in seven normal volunteers and patients establishes that it is only a mediocre myocardial imaging agent in man.
Animals↗
Abnormal cardiovascular response to exercise in young asymptomatic diabetic patients with retinopathy.
Heart rate, blood pressure, and left ventricular ejection fraction (LVEF) were measured by means of Au 195 m first-pass angiocardiography, during maximal supine bicycle exercise in 20 young asymptomatic patients with insulin-dependent diabetes (IDD) (10 retinopathic and 10 uncomplicated) and in 10 control subjects. Five patients with retinopathic IDD also had mild subclinical autonomic neuropathy. Exercise capacity was diminished, although not significantly, in patients with retinopathic IDD. Heart rate and LVEF were similar in all groups at rest and at submaximal exercise. At peak exercise patients with retinopathic IDD had significantly lower heart rate (134 +/- 4 bpm) and LVEF (62.9 +/- 3.7%) than those with umcomplicated IDD (158 +/- 8 bpm and 76.6 +/- 2.4%, respectively) and control subjects (152 +/- 6 bpm and 73.5 +/- 1.9%, respectively). LVEF increased vs baseline in all control subjects and patients with uncomplicated IDD, but in only three with retinopathic IDD. Leg muscle blood flow (MBF) was also evaluated at rest and during exercise by 133Xe washout. Exercise MBF was significantly lower in patients with retinopathic IDD (40.5 +/- 2.23 ml X min-1 X 100 gm-1) than in control subjects (49.9 +/- 1.87 ml X min-1 X 100 gm-1) and in those with uncomplicated IDD (49.0 +/- 1.87 ml X min-1 X 100 gm-1). Diffuse microangiopathy, alone or in combination with neuropathy, might be responsible for the impairment of cardiovascular function in diabetes.
Adult↗
Sequential assessment of regional cerebral blood flow, regional cerebral blood volume, and blood-brain barrier in focal cerebral ischemia: a case report.
Regional CBF (rCBF) and regional cerebral blood volume (rCBV) were evaluated by N,N,N'-trimethyl-N'-(2)-hydroxy-3-methyl-5-[123I]iodobenzyl-1, 3-propanediamine-2 HCl- and 99mTC-labeled red blood cells, respectively, and single-photon emission computerized tomography (SPECT) in a patient with focal cerebral ischemia. Sequential transmission computerized tomography (TCT) and SPECT functional data were compared with clinical findings to monitor the pathophysiological events occurring in stroke. A lack of correlation between rCBF-rCBV distributions and blood-brain barrier (BBB) breakdown was found in the acute phase. In the face of more prolonged alteration of BBB, as seen by TCT enhancement, a rapid evolution of transient phenomena such as luxury perfusion was shown by SPECT studies. Follow-up of the patient demonstrated a correlation between the neurological recovery and a parallel relative improvement of the cerebral perfusion.
Adult↗