Biomedical subjects

A Soricelli

Publications and source records attributed to A Soricelli.

At least 19 recordsLinked to original sources

PubMed2005

Mediastinal images resembling thymus following 131-I treatment for thyroid cancer.

The follow-up of Differentiated Thyroid Cancer conventionally includes serum thyroglobulin and periodic Whole Body Scans. The uptake of 131-I in normal and pathological tissues different from metastatic thyroid cancer sites is a cause of false-positive scans. Among them, mediastinal uptake caused by thymic hyperplasia can be observed. The aim of the present study was to review a series of 573 patients with differentiated thyroid cancer treated with 131-I after surgery between 1992 and 2003 looking above all for those with mediastinal images resembling thymus. This evaluation is presented together with some hypotheses on the relationships between thymus and thyroid. Moreover, some considerations are made on the differential diagnosis between thymus and mediastinal tumour thyroid residues.

Adenocarcinoma↗

PubMed2000

Measurement of global brain atrophy in Alzheimer's disease with unsupervised segmentation of spin-echo MRI studies.

In 16 patients with probable Alzheimer's disease (AD; NINDS criteria, age range 56-78 years), gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) absolute and fractional volumes were measured with an unsupervised multiparametric post-processing segmentation method based on estimates of relaxation rates R1, R2 (R1 = 1/T1; R2 = 1/T2) and proton density [N(H)] from conventional spin-echo studies (Alfano et al. Magn. Reson. Med. 1997;37:84-93). Global brain atrophy, and GM and WM fractions significantly correlated with Mini-Mental Status Examination and Blessed Dementia Scale scores. Compared with normals, brain compartments in AD patients showed decreased GM (-6.84 +/- 1.58%) and WM fractions (-9.79 +/- 2.47%) and increased CSF fractions (+58.80 +/- 10.37%). Changes were more evident in early-onset AD patients. In AD, measurement of global brain atrophy obtained by a computerized procedure based on routine magnetic resonance studies could complement the information provided by neuropsychological tests for the assessment of disease severity.

Aged↗

PubMed1999

Comparison between cortical distribution of I-123 iomazenil and Tc-99m HMPAO in patients with Alzheimer's disease using SPECT.

PURPOSE: To compare brain perfusion and synaptic density in Alzheimer's disease assessed using I-123 iomazenil SPECT with brain perfusion assessed using Tc-99m HMPAO SPECT. MATERIALS AND METHODS: Early and delayed I-123 iomazenil SPECT images acquired 20 and 180 minutes after injection were compared with Tc-99m HMPAO SPECT studies acquired 15 to 20 minutes after injection in five patients with Alzheimer's disease. RESULTS: Visual analysis of I-123 iomazenil images showed more severe (n = 4) and extensive (n = 3) defects than did Tc-99m HMPAO. Semiquantitative analysis was performed by normalizing the uptake of Tc-99m HMPAO and I-123 iomazenil in individual brain regions in the cerebellum and expressing these values as a ratio of the occipital regions. The analysis of brain regional ratios in Tc-99m HMPAO studies showed a low but significant correlation with ratios of delayed (r = 0.325, P < 0.05) images in the I-123 iomazenil studies. Furthermore, when compared with Tc-99m HMPAO, early (P < 0.01) and delayed mean ratios (P < 0.05) were significantly less in the frontal regions; early mean ratios were significantly less in the temporal regions (P < 0.05), and delayed (P < 0.05) mean ratios were significantly less in the parietal regions. CONCLUSIONS: Tc-99m HMPAO images were better correlated with I-123 iomazenil images, indicating cortical synaptic density (delayed images). I-123 iomazenil SPECT in patients with Alzheimer's disease provided more sensitive information than Tc-99m HMPAO, allowing evaluation of brain perfusion and synaptic density.

Alzheimer Disease↗

PubMed1998

Cerebral blood flow in spinocerebellar degenerations: a single photon emission tomography study in 28 patients.

We used single photon emission tomography to study regional cerebral perfusion in patients with different forms of spinocerebellar degeneration: 6 patients with Friedreich's ataxia (FA), 6 with early-onset cerebellar ataxia with retained tendon reflexes (EOCA), 5 with autosomal dominant cerebellar ataxia type 1 (ADCA I) and 11 with idiopathic late-onset cerebellar ataxia (ILOCA). The results were related to clinical and magnetic resonance imaging (MRI) findings. Cerebellar hypoperfusion was constant in ADCA I and frequent in patients with other spinocerebellar degenerations. Brain stem hypoperfusion was constant in ADCA I, frequent in ILOCA patients with pontocerebellar atrophy and absent in FA and EOCA. FA and EOCA often showed a reduction in the parietotemporal cortex blood flow, which was not related to cortical atrophy. ILOCA patients had an asymmetric pattern in the temporal areas with decreased blood flow in the right side only. Caudate hypoperfusion was found in ADCA I patients. Cerebral atrophy did not account for changes in regional blood flow, which probably indicate early involvement of cerebral structures.

Adult↗

PubMed1998

Alterations of cerebral blood flow and antiphospholipid antibodies in patients with systemic lupus erythematosus.

Twenty-two patients with systemic lupus erythematosus and 13 healthy controls were included in a cerebral blood flow study and underwent brain-dedicated single-photon emission computed tomography using 99m technetium-d, l-hexamethylpropylene amine oxime together with a brain computed tomography scan. Plasma levels of antiphospholipid antibodies (lupus anticoagulant and anticardiolipin IgM and IgG antibodies) were also determined. Brain computed tomography showed signs of focal cerebral ischemia in 4 patients (18%), whereas cerebral blood flow by single-photon emission computed tomography was abnormal in 13 of 22 patients (59%), who showed bilateral or monolateral hypoperfusion in the temporo-parietal regions. Patients with abnormal cerebral blood flow had a longer duration of disease than those with normal blood flow (8.9 +/- 1.9 years vs. 5.3 +/- 1.5 years, P < 0.05). Plasma antiphospholipid antibodies were present in 15 patients (68%), but the prevalence was similar in those with normal (6/9, 66%), or abnormal (9/13, 69%) cerebral blood flow. No statistically significant difference in lupus anticoagulant or anticardiolipin antibodies was observed between patients with and without cerebral blood flow abnormalities. Our study shows that patients with systemic lupus erythematosus frequently have cerebral blood flow abnormalities, which could precede those observed by computed tomography. Plasma lupus anticoagulant and anticardiolipin titers were not correlated with normal cerebral blood flow.

Adolescent↗

PubMed1998

Atypical pleomorphic xanthoastrocytoma.

A 65-year-old man experienced an ictal episode. CT revealed a left capsulo-thalamic mass, and SPET showed hypoperfusion of the left cerebral emisphere. The lesion was subtotally removed, and postoperative radiotherapy was given. Pathological examination demonstrated an "atypical" pleomorphic xanthoastrocytoma. The patient died of massive regrowth of the tumor 22 months after surgery. This case is discussed in light of the pertinent literature.

Aged↗

PubMed1998

Technetium-99m-tetrofosmin uptake in brain tumors by SPECT: comparison with thallium-201 imaging.

UNLABELLED: Thallium-201 is clinically used for the assessment of primary and recurrent brain tumors. The biologic properties of 201Tl that allow it to accumulate within the tumor cells render 201Tl useful in evaluating tumor malignancy, but its physical characteristics and nonroutine availability limits its use in some institutions, as compared to 99mTc-labeled compounds. The aim of this study was to assess the feasibility of using 99mTc-tetrofosmin for imaging brain tumors and to compare its uptake with that of 201Tl. METHODS: Twenty-six patients with 27 intracranial masses were studied with SPECT. In the first group of seven patients (Group A), the timing for optimal acquisition of the 99mTc-tetrofosmin scan was assessed. In the second group of 19 patients (Group B), two sequential 201Tl (74-148 MBq intravenous) and 99mTc-tetrofosmin (740-925 MBq intravenous) studies were performed 20 min after tracer injection and compared. RESULTS: In Group A, no significant difference in the tumor-to-background (T/B) ratio among the 20-, 40- and 120-min postinjection studies was observed. In Group B, the quality of reconstructed images with 99mTc-tetrofosmin, judged visually, was superior to that of 201Tl in 47% of all studies and was comparable in the remaining 53%. A significant relationship between 201Tl and 99mTc-tetrofosmin T/B ratio (r = 0.75, p < 0.01) was found. The T/B ratio of 99mTc-tetrofosmin was significantly higher than that of 201Tl (23.3 +/- 21.5 compared to 6.1 +/- 2.9, p < 0.005). CONCLUSION: Technetium-99m-tetrofosmin is a suitable radiotracer for the imaging of intracranial lesions with SPECT. Moreover, a better definition of tumor margins and a higher contrast between neoplastic and normal brain tissue can be achieved.

Brain Neoplasms↗

PubMed1998

Identification of viable myocardium in patients with chronic coronary artery disease using rest-redistribution thallium-201 tomography: optimal image analysis.

UNLABELLED: With the widely used 50% threshold, sensitivity is high, but specificity is low in detecting viable myocardium on 201Tl SPECT. In this study, we sought to identify the best threshold for semiquantitative 201Tl analysis. METHODS: Rest-redistribution 201Tl SPECT was performed in 46 patients with chronic coronary artery disease before and after myocardial revascularization. Regional function was evaluated by two-dimensional echocardiography before and after myocardial revascularization using a 3-point scale (1 = normal, 2 = hypokinetic, 3 = a/dyskinetic). Myocardial segments with abnormal systolic function were defined as viable if the systolic function score decreased > or = 1 after myocardial revascularization. A second group of 12 patients with chronic coronary artery disease constituted the validation population. Sensitivity-specificity curves, as well as receiver operating characteristic curves, for rest and redistribution mages were generated by varying the 201Tl uptake threshold. RESULTS: A 65% threshold uptake using resting images was found to be the best for detecting a/dyskinetic segments that improve after myocardial revascularization from those that do not improve. Sensitivity was lower with a 65% threshold (75%) than with a 50% threshold (90%, p < 0.05), but specificity was higher (76% versus 26%, p < 0.05) resulting in better accuracy (76% versus 57%, p < 0.05) and positive predictive value (77% versus 55%), while the negative predictive value was not different (69% versus 75%, p not significant). The area under the receiver operating characteristic curve was significantly (p < 005) larger for rest (0.80 +/- 0.05) as opposed to redistribution (0.72 +/- 0.05) images. Similar results were obtained in a subgroup of patients with low ejection fraction. Significant correlations between the percentage of revascularized viable segments and both the change in ejection fraction and in postrevascularization ejection fraction were found. When these findings were applied in the validation group, a gain in specificity, accuracy and positive predictive value was obtained with the 65% threshold compared with the 50% threshold. CONCLUSION: This study demonstrated that analysis of resting images and use of the 65% 201Tl uptake threshold is preferable for separating viable from not viable dyssynergic myocardial segments in patients with chronic coronary artery disease.

Case-Control Studies↗

PubMed1996

Assessment of myocardial viability in patients with chronic coronary artery disease. Rest-4-hour-24-hour 201Tl tomography versus dobutamine echocardiography.

BACKGROUND: To date, late redistribution after resting 201Tl injection has not been evaluated. In addition, the concordance between resting 201Tl imaging and dobutamine echocardiography in identifying viable myocardium has not been assessed. METHODS AND RESULTS: Forty patients with coronary artery disease underwent rest-4-hour-24-hour 201Tl tomography and dobutamine echocardiography (5 to 10 micrograms.kg-1.min-1). Late redistribution occurred in 46 (21%) of 219 persistent defects at 4 hours. Systolic function and contractile reserve were similar among persistent defects at 4 hours with and without late redistribution. Contractile reserve was more frequent in segments with normal 201Tl uptake (59%), completely reversible defects (53%), or mild to moderate defects at 4 hours (56%) compared with severe defects (14%; P < .02 versus all). Of 105 hypokinetic segments, 99 (94%) were viable by 201Tl, and 88 (84%) showed contractile reserve. In contrast, of 155 akinetic segments, 119 (77%) were viable by 201Tl, but only 34 (22%) had contractile reserve. Concordance between 201Tl and dobutamine was 82% in hypokinetic segments but 43% in akinetic segments. In 109 revascularized segments, positive accuracy for functional recovery was 72% for 201Tl and 92% for dobutamine, whereas negative accuracy was 100% and 65%, respectively. Sensitivity was 100% for 201Tl and 79% for dobutamine. CONCLUSIONS: Late redistribution occurs in one fifth of persistent defects at 4 hours, and it does not correlate to systolic function or contractile reserve. Dobutamine and 201Tl yield concordant information in the majority of hypokinetic segments, whereas concordance is low in akinetic segments. Dobutamine demonstrates higher positive accuracy and sensitivity in predicting recovery of dysfunctional myocardium, whereas 201Tl shows higher negative predictive accuracy but reduced positive accuracy.

Aged↗

PubMed1996

Prolonged impairment of regional contractile function after resolution of exercise-induced angina. Evidence of myocardial stunning in patients with coronary artery disease.

BACKGROUND: Delayed recovery of contractile function in spite of normal perfusion (ie, "stunning") has been described in animal models of exercise-induced myocardial ischemia. Therefore, we investigated whether stunning may result from effort angina in patients. METHODS AND RESULTS: Patients with coronary artery disease underwent exercise testing combined with quantitative measurements of contractile function for up to 240 minutes after exercise determined by either measurement of regional ejection fraction (99mTc radionuclide angiography; n = 17, group A) or computer-assisted measurement of systolic wall thickening (n = 14, group B). In the latter group, myocardial perfusion was also evaluated by 99mTc-sestamibi tomographic imaging. Angina induced marked contractile dysfunction. Hemodynamic and ECG changes brought about by ischemia were promptly normalized. Furthermore, no perfusion defects could be detected in group B patients 30 minutes after exercise, yet contractile function remained impaired well after cessation of exercise. Thirty minutes into recovery, regional ejection fraction of previously ischemic areas was still 82.6 +/- 4.6% of baseline in group A (P < .05). Similarly, in group B patients, systolic thickening of previously ischemic segments was still significantly impaired 60 minutes after exercise, averaging 33.8 +/- 2.8% versus 40.5 +/- 2.7% at baseline (P < .05). Contractile impairment was fully reversible, as the functioning of previously ischemic segments normalized between 60 and 120 minutes of recovery. CONCLUSIONS: Prolonged yet ultimately reversible impairment of regional myocardial function may occur in patients after exercise-induced angina in the absence of perfusion abnormalities. These findings indicate that myocardial stunning may ensue after effort angina in patients with severe coronary artery disease.

Adult↗

PubMed1996

Different thallium-201 single-photon emission tomographic patterns in benign and aggressive meningiomas.

To evaluate the possibility of preoperatively obtaining an index of aggressiveness for intracranial meningiomas, we prospectively studied 22 patients with computed tomographic or magnetic resonance imaging evidence of meningeal tumour, using single-photon emission tomography (SPET) of the brain and thallium-201 (201Tl). On a brain-dedicated SPET scanner, a rapid acquisition protocol with early, short scans was started simultaneously with the intravenous administration of 111 MBq 201Tl, covering the initial intratumoral distribution of the tracer. Twenty minutes post injection, a delayed SPET scan was also obtained. On the reconstructed and attenuation-corrected images we calculated the 201Tl concentration in tumour and normal contralateral brain tissue, and compared intratumoral tracer concentration in the initial and the final part of the rapid acquisition protocol. Benign and malignant meningiomas were classified as such based on histological examination. In malignant lesions, the ratio of the 201Tl concentration at 2-4 min post injection to that at 14-16 min was found to be significantly higher than in non-aggressive neoplasms (mean+/-1 SD: 1.14+/-0.31 and 0.56+/-0.13, respectively, P <0.01). Conversely, in the delayed scan, most lesions showed high tracer concentration, and the two groups could not be distinguished. In addition, three recurrent meningiomas displayed the same imaging behaviour as the malignant group, i.e. had similar 201Tl concentration values at 2-4 and at 14-16 min. Our findings suggest that the comparative assessment of intratumoral 201Tl concentration at 2-4 and at 14-16 min post injection could provide a fast, simple method to differentiate preoperatively intracranial meningiomas with different biological behaviour.

Female↗

PubMed1996

Reduced cortical distribution volume of iodine-123 iomazenil in Alzheimer's disease as a measure of loss of synapses.

Iodine-123 labelled iomazenil (IMZ) is a specific tracer for the GABAA receptor, the dominant inhibitory synapse of the brain. The cerebral distribution volume (Vd) of IMZ may be taken as a quantitative measure of these synapses in Alzheimer's disease (AD), where synaptic loss tends indiscriminately to affect all cortical neurons, albeit more so in some areas than in others. In this pilot study we measured Vd in six patients with probable AD and in five age-matched controls using a brain-dedicated single-photon emission tomography scanner allowing all cortical levels to be sampled simultaneously. Reduced values were found in all regions except in the occipital (visual) cortex. In particular, temporal and parietal cortex Vd was significantly (P<0.02) reduced: temporal Vd averaged 69 ml/ml in normals and 51 ml/ml in AD, and parietal Vd averaged 71 ml/ml in normals and 48 ml/ml in AD. These results accord well with emission tomographic studies of blood flow or labelled glucose. This supports the idea that while only measuring a subpopulation of synapses, the IMZ method reflects synaptic loss and hence functional loss in AD. The method constitutes an in vivo version of synaptic quantitation that in histopathological studies has been shown to correlate closely with the mental deterioration in AD.

Alzheimer Disease↗

PubMed1996

Functional characterization of brain tumors: an overview of the potential clinical value.

Early detection and characterization are still challenging issues in the diagnostic approach to brain tumors. Among functional imaging techniques, a clinical role for positron emission tomography studies with [18F]-fluorodeoxyglucose and for single photon emission computed tomography studies with [201Tl]-thallium-chloride has emerged. The clinical role of magnetic resonance spectroscopy is still being defined, whereas functional magnetic resonance imaging seems able to provide useful data for presurgical localization of critical cortical areas. Integration of morphostructural information provided by computed tomography and magnetic resonance imaging, with functional characterization and cyto-histologic evaluation of biologic markers, may assist in answering the open diagnostic questions concerning brain tumors.

Brain Neoplasms↗

PubMed1996

Accuracy in the diagnosis of mandibular involvement by oral cancer.

Cancer of the mandibular region usually has a poor prognosis; this is particularly correlated to invasion of the mandible. To reduce the consequences of poor therapeutic planning, careful preoperative assessment of bone infiltration is necessary. We have examined the records of 50 patients evaluated by clinical examination, conventional radiography, computed tomography (CT), bone scintigraphy with 99mTc and magnetic resonance imaging (MRI). The highest sensitivity (100%) was attained by scintigraphy; the highest values of specificity (96.3%) were reached by CT scan and MRI. A CT scan showed the highest predictive positive value (95.4%) and efficiency (94%), this plus MRI have good values and the associated sensitivity and efficiency are higher than when these techniques are used alone.

Adult↗

PubMed1996

Evaluation of brain perfusion with high resolution single photon emission tomography in the diagnosis of brain death.

Nuclear Medicine studies performed with tomographic acquisition and tracers such as Technetium-99m hexamethyl-propyleneamine oxime (99mTc-HMPAO) are able to assess cerebral blood flow. A case is reported of a patient with a large intracranial tumor, of possible pituitary origin, with a clinical and electroencephalographic suspicion of brain death. The patient had endocrinous-metabolic impairments for a history of impotence, since 18 months, and diabetes insipidus with a urine output of 350 ml/hr in the first 24 hours from the clinical suspicion of brain death. Due to the endocrinous-metabolic impairments, according to Italian law, it was necessary to confirm the diagnosis of brain death by performing a study able to assess cerebral blood flow. A single Photon Emission Tomography (SPET) scan was performed after the intravenous administration of 99mTc-HMPAO using a high resolution, brain dedicated device. No tracer uptake was evident in cerebral, cerebellar and brain stem structures. The cerebral blood flow study by SPET confirmed the diagnosis of brain death and made the organ transplant possible in a short period of time. High resolution SPET studies are useful to confirm the diagnosis of brain death when there are factors that can influence clinical and electroencephalographic signs, reducing time to authorise the organ explant.

Adult↗

PubMed1996

[Computerized tomography with single photon emission (SPECT) with technetium-99m MIBI (99mTc-MIBI) in the identification of viable myocardium in patients with chronic ischemic cardiopathy and left ventricular dysfunction].

Resting 99mTc-MIBI cardiac imaging may be poorly accurate in identifying the presence of viable myocardium in patients with chronic coronary artery disease (CAD). In this study, we directly compared the results of resting 99mTc-MIBI SPECT with initial (1 hr) and delayed (5 hrs) images with those of 99mTc-MIBI SPECT after nitroglycerine (NTG) administration in 31 patients with chronic CAD. All patients also underwent rest-redistribution thallium-201 (201Tl) SPECT. In 8 patients, echocardiography was performed before and after coronary revascularization (Rev). Of 682 myocardial segments, 197 showed a marked reduction (< 50% of peak) in MIBI uptake on initial images. MIBI uptake (> or = 10%) was increased in 47 (24%) segments on delayed images (from 43 +/- 8% to 60 +/- 8%, p < 0.001) and in 54 (27%) segments after NTG (from 42 +/- 8% to 60 +/- 8%, p < 0.001). The results of delayed and NTG MIBI images were in agreement in most segments (n = 160, 81%). The results of delayed and NTG MIBI images were in disagreement in the remaining 37 (19%) segments. In particular, 15 segments showed reversible defects on delayed, but not on NTG MIBI images, while 22 on NTG, but not on delayed MIBI images. All the segments with reversible MIBI defects on delayed and/or NTG images were identified as viable on TI-201. In the 8 pts examined before and after Rev. 83% of segments with reversible MIBI defects on delayed images and 87% of those with reversible defects after NTG showed functional recovery after Rev; furthermore, in these patients a significant improvement in global left ventricular function was observed after Rev, as shown by ejection fraction values (from 42 +/- 7% to 47 +/- 7%, p < 0.01). These comparative results show that resting delayed and NTG MIBI imaging provide similar information to identify viable myocardium and to predict functional recovery after coronary Rev in chronic CAD.

Adult↗

PubMed1996

[Left ventricular function in patients with chronic ischemic cardiopathy: relationship with the status of myocardial perfusion].

The aim of this study was the evaluation of left ventricular function compared to myocardial perfusion in patients with chronic coronary artery disease (CAD). Thirty-two patients with chronic CAD (27 men and 5 women, mean age 58 +/- 9 years) underwent radionuclide angiography and rest-redistribution thallium-201 (TI-201) single photon emission Computed Tomography (SPECT). Ejection fraction (EF, %), peak filling rate (PFR, end diastolic volume/second), and the coefficient of variation of the regional time to PFR (CV-TPFR, %) were computed. Patients with severe irreversible defects (i.e. with TI-201 uptake < 50%) had lower EF (42 +/- 7% vs 52 +/- 11%, p < 0.01) and lower PFR (1.9 +/- 0.4 vs 3.1 +/- 1.0, p < 0.0005) than those without. Patients with severe irreversible perfusion defects in the left anterior descending artery territory had lower EF (41 +/- 6% vs 50 +/- 11%, p < 0.01), lower PFR (1.8 +/- 0.3 vs 2.8 +/- 1.0, p < 0.005), and higher CV-TPFR (39 +/- 22 vs 13 +/- 7, p < 0.001) than those without. The results of the present study indicate that in patients with chronic CAD left ventricular systolic and diastolic function is more deteriorated when the left anterior descending artery is involved. Similarly, the presence of severe irreversible perfusion defects is clearly associated with significantly lower EF and PFR.

Adult↗

PubMed1995

Dobutamine echocardiography predicts improvement of hypoperfused dysfunctional myocardium after revascularization in patients with coronary artery disease.

BACKGROUND: In patients with coronary artery disease, dysfunctional hypoperfused myocardium at rest may represent either necrotic or viable hibernating myocardium. The accuracy of inotropic stimulation in identifying hypoperfused, reversibly dysfunctional myocardium has not been extensively investigated. METHODS AND RESULTS: Eighteen patients with stable chronic coronary artery disease underwent, while off drugs, quantitative 201Tl single-photon emission computed tomography after rest injection (2 to 3 mCi), two-dimensional echocardiography at rest and during dobutamine (5 to 10 micrograms/kg per minute i.v.), and radionuclide angiography. Single-photon emission computed tomography and echocardiography at rest were repeated 34 +/- 10 days after coronary revascularization, and radionuclide angiography was repeated 45 +/- 13 days after revascularization. Resting hypoperfusion was defined as 201Tl uptake < 80% of maximal activity. Systolic function was scored from 1 (normal) to 4 (dyskinesia), and functional improvement was defined as a score change > 1 grade. Of 79 dysfunctional hypoperfused segments, 48 (61%) improved function after revascularization. In 42 (88%) of these latter segments, function had improved during dobutamine. Conversely, systolic function after revascularization did not improve in 31 segments, and in 27 (87%), it had not improved during dobutamine. Functional improvement after revascularization was observed in 42 (91%) of 46 segments manifesting an improvement during dobutamine as opposed to 6 (18%) of 33 segments that did not improve during dobutamine. Resting 201Tl uptake (% of maximal activity) before revascularization (65 +/- 9%) significantly increased at follow-up in segments where function improved (70 +/- 12%, P < .005), whereas it did not change significantly in segments with unchanged systolic function after revascularization (from 57 +/- 13% to 60 +/- 17%, P = NS). In 10 patients with prerevascularization ejection fraction < 45%, left ventricular ejection fraction significantly increased from 36 +/- 7% before revascularization to 42 +/- 7% at follow-up (P < .05). CONCLUSIONS: Inotropic stimulation using dobutamine echocardiography identifies hypoperfused reversibly dysfunctional myocardium. Functional improvement during dobutamine is highly predictive of improvement after revascularization.

Aged↗