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A 66-year-old man with a past medical history of hypertension and arthritis was hospitalized and treated for bacterial pneumonia. Chest X-ray revealed a left-sided chest mass. Computed tomography (CT) scan of the chest demonstrated a large heterogeneously enhancing mass occupying most of the left lower lobe and extending to the inferior aspect of the hilum. It measured 16.6 × 12 cm and caused a mild shift of the mediastinum to the right. The patient declined further work-up or surgical resection of the mass. Dermatologic examination was unremarkable at that time. Over the next 5 months, numerous skin lesions erupted on the patient's trunk. He then experienced several syncopal episodes, at which time he was found to be profoundly hypoglycemic. It was suspected that the chest tumor was producing high serum levels of insulin-like growth factor (IGF) resulting in hypoglycemia and syncope. Serum laboratory investigations were significant for glucose of 20 mg/dL (normal, 60–120 mg/dL), IGF-1 of 39 ng/mL (normal, 152–494 ng/mL), IGF-2 of 927 ng/mL (normal, 210–750 ng/mL), and insulin of

Observer variability has been shown with interpretation of planar thallium-201 images. The interpretive reproducibility of technetium-99m sestamibi tomographic imaging is unknown. This study evaluated the interpretive reproducibility of interpretable Tc-99m sestamibi tomographic images among nuclear cardiologists with a wide range of training and experience.Three experienced readers (EX) and 3 less-experienced readers (LEX) interpreted 138 exercise and rest Tc-99m sestamibi tomographic images (101 were abnormal in patients with coronary artery disease [CAD], 37 were normal in patients with5% likelihood of CAD) twice in random sequence without clinical data. Images of good to excellent quality were randomly selected from a database at 2 nuclear cardiology laboratories. Intraobserver and interobserver agreement for global, left anterior descending (LAD) territory, non-LAD first (normal/abnormal) and second (normal/fixed/reversible) order, and defect extent (normal/single-vessel CAD/multi-vessel CAD) were assessed with percent agreement and Cohen's kappa (kappa) statistic.With regard to intraobserver agreement, first and second order ranged from 87% to 94% and 80% to 90% for global, 82% to 96% and 78% to 95% for LAD, and 88% to 91% and 80% to 90% for non-LAD, respectively. Defect extent ranged from 75% to 90%. There were no differences between EX and LEX for global and non-LAD first and second order, LAD first order, and defect extent. LAD second order was 93% for EX compared with 88% (P = .015) for LEX. With regard to interobserver agreement, first and second order ranged from 73% to 89% and 64% to 85% for global, 73% to 93% and 69% to 91% for LAD, and 76% to 88% and 68% to 84% for non-LAD, respectively. Defect extent ranged from 61% to 82%. Global first and second order ranged from 85% to 87% and 78% to 82% for EX compared with 73% to 84% and 64% to 79% for LEX. LAD first and second order ranged from 89% to 91% and 88% to 89% for EX compared with 73% to 91% and 69% to 70% for LEX. Non-LAD first and second order ranged from 82% to 86% and 76% to 77% for EX compared with 76% to 86% and 68% to 81% for LEX. Defect extent ranged from 69% to 75% for EX compared with 59% to 77% for LEX.There is moderate to excellent interpretive reproducibility with stress Tc-99m sestamibi SPECT imaging among nuclear cardiologists with a wide range of training and experience.

Objectives. We sought to evaluate the clinical use and cost-analysis of acute rest technetium-99m (Tc-99m) tetrofosmin single-photon emission computed tomographic (SPECT) myocardial perfusion imaging in patients with chest pain and a normal electrocardiogram (ECG). Background. Current approaches used in emergency departments (EDs) for treating patients presenting with chest pain and a nondiagnostic ECG result in poor resource utilization. Methods. Three hundred fifty-seven patients presenting to six centers with symptoms suggestive of myocardial ischemia and a nondiagnostic ECG underwent Tc-99m tetrofosmin SPECT during or within 6 h of symptoms. Follow-up evaluation was performed during the hospital period and 30 days after discharge. All entry ECGs, SPECT images and cardiac events were reviewed in blinded manner and were not available to the admitting physicians. Results. By consensus interpretation, 204 images (57%) were normal, and 153 were abnormal (43%). Of 20 patients (6%) with an acute myocardial infarction (MI) during the hospital period, 18 had abnormal images (sensitivity 90%), whereas only 2 had normal images (negative predictive value 99%). Multiple logistic regression analysis demonstrated abnormal SPECT imaging to be the best predictor of MI and significantly better than clinical data. Using a normal SPECT image as a criterion not to admit patients would result in a 57% reduction in hospital admissions, with a mean cost savings per patient of $4,258. Conclusions. Abnormal rest Tc-99m tetrofosmin SPECT imaging accurately predicts acute MI in patients with symptoms and a nondiagnostic ECG, whereas a normal study is associated with a very low cardiac event rate. The use of acute rest SPECT imaging in the ED can substantially and safely reduce the number of unnecessary hospital admissions.

Left ventricular (LV) cavity dilation during stress myocardial perfusion imaging has been associated with multivessel disease, and may be an independent prognostic marker in addition to perfusion defects. The present study examines the predictive value for future cardiac events of transient or fixed LV dilation during dipyridamole technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) imaging. The study included 512 consecutive patients who underwent SPECT imaging with Tc-99m sestamibi after dipyridamole infusion. Transient LV dilation was seen in 70 patients (14%) and 74 had fixed cavity dilation (14%); cavity size was normal in 368 patients (72%). Each perfusion scan was classified as normal or abnormal, and if abnormal, defects were categorized as transient or fixed, and as small, medium, or large (depending upon the number of abnormal vascular territories). Events during a mean follow-up of 12.8 +/- 6.8 months were tabulated by direct review of hospital charts and death certificates. The cardiac event rate (cardiac death or nonfatal infarction) was 1.9% in patients with normal cavity size, 11.4% with transient LV dilation, and 13.5% with fixed LV dilation (p < 0.01). Compared with patients with normal cavity size, those with transient LV dilation were more likely to sustain a myocardial infarction (p < 0.01) and those with fixed dilation more frequently suffered cardiac death (p < 0.01) and hospitalization for heart failure (p < 0.01). The group with the highest risk had both a large perfusion defect and cavity dilation. By Cox proportional hazard regression analysis, both transient and fixed LV dilation were strong independent predictors of cardiac events. Transient or fixed LV dilation are commonly seen during dipyridamole Tc-99m sestamibi SPECT imaging (14% incidence for each) and are useful predictors of cardiac events.

To evaluate the effectiveness of published nuclear cardiology training guidelines, the diagnostic accuracy of image interpretation by nuclear cardiology trianees was compared with that of experienced nuclear cardiologists. The accuracy of three experienced nuclear cardiologists and three trainees with level II experience following Society of Nuclear Medicine/American College of Cardiology/American Society of Nuclear Cardiology guidelines in the interpretation of 114 exercise 99mTc-labeled sestamibi single-photon emission computed tomographic imaging studies was evaluated. Studies were selected randomly and included patients with less than 5% likelihood of coronary artery disease, as well as patients with angiographically demonstrated single and multivessel disease. Studies were interpreted by each reader without knowledge of clinical or exercise data. Each reader classified perfusion as normal or abnormal. Accuracy was assessed according to sensitivity, normalcy rate, and predictive accuracy. In addition, the ability of experienced readers and trainees to identify abnormal perfusion in patients with multivessel disease was compared. Trainees had high accuracy, comparable to experienced readers for sensitivity, normalcy rate, and predictive accuracy, as well as the ability to identify abnormal perfusion in patients with multivessel disease. In all categories, experienced interpretors demonstrated a trend toward greater accuracy with less observer variability than did trainees. Structured training in nuclear cardiology following Society of Nuclear Medicine/American College of Cardiology/American Society of Nuclear Cardiology guidelines during clinical cardiology fellowship is effective, and trainees possess the skills to interpret myocardial perfusion images accurately. Interpretive skills can be expected to improve further with experience.

Objectives.This study sought to establish the prognostic value of intravenous dipyridamole technetium-99m (Tc-99m) sestamibi single-photon emission computed tomographic (SPECT) myocardial perfusion imaging.Background.Optimal management of patients with coronary artery disease involves strategies designed to reduce the risk of myocardial infarction and cardiac death. The role of myocardial perfusion imaging using newer clinical techniques to determine risk and possible benefit from therapy has not been evaluated.Methods.Myocardial imaging results were classified as normal or abnormal (fixed or reversible defects; small, moderate or large). Follow-up evaluation of all patients included the occurrence of cardiac death or nonfatal myocardial infarction and other cardiac-related hospital admissions.Results.During a mean (±SD) follow-up period of 12.8 ± 6.8 months in 512 patients, 25 had a cardiac event. Patients with abnormal perfusion had significantly more cardiac events than those with normal perfusion (22 vs. 3, p < 0.01). Patients with reversible defects had the highest event rates (8.6%), and those with normal study results had a very low event rate (1.4%). Large defects were strongly associated with more cardiac events and hospital admissions than either normal scan results or abnormal results showing small defects.Conclusions.Patients with normal study results or a small defect after intravenous dipyridamole Tc-99m sestamibi SPECT imaging had an excellent short-term prognosis. Those with abnormal results (reversible or large defect) had an increased risk of subsequent cardiac death, nonfatal myocardial infarction and other cardiac-related hospital admissions.

Studies using dobutamine thallium-201 myocardial perfusion imaging have suggested a high sensitivity and specificity for the detection of coronary artery disease. However, few data are available comparing dobutamine with exercise stress for the detection and localization of perfusion defects. This study compared the effects of dobutamine and exercise stress using technetium-99m sestamibi single-photon emission computed tomographic imaging in the same patients in a prospective crossover trial. Twenty-four patients with a high likelihood of coronary artery disease underwent tomographic myocardial imaging at rest, after symptom-limited treadmill exercise, and after intravenous dobutamine (maximum 30 μg/kg/min). Tomograms of the left ventricle were divided into 20 segments and were interpreted without knowledge of patient identity or stress protocol. Dobutamine was well tolerated by all patients. Segment-by-segment concordance between exercise and dobutamine images was highly significant (kappa = 0.56, p < 0.0001). Global first-order agreement (normal vs abnormal) between exercise and dobutamine studies was 96% (kappa = 0.65, p = 0.02); global second-order agreement (normal vs fixed vs ischemic defect) was 88% (kappa = 0.45, p = 0.02). Regional first-and second-order agreement were 96 and 93%, respectively (p < 0.001 for both). Twenty patients underwent coronary angiography. Comparisons between exercise and angiography and between dobutamine and angiography were similar for both global agreement (95 vs 100%, p = NS) and regional agreement (77 vs 72%, p = NS). In conclusion, technetium-99m sestamibi tomograms obtained after exercise and dobutamine stress in the same patients with a high likelihood of coronary artery disease show very similar results with regard to the identification, localization and reversibility of perfusion defects.

Many neoplastic tumors exhibit paraneoplastic syndromes manifested by endocrinopathy. This is particularly true of intrathoracic tumors such as lung cancers, thymomas, carcinoid tumors and mediastinal germ cell neoplasm. Fibrous tumors of the pleura are rare intrathoracic tumors, which are usually benign and often grow to huge size. A subset of these neoplasms present with the syndrome of hypoglycemia. Although first reported more than 70 years ago, the diagnosis is rarely considered when a patient presents with syncope and hypoglycemia. This article reports a patient who presented with a large pleural mass and a hypoglycemic syndrome. (The disease was surgically cured.) The probable mechanism of hypoglycemia is discussed.

We report a patient with tissue-proven sarcoidosis receiving adrenocorticosteroid medication, who developed an enlarging mediastinal mass. Transcutaneous needle biopsy of the mass yielded pus which grew Nocardia asteroides on culture. Pleural effusion, bronchoesophageal fistula and brain nocardia metastases occurred. All evidence of active infection cleared with sulfa therapy. An enlarging mass in a patient with sarcoidosis unresponsive to corticosteroid therapy should provoke studies for other causes of mediastinal disease, including opportunistic infections.

Beta-blocker therapy may delay or completely prevent myocardial ischemia during exercise testing, as assessed by ST-segment shifts, myocardial perfusion defects, or echocardiographic wall motion abnormalities. However, the impact of beta-blocker therapy on these end points during dobutamine stress testing has not been well established. The purpose of this study was to determine the impact of propranolol on dobutamine stress testing with ST-segment monitoring, technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) imaging, and echocardiography. In 17 patients with known reversible perfusion defects, dobutamine stress tests with and without propranolol were performed in randomized order and on separate days, following discontinuation of oral beta blockers and calcium antagonists. Propronolol was administered intravenously to a cumulative dose of 8 mg or to a maximum heart rate reduction of 25% and dobutamine was infused in graded doses in 3 minute stages until a standard clinical end point or the maximum dose of 40 microg/kg/min was achieved. The dobutamine stress test after propranolol was associated with a lower maximum heart rate (83 +/- 18 vs 125 +/- 17, p

We analyzed potential gender differences in the use and prognostic value of stress technetium 99m sestamibi tomography, image results, and cardiac event rates over a period of 15 +/- 8 months in 1226 men and 1151 women. Men had more abnormal tomographic images, but referral for catheterization and revascularization similarly increased in relation to the number of defects. Men and women with abnormal images had similar event rates, 19.6% and 18.2%, respectively, although men more often had myocardial infarction or cardiac death (7.6% vs 4.1 %, p0.05), whereas women had an increased likelihood of unstable angina or congestive heart failure (11.5% vs 7.6%, p0.05). Normal images predicted a low yearly rate of myocardial infarction or death: 1.7% for men and 0.8% for women. Image findings, particularly defect extent, were independent predictors of events in both groups. Thus, after stress Tc-99m sestamibi single-photon emission computed tomography perfusion imaging, there was no gender bias in referral for invasive procedures, and for both men and women image findings were strongly associated with prognostic outcome.

Although the presence of perfusion defects on stress myocardial perfusion imaging has been shown to correlate with future cardiac events, including acute myocardial infarction (AMI), it is unknown whether the location of the AMI can be predicted. Therefore, for 25 patients who had an AMI following a stress technetium-99m sestamibi single-photon emission computed tomographic (SPECT) imaging study and whose infarct location could be determined, the territory of infarction was correlated with the location of previous myocardial perfusion defects. A SPECT perfusion defect had been present in 24 patients (96%). The AMI occurred in territories that showed a reversible defect in 14 patients (56%), whereas 3 infarctions (12%) were in territories that revealed a fixed defect, and 8 infarctions (32%) were in territories that had not shown a defect on prior SPECT imaging. Whereas the incidence of infarction in territories with a reversible defect was highest at 14 of 26 (54%), the incidence of infarction in territories with a fixed defect was 3 of 7 (43%), and in territories with no defect was 8 of 42 (19%) (p = 0.011). Neither the time interval between SPECT imaging and infarction, nor the perfusion defect severity, was related to the correlation between perfusion defect and infarct location. Thus, although AMI occurs most often at the site of previous perfusion defects, reversible or fixed, a substantial percentage occur in territories without a perfusion defect. These findings suggest that abnormalities on SPECT perfusion imaging, although they serve as markers of significant coronary disease and increase the likelihood of infarction, do not always predict the exact location of infarction.

Pharmacologic stress has been shown in animal studies to induce high degrees of myocardial hyperemia. At these levels of myocardial blood flow, the myocardial uptake of technetium 99m sestamibi may plateau and may affect the diagnostic accuracy. This study compared the effects of myocardial hyperemia induced by exercise, dipyridamole, and adenosine on 99mTc sestamibi tomographic imaging in normal subjects and patients with ischemic coronary artery disease.Twenty subjects (group I, 10 normal subjects; group II, 10 patients with known coronary artery disease) underwent 99mTc sestamibi tomographic imaging after rest, exercise, dipyridamole infusion, and adenosine infusions on separate occasions. Total and background-corrected myocardial counts of the resulting images were calculated. Visual and computer-generated quantitative myocardial perfusion defect analysis was performed in subjects in group II. For subjects in both groups I and II, there were no significant differences in the background-corrected myocardial counts obtained with exercise, dipyridamole, and adenosine stress. There were no significant differences in the myocardial perfusion defects obtained after the three different modes of stress, including percentage defect size, stress deficit percentage, percentage of ischemia, count deficit index, and defect nadir.The myocardial uptake of 99mTc sestamibi in normal subjects and patients with coronary artery disease is comparable after exercise, dipyridamole, and adenosine stress. In addition, the defect sizes and intensities with 99mTc sestamibi after all forms of stress were equivalent. Thus 99mTc sestamibi, in combination with either adenosine or dipyridamole infusions, provides imaging data equivalent to those with exercise and may be considered an alternative in patients unable to undergo adequate exercise.

Optimal management of patients with coronary artery disease requires identification of those at greatest risk of future adverse cardiac events. The relationship between defect size after IV dipyridamole with Tc-99m Sestamibi SPECT imaging and cardiac events (death, MI) or need for other cardiac hospitalizations for CHF, unstable angina (UA) or late revascularization (REV) (g6 months after imaging) was evaluated in 512 pts followed for 12.8 ± 9.8 months. Defects were classified as small (Sml), moderate (Mod) or large (Lrg). Of 216 pts with normal scans, there were 3 cardiac events and 11 other cardiac hospitalizations. Of the 296 pts with abnormal scans, there were 22 cardiac events (Sml 1.5%, Mod 6.9%, Lrg 12.5%) and 51 other cardiac hospitalizations (Sml 6%, Mod 12%, Lrg 20%). An abnormal scan was a Download : Download high-res image (62KB) Download : Download full-size image significant and independent predictor of these events when compared with clinical variables. Multiple logistic regression analysis compared to normal scans (normal = 1.0) demonstrated that the defect size predicted a progressively increased likelihood of cardiac events as well as need for other cardiac hospitalizations (Figure). There was a low event rate with small defects (similar to normal scans) while the highest event rates occurred in patients with large defects. Conclusion Defect size with IV dipyridamole Tc99m Sestamibi SPECT myocardial perfusion imaging is an independent predictor of future cardiac events (death, Ml) and other cardiac hospitalizations. This information may have important implications regarding the selection of patients for interventions.

In six cases of giant cell tumor the magnetic resonance (MR) images obtained with various pulse sequences and field strengths were compared to the corresponding computed tomography (CT) scans and plain roentgenograms. MRI was superior to CT and plain films in demonstrating areas of tissue inhomogeneity within the tumor as well as soft tissue extension. CT was superior in demonstrating cortical thinning. Multiplanar imaging capability and visualization of articular cartilage may demonstrate intra-articular tumor spread. The characteristic MRI findings with short TR/TE (T1-weighting) and long TR/TE (T2-weighting) are described. We also describe one case where serial MR scans were used to assess response to therapy.

The authors report magnetic resonance (MR) studies in a case of papillary renal cell carcinoma. The preoperative ultrasound and computed tomographic scans suggested either a hemorrhagic cyst or a carcinoma, but the angiogram demonstrated avascularity. The magnetic resonance scan was more consistent with carcinoma than complicated cyst. We report the MR findings with pathologic correlation.

Sonography detected a paraaortic pulsatile tubular mass in a patient 10 years after “stump” nephrectomy, which was subsequently confirmed as a renal artery-renal vein fistula by computed tomography, angiography, and laparotomy.

An 84-year-old man, who had had a colostomy and abdominopermeal resection for rectal carcinoma 3 years earlier, was being evaluated for possible recurrent tumor in the presacral space. The CT scan showed an irregular soft-tissue mass in the operative bed suspicious for recurrent tumor (fig. 1A). MRI using a Fonar 0.3-T nonsuperconductive magnet was performed with a slice thickness of 9 mm and slice interval of 12 mm. Transverse scans were obtained using the spin-echo (SE) pulse sequence with a repetition time (TA) of 2000 msec and echo times (TE) of 28 and 56 msec. Sagittal views wereobtained using SE 2000/28, SE 2000/56, and inversion recovery (IA) with 1500 msec TA, 310 msec TI (inversion time), and 28 msec TE. A discrete nodule 2.0 cm in diameter, which was hypointense in comparison with the surrounding parenchyma, was seen in the left lateral lobe of the prostate on the SE 2000/28 scan only (fig. 1B). The nodule could not be identified retrospectively on the CT scan at comparable transverse levels. The patient was already scheduled for CT-9uided fine-needle aspiration for cytology of his suspected recurrent tumor mass, so we decided to do a biopsy of the prostatic nodule at the same time, even though we could not see it on CT. Using the bony and soft-tissue landmarks from the transverse MA scan at the level ofthe nodule, we placed the needle into the expected location of the mass using CT guidance (fig. 1A). Cytology on the aspirates were conclusive for malignancy from both locations. The recurrent tumor mass was well differentiated adenocarcinoma, and the prostatic nodule was moderate to poorly differentiated adenocarcinoma.

While the presence of ischemia on stress myocardial perfusion imaging has been shown to correlate with a future myocardial infarction (MI), it is unknown whether the location of the ischemia predicts the location of the subsequent MI. Therefore, 24 patients (83% male, mean age: 66 ± 13 yrs, 46% exercise, 54% pharmacologic stress) who had an enzyme proven myocardial infarction following a stress Tc-99m sestamibi (MIBI) SPECT imaging study were analyzed. The location of the MI, as determined by either standard electrocardiographic criteria, or by a new wall motion abnormality on echocardiography or contrast ventriculography, was related to the location of a reversible defect on the preceding stress/rest MIBI images. Two territories per patient—anterior (including anterolateral and anteroseptal) and inferior (including inferolateral and inferoseptal)—were assessed for the presence of a reversible defect, and for the location of the subsequent MI. In 5 patients, the location of the MI could not be determined, leaving 38 territories in the remaining 19 pts for analysis: Download : Download high-res image (66KB) Download : Download full-size image Of 19 territories with a reversible defect, 9 (47%) were the site of a subsequent MI, compared with 3 (50%) of 6 territories with a fixed defect, and 6 (46%) of 13 territories with no defect (p = NS). The remaining patient had a lateral MI after MIBI images had shown a reversible apical defect. Thus, 10 (53%) of the 19 Ml's occurred in a territory that did not show ischemia on the preceding MIBI images. Conclusion The location of ischemia on a stress Tc-99m sestamibi SPECT imaging study does not consistently predict the location of a future myocardial infarction. This is in accord with previous findings from coronary angiography that the most severe stenoses frequently do not correlate with the locations of subsequent infarctions.

To evaluate the effectiveness of structured nuclear cardiology training. the reproducibility and accuracy of image interpretation by nuclear cardiology faculty and senior cardiology fellows were compared. The reproducibility and accuracy of 3 faculty and 3 trainees with 6 months training following Nuclear Regulatory Commission/American College of Cardiology guidelines were assessed using 138 exercise Tc-99 m Sestamibi SPECT studies. Studies were randomly selected and included patients with l 5% likelihood of CAD as well as patients with angiographically demonstrated single and multivessel disease. Studies were interpreted twice by each reader without knowledge of clinical or exercise data. Each reader classified perfusion as normal (N) or abnormal (AB). AB perfusion was further classified as fixed (F) or ischemic (I). Reproducibility was compared with respect to first order (N vs AB) and second order (N vs F vs I) intra and inter observer agreement and assessed using percent agreement (%) and Cohen's kappa. Accuracy was assessed using sensitivity and normalcy rate and compared using percent agreement and Cohen's kappa. Trainees Faculty % kappa % kappa Reproducibility First order Intra: 89 0.78 92 0.82 inter: 80 0.59 86 0.71 * Second order intra: 81 0.66 87 0.74 * inter: 69 0.46 82 0.64 * Accuracy Sensitivity 82 87 Normalcy Rate 85 89 % agreement/kappa 83 063 87 0.73 * * p l 0.05 compared with trainees Trainees had high reproducibility and accuracy. comparing favorably with faculty in all categories. Faculty had significantly higher results in several categories. Conclusion Structured training in nuclear cardiology following Nuclear Regulatory Commission/American College of Cardiology guidelines during clinical cardiology fellowship is very effective. resulting in high reproducibility and accuracy. Interpretive skills can be expected to further improve with experience.