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Background: Attenuation correction (AC) has been shown to improve the accuracy of myocardial perfusion single photon emission computed tomography (SPECT) for the detection and evaluation of patients with coronary artery disease. Attenuation artifacts, because of diaphragmatic attenuation, frequently affect the evaluation of the inferior wall, especially in male patients., Purpose: The aim of this study was to evaluate the value of AC for the assessment of infarct size in coronary artery disease patients after inferior myocardial infarction., Materials and Methods: Gated-SPECT with Tc-labeled compounds with AC by hybrid SPECT/computed tomography (CT) was performed in 56 male patients with documented previous inferior myocardial infarction. Both corrected and uncorrected SPECT images were processed after motion and scatter correction by ordered-subset expectation maximization iterative reconstruction. When needed, a manual realignment between SPECT and computed tomography (CT) sections was performed. Uncorrected and corrected SPECT images were analyzed for perfusion using a 5-point segmental scoring scale from 0 (normal) to 4 (absent). Summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) of the inferior left ventricle wall (inferoseptal, inferior, infero-apical and infero-lateral segments) were determined and compared with the regional wall motion score as determined by uncorrected gated-SPECT., Results: The SSS, SRS, SDS for attenuation-uncorrected and attenuation-corrected studies were 14.02 ± 7.9, 9.51 ± 7, 4.5 ± 3.2 and 9.39 ± 7.1, 5.6 ± 6.1, 3.8 ± 2.8, respectively. Differences were statistically significant (P<0.0001) for SSS and SRS but not for SDS. The regional summed rest score of the inferior wall (SRS of inferior segments) showed a better correlation with the regional summed wall motion score of the same segments: R²=0.50 in comparison to uncorrected SRS, R²=0.46., Conclusion: The combination of diaphragmatic attenuation and inferior myocardial infarction determines an artifactual overestimation of infarct size of inferior infarcts. The AC regional perfusion score (SRS) correlates with the regional wall motion score of the inferior wall. AC does not affect the detection and size of residual ischemia (SDS).

Purpose: In clinical myocardial single photon emission computed tomography (SPECT), attenuation artefacts may cause a loss of specificity in the identification of diseased vessels that can be corrected by means of gated SPECT (GSPECT) acquisition or CT attenuation correction (AC). The purpose of this multicentre study was to assess the impact of GSPECT and AC on the diagnostic performance of myocardial scintigraphy, according to patient's sex, body mass index (BMI) and site of coronary artery disease (CAD)., Methods: We studied a group of 104 patients who underwent coronary angiography within 1 month before or after the SPECT study. Patients with a BMI>27 were considered "overweight". Attenuation-corrected and standard GSPECT early images were randomly interpreted by three readers blinded to the clinical data., Results: In the whole group, GSPECT and AC showed a diagnostic accuracy of 86.5% (sensitivity 82%, specificity 93%) and 77% (sensitivity 75.4%, specificity 81.4%), respectively (p<0.05). In women, when anterior ischaemia was matched with CAD, AC failed to show any increase in specificity (AC 63.6% vs GSPECT 63.6%) with evident loss of sensitivity (AC 72.7% vs GSPECT 90.9%). AC significantly improved SPECT specificity in the identification of right CAD in overweight men (AC 100% vs GSPECT 66.7%, p<0.05)., Conclusion: AC improved specificity in the evaluation of right CAD in overweight men. In the other evaluable subgroups specificity was not significantly affected while sensitivity was frequently reduced.

¹¹¹In-Pentetreotide SPECT/CT scan has been widely validated in diagnosis and follow-up of carcinoid and other neuroendocrine tumors. A 70-year-old man, who underwent an ileal resection for carcinoid 5 years ago, came to our observation during follow-up. We performed a In-DTPA-Pentetreotide (150 MBq) SPECT/CT scan. Images taken after 2 hours showed a focal, pathologic uptake on the left leg, confirmed at later acquisitions. Lateral projection showed that the uptake area was located in a leg muscle; the lesion was confirmed as an intramuscular metastasis by biopsy. Intramuscular metastasis of carcinoid tumors is an extremely rare manifestation, particularly if not adjacent to the primary tumor, because the muscle is a very uncommon location of hematogenous metastases.

Background: The aim of this study is the 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) evaluation following radioimmunotherapy (RIT) with ibritumomab tiuxetan Y 90 in patients with non-Hodgkin's follicular lymphoma (FL)., Materials and Methods: We retrospectively analyzed data from 59 relapsed or refractory FL patients treated with ibritumomab tiuxetan Y 90 in four different PET centers who had a PET scan carried out before and after RIT. Possible predictive factors of progression-free survival (PFS) were studied through univariate and multivariate analysis., Results: The post-RIT PET documented 45.8% complete responders (CR), 25.4% partial responders (PR) and 28.8% nonresponders [stable disease + progressive disease], with an overall survival of 71.2% (range 59.5%-90.9%). With a median follow-up period of 23 months, the univariate analysis documented a statistically significant relation between disease extent before RIT and response to treatment with respect to PFS (P = 0.015), while all the other prognostic factors showed no significant correlation. When carrying out the multivariate analysis, post-RIT PET resulted as the lonely independent predictor of PFS (P < 0.00001)., Conclusions: RIT is an effective therapy in FL patients, as confirmed in our study too. Disease extension before treatment and response to RIT, as assessed by FDG-PET, result as main predictors of PFS, with the post-RIT PET result being the only independent predictive factor.

Aim: Treatment of toxic nodular goiter with ¹³¹I is a first-line therapy for hyperthyroidism. To avoid a thyrotoxic storm, ¹³¹I is usually administered after pretreatment with antithyroid drugs, with thyroid-stimulating hormone (TSH) increase and functional recruitment of inhibited normal tissue. Therefore, both autonomous nodule(s) and normal tissue are irradiated. This may be a reason for late hypothyroidism occurring in 15-25% of patients. This study aimed at assessing different pretreatment modalities with combined methymazole and triiodothyronine, achieving euthyroidism with suppressed TSH., Methods: After diagnosis of autonomously functioning toxic nodule, patients were subjected to thyrostatic medication. Two months later, TSH was checked; if >0.5 mU/L triiodothyronine treatment was associated. After 2 more months, if the TSH level was suppressed, patients received ¹³¹I-therapy. A total of 149 patients were consecutively enrolled, 41 of whom with uninodular and 108 with multinodular goiter. They were evaluated at diagnosis, pretreatment, 3 and 6 months after therapy and at late follow-up (6.8+/-4.2 years; range: 1-22 years)., Results: Administered activity was calculated according to ¹³¹I uptake and gland weight. Methymazole was discontinued 6 days before treatment and T3 was maintained until administration of ¹³¹I-therapy. Euthyroidism was achieved in 88% of patients. At late follow-up, subclinical hypothyroidism was observed in 10 patients (6.7%) and overt hypothyroidism in 5 patients (3.3%). No pathological consequences or side effects of ¹³¹I-therapy were found during the 6.8+/-4.2 year follow-up period., Conclusion: Treatment of toxic nodular goiter with ¹³¹I-therapy, under combined thyrostatic-thyromimetic treatment is a simple, safe, well-tolerated, and effective procedure.

Spondylodiscitis (SPD) is an inflammatory process of the intervertebral disc space. We report two cases of patients affected by SPD evaluated by fluorine-18 fluorodesoxyglycose positron emission tomography/computed tomography, which was useful in detecting SPD and supporting differential diagnosis.

Lynch syndrome (LS) is the most common hereditary syndrome that predisposes patients to colorectal cancer, and it accounts for 2-5% of the total burden of colorectal cancer. We report a case of a 61-year-old female affected by Lynch syndrome who underwent multiple adenocarcinoma resections, studied by F18-FDG-PET/CT for 5 years. This case report suggests a potential role of F18-FDG-PET/CT in the evaluation of patients affected by Lynch syndrome.

Neurofibromatosis type I (NF1) is an autosomal dominant multisystem disorder. Patients with NF1 are at increased risk for developing both benign and malignant tumours. We report the case of a patient with histologically documented NF1, who underwent F18-FDG-PET/CT for staging purposes. The study revealed intense uptake at multiple masses located at the thighs (the largest presented SUV max of 6.8), popliteal regions, legs, left foot, left supraclavicular region, and at the thoracic wall between the 11th and 12th right ribs. The surgical biopsy of the largest popliteal lesion with higher uptake at F18-FDG-PET/CT documented the presence of a malignant schwannoma at histological examination. In conclusion, F18-FDG-PET/CT was probably able to help the discrimination between benign lesions related to known NF1 and the malignant transformed ones, and to assist clinical decision making.

Background: Gastrointestinal stromal tumours (GISTs) are a subset of mesenchymal tumours that represent the most common mesenchymal neoplasms of the gastrointestinal (GI) tract and account for less than 1% of all gastrointestinal tumours., Material and Methods: We retrospectively evaluated 19 patients (6 females and 13 males; median age: 61 years ± 15 standard deviation) affected by GIST histologically documented after surgical intervention or biopsy., Results: F18-FDG-PET/CT had identified pathologic uptakes and was considered positive for neoplastic tissue in 10 patients (53%) and negative in 9 (47%), in concordance with radiological findings., Conclusions: F18-FDG-PET/CT is a feasible, reliable, and accurate method to restage patients affected by previously histologically confirmed GIST, also in the absence of a staging study.

The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure.

Purpose: The aim was to evaluate the incremental diagnostic rate of F-18 fluoro-fluorodeoxygulose positron emission tomography/computed tomography (F-18 FDG-PET/CT) in patients with negative I-131 whole body scans and high Tg levels. The secondary end points were correlations between F-18 FDG-PET/CT positive results and Tg levels and comparison between F-18 FDG-PET/CT accuracy in patients "on-therapy" with suppressed thyroid stimulating hormone (TSH) and those with high TSH levels., Methods: We studied 52 patients who had undergone total thyroidectomy and remnant ablation; they had high Tg levels (average = 156 ng/mL; SD +/- 274) after 3 weeks of levothyroxine withdrawal and negative I-131 total body scans after therapeutic doses., Results: We noted a statistically significant positive correlation between F-18 FDG-PET/CT positive results and Tg levels, irrespective of levothyroxine therapy regimen. Tg levels between F-18 FDG-PET/CT positive/negative groups were significantly different and we did not note any statistically significant correlation between F-18 FDG-PET/CT results and TSH levels, tumor size, and combination of Tg/TSH levels., Conclusions: Our results indicate that F-18 FDG-PET/CT is a useful diagnostic tool in patients with differentiated thyroid carcinoma and with negative I-131 total body scans and high Tg levels. The levothyroxine therapy regimen does not influence F-18 FDG-PET/CT results and the rate of F-18 FDG-PET/CT positive results appears to correlate with the Tg levels. The highest accuracy is reached when the study is performed for patients with Tg levels higher than 21 ng/mL.

Background: In 1968, the Harvard criteria for brain death diagnosis were introduced in clinical practice. These include no movements or breathing, no reflexes, and flat electroencephalogram in the absence of confounding factors, including hypothermia, drugs, electrolyte, and endocrine disturbances. When confounding factors occur, confirmatory tests documenting the absence of cerebral blood flow, such as cerebral angiogram, transcranial Doppler sonography, computed tomography angiography, and nuclear techniques, are required., Aim: The aim of this study was to evaluate the clinical value of single-photon emission computed tomography (SPECT) with technetium-99m (Tc)-ECD in the diagnosis of brain death in a cohort of patients with confounding factors. Fifty-two patients were studied between 1 January 2000 and 23 September 2008. The criteria for the request for Tc-ECD SPECT were sodic thiopental withdrawal after less than 24 h, unreceptivity and unresponsivity of brainstem reflexes, anesthesia in the last 24 h, hypothermia, anamnesis for barbiturate use, electroencephalogram artefacts, toxic state, and pediatric criteria. All patients underwent Tc-ECD SPECT using a dual-headed camera fitted with a high-resolution low-energy collimator. Images were reconstructed and processed according to standard procedures and interpreted qualitatively by two experienced observers., Results: The presence of spots of residual brain viability was observed in 13 patients: 25% of our patient cohort. The patients with residual viability were younger (aged 30.92+/-17.28 years) in comparison with those with no viability (41.91+/-18.77 years, P<0.031). Considering the eligibility for transplantation, there were 12 of 13 patients in the residual viability group and 31 of 39 in the no viability group (P<0.0001). All patients with spots of brain uptake were monitored daily by Tc-ECD SPECT, and all of them reached the condition of empty skull after one or multiple studies. The opposition to organ donation was observed in six of 13 patients with spots of viable brain tissue and in three of 39 with no signs of residual viability (P<0.001)., Conclusion: In patients with confounding factors in whom brain death diagnosis is equivocal, Tc-ECD SPECT is a helpful and safe diagnostic approach, allowing a three-dimensional evaluation of cortical and brainstem viability. It guarantees an unequivocal diagnosis of brain death for patients who are potential candidates for organ donation. The persistence of viable spots of brain tissue was found in 25% of our patients and was more frequent in young patients. This affects the opposition to donation.

Medullary thyroid carcinoma (MTC) is rare derived from C cells of the thyroid gland and represents approximately 5% of all thyroid carcinomas. We report a case of a 74 years old male with MTC, diagnosed in 2002 and treated with total thyroidectomy and lymphadenectomy. A metastatic lesion was diagnosed on the right ventricle by indium-111-octreoscan, fluorine-18-fluorodeoxyglucose-positron emission tomography/computerized tomography, echocardiography, magnetic resonance imaging, high resolution computed tomography and was confirmed by histopathology. We present the results of treatment of this patient with yttrium-90-DOTA-tyr(3)-octreotide.

Although some clinical and radiological features may predict malignancy presence in intraductal papillary mucinous pancreas neoplasms, preoperative diagnosis remains difficult. In this study we present 7 patients with Intraductal Papillary Mucinous Neoplasm (IPMN) studied both with 18FDG-PET and magnetic resonance cholangiopancreatography (MRCP). A focal hypermetabolism was documented in 2 patients (the standardized uptake value in the neoplastic foci was 6.7 and 9), while absence of FDG uptake in the neoplasm area was recorded in the remaining 5 cases. Mean follow-up was 27 months (range 21-34). The final judgement was benign IPMN in 5 cases and malignant IPMN in 2. PET scan always correctly predicted the presence or absence of malignancy, while MRCP failed to detect malignancy in 3/7 cases. In conclusion, this preliminary experience suggests that 18FDG-PET may prove useful for malignancy detection in IPMN, improving differential diagnosis with benign intraductal papillary growth by functional data.

Purpose: The aim of this study was the evaluation of septal wall motion, perfusion and wall thickening after CABG in two groups of consecutive patients, one with grafted left anterior coronary artery and no history of myocardial infarction, and the other with previous anteroseptal myocardial infarction and impaired septal motion before surgery. The issue addressed was the ability of gated SPECT to differentiate between true paradoxical septal motion, characterised by paradoxical wall motion, depressed ejection fraction (EF), poor viability and compromised wall thickening, and pseudo-paradoxical motion, characterised by abnormal wall motion and regional EF but preserved perfusion and wall thickening., Methods: One hundred and thirty-two patients with previous anterior myocardial infarction, 82 patients with left anterior descending coronary disease and no history of myocardial infarction and 27 normal subjects underwent rest gated SPECT after 99mTc-sestamibi injection, according to the standard QGS protocol. Quantitative regional EF, regional perfusion, regional wall motion and regional wall thickening were determined using a 20-segment model., Results: Despite the presence of similar regional wall motion impairment in patients with and patients without septal infarction, in terms of regional EF (2.5%+/-3% vs 1.9%+/-4.9% p=NS) and inward septal motion (3+/-4.9 mm vs 2.3+/-6.1 mm p=NS), significant differences were observed in both perfusion (74.7%+/-6.2% vs 63.3%+/-13%, p>0.0001) and regional wall thickening (17.2%+/-7.4% vs 12.6%+/-7.2%, p>0.0001)., Conclusion: Gated SPECT with perfusion tracers can reliably differentiate pseudo-paradoxical from true paradoxical septal motion in patients with previous CABG, and it may be the method of choice for evaluating left ventricular performance in this patient population.