The prognostic significance of stress-only myocardial perfusion scan: A 5 year observational study.

OBJECTIVE: Stress-only myocardial perfusion imaging protocol has a prognostic value similar to that of a stress-rest protocol. The aim of the study was to assess stress myocardial perfusion by gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (GSMPI) in patients who had a normal stress-only study 4.9 years (mean time) before and assess the possible influence of various factors on the results. SUBJECTS AND METHODS: Three hundred and forty patients who had a normal stress-only study in the past, were reexamined with GSMPI after a mean period of 4.9 years. RESULTS: Thirty out of 340 patients (8.8%) had an ischemic result on stress and were therefore submitted to a rest study. Differences between normal and pathological results across levels of potential prognostic factors (age, gender, diabetes mellitus, dyslipidemia, arterial hypertension, smoking and family history), symptoms,left ventricular ejection fraction (LVEF) on ultrasound (U/S), coronary angiography and pre-test probability did not prove statistically significant. On multivariable analysis patients with the combination of family history, diabetes mellitus and hypertension had a 10.7 times higher risk of a pathological scan than the patients without. DISCUSSION: The information delivered by stress-only GSMPI proved to be a prognostically reliable method for follow-up of low and intermediate pretest probability coronary artery disease (CAD) patients. CONCLUSION: The 91.2% of the patients with an initial normal stress-only GSMPI had a repeat normal stress-only GSMPI after a mean period of 4.9 years. The combination of family history, diabetes mellitus and hypertension increases the risk of a pathological scan significantly.

I-131 Postablation SPECT/CT Predicts Relapse of Papillary Thyroid Carcinoma more Accurately than Whole Body Scan.

BACKGROUND/AIM: The aim of the study was to prospectively compare I-131 postablation Whole Body scan (WBS) and Single Photon Emission Computerized Tomography/Computerized Tomography (SPECT/CT) scan on thyroid cancer patients. PATIENTS AND METHODS: Overall, 58 patients with papillary thyroid carcinoma were submitted to total thyroidectomy and I-131 remnant ablation. Post-ablation WBS and SPECT/CT scans performed on the same day were compared. Results of SPECT/CT were confirmed by neck and upper mediastinum ultrasound scan and on specific cases by a fully diagnostic CT scan, other tests and definitive histology acting as the gold standard. A total of 36/58 patients were followed-up for 5 years to detect relapse. RESULTS: Mac Nemar Chi square and Fisher's exact tests disclosed statistically significant differences between WBS and SPECT/CT scan, concerning cervical lymphadenopathy detection (p=0.031) and relapse prediction by NM stage (p=0.033), respectively; SPECT/CT was more accurate in both comparisons. CONCLUSION: In papillary thyroid carcinoma I-131 post-ablation SPECT/CT scan detects cervical lymphadenopathy and predicts relapse by NM stage more accurately than WBS.

Gender-related differences in side-effects and hemodynamic response to regadenoson in patients undergoing SPECT myocardial perfusion imaging.

PURPOSE: To evaluate differences in side-effects and hemodynamic response between men and women undergoing regadenoson-stress SPECT myocardial perfusion imaging (MPI). METHODS: The initial population of the study included 858 consecutive patients who underwent regadenoson-stress MPI at our institution. These patients underwent prospective assessment and classification of regadenoson-induced side-effects in six categories and recording of heart rate (HR) and blood pressure (BP) before and after regadenoson administration. From this initial population, after adjustment with 1:1 propensity matching using gender as the dependent variable and age, BMI, diabetes mellitus, hypertension, smoking, presence of coronary artery disease, LVEF, baseline systolic and diastolic blood pressure (BP) and HR, on-going use of cardio-active medications during test, and abnormal MPI scan as independent variables, a population of 279 pairs of opposite gender was formed and studied. RESULTS: Compared with men, women had a significantly higher rate of any side-effect (71% vs. 58%, p = 0.002), chest pain (23% vs. 12%, p < 0.001), gastrointestinal discomfort (20% vs. 12%, p = 0.01), dizziness (12% vs. 5%, p = 0.002), and headache (20% vs. 13%, p = 0.03) and similar rates of dyspnea and other side-effects. Women demonstrated a higher median HR-response compared with men (41% (- 8, 127) vs. 34% (- 5, 106), p = 0.001) while men demonstrated a lower median systolic BP response (- 3% (- 27, 48) vs. 0% (- 36, 68), p = 0.02) compared with women. CONCLUSIONS: Gender is independently associated with a differential response to regadenoson with regard to overall side-effects and HR-response. These observations have the potential of important management and prognostic implications respectively.

SPECT and PET imaging in Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia. Beta-amyloid (Aß) deposition and neurofibrillary tangles (NFTs) of abnormal hyperphosphorylated tau protein are the pathological hallmarks of the disease, accompanied by other pathological processes such as microglia activation. Functional and molecular nuclear medicine imaging with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) techniques provides valuable information about the underlying pathological processes, many years before the appearance of clinical symptoms. Nuclear neuroimaging in AD has made great progress in the past two decades and has extended beyond the traditional role of brain perfusion and glucose metabolism evaluation. Intense efforts in radiopharmaceuticals research have led to the development of various probes able to detect Aß deposits, tau protein accumulation, microglia activation and neuroinflammation. As a result, SPECT and PET have proposed to serve as biomarkers in recently revised diagnostic clinical criteria for the early diagnosis of AD and the prediction of progression to AD in mild cognitive impairment (MCI) subjects.

Internal Auditory Canal Tumor as an Incidental Finding on a Choline PET/CT Scan in a Prostate Cancer Patient.

An 84-year-old man with a history of prostate cancer, treated with radiotherapy, presented with an increase in PSA levels. F-choline PET/CT showed foci of increased choline uptake in L4 and L5 vertebrae, suggestive of bone metastases and another focus in the right cerebellopontine angle. A brain MRI revealed a focus of intense contrast enhancement in the same region, consistent with an acoustic neuroma.

Although Non-diagnostic Between Necrosis and Recurrence, FDG PET/CT Assists Management of Brain Tumours After Radiosurgery.

AIM: To re-evaluate the role of (18)F-fluoro-deoxy-D-glucose (FDG) positron emission tomography/ computer assisted tomography (PET/CT) co-registered with magnetic resonance imaging (MRI) in differentiating adverse radiation effect (ARE) from tumour recurrence after Gamma Knife radiosurgery of brain tumours. PATIENTS AND METHODS: Twenty-seven PET/CT studies co-registered with MRI were performed on 16 patients after radiosurgery, with 12/16 patients having multiple radiosurgery treatments. Long term follow-up was used for evaluation, with 3/16 patients being histopathologically confirmed. RESULTS: PET/CT was positive in all studies in 6/16 patients, negative in all studies in 6/16 and changed from negative to positive in one. In 2/16 patients, PET/CT was both positive and negative in separate tumour foci. In 9/16 cases with a positive PET/CT, tumour was confirmed. In 6/16 patients with a negative PET/CT, 3/6 had recurrence and 3/6 ARE. In 1/16, equivocal results became negative after retreatment. PET/CT/MRI identified tumour within ARE. Sensitivity of PET/CT/MRI proved to be 64.7%, and specificity 100%. CONCLUSION: PET/CT/MRI assists management, by revealing metabolism rather than histology.

Reticuloendothelial system involvement in untreated sarcoidosis patients as assessed by 18F-FDG PET scanning.

Not available.

The value of successive Infecton scans in assessing the presence of chronic bone and joint infection and in predicting its evolution after treatment and after a prolonged follow-up.

OBJECTIVE: Our objective was to monitor the evolution of bone and/or joint infections with the aid of successive radiolabelled ciprofloxacin (Infecton) scans during antimicrobial treatment and to compare the results of an Infecton scan at the end of therapy with the respective results of clinical evaluation, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in predicting resolution or recurrence of infection after a long period of posttreatment follow-up. METHODS: Thirty-three patients with documented bone and/or joint infection were subjected to successive Infecton scans on two or three visits. Infecton scans were evaluated visually and scored accordingly. Clinical evaluation was scored by the referring clinicians. ESR and CRP values were evaluated independently. A minimum of 2-year free-of-infection follow-up after discontinuation of the antibiotic treatment served as a measure of successful antimicrobial therapy and nonrecurrence of infection. Statistics included survival analysis (Cox regression). RESULTS: During follow-up, five patients in the study presented with recurrence, and three died as a result of an irrelevant cause. The remaining patients were followed up for a median of 108 months (range 97-132 months) without any signs of recurrence of infection. Recurrence of infection was 4.2 times more likely to occur in patients with positive Infecton scans [hazard ratio (HR): 4.2, confidence intervals 95%: 1.39-12.67, P=0.011]. Infecton had the highest sensitivity (83.3%), accuracy (69.69%) and negative predictive value (94.74%), whereas CRP had the highest specificity (76.92%). CONCLUSION: Infecton scintigraphy proved to be more sensitive and accurate and had a higher negative predictive value compared with clinical evaluation, ESR and CRP in predicting infection resolution or recurrence in patients with chronic bone and joint infections.

Is sentinel node mapping useful in anorectal melanoma?

Anorectal melanoma (AM) is a rare disease and few guidelines have been established regarding its therapeutic management. Wide local excision, or less frequently, abdominoperineal resection is the treatment of choice. We present a female patient with an excised AM who was submitted to our Nuclear Medicine department for sentinel lymph node (SLN) mapping of the area. Under rigid proctoscopy the anal scar received four submucosal injections of technetium-99m-sulfur nanocolloid of 29.6 MBq each. Lymphoscintigraphy and intraoperative gamma-probe guided detection of the SLNs followed. SLNs were localized in the inguinal basins bilaterally and were negative on histology. A wide local excision followed the above test. Thirty months postoperatively the patient developed distant metastases, underwent radiotherapy and died six months later. Without changing prognosis sentinel lymph node detection, excision and histology were important in sparing the patient a futile inguinal lymph node dissection.

Negative gallium-67 citrate and positive positron emission tomography/computed tomography spleen scans, in Hodgkin's stage IV lymphoma.

An 18-year-old male patient with Hodgkin's lymphoma stage IVB (HL-IVB), is presented. On a follow-up examination a splenic ultrasound scan showed the presence of multiple intense nodules. The gallium-67 citrate, single photon emission tomography scan was negative, while positron emission tomography/computerized tomography (PET/CT) scan with fluoro-18-fluordeoxyglucose was strongly positive. Massive infiltration of the spleen by HL-IVB tissue was confirmed by pathology after splenectomy. Two successive PET/CT studies for follow-up purposes three and twelve months after completion of chemotherapy, were normal.

99mTechnetium-ciprofloxacin scintigraphy for the evaluation of spinal infections: a preliminary report.

UNLABELLED: Currently available laboratory and imaging tests have limitations diagnosing and following patients with spinal infections. We evaluated 17 Technetium-99m labeled ciprofloxacin scintigraphy studies in 11 patients who had the diagnosis of a spinal infection based on the Centers for Disease Control and Prevention criteria. Three of the 17 studies were performed in three patients within 2 months from the onset of the symptoms. All of these three studies showed increased uptake of the radiopharmaceutical in the area of the spinal infection. Fourteen studies were performed during the followup period (from 210 to 690 days after the onset of symptoms) in nine patients with spinal infections. Ten of the 14 studies performed in five patients with an active spine infection showed positive results while the patients had evidence for active spinal infection at the time of the testing. Four studies were performed during the followup period in four patients who at the time of the nuclear imaging testing had no symptoms, signs, or laboratory or other imaging evidence for active infection. All four studies showed negative results. The results of this preliminary study show that scintigraphy with 99mTc-ciprofloxacin may be useful in the diagnosis of active spinal infections. LEVEL OF EVIDENCE: Diagnostic study, level II-1 (Testing of previously developed diagnostic criteria on consecutive patients [with universally applied reference "gold" standard]). Please see Guidelines for Authors for a complete description of levels of evidence.