Amparo García-Burillo

Simultaneous dipyridamole/maximal subjective exercise with 99mTc-MIBI SPECT: improved diagnostic yield in coronary artery disease.

OBJECTIVES We attempted to demonstrate that simultaneous dipyridamole administration and maximal subjective exercise in patients who are unable to achieve a good exercise level can improve the diagnostic efficacy of technetium-99m methoxy isobutyl isonitrile (99mTc-MIBI) myocardial single-photon emission computed tomography (SPECT). BACKGROUND The results of myocardial perfusion scintigraphy are unsatisfactory if the level of exercise achieved by the patient is insufficient. The use of dipyridamole with maximal subjective stress testing has been shown to improve the quality of the thallium-201 myocardial perfusion images, but there are no studies demonstrating that this combination improves the diagnostic accuracy of myocardial perfusion SPECT. METHODS Two hundred thirty-one consecutive patients, without a previous myocardial infarction, were classified into three groups: group 1, 91 patients with an adequate exercise test; group 2, 68 patients with an inadequate exercise test; group 3, 72 patients with an inadequate exercise test who then received intravenous dipyridamole (0.56 mg/kg body weight over 4 min) simultaneously with exercise. RESULTS Results for sensitivity (89%) and negative predictive value (83%) in group 3 were significantly better than those in group 2 (71% [p = 0.03] and 56% [p = 0.002], respectively) and not significantly different from those in group 1. The polar maps of 20 patients studied with an without dipyridamole at the same exercise level revealed a significantly greater extent of ischemia in each territory and in a global assessment (19 + 20% vs. 8 + 11%, p < 0.0001) when dipyridamole was administered during physical exercise. CONCLUSIONS Intravenous dipyridamole administration during exercise testing is advisable in all patients who are unable to achieve an adequate exercise level. This approach permits physicians to avoid missing ergometric information while optimizing myocardial SPECT results.

Intimal injury in a transiently occluded coronary artery increases myocardial necrosis. Effect of aspirin

This study tested the hypothesis that intimal injury in a transiently occluded coronary artery limits myocardial salvage. The effect of intimal injury on reactive hyperaemia was investigated in 17 pigs submitted to a 30-min occlusion of the left anterior descending coronary artery (LAD), not resulting in myocardial infarction. Catheter-induced intimal damage increased local platelet deposition (99mTc) and reduced hyperaemia, but did not modify myocardial platelet or polymorphonuclear leucocyte content (myeloperoxidase activity) after 6 h reperfusion. To investigate the influence of intimal injury on the extent of myocardial necrosis secondary to a more prolonged coronary occlusion, and the role of platelets on this influence, 52 pigs were submitted to a double randomization (2×2 factorial design) to 250 mg i.v. aspirin vs. placebo and to coronary intimal injury vs. no coronary damage before a 48-min occlusion of the LAD and 6 h of reperfusion. After excluding 12 animals with reocclusion, coronary intimal injury was associated with larger infarcts (triphenyltetrazolium reaction) in animals receiving placebo (36.2±7.0% of the area at risk in animals with intimal injury vs. 10.8±3.9% in animals without coronary injury, P=0.006) but not in those receiving aspirin (20.3±6.5 vs. 21.7±6.5% of the area at risk in animals with and without intimal injury respectively). These results suggest that coronary intimai injury in the reperfused artery may have adverse effects on myocardial salvage by mechanisms other than reocclusion or embolization of platelet aggregates.

Differential uptake of myocardial perfusion radiotracers in normal, infarcted, and acutely ischemic peri-infarction myocardium

OBJECTIVES We measured the uptake of technetium-99m tetrofosmin (99m Tc) and thallium-201 (201 TI) in areas of healed transmural myocardial infarction and in the regions of acute peri-infarction ischemia. METHODS Anesthetised pigs with a 1-month old transmural infarction elicited by permanent ligature of the left anterior descending (LAD) coronary artery below the first branch underwent one hour of proximal LAD occlusion followed by injection of 99m Tc-tetrofosmin and 201TI either in the left atrium (GI, n= 19) or in the jugular vein (GII, n = 6). Twelve other pigs (GIII) with similar acute peri-infarction ischemia received 99m Tc-tetrofosmin and 201Tl into the left ventricle during cardiocirculatory arrest to rule out the effect of coronary collaterals. Radiotracer counting was determined in samples from normal, acute ischemic and necrotic regions. RESULTS Uptake of 99m Tc-tetrofosmin and 201 Tl was greater in the infarct scar (median % of normal tissue: 20 for 99m Tc and 8.6 for 201 Tl in GI; 22 and 15 in GII) than in acute ischemic myocardium (3.2 and 2.5 in GI; 6.4 and 3.3 in GII). Radiotracer injection in arrested hearts (GIII) depicted a similar pattern (median % of injected dose: 6.2 for 99m Tc and 10 for 201Tl in the scar; 2.3 and 4.0 in acute ischemia; 2.9 and 3.5 in normal tissue). The infarcted region showed connective tissue and lack of viable myocardium. CONCLUSION A 1-month old infarct scar with no viable myocardial tissue can take up significant fractions of 99mTc-tetrofosmin and 201Tl even in the absence of coronary collateral perfusion. Data suggest that the infarct scar can extract these radiotracers from the intraventricular blood.

Detection of Thyroid Papillary Carcinoma Lymph Node Metastases Using One Step Nucleic Acid Amplification (OSNA): Preliminary Results

ABSTRACT Purpouse: One Step Nucleic Acid Amplification (OSNA) has been previously proposed for the diagnosis of lymph node metastases (LNMs) from several malignant conditions by quantifying the number of copies of cytokeratin 19 mRNA. Our aim was to evaluate the results obtained by OSNA in the lymph nodes of patients with papillary thyroid carcinoma (PTC) by comparing our results with the findings observed using standard pathological examination. Materials and Methods: Fifty human lymph nodes (from five patients with diagnosed PTC) were studied. Each node was divided into two: one half was used for molecular study (“OSNA-node”), and the other half was used for conventional staining with hematoxylin and eosin (“HE-non-OSNA node”). Three cytological imprints using Papanicolaou and May-Grunwald-Giemsa strains were obtained from both node halves. The results from each technique were compared, and ROC analysis was performed. Results: The OSNA study showed 22 positive samples for LNM (44%), which demonstrate a high concordance rate with the results observed using conventional pathological examination (cytology of “OSNA-node” and HE of “Non-OSNA node”) with specificity and sensitivity values greater than 86% and 89%, respectively. However, both comparisons differed in the number of copies of mRNA as the best cut-off (260 copies in the first case and 93 in the second case). Conclusions: The OSNA results for the detection of LNM in patients with PTC are comparable with those observed using conventional techniques. However, its quantitative nature could be useful to more accurately detect lymph node involvement.

Functional neuroimaging in Hashimoto’s encephalitis: a physiopathological imaging?

Tc-ECD brain perfusion single photonemission computed tomography (SPECT) scan, whichshowed global and severe hypoperfusion of the whole braincortex (upper row). Anatomical neuroimaging (CT, MRI)was near-normal, showing only mild age-related corticalatrophy. After 8 months of corticoid therapy, the patientexperienced a progressive clinical recovery of superiorfunctions, and a control SPECT scan showed normal brainperfusion (lower row). The hypoperfusion pattern found inthis patient might have been related to a vasculitic mechanismas has been reported in this kind of encephalopathy [2, 3].References

Reproducibility of measurements of left ventricular function with gated myocardial perfusion SPECT and comparison with blood pool radionuclide ventriculography

INTRODUCTION AND OBJECTIVE This study was designed to evaluate the reproducibility of ejection fraction (EF) and ventricular volume measurements obtained with single photon emission computed tomography (gated-SPECT), and to assess the correlation between EF values obtained with this method and blood pool planar radionuclide ventriculography. PATIENTS AND METHOD A total of 55 patients were included (37 men, mean age 61.3 years) upon referral to two nuclear cardiology units for diagnosis (50%) or follow-up of known coronary artery disease. In a standard 2-day protocol, patients received a dose of [99mTc]tetrofosmin (800 MBq) at stress and at rest. Two resting gated-SPECT studies were performed. QGS software was used to obtain left ventricular EF, end-diastolic volume (EDV) and end-systolic volume (ESV). Forty-nine patients agreed to undergo blood pool ventriculography on the third day. RESULTS Interobserver variability was 0.5 (2.6)% (r=0.99) for EF, 1.9 (10.7) mL for EDV (r=0.98) and 0.5 (5.4) mL for ESV (r=0.99). Interassay variability was 2 (5.1)% (r=0.94) for EF, 4.5 (8.6) mL for EDV (r=0.99) and 3.4 (6.6) mL for ESV (r=0.99). The correlation between gated-SPECT EF and blood pool EF was suboptimal (r=0.75, 95%CI, 0.59-0.85). CONCLUSIONS There was excellent interobserver and interassay reproducibility for left ventricular functional parameters measured with gated-SPECT and QGS software, and this method can be used for serial evaluations of ventricular function. Although the correlation between values obtained with gated-SPECT and blood pool ventriculography was acceptable, the differences show that the two techniques cannot be considered equivalent.

Gammagrafía suprarrenal cortical con frenación y supresión de la frenación con dexametasona en el estudio del hiperaldosteronismo primario

Resumen Objetivo Valorar el rendimiento diagnostico y la eficacia en la deteccion del tejido suprarrenal normofuncionante de la gammagrafia cortical suprarrenal en el hiperaldosteronismo primario, siguiendo el protocolo que combina en un solo estudio la obtencion de imagenes de frenacion e imagenes tardias tras la supresion de la frenacion con dexametasona. Material y metodos Se estudiaron 20 pacientes remitidos a nuestro servicio con la sospecha de hiperaldosteronismo primario y se exploraron mediante gammagrafia combinada. 13 hombres y 7 mujeres, rango de edad de 31 a 73 anos y edad media de 52 anos. Se bloqueo la glandula tiroidea con Lugol y se administro al paciente dexametasona 1 mg c./6h desde 7 dias antes de la dosis hasta el tercer dia de la exploracion, momento en el que se suspendio la frenacion. El radiotrazador fue I-131-norcolesterol (37 MBq e.v.). Adquisicion Estudio planar posterior de 30 min. Detecciones a las 24 y/o 48h y al tercer dia, despues de la cual se suspendio la dexametasona y se obtuvo una ultima deteccion al 5. ° y/o 7. ° dia. El resultado de la gammagrafia se confirmo con la valoracion clinica final (VCF) del paciente. Resultados 11 resultados positivos, 9 catalogados de adenoma hiperfuncionante (8 VP y 1 FP) y dos de hiperplasia bilateral (2VP); 7 fueron negativos (6 VN y 1 VCF no concluyente) y dos gammagrafias indeterminadas (1 incidentaloma y 1 VCF no concluyente). En todos los casos la gammagrafia del 5. ° y/o 7. ° dia mostro la aparicion de las glandulas suprarrenales normofuncionantes. Conclusiones El estudio del funcionalismo suprarrenal mediante el protocolo combinado de gammagrafia suprarrenal con frenacion y suspension de la frenacion con dexametasona permitio identificar con elevada precision diagnostica los hiperaldosteronismos primarios y caracterizar la funcion de las glandulas suprarrenales normales.

Biopsia selectiva del ganglio centinela en el carcinoma papilar de tiroides en pacientes sin evidencia preoperatoria de metástasis ganglionar

INTRODUCTION Lymphadenectomy is recommended during surgery for papillary thyroid carcinoma when there is evidence of cervical lymph node metastasis (therapeutic) or in high-risk patients (prophylactic) such as those with T3 and T4 tumors of the TNM classification. Selective sentinel lymph node biopsy may improve preoperative diagnosis of nodal metastases. OBJECTIVE To analyze the results of selective sentinel lymph node biopsy in a group of patients with papillary thyroid carcinoma and no evidence of nodal involvement before surgery. PATIENTS AND METHOD A retrospective, single-center study in patients with papillary thyroid carcinoma and no clinical evidence of lymph node involvement who underwent surgery between 2011 and 2013. The sentinel node was identified by scintigraphy. When the sentinel node was positive, the affected compartment was removed, and when sentinel node was negative, central lymph node dissection was performed. RESULTS Forty-three patients, 34 females, with a mean age of 52.3 (±17) years, were enrolled. Forty-six (27%) of the 170 SNs resected from 24 (55.8%) patients were positive for metastasis. In addition, 94 (15.6%) out of the 612 lymph nodes removed in the lymphadenectomies were positive for metastases. Twelve of the 30 (40%) low risk patients (cT1N0 and cT2N0) changed their stage to pN1, whereas 12 of 13 (92%) high risk patients (cT3N0 and cT4N0) changed to pN1 stage. CONCLUSIONS Selective sentinel lymph node biopsy changes the stage of more than 50% of patients from cN0 to pN1. This confirms the need for lymph node resection in T3 and T4 tumors, but reveals the presence of lymph node metastases in 40% of T1-T2 tumors.

Giant urinary bladder stone: incidental finding in (99m)Tc-DTPA renography.

A 27-year-old woman presented with a history of recurrent urinary tract infections in infancy and urinary incontinence secondary to lipomyelomeningocele. At the age of 7, she underwent bladder augmentation enterocystoplasty, requiring intermittent catheterization without urinary tract infections until present. A Tc-DTPA renography was performed to evaluate renal function, in which an abnormal tracer distribution was seen in urinary bladder, and furthermore, a retrograde cystography shows a giant bladder stone.

Why do we need accreditation of nuclear medicine departments

Nuclear medicine is one of the most dynamic areas of medicine with continual technological innovations and developments of new radiotracers. The International Atomic Energy Agency (IAEA) defines nuclear medicine as a medical specialty that uses techniques with high cost-benefit index to obtain functional and anatomical information, constituting a tool for the detection, staging, treatment, prognosis and monitoring of patients [1]. Nuclear medicine has been an independent European medical specialty since 1988. The Section of Nuclear Medicine was created in 1990 within the European Union of Medical Specialists (UEMS), the entity that represents the medical specialties inside the European Union (EU) and that defines the basic principles of training in medical specialties in Europe in order to achieve a comparable level of knowledge and to allow the free movement of specialists among the member countries. The European Board of Nuclear Medicine (EBNM) was established in 1993 with the main objective of ensuring the highest possible levels of quality in the field of nuclear medicine. In 2000 the European Association of Nuclear Medicine (EANM) set up a Task Group on departmental accreditation. In 2003, the UEMS Section and the EBNM merged as the UEMS/EBNM to unify and facilitate their activities and created several committees, including the Committee for Accreditation of Nuclear Medicine Departments (CANMD). This was the EANM Task Group which transferred from the EANM. In practice, the UEMS/EBNM and the CANMD work in cooperation with the EANM. Technological innovations and advances in the field of new radiopharmaceuticals are very important for the continuous development of the nuclear medicine specialty. Any department of nuclear medicine must assure minimum quality requirements according to its available resources. Quality! Never has this word been used so frequently. In fact, in recent times there has been a significant reorganization of the concept of quality. Since 1947, the year the International Standards Organization (ISO) was created, there has been increasing emphasis on the quality of products and services. What before had been performed in a routine local way, nowadays attempts are made to globalize the process through standards and a good quality program and well-defined operating procedures, all of which, in our case, are to be applied to a department of nuclear medicine. Whether a department of nuclear medicine is public or private, it is assumed that it works correctly and assures minimum quality requirements. On this basis, one could ask: “what do I need to get an official accreditation by EANM?—why, in addition to possible certification by ISO and all the daily problems of budget cuts or concern for expenses generated by the cost of new equipment?” It is possible that many European nuclear medicine doctors have received training in concepts such as total quality, standardization, Deming circles, development of quality policies, objectives and indicators, and that they may now be applying those concepts in their daily work, in an effort to improve patient care and the quality of the services provided by their departments of nuclear medicine, in order to stand out from the other competitors and (why not) to survive in these very competitive times marked by the rampant crisis in all sectors. But it is also true that some other nuclear medicine physicians are unaware of these concepts. At CANMD we believe that the accreditation of nuclear medicine services is not the mere collection of a diploma to hang on the wall. To have this official accreditation is relevant and provides multiple benefits that outweigh any sacrifice. Eur J Nucl Med Mol Imaging (2012) 39:1643–1645 DOI 10.1007/s00259-012-2184-y