Appropriate use of noninvasive ischemia testing to guide revascularization decision making following acute ST elevation myocardial infarction in Latin American countries: Results from an expert panel meeting of the International Atomic Energy Agency. / Uso adecuado de las pruebas no invasivas de isquemia para guiar la toma de decisión sobre revascularización tras un infarto agudo de miocardio con elevación del segmento ST en países iberoamericanos: Resultados de la reunión de un panel de expertos de la International Atomic Energy Agency.

Across Latin American and Caribbean countries, cardiovascular disease and especially ischemic heart disease is currently the main cause of death both in men and in women. For most Latin American and Caribbean countries, public and community health efforts aim to define care strategies which are both clinically and cost effective and promote primary and secondary prevention, resulting in improved patient outcomes. The optimal approach to deal with acute events such as ST-elevation myocardial infarction (STEMI) is a matter of controversy; however, there is an expanding role for assessing residual ischemic burden in STEMI patients following primary percutaneous coronary intervention. Although randomized clinical trials have established the value of staged fractional flow reserve-guided revascularization, the use of noninvasive functional imaging modalities may play a similar role at a much lower cost. For LAC, available stress imaging techniques could be applied to define residual ischemia in the non-infarct related artery and to target revascularization in a staged procedure after primary percutaneous coronary intervention The use of nuclear cardiac imaging, supported by its relatively wide availability, moderate cost, and robust quantitative capabilities, may serve to guide effective care and to reduce subsequent cardiac events in patients with coronary artery disease. This noninvasive approach may avert potential safety issues with repeat and lengthy invasive procedures, and serve as a baseline for subsequent follow-up stress testing following the index STEMI event. This consensus document was devised from an expert panel meeting of the International Atomic Energy Agency, highlighting available evidence with a focus on the utility of stress myocardial perfusion imaging in post-STEMI patients. The document could serve as guidance to the prudent and appropriate use of nuclear imaging for targeting therapeutic management and avoiding unnecessary invasive procedures within Latin American and Caribbean countries, where resources could be scarce.

Indice de captación de 99mTc-MIBI en el ventrículo derecho como marcador indirecto de isquemia en los estudios de perfusión miocárdica / Right ventricular uptake index of 99mTc-MIBI in myocardial perfusion studies

Se describe un nuevo método para cuantificar la captación relativa del ventrículo derecho en los estudios de perfusión miocárdica. Se demuestra que el índice de captación propuesto está en relación con el grado de isquemia miocárdica en el ventrículo izquierdo.

A new method for quantification of relative right ventricular uptake in myocardial perfusion Studies is described. A direct relationship between the proposed uptake index and the degree of left ventricular myocardial ischemia is demonstrated.

Changes in the cerebral blood flow in postlingual cochlear implant users.

Five postlingually deaf patients (age range 28-58 years) with multichannel cochlear implants were examined with single photon emission tomography (SPECT) (triple-head rotating gamma camera). Changes in the regional cerebral blood flow (rCBF) after intravenous administration of technetium-99m ethyl cysteinate dimer (Tc-99m ECD) were assessed through a stimulation paradigm, consisting of: i) click stimuli (75 dB SPL) in the ear that was to be implanted, 2 weeks before surgery; ii) stimulation with the same click, one month after initial fitting; iii) stimulation with hearing sequential Spanish sentences one month after initial fitting. The results showed a significant increase in the rCBF in the primary left auditory area and in the right auditory cortex, in conditions ii) and iii). The rCBF also showed a significant asymmetrical increase in the frontal lobes when the patient was hearing sequential sentences (condition iii)) with asymmetrical distribution among patients. These results are discussed, principally the correlation between speech discrimination scores and the rCBF distribution in the frontal and temporal lobes.

Scintigraphic detection of invasive cutaneous malignant melanoma with Tc-99m MIBI.

Malignant melanoma is a relatively uncommon cancer of increasing incidence. The authors report on two cases of malignant melanoma lesions (primary and lymph node metastasis) imaged with Tc-99m MIBI. One patient revealed intense accumulation of the radiotracer in a primary skin lesion of the thorax, whereas the other patient showed increased Tc-99m MIBI uptake in a lymph node metastasis of the neck. Tc-99m MIBI imaging could be helpful in the evaluation of patients with suspicious skin lesions and in patients with known cutaneous malignant melanoma, in the investigation of lymph nodal invasion, local recurrence, and metastatic spread.

Thyroid imaging with Tc-99m MIBI in patients with solitary cold single nodules on pertechnetate imaging.

Thyroid imaging was performed in 30 patients with the standard pertechnetate technique, as well as with Tc-99m MIBI using a double-phase acquisition protocol. All patients had normal thyroid function confirmed by hormone measurements and cold solitary thyroid nodules, which were evaluated by pertechnetate scanning. Tc-99m MIBI scans were reported as showing cold (N = 14), warm (N = 7), or hot (N = 9) nodules. Nodule classification was made according to fine needle aspiration biopsy findings in 20 patients. The remaining 10 proceeded to surgery and had histopathologic confirmation of their lesions. Although all cold nodules with Tc-99m MIBI were cystic, six of the warm nodules were benign lesions. No histologically proven benign nodule was hot with Tc-99m MIBI. Of the hot nodules, seven were suspicious for follicular carcinoma with fine needle aspiration biopsy (N = 3), or had histologically proven papillary carcinoma (N = 4). Delayed images in five of seven of these lesions showed nodular retention of the radiopharmaceutical. In conclusion, double-phase Tc-99m MIBI scanning of the thyroid gland could be helpful in the preoperative assessment of patients with cold solitary thyroid nodules in order to evaluate the malignancy probability of these lesions.

Tc-99m isonitrile uptake in a brain metastatic lesion. Comparison with Tc-99m DTPA using planar and SPECT imaging.

Tc-99m isonitrile uptake in a metastatic brain tumor is demonstrated using planar and SPECT imaging. Comparison with Tc-99m DTPA shows a different distribution pattern and uptake intensity, suggesting a different mechanism for both tracers. It is possible that Tc-99m CPI could reflect metabolic activity of the tumor cells and might be useful to evaluate the grade of malignancy as well as the recurrence of brain tumors.

Colecentellografia: comunicacion preliminar sobre 50 observaciones. / Cholescintigraphy: preliminary communication of 50 observations

Se presenta un nuevo procedimiento incruento para la exploracion morfologica y funcional de la via biliar. El metodo esta basado en la administracion de compuestos marcados con 99m Tc (99mTc P G y 99mTc-HIDA) que son depurados de la sangre por el hepatocito y excretados conjuntamente con la bilis. El transito del radiofarmaco permite obtener imagenes secuenciales del relleno de la via biliar principal y accesoria, poniendo en evidencia la existencia o no, de pasaje de bilis al intestino.En la serie de pacientes estudiados fue posible observar alteraciones funcionales expresadas por el retraso de la excrecion biliar.El valor fundamental del metodo se mostro en la separacion del grupo de ictericias por obstruccion extrahepaticas, de las ictericias intrahepaticas con factor colostaticas predominante. En el grupo de las extrahepaticas se pudo evidenciar la altura de la obstruccion en relacion con la via biliar accesoria.Tambien se utilizo el procedimiento para el control de las anastomosis bilio digestivas y en el diagnostico de los cuadros agudos de origen vesicular