[Usefulness of FDG-PET in the diagnosis of patients with chronic severe brain injury]. / Utilidad de la PET con FDG en la valoración del paciente con traumatismo craneoencefálico severo crónico.

INTRODUCTION: To describe the changes in cerebral glucose metabolism after a severe traumatic brain injury (TBI), at the beginning of the rehabilitation, to analyze its diagnostic agreement with morphologic neuroimaging technologies (MR/CT) and to correlate the neuroimaging findings with the intensity of the TBI and the functional ability for daily activities. MATERIAL AND METHODS: Prospective study of 55 patients who had sustained a severe TBI (GCS < or = 8) by means of 18F-FDG PET and MR/CT. The agreement between anatomical and functional neuroimagen studies was measured. Correlation between cerebral injury severity in neuroimaging, clinical functional evaluation assessed with Barthel-M Index and GCS were tested. RESULTS: 100 % of patients showed changes in cerebral metabolism, being the thalamus the area more frequently affected. 60 % of patients showed injuries in MR/CT, more frequently in frontal areas. The agreement for the diagnosis of pathology between morphologic and functional neuroimagen was very low. The TBI severity showed significant statistical correlation with the degree of cerebral metabolism and the level of disability. CONCLUSIONS: 18F-FDG PET allows to know the cerebral glucose metabolism at the beginning of the rehabilitation, being correlated with the TBI severity and the level of patient's disability for daily activities. 18F-FDG PET diagnoses major number of injuries that traditional neuroimaging and demonstrates a high thalamic vulnerability, with injuries in up to 76 % of patients with severe TBI.

Focal nodular hyperplasia (FNH): a potential cause of false-positive positron emission tomography.

Positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG) has been proven to be a useful tool in the differential diagnosis of liver tumors. Focal nodular hyperplasia (FNH) is an uncommon benign liver lesion, which can be difficult to differentiate from other benign and malignant liver pathologies. FDG PET imaging usually shows uptake similar or even decreased compared to that of the normal liver. We describe a hypermetabolic FNH lesion in a patient with a history of breast cancer. Computed tomography scan, ultrasonography (US), and magnetic resonance imaging were negative. The lesion was resected, and histologic findings were consistent with FNH.

99Tcm-MAG3 for quantitation of differential renal function.

We studied two different methods for the evaluation of differential renal function in a group of 100 patients with various kidney disorders whose effective renal plasma flow (ERPF) had been calculated previously by single 125I-orthoiodohippurate (OIH) injection and multiple blood sampling. Patients were divided into three groups according to their ERPF:ERPF is greater than or equal to 250 ml min-1; ERPF less than or equal to 100 ml min-1; and ERPF greater than 100 ml min-1 and less than 250 ml min-1. The two methods used to assess differential renal function were: first, relative 99Tcm-dimercaptosuccinic acid (DMSA) uptake calculated by normalized background and attenuation corrected cumulative counts in each kidney 24 h p.i.; and second, relative 99Tcm-mercaptoacetyl-triglycine (MAG3) uptake within 1 and 2 min p.i. calculated by normalized background and attenuation corrected counts on each renal area. The results obtained with each method correlated strongly with high significance (p less than 0.0001). In the right kidney, mean values obtained with 99Tcm-MAG3 tend to be higher than mean values obtained with 99Tcm-DMSA.

Muscarinic control of gallbladder dynamics. A study using 99Tcm-HIDA and cholinergic agonists and antagonists.

We studied 12 normal subjects who underwent four 99Tcm-HIDA examinations. Imaging was performed with 111 MBq at 1 image/min for 60 min, and was registered on a computer on a 64 x 64 word matrix. Normalized and background corrected time-activity curves on the gallbladder were obtained from which total and cumulative 10 min interval emptying was calculated. During the first examination (control), 10 min after the beginning of acquisition, 1 ml saline solution was injected subcutaneously. The second examination was performed injecting 5 mg bethanechol subcutaneously instead of saline solution. During the third and fourth examinations 10 mg pirenzepine and 0.15 mg/10 kg atropine were injected i.v. respectively, 5 min before bethanechol injection. Wilcoxon's test was used to compare the first and second studies and the latter with the third and fourth studies. The median value of gallbladder emptying at 60 min was 2% with saline solution injection and 27.5% with bethanechol. This difference was significant from minute 30 onwards. Atropine administration inhibited gallbladder emptying completely in all cases, with significant differences (P less than 0.01) in relation to bethanechol values following the first 30 min of the examination. Gallbladder emptying was observed in the study with pirenzepine, but was significantly inferior to the bethanechol values after the first 30 min.

[Peroperative myocardial infarction and myocardial ischemia in non cardiac surgery: prevalence and predictive factors]. / Infarto e isquemia miocárdica peroperatoria en cirugía no cardíaca: prevalencia y factores predictivos.

BACKGROUND: The decrease in the prevalence of infarction in the population has not been accompanied by a reduction in postinfarct mortality, particularly in the population segment which does not present major symptoms of coronary disease. The aim of the present study was to determine the incidence and predictive factors of cardiac complications in patients undergoing non cardiac surgery. METHODS: Eight hundred seventy-five patients undergoing elective surgery from May 1990-1991 had some of the following criteria: history of heart disease, major surgery, and medical risk other than cardiac. A sample of 328 patients was selected to whom an ECG an CK-MB isoenzyme test were performed on admission, every 8 h, and at the second and third days. Infarction or ischemia were diagnosed by electrocardiographic and enzymatic criteria. Minimum follow up was 72 hours. RESULTS: IAM was diagnosed in 10 cases (3%, confidence interval 95%, 2 to 4%) and ischemia in 47 cases (14%, CI 95%, 11 to 18%). Operative mortality of cardiac origin was 4% (CI 95%, 2 to 6%). Arrhythmia not preoperatively present was detected in 11%, hemodynamic instability in 25%, and sinusal tachycardia in 21%. Other complications were: abdominal 12%, respiratory 14%, neurologic 6% and renal 4%. The appearance of cardiac complications was related with: ASA classification (p < 0.05), previous history of heart disease (p < 0.01), cardiovascular drug administration (p < 0.01) and changes in preoperative electrocardiogram (p < 0.001). CONCLUSIONS: The present study suggests that patients with changes of the ST-T segment in the preoperative ECG should undergo examination to determine the degree of cardiac involvement. A strict peroperative hemodynamic control may reduce the prevalence of cardiac complications in those patients at high risk.

[Study of gastric emptying by dual isotopes. Corrections due to contamination]. / Estudio del vaciamiento gástrico mediante técnica con doble isótopo. Consideraciones con respecto a la corrección de la contaminación.

The evaluation of gastric emptying by the double isotope technique involves some methodologic conditioning. Among them contamination correction or interference in the energy windows of the activity of the two isotopes used in the marking of the solids and fluids of the test food are important. The results of an experiment in which a phantom was used to evaluate the contamination between indio 111 (DTPA-Ca111In) and technecium 99m (colloid99mTc). Three test studies were posteriorly performed in healthy volunteers and 27 studies in a control group (13 males, mean age of 33 years, mean body mass index 39.02 kg/m). In these studies the contamination was corrected with the acquisition, following an initial swallow of juice marked with 111In, of activity in the windows of both isotopes. The contamination of 111In (isotope of greatest radiation energy) in the window of 99mTc was 24% in the phantom and 20%, 23% and 26% in the three initial study tests. The mean contamination in the control group was of 22% with limits of 19% to 29% and a standard deviation of 3%. Despite the comparable results, the usefulness of the individualized contamination calculation in the studies of gastric emptying with dual isotope to minimize the methodologic errors of this technique is discussed.

[Dynamic ultrasonography in the diagnosis of gallbladder dysfunction: reliability of a simple method with easy clinical application]. / Ultrasonografía dinámica en el diagnóstico de la disfunción vesicular: fiabilidad de un método sencillo de fácil aplicación clínica.

AIMS: Although the results of dynamic ultrasonography (DUS) are similar to those of dynamic cholescintigraphy (DCS) in the study of gallbladder function, the methodology required for this technique is laborious and sometimes complex. The aim of this study was to investigate the reliability of a simple method of DUS to evaluate gallbladder function using DCS as a reference. PATIENTS AND METHODS: Gallbladder function was studied using DUS and DCS in 80 consecutive patients with clinical findings compatible with gallbladder dysfunction. For DUS the ellipsoid method was used with measurement of three gallbladder diameters (transversal, longitudinal and anteroposterior) in basal conditions and after applying a cholecystokinetic stimulus (meal test); gallbladder emptying of less than 50% was considered abnormal. In DCS intravenous cholecystokinin (CCK) (0.40 IDU/kg in 20 minutes) was used as stimulus and an ejection fraction < or = 40% was considered abnormal. RESULTS: In 15 patients (19%; 95% CI, 11-29%) abnormal gallbladder response was found using DUS. The ejection fraction in the entire group of patients studied was 48 26.2%. Ejection fraction was abnormal in 41 patients (51%; 95% IC, 40-63%) with a value of 25 8.5% and was normal in 39 patients (49%; 95% IC, 40-63%) with a value of 71.5 14.5%. The correlation coefficient between the values of gallbladder emptying calculated with DUS and the ejection fraction obtained with DCS was 0.199 (p = 0.079). When patients were divided according to gallbladder emptying measured by DUS and the ejection fraction obtained with DCS the concordance was very low (k = 0.065; EE = 0.085). CONCLUSIONS: DUS performed using a simple technique lacks diagnostic value in gallbladder dysfunction when DCS is taken as a reference test

[Quality in anesthetic management during hepatic transplant. Hepatic Transplant Anesthesia Group]. / Estudio de la calidad en el manejo anestésico durante el transplante hepático. Grupo de Anestesia de Trasplante Hepático (GATHa).

INTRODUCTION: To measure the quality of anesthetic management during liver transplants (LT) and to assess the effect on improving patient care after establishing a quality policy based on self evaluation of quality indicators. MATERIAL AND METHODS: Two periods were studied: January 1993 through December 1994 (93 LT) and March 1995 through November 1995 (45 LT). Compliance with the anesthetic protocol was assessed by way of 14 indicators as follows: exposure and analysis of the results for the 1993-1994 period followed by later evaluation of quality indicators for the period 1995. RESULTS: The index for revascularization of the graft was lower than any of the following six indicators: temperature, systolic arterial pressure, hemoglobin, fibrinogen, pH value and sodium values over 155 mmol/l. In the phase during which the liver was removed, the indicator for calcium level lower than 1 mmol/l was the only indicator with low compliance. Multiple regression analysis showed that mechanical ventilation was associated to transfusion requirements, to non compliance with hemostatic and coagulation indicators, and to presence of a decrease in systolic arterial pressure below 70 mmHg. CONCLUSION: We conclude that adverse effects can be partially improved by implementing a quality policy based exclusively on analysis of results and ongoing professional training. The impact of non compliance with the indicators, policy structure and process of delivering health care should be explored.

[Utility of the brachial plexus block combined with continuous intradural anesthesia for axillo-femoral bypass surgery]. / Utilidad del bloqueo del plexo braquial asociado a la anestesia intradural continua para la cirugía de derivación axilofemoral.

Extra-anatomic axillofemoral bypass is a surgical procedure that is indicated in cases of occlusive aortoiliac pathology in which the transabdominal way is not feasible or in patients of high risk. We present a preliminary study in which we have prospectively evaluated 14 patients who were received an axillofemoral bypass during 1990. After preoperative evaluation two groups were identified: Group ALR (5 patients) with combined anesthetic blockade of supraclavicular brachial plexus and continuous subarachnoid blockade. Group AG (9 patients) who received balanced general anesthesia. In all cases we obtained a good anesthetic level for surgery. The incidence of complications was similar in both groups. One patient subjected to general anesthesia died. Combined blockade induces a satisfactory analgesia in all surgical interventions without exceeding in any case the maximal doses of anesthetic drugs. Additionally, this technique affords the advantages of regional anesthesia and can be used as an alternative anesthetic procedure in patients of high risk who undergo axillofemoral bypass.

[Specificity of CK-MB enzyme in the diagnosis of acute myocardial infarction in the postoperative period following non-cardiac surgery]. / Especificidad de la enzima CK-MB en el diagnóstico de infarto agudo de miocardio en el postoperatorio de cirugía no cardíaca.

OBJECTIVES: 1) To determine plasma concentrations of creatinphosphokinase-MB (CK-MB) enzyme during non-cardiac surgery for detecting postoperative myocardial infarction or ischemia. 2) To assess the specificity of CK-MB levels for the diagnosis of acute myocardial infarction (AMI) in patients undergoing non-cardiac surgery. PATIENTS AND METHOD: Three hundred twenty-eight patients were studied prospectively. Inclusion criteria were as follows: 1) presenting cardiac risk factors; 2) major surgery; and 3) presence of associated pathology, unrelated to cardiac pathology. All patients were given an electrocardiogram and CK-MB levels were determined every 8 hours over the first 24 hours and on the second and third days. Total CK was measured at 24 hours. RESULTS: AMI was detected by electrocardiogram in 3.3% of the patients. ST-segment/T-wave changes were detected in 5.7% and myocardial ischemia was found in 14.7%. Mean levels of CK-MB in patients with postoperative AMI were significantly higher than in patients without AMI. Total CK levels in patients with electrocardiographic changes were not significantly different from those of other patients. Thoracic surgery produced a significant increase in total CK but no increase in CK-MB. Patients undergoing esophageal surgery presented high initial levels of CK-MB that became normal. CONCLUSIONS: 1) The CK-MB/total CK ratio is highly specific for detection AMI after surgery. 2) Type of surgery affects total CK levels. 3) Detection of high levels of MB fraction should lead to a suspicion of myocardial damage. 4) Total CK level is not a good marker of myocardial necrosis in the postoperative period.

[Thalamic metabolism and neurological outcome after traumatic brain injury. A voxel-based morphometric FDG-PET study]. / Metabolismo talámico y situación neurológica tras un traumatismo craneoencefálico. Estudio mediante PET-FDG y morfometría basada en vóxel.

OBJECTIVE: to study the relationship between thalamic metabolism and neurological outcome in patients who had sustained a traumatic brain injury (TBI). METHODS: nineteen patients who had sustained a severe TBI and ten control subjects were included in this study. Six of the 19 patients had a low level of consciousness (vegetative state or minimally conscious state), while thirteen showed normal consciousness. All patients underwent a PET with 18F-FDG, 459.4 +/- 470.9 days after the TBI. The FDG-PET images were normalized in intensity, with a metabolic template being created from data derived from all subjects. The thalamic trace was generated automatically with a mask of the region of interest in order to evaluate its metabolism. A comparison between the two groups was carried out by a two sample voxel-based T-test, under the General Linear Model (GLM) framework. RESULTS: patients with low consciousness had lower thalamic metabolism (MNI-Talairach coordinates: 12, -24, 18; T = 4.1) than patients with adequate awareness (14, -28, 6; T = 5.5). Control subjects showed the greatest thalamic metabolism compared to both patients groups. These differences in metabolism were more pronounced in the internal regions of the thalamus. CONCLUSIONS: the applied method may be a useful ancillary tool to assess neurological outcomes after a TBI, since it permits an objective quantitative assessment of metabolic function for groups of subjects. Our results confirm the vulnerability of the thalamus to suffering the effects of the acceleration-deceleration forces generated during a TBI. It is hypothesized that patients with low thalamic metabolism represent a subset of subjects highly vulnerable to neurological and functional disability after TBI.

[Receptors and markers: toward a science of imaging through hybridization]. / Los receptores y los marcadores: hacia la Ciencia de la Imagen a través de las hibridaciones.

Genomic- and proteomic-based imaging will enable the selection of populations and individuals "at risk"of suffering a certain disease before the clinical symptoms appear, identifying the existence, location, and extension of the bases of the disease, stratifying the risk, and making it possible to carry out and control treatments designed for each patient. In order to be efficacious, these molecular imaging techniques must generate both functional and structural information. The use of imaging probes together with advanced equipment allows numerous molecular complexes and cellular structures to be seen. Molecular imaging makes it possible to acquire, whether directly or indirectly, information about the spatial and temporal distribution of molecular or cellular processes that have not only clinical (diagnostic and therapeutic) applications but also basic (biochemical and physiological) applications. In the clinical area, nuclear medicine and radiology must work together to lead the development, implementation, and technological evaluation of molecular imaging. From this perspective, molecular hybridization techniques must progress toward the coordination of efforts, in training and in application as well as in research, to enable us to develop fully as imaging professionals in the service of healthcare. Molecular imaging provides imaging physicians with the possibility to advance substantially in early diagnosis, in the stratification of risk and prognosis, as well as in treatment monitoring in numerous biological and cellular processes related to the disease.

Effect of selective and nonselective muscarinic blockade on cholecystokinin-induced gallbladder emptying in man.

In this study we investigated the effect of selective (M1) and non-selective (M1 and M2) pharmacologic blockade of muscarinic receptors on cholecystokinin-induced gallbladder emptying. After validating the method of study, the gallbladder function was evaluated in 15 normal volunteers by quantitative biliary scintigraphy, and the effect of intravenous atropine (0.15 mg/10 kg) and pirenzepine (10 mg) was analyzed in each subject. Atropine significantly reduced the ejection period and the ejection fraction of gallbladder evacuation. Pirenzepine reduced the ejection period, but the ejection fraction remained unchanged. We conclude that the effect of cholecystokinin on gallbladder motility is mediated through muscarinic receptors. Our results suggest that M2 receptors, but not M1 receptors, are involved in this response.

Practice of nuclear medicine in Spain.

This survey presents the results of a poll sent to all Spanish nuclear medicine departments between July 1999 and March 2000, with the aim of clarifying the current situation of nuclear medicine in Spain. This survey is believed to be the first of its kind, and it is anticipated that the data will be of assistance to health authorities in ensuring that the needs of the population with regard to nuclear medicine facilities are met.

Metabolismo talámico y situación neurológica tras un traumatismo craneoencefálico. Estudio mediante PET-FDG y morfometría basada en vóxel / Thalamic metabolism and neurological outcome after traumatic brain injury. A voxel-based morphometric FDG-PET study

Objetivos: Estudiar la relación entre el metabolismo talámico y la situación neurológica en pacientes que han sufrido un traumatismo craneoencefálico (TCE). Material y métodos: Se incluyó a 19 pacientes que habían sufrido un TCE grave y 10 sujetos control. De los 19 pacientes, 6 presentaban un grado de alerta bajo (estado vegetativo o estado de mínima conciencia), mientras que 13 mostraban un grado de alerta normal. A todos los pacientes se les realizó una tomografía con emisión de positrones (PET) con 18-fluorodesoxiglucosa (18F-FDG) 459,4 ± 470,9 días después del TCE. Las imágenes de PET-FDG se normalizaron en intensidad, creándose posteriormente una plantilla metabólica del grupo entre todos los sujetos. El trazado talámico se generó automáticamente con una máscara de la región de interés. Se comparó el metabolismo talámico de los dos grupos de pacientes respecto al grupo control, para ello se utilizó un método de análisis basado en vóxel, con significación estadística, p < 0,05 corregido para múltiples comparaciones. Resultados: Los pacientes con grado de alerta bajo mostraron menor metabolismo talámico (coordenadas MNI-Talairach, 12, -24, 18; T = 4,1), con respecto a los sujetos control, que los pacientes con grado de alerta adecuado (14, -28, 6; T = 5,5). Estas diferencias en el metabolismo fueron más acentuadas en las regiones internas del tálamo. Conclusiones: La PET-FDG puede ser una herramienta útil para valorar la situación neurológica después de un TCE. El método utilizado permite una evaluación objetiva y cuantitativa de imágenes de PET-FDG para grupos de sujetos. Nuestros resultados confirman la vulnerabilidad del tálamo a sufrir los efectos de las fuerzas de aceleración-desaceleración generadas durante un TCE (AU)

Objective: To study the relationship between thalamic metabolism and neurological outcome in patients who had sustained a traumatic brain injury (TBI). Methods: Nineteen patients who had sustained a severe TBI and ten control subjects were included in this study. Six of the 19 patients had a low level of consciousness (vegetative state or minimally conscious state), while thirteen showed normal consciousness. All patients underwent a PET with 18F-FDG, 459.4 ± 470.9 days after the TBI. The FDG-PET images were normalized in intensity, with a metabolic template being created from data derived from all subjects. The thalamic trace was generated automatically with a mask of the region of interest in order to evaluate its metabolism. A comparison between the two groups was carried out by a two sample voxel-based T-test, under the General Linear Model (GLM) framework. Results: Patients with low consciousness had lower thalamic metabolism (MNI-Talairach coordinates: 12, -24, 18; T = 4.1) than patients with adequate awareness (14, -28, 6; T = 5.5). Control subjects showed the greatest thalamic metabolism compared to both patients groups. These differences in metabolism were more pronounced in the internal regions of the thalamus. Conclusions: The applied method may be a useful ancillary tool to assess neurological outcomes after a TBI, since it permits an objective quantitative assessment of metabolic function for groups of subjects. Our results confirm the vulnerability of the thalamus to suffering the effects of the acceleration-deceleration forces generated during a TBI. It is hypothesized that patients with low thalamic metabolism represent a subset of subjects highly vulnerable to neurological and functional disability after TBI (AU)