Longitudinal evaluation using FP-CIT in patients with parkinsonism.

OBJECTIVE: To assess a group of patients with parkinsonism using serial studies with FP-CIT, basically the initial false negative results. METHODS: Restrospective study of 92 patients (55 men and 37 women) who had undergone 2 different FP-CIT studies because of discrepancies between study results and clinical progression. The mean elapsed time between the studies was 26 months (SD: 6). We performed a semi-quantitative study using the patient's clinical history and the available literature to analyse discrepant cases with a normal initial study and subsequent pathological findings. RESULTS: A total of 184 studies were completed for 92 patients; 11 of those 92 showed discrepancies between initial and subsequent studies. Among the 11 discrepant cases, 7 showed a normal initial study and pathological findings at a later date. Analysis of the predominant clinical features that might explain this behaviour revealed that 4 of these 7 subjects presented tremor-dominant parkinsonism. Regarding the rest, 1 presented early stage parkinsonism and was treated with antidopaminergic agents; 1 was classified as probable multisystem atrophy type C, and the third showed clinical signs of atypical parkinsonism without any causes of those signs being identified. CONCLUSIONS: Serial FP-CIT studies are unnecessary in the large majority of cases, but they may be justifiable in certain clinical situations.

Automatic assistance to Parkinson's disease diagnosis in DaTSCAN SPECT imaging.

PURPOSE: In this work, an approach to computer aided diagnosis (CAD) system is proposed as a decision-making aid in Parkinsonian syndrome (PS) detection. This tool, intended for physicians, entails fully automatic preprocessing, normalization, and classification procedures for brain single-photon emission computed tomography images. METHODS: Ioflupane[(123)I]FP-CIT images are used to provide in vivo information of the dopamine transporter density. These images are preprocessed using an automated template-based registration followed by two proposed approaches for intensity normalization. A support vector machine (SVM) is used and compared to other statistical classifiers in order to achieve an effective diagnosis using whole brain images in combination with voxel selection masks. RESULTS: The CAD system is evaluated using a database consisting of 208 DaTSCAN images (100 controls, 108 PS). SVM-based classification is the most efficient choice when masked brain images are used. The generalization performance is estimated to be 89.02 (90.41-87.62)% sensitivity and 93.21 (92.24-94.18)% specificity. The area under the curve can take values of 0.9681 (0.9641-0.9722) when the image intensity is normalized to a maximum value, as derived from the receiver operating characteristics curves. CONCLUSIONS: The present analysis allows to evaluate the impact of the design elements for the development of a CAD-system when all the information encoded in the scans is considered. In this way, the proposed CAD-system shows interesting properties for clinical use, such as being fast, automatic, and robust.

[Quantitative evaluation of SPECT with FP-CIT. Importance of the reference area]. / Valoración cuantitativa del SPECT con FP-CIT. Importancia del área de referencia.

OBJECTIVE: The aim of this study is to compare several uptake indexes between specific and non-specific activity to determine the existence of degenerative Parkinsonism according to different reference areas. MATERIAL AND METHODS: A total of 46 patients (23 men and 23 women), randomly selected from individuals referred to our center with a movement disorder, were included in the study. Mean age was 70.2 ± 10.2 years (41-87). The uptake indexes were obtained through the areas of interest (ROIs) located in the striate (specific uptake) and other reference ROIs located in areas with different concentrations of serotonin receptors: low-cerebellum, medium-occipital cortex and high-midbrain. RESULTS: A high linear correlation was found between indexes having low and medium concentration of serotonin receptors. The ROC curve analysis shows an area under the curve of 0.874, 0.886 and 0.739 and regression coefficients of 5.41, 6.62 and 3.41, respectively for the striatum/cerebellum (E/C), striatum/occipital (E/O) and striatum midbrain (E/M) indexes. Optimal cutoff for E/O (1.35), index with the best behavior, provides a sensitivity of 0.84 and specificity of 0.89. CONCLUSION: The reference area selected may alter the predictive power of the different indexes to determine the existence of a degenerative Parkinsonism.

[CT-PET application in the liposarcoma feature determination]. / Utilidad de la PET/TAC para la caracterización del liposarcoma.

The indication taken from the maximun tumor standarizad uptake (SUVmax) in soft tissue's cancer such as the liposarcomas leads to determine its methabolic behavicur and indicates the histologic subtype classification (myxoid).

[Diagnostic accuracy of FP-CIT SPECT in patients with parkinsonism]. / Utilidad diagnóstica de la SPECT con FP-CIT en el estudio de pacientes con parkinsonismo.

OBJECTIVE: To determine the diagnostic accuracy of FP-CIT SPECT in entities with and without presynaptic involvement of the nigral-striatal dopaminergic pathway in a large group of patients with movement disorders, evaluating the usefulness of quantitative analysis. MATERIALS AND METHODS: A group of 183 consecutive patients clinically diagnosed as either having or not having degenerative Parkinsonism. These results were then contrasted with those of FP-CIT SPECT to determine the diagnostic accuracy of the procedure. The specific binding index was evaluated with ROC curves. RESULTS: FP-CIT SPECT was highly accurate in the diagnosis of neurodegenerative Parkinsonism (sensitivity: 95 %, specificity: 90 %). Most of the false positive results arose in patients with vascular Parkinsonism and the false negative results in patients with Parkinson disease. ROC curve analysis of semiquantitative evaluation had a sensitivity of 83 % and specificity of 82 % with an optimal cut-off of 1.44. The area under the curve was not significantly different between patients 60 years (0.899 vs 0.884) of age. CONCLUSIONS: FP-CIT SPECT has a high degree of diagnostic accuracy for striatal dopaminergic involvement. No significant changes in diagnostic accuracy were seen with respect to patient age.

[Hemiparkinsonism secondary to mesencephalic bleeding]. / Hemiparkinsonismo secundario a hemorragia mesencefálica.

Vascular parkinsonism is the second cause of secondary parkinsonism, and can cause a complex clinical syndrome. In spite of this, it is not common to find an isolated vascular injury in the mesencephalic region, and even rarer for it to give rise to clinical parkinsonism. We present the case of a young patient who developed left hemiparkinsonism with a fluctuating clinical evolution and unpredictable response to the treatment after suffering right mesencephalic bleeding. Structural and functional neuroimaging techniques showed injury on the mesencephalic level and no uptake in the right striatal region, respectively.

[Utility of myocardial perfusion scintigraphy in the emergency department for evaluation of patients with chest pain]. / Utilidad de la gammagrafía de perfusión miocárdica para la evaluación de pacientes con dolor torácico en el servicio de urgencias.

OBJECTIVE: To evaluate diagnostic efficacy of rest myocardial perfusion scintigraphy in the detection of acute coronary syndrome in patients with chest pain and non diagnostic electrocardiogram, comparing it with reference techniques, in Emergency Department. MATERIAL AND METHODS: Myocardial perfusion scintigraphy was carried out in 40 patients with those defined characteristics in the Emergency Department, administering the radiopharmaceutical in the next 6 hours after the pain was over. All subjects followed routine diagnostic and treatment management. Final diagnosis of coronary disease was established by coronariography and/or stress perfusion myocardial scintigraphy. Patients were followed up for 9-12 months. RESULTS: Myocardial perfusion scintigraphy showed a negative predictive value of 96,15 % (CI 95 %: 86.84-100.00). The main limitation of its application was breast and diaphragmatic attenuation phenomenon, given that correction algorithms were not available. Global kappa coefficient was 0.78 when to compared interobserver agreement. CONCLUSION: Rest myocardial perfusion scintigraphy is a safe and efficient test in the screening of patients with chest pain suggestive of angor with non-diagnostic ECG in Emergency Department, and also provides prognostic information and risk stratification.

[Diagnostic accuracy of FP-CIT SPECT in the evaluation of patients with clinically uncertain parkinsonian syndrome]. / Validez diagnóstica de la SPECT con FP-CIT en la evaluación de pacientes con síndrome parkinsoniano clínicamente incierto.

OBJECTIVE: To determine diagnostic accuracy of FP-CIT SPECT in a subgroup of patients who clinically present nonconclusive or atypical characteristics of parkinsonism (Clinically Uncertain Parkinsonian Syndromes, CUPS), and assess the contribution of the quantitative analysis in this group of patients. PATIENTS AND METHODS: We included 54 patients who make up the CUPS group. After a variable follow-up period, we evaluated the existence of a degenerative parkinsonism and compared it with the result of the FP-CIT SPECT, establishing the diagnostic accuracy of this procedure in the CUPS patient group. RESULTS: We obtained a high diagnostic accuracy of neurodegenerative Parkinsonism in the CUPS patient group (sensitivity: 85%; specificity: 93%). False positive results were obtained in patients with vascular parkinsonism and most of the false negative results in patients with Parkinson's disease. The quantitative evaluation did not contribute data of relevance to the qualitative evaluation. CONCLUSIONS: FP-CIT SPECT makes it possible to show the involvement of nigrostriatal dopaminergic pathway, also contributing with information of relevance to the clinician about the etiology of the extrapyramidal symptomatology in patients with nonconclusive signs and symptoms of the existence of a Parkinsonism.

[Application of 123I-FP-CIT in the clinical practice in Parkinsonism patients]. / Aplicación del FP-CIT-I-123 en la práctica clínica de pacientes con Parkinsonismo.

INTRODUCTION: 123I-FP-CIT scan has been supported in the last years by numerous studies as a technique of undeniable value to assess presynaptic integrity of the nigrostriatal pathway. The objective of this study is to perform a descriptive analysis of the main diagnostic aspects obtained from the first 110 studies made with FP-CIT in our center. MATERIAL AND METHODS: The study population consisted of 110 consecutive patients distributed into 5 groups according to the clinical diagnosis, after a follow-up period of at least one year. Qualitative and quantitative scintigraphy was done. RESULTS: A total of 61.8 % (68/110) of the studies were considered abnormal and 38.2 % (42/110) as normal. Among the abnormal examinations there was 88.3 % (60/68) agreement with the clinical diagnosis and agreement was 83.4 % (35/42) in the normal examinations. Inverse significant correlation was assessed between striatal binding and severity according to the H and Y scale (r = -0.4) and between qualitative and quantitative assessment (r = -0.86). There was no significant correlation between the degeneration of dopaminergic function according to age and degree of asymmetry on striatal binding in the different groups. CONCLUSIONS: Generally an adequate agreement between clinical diagnosis and SPECT-FP-CIT was observed. Inverse correlation between striatal binding and H and Y scale and greater asymmetry at striatal binding was obtained among Parkinson patients than in the rest of groups.

[Utility of Tc-99m labeled heat-denatured red blood cell scintigraphy in a case of hepatic splenosis]. / Utilidad de la gammagrafía selectiva con hematíes desnaturalizados Tc-99m en un caso de esplenosis hepática.

The term splenosis, first used in the medical literature in 1939, refers to the autotransplantation of splenic tissue in a heterotopic location. We report the case of a known hepatitis C carrier in whom computed tomography scanning revealed a hepatic lesion suggestive of hepatocarcinoma. Magnetic Resonance imaging was performed for suspected hepatic splenosis, which was confirmed by Tc-99m labeled heat-denatured red blood cell scintigraphy. In addition to confirming the suspected diagnosis, this technique showed several pathological foci in distinct abdominal locations compatible with splenosis that had not previously been identified.

[Application of recombinant human TSH in the diagnostic protocol of differentiated thyroid carcinoma]. / Aplicación de la TSH humana recombinante en el protocolo diagnóstico del cáncer diferenciado de tiroides.

OBJECTIVES: To describe the preliminary results of the application of this new technique in the diagnostic protocol in the management of differentiated thyroid cancer (DTC). MATERIAL AND METHODS: 131I Whole body scan (WBS) was made under rhTSH stimulation in a group of 102 patients with DTC in follow-up, all treated by means of total thyroidectomy. The administration guideline was a dose of 0.9 mg of rhTSH (intramuscular) for two consecutive days, followed by oral activity of 185 MBq of 131I 24 hours after the last rhTSH injection, and later scintigraphic scan after 48 hours of the administration of 131I. Serum samples for TSH, thyroglobulin and antithyroglobulin antibodies determination were collected at 24 and 72 hours of the last administration of the rhTSH. Measures were made by means of immunometric assays. RESULTS: TSH values at 24 hours after exogenous stimulation were 147.54 +/- 46.46 mIU/l. In 62 patients values of negative Tg were obtained (< 1 ng/ml), 50 of which presented negative WBS and 12 positive. 37 patients had positive Tg, 17 of whom presented negative WBS (confirming presence of disease in 7 patient by means of other imaging techniques) and 20 positive. CONCLUSIONS: In every case, administration of rhTSH produced a significant increase of the TSH, making it possible to perform the usual controls of patient management (determination of serum Tg and WBS), similarly to the hormone withdrawal situation. There is no evidence of significant side effects, and its use makes it possible to avoid disadvantages derived from the hormonal withdrawal, maintaining a good quality of life in patients.

[Progressive myositis ossificans. Utility of bone scintigraphy]. / Miositis osificante progresiva. Utilidad de la gammagrafía ósea.

47 year old woman affected by myositis ossificans, with muscular calcifications in her evolution. Bone scintigraphy showed increased polyfocal activity as well as uptake of different intensity in soft tissues. The bone scintigraphy allows for early identification of ossification areas in soft tissues, as it can even detect injuries earlier than that observed with other image techniques. It is considered to be very useful in the diagnosis and establishment of the extension of the process, as well as follow-up.

[Quality control dose calibrators]. / Control de calidad de activímetros.

We have reviewed the legislation about the quality control of dose calibrator. The importance of verifying the correct work of these instruments, is fundamental in daily practice of radiopharmacy and nuclear medicine. The Spanish legislation establishes to include these controls as part of the quality control of radiopharmaceuticals, and the program of quality assurance in nuclear medicine. We have reviewed guides and protocols from international eminent organizations, summarizing the recommended tests and periodicity of them.

[Value of thallium 201-SPECT in typing brain space-occupying lesions]. / Valor de la SPECT con Talio-201 en la tipificación de lesiones ocupantes de espacio intracerebrales.

OBJECTIVE: This study was designed to assess the diagnostic accuracy of single photon emission computed tomography with Tl-201 (SPECT Tl-201) to establish the tumoral or non-tumoral nature of brain space occupying lesions in comparison with usual diagnostic techniques. MATERIAL AND METHODS: The study population consisted of 37 patients, 24 men (64.9 %) and 13 women (35.1 %), mean age 48 +/- 16 years. After establishing the clinical and radiological diagnosis of brain lesion, all patients underwent SPECT Tl-201, evaluating it only by subjective analysis and blinded to neuroestructural techniques. After surgical resection all patients were evaluated anatomopathologically to establish the histologic nature. RESULTS: The sensitivity of SPECT Tl-201 (0.87) was higher than standard neuroimaging techniques (0.78). Specificity (0.43), positive (0.87) and negative (0.43) predictive values of SPECT were similar to neuroestructural procedures (MRI and CT scan) with 0.43, 0.82 and 0.38 values. Tumoral disease prevalence was 0.81. Neuroestructural procedures were non-conclusive in 18.9 % of the studies. No non-conclusive results were obtained with SPECT Tl-201. CONCLUSIONS: SPECT Tl-201 is a diagnostic procedure of high sensitivity to establish the tumoral nature of brain lesions, with poor specificity, similar to structural X-ray techniques.