RESUMEN
AIM: The objective of this study was to determine whether dopamine transporter (DAT) scintigraphy influences the management of movement disorders in clinically indeterminate cases. MATERIALS AND METHODS: Seventeen patients (ten women, seven men; age range 44-84 years) with a presumptive diagnosis of Parkinson's disease (PD) were referred for single-photon emission computed tomography (SPECT) scintigraphy using [(123)I]ioflupane between November 2002 and August 2003. The scintigraphic results, clinical diagnosis, and management intentions pre- and post-examination were recorded. RESULTS: Of the 17 patients who underwent scintigraphy, two patients on neuroleptic medication exhibited features of PD; one had an abnormal scintigraphic examination that confirmed PD, the other had a negative examination, confirming drug-induced parkinsonism, and these were managed accordingly. Of the other cases, the results of 10 examinations were compatible with PD. Five were reported as being normal, the final diagnoses in this group included: cerebrovascular disease (CVD); early Alzheimer's; provisional clinical diagnosis of generalized movement disorder; and possible Wilson's disease. One patient was felt to have a parkinsonian syndrome despite the normal result (this patient had a positive apomorphine test). CONCLUSION: This series illustrates the value of DAT scintigraphy in the management of clinically indeterminate movement disorders at a tertiary referral centre arguing for its use in the initial diagnostic process. However, it is clear that the use of DAT scintigraphy poses significant resource implications. Further evidence should clarify the exact role of DAT scintigraphy in clinically indeterminate cases.
Asunto(s)
Proteínas de Transporte de Dopamina a través de la Membrana Plasmática , Radioisótopos de Yodo , Nortropanos , Enfermedad de Parkinson/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/terapia , Enfermedad de Parkinson Secundaria/inducido químicamente , Enfermedad de Parkinson Secundaria/diagnóstico por imagen , Enfermedad de Parkinson Secundaria/terapia , Cintigrafía , Estudios RetrospectivosRESUMEN
The Magenstrasse and Mill (M&M) procedure for obesity is designed to preserve normal gastric emptying mechanisms. The hypothesis investigated in this study was that gastric emptying would be normal after the M&M gastroplasty. Gastric emptying studies were performed using both liquid and solid test meals, in ten morbidly obese patients (MO group) and in 13 patients after the M&M procedure (MM group). Seven people of normal weight served as controls and were matched for age, sex and height to the M&M and MO groups. Three years after the M&M procedure, mean (SD) weight loss was 42 (19) kg, with a mean loss of excess weight of 58% (20%). Gastric emptying half-times (t 1/2) are expressed in minutes, as median values (25th and 75th percentiles). The t 1/2 for solids was 97 (85-110) min in the control group, 140 (86-220) min in the MO group and 79 (46-150) min in the MM group. Median gastric emptying for solids was 0.7% (0.6%-0.8%) per minute in the control group, 0.5% (0.3%-0.8%) in the MO group and 0.9% (0.4%-1.4%) in the M&M group. There were no statistically significant differences in the emptying times of the three groups. It is concluded that the M&M procedure achieves acceptable weight loss, while preserving gastric emptying mechanisms and thus minimising possible side-effects such as vomiting, dumping and diarrhoea, which are common complications of gastric bypass procedures.
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Vaciamiento Gástrico , Gastroplastia , Obesidad Mórbida/cirugía , Administración Oral , Adulto , Sistema Digestivo/diagnóstico por imagen , Femenino , Gastroplastia/métodos , Humanos , Masculino , Persona de Mediana Edad , Obesidad Mórbida/diagnóstico por imagen , Obesidad Mórbida/fisiopatología , Cintigrafía , Radiofármacos/administración & dosificación , Agregado de Albúmina Marcado con Tecnecio Tc 99m/administración & dosificación , Pentetato de Tecnecio Tc 99m/administración & dosificaciónRESUMEN
This paper outlines how objective measurements of both image quality, in terms of signal-to-noise ratio, and effective dose may be used as tools to find the optimum kVp range for a digital chest radiography system. Measurements were made with Thoravision, an amorphous selenium-based digital chest X-ray system. The entrance surface dose and the effective dose to an anthropomorphic chest phantom were determined demonstrating how effective dose is related to beam quality. The image quality was measured using detective quantum efficiency, threshold contrast and a radiologist preference trial involving 100 patients. The results show that, despite the fact that the entrance surface dose decreases as the kVp increases, the effective dose, a better measure of the risk, reaches a minimum value between 90 and 110 kVp; however, the image quality decreases as the kVp increases. In this study the optimum kVp for chest radiography, using a selenium-based radiography system, is in the range 90-110 kVp. This is contrary to the 120- to 150-kVp range that is commonly used. Also, this study shows how objective measurements can be used to optimise radiographic technique without prolonged patient trials.
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Intensificación de Imagen Radiográfica , Radiografía Torácica/normas , Dosis de RadiaciónRESUMEN
Solid-state digital x-ray imaging detectors of flat-panel construction will play an increasingly important role in future medical imaging facilities. Solid-state detectors that will support both dynamic (including fluoroscopic) and radiographic image recording are under active development. The image quality of an experimental solid-state digital x-ray image detector operating in a continuous fluoroscopy mode has been investigated. The threshold contrast detail detectability (TCDD) technique was used to compare the fluoroscopic imaging performance of an experimental dynamic solid-state digital x-ray image detector with that of a reference image intensifier television (IITV) fluoroscopy system. The reference system incorporated Plumbicon TV. Results were presented as a threshold detection index, or H(T)(A), curves. Measurements were made over a range of mean entrance air kerma (EAK) rates typically used in conventional IITV fluoroscopy. At the upper and mid EAK rate range (440 and 220 nGy/s) the solid-state detector outperformed the reference IITV fluoroscopy system as measured by TCDD performance. At the lowest measured EAK rate (104 nGy/s), the solid-state detector produces slightly inferior TCDD performance compared with the reference system. Although not statistically significant at this EAK rate, the difference will increase as EAK is lowered further. Overall the TCDD results and early clinical experiences support the proposition that a current design of dynamic solid-state detector produces image quality competitive with that of modern IITV fluoroscopy systems. These findings encourage the development of compact and versatile universal x-ray imaging systems based upon solid-state detector technology to support R & F and vascular/interventional applications.
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Intensificación de Imagen Radiográfica/métodos , Fenómenos Biofísicos , Biofisica , Fluoroscopía/métodos , Fluoroscopía/estadística & datos numéricos , Humanos , Tecnología Radiológica , Pantallas Intensificadoras de Rayos XRESUMEN
The aim of this study was to evaluate the physical performance of an experimental flat-panel digital X-ray detector plate (FDXD), and to assess its clinical potential in radiographic and fluoroscopic mode. The efficiency of the detector was assessed by calculating the low-frequency detective quantum efficiency (DQE(0)), and a measure of image quality was obtained using a threshold contrast detail detectability (TCDD) test object. A range of clinical examinations were also carried out, and the results reviewed by members of the radiology staff. The DQE(0) of the system was calculated to be almost 75%, compared with a value of approximately 20 % for modern computed radiography equipment, offering the potential for increased image quality or significant dose reduction. Measurements using the TCDD test object demonstrated a corresponding advantage for the FDXD in image quality and dose efficiency. Clinical studies are producing radiographic results which are at least the equal of the best currently available digital technology, and a limited number of examinations using fluoroscopic mode at 25 frames per second have been equally encouraging. Equipment using FDXD technology could potentially fulfill all the radiographic and fluoroscopic requirements of the digital department, with improved image quality and dose efficiency.
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Intensificación de Imagen Radiográfica/instrumentación , Diseño de Equipo , Fluoroscopía/instrumentación , HumanosRESUMEN
This paper presents a brief technical evaluation and first review of clinical experiences with an experimental direct digital X-ray image detector designed to support both dynamic and snap-shot imaging. Derivatives of this type of image detector can potentially fulfil the majority of the fluoroscopic and radiographic imaging requirements of clinical radiology departments, and initial results suggest that imaging systems using the new technology will provide a high quality dose-efficient solution to the search for a universal digital X-ray image detector.
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Intensificación de Imagen Radiográfica/instrumentación , Tecnología Radiológica/instrumentación , Ciego/diagnóstico por imagen , Diagnóstico por Computador , Estudios de Evaluación como Asunto , Fluoroscopía , Humanos , Estómago/diagnóstico por imagen , Articulación de la Muñeca/diagnóstico por imagenRESUMEN
Thyroid imaging has historically relied heavily on scintigraphy, although, not surprisingly in view of the superficial position of the gland, ultrasound has assumed an increasingly prominent role in recent years. The other cross-sectional imaging modalities can also be useful, and the emergence of new radiopharmaceuticals and the increasingly central role of fine needle aspiration cytology have further added to the range of diagnostic techniques available. This review attempts to summarize the current state of knowledge, and makes some suggestions for the most efficient use of imaging resources in the investigation of thyroid disease.
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Enfermedades de la Tiroides/diagnóstico , Bocio/diagnóstico , Bocio/diagnóstico por imagen , Humanos , Hipertiroidismo/diagnóstico , Hipertiroidismo/diagnóstico por imagen , Radiografía , Enfermedades de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/diagnóstico , Neoplasias de la Tiroides/diagnóstico por imagen , Nódulo Tiroideo/diagnóstico , Nódulo Tiroideo/diagnóstico por imagen , Tiroiditis/diagnóstico , Tiroiditis/diagnóstico por imagen , UltrasonografíaRESUMEN
PURPOSE: To assess diagnostic performance and reader preference when reporting results from digital hard-copy and two soft-copy formats of skeletal digital radiography. MATERIALS AND METHODS: The data comprised hand radiographs of patients undergoing renal dialysis. Normal hand radiographs obtained in trauma patients were assessed as control images. One hundred fifteen images acquired with a photostimulable-phosphor computed radiography system were analyzed. Image selection and initial assessment were by consensus of two experienced radiologists, who graded the radiographic changes of hyperparathyroidism with the Ritz scoring system. The images were then presented to four readers in three formats: hard-copy output and soft-copy presentations at 2K2 and 1K2 resolutions. These readers scored pathologic change and image preference. The results were analyzed with the receiver operating characteristic technique. RESULTS: There was a significant improvement in diagnostic performance for both soft-copy formats relative to the hard-copy format (P < .001). No significant difference in diagnostic performance was found between the two soft-copy formats. There was a significant preference for both soft-copy formats relative to the hard-copy format (P < .01), with the 2K2 soft-copy images preferred to the 1K2 images (P < .01). CONCLUSION: Soft-copy reporting can provide superior diagnostic performance even for images viewed at a modest (1K2) resolution. The lack of difference between the two soft-copy formats has important economic implications with respect to departmental hardware requirements.
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Huesos/diagnóstico por imagen , Intensificación de Imagen Radiográfica , Mano/diagnóstico por imagen , Humanos , Hiperparatiroidismo/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador , Curva ROC , Pantallas Intensificadoras de Rayos XAsunto(s)
Calcitonina/uso terapéutico , Distrofia Simpática Refleja/tratamiento farmacológico , Administración Intranasal , Antiinflamatorios no Esteroideos/uso terapéutico , Calcitonina/administración & dosificación , Calcio/administración & dosificación , Calcio/uso terapéutico , Estudios de Seguimiento , Humanos , Cintigrafía , Distrofia Simpática Refleja/diagnóstico por imagenRESUMEN
A questionnaire was sent to 221 nuclear medicine departments in the UK asking about their staffing and work patterns. In particular, we wanted to know how many of them offered an on-call service. In those cases where departments wished to offer this service but did not do so, they were asked what was stopping them. Replies were received from 150 departments, a response rate of 68%. Of these, 43 (29%) offered an on-call service, although only 21 (14%) performed ten or more out-of-hours scans in an average year. The examinations most commonly offered were lung scans, localization of gastrointestinal bleeding and renography. In those centres wishing to offer an on-call service but which were unable to do so, limitation of resources was the reason most frequently advanced. Lack of clinical demand was the factor most often quoted by those not wishing to extend their service. The issue of emergency scintigraphy is discussed in the light of these results.
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Servicio de Medicina Nuclear en Hospital/organización & administración , Admisión y Programación de Personal/estadística & datos numéricos , Cintigrafía/estadística & datos numéricos , Actitud del Personal de Salud , Inglaterra , Humanos , Encuestas y Cuestionarios , Recursos Humanos , Carga de TrabajoRESUMEN
The Royal Air Force (RAF) experience on local back injury with all ejection seats is that 50% have vertebral fractures on radiographic examination, with or without symptoms. These aviators are placed under the care of an orthopedic specialist and restricted from flying duties for 3 months or more. About half of the remainder demonstrate positive bone scans. Until recently, RAF policy was to treat these individuals the same as those with radiographically defined fractures. The author recommends this group of pilots be examined by orthopedic surgeons, and reviewed annually to assess long-term sequelae. Meanwhile, if asymptomatic, they are allowed to return to flying duties. The RAF recently incorporated most of these recommendations into a policy change.
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Aeronaves/instrumentación , Fracturas Óseas/diagnóstico por imagen , Personal Militar , Traumatismos Vertebrales/diagnóstico por imagen , Tecnecio , Medicina Aeroespacial , Humanos , Cintigrafía , Reino UnidoRESUMEN
A case of emphysematous gastritis associated with extensive gastric infarction after acute pancreatitis and acute renal failure is described. This complication was diagnosed on a plain abdominal radiograph and confirmed endoscopically. Extensive gastric and hepatic infarction was seen at necropsy.