Protocolo de un día vs protocolo de dos días de adquisición mediante gammagrafía con leucocitos marcados in vitro para el diagnóstico de infección osteoarticular / One-day protocol versus two-day protocol in acquisition of scintigraphy with "in vitro" labelled white blood cells for diagnosis of osteoarticular infection

Introducción: Resulta difícil determinar la infección osteoarticular y diferenciar entre inflamación e infección mediante procedimientos de laboratorio e imagen (TC, RM, US). La gammagrafía con leucocitos marcados (GLM) constituye la prueba de medicina nuclear de elección, pero su duración es de dos días, y a veces es difícil diferenciar entre tejido blando e infección, por lo que se produce una variabilidad interobservador que hace disminuir su especificidad. Objetivo: Demostrar la utilidad del protocolo de un día de GLM con corrección por decaimiento del tiempo de adquisición para diagnosticar la infección osteoarticular y reducir la variabilidad interobservador. También se evaluó la función de SPECT/TC en GLM en la localización del foco de infección. Métodos: Se estudiaron prospectivamente 110 pacientes con sospecha de infección osteoarticular. Se obtuvieron imágenes planares con corrección por decaimiento del tiempo de adquisición a 30min, 4h, 8h y 24h. Las imágenes planares de GLM se agruparon en dos protocolos: Protocolo de un día: los expertos evaluaron imágenes de 30min, 4h y 8h. Protocolo de dos días: los expertos evaluaron imágenes de 30min, 4h y 24h. Ambos protocolos fueron clasificados como: Negativos: ausencia de migración leucocitaria. Positivos: persistencia o incremento de la captación con el tiempo. Inflamación aséptica: disminución de la captación con el tiempo. La SPECT/TC se realizó en 72 pacientes. Se calculó el índice kappa para evaluar la variabilidad interobservador. Resultados: Se confirmó infección en 34 casos. Los valores de sensibilidad, especificidad, valor predictivo positivo, valor predictivo negativo y precisión diagnóstica fueron del 97,1, del 97,4, del 94,3, del 98,7 y del 97,3% para el protocolo de un día, y del 94,1, del 97,4, del 94,1, del 97,4 y del 96,4 para el protocolo de dos días, respectivamente. SPECT/TC contribuyó al diagnóstico en 45 de 50 pacientes con GLM planar positiva. Índice kappa: 0,8 para el protocolo de un día y 0,79 para el protocolo de dos días. Conclusión: El protocolo de un día de GLM con corrección por decaimiento del tiempo de adquisición y SPECT/TC permite el diagnóstico precoz y preciso de la infección osteoarticular

Introduction: It is difficult to determine osteoarticular infection and differentiate inflammation from infection with laboratory and imaging procedures (CT, MRI, US). Labelled white-blood-cell scintigraphy (WBCS) is the nuclear medicine test of choice but it takes two days, sometimes finds it difficult to differentiate soft tissue from bone infection and therefore causes interobserver variability, which decreases its specificity. Objective: To demonstrate the usefulness of the one-day protocol with time decay-corrected acquisition in WBCS to diagnose osteoarticular infection and to reduce interobserver variability. The role of SPECT/CT in WBCS in locating the infected focus was also evaluated. Methods: 110 patients with suspected osteoarticular infection were studied prospectively. Planar images were obtained with time decay-corrected acquisition at 30min, 4h, 8h and 24h. WBCS planar images were grouped in two protocols: One-day protocol: experts evaluated 30min, 4h and 8h images. Two-day protocol: experts evaluated 30min, 4h and 24h images. Both protocols were classified as: Negative: absence of leukocyte migration. Positive: uptake persisted or increased over time. Aseptic inflammation: uptake decreased over time. SPECT/CT was performed in 72 patients. Kappa index was calculated to evaluate interobserver variability. Results: Infection was confirmed in 34 cases. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 97.1%, 97.4%, 94.3%, 98.7%, and 97.3% for the one-day protocol and 94.1%, 97.4%, 94.1%, 97.4%, and 96.4% for two-days-protocol. SPECT/CT contributed to diagnosis in 45/50 patients with planar WBCS positive. Kappa index: 0.8 for one-day protocol and 0.79 for two-day protocol, respectively. Conclusion: One-day protocol with time decay-corrected acquisition WBCS and SPECT/CT enables early and accurate diagnosis of osteoarticular infection

Hipoestesia mentoniana como manifestación de metástasis mandibular diagnosticada en la gammagrafía ósea / Numb chin syndrome as a manifestation of jaw metastasis diagnosed in a bone scan

El síndrome del mentón entumecido (numb chin syndrome [NCS]) en muchos casos puede representar una patología banal, pero al poder asociarse con procesos malignos, su presencia debe alertar al clínico como posible manifestación de una enfermedad maligna oculta. En pacientes previamente diagnosticados de una neoplasia, representa a menudo un signo ominoso que indica mal pronóstico por el rápido progreso de la enfermedad. Se presenta el caso de un paciente de 62 años diagnosticado de cáncer de pulmón y de vejiga que aqueja sensación de «acorchamiento» en zona mentoniana. La gammagrafía ósea confirma la sospecha de enfermedad metastásica ósea falleciendo a los 2 meses de manifestarse este signo (AU)

In many cases, numb chin syndrome (NCS) may represent a banal pathology. However, as it can be associated with malignant processes, its presence should alert the clinician of a possible occult disease. In patients already diagnosed with cancer, it often represents an ominous sign that indicates poor prognosis, due to the rapid progress of the disease. The case is presented of a 62-year-old man diagnosed with synchronous lung and bladder cancer, who suddenly complained of numbness in the chin. The bone scan confirmed the suspicion of metastastic bone disease, and the patient died two months after the appearance of this sign (AU)

Condrosarcoma secundario: correlación radiopatológica / Secondary chondrosarcoma: radiopathological correlation

El condrosarcoma es un tumor óseo maligno de origen cartilaginoso. Es el tercero en frecuencia de los tumores óseos malignos, solo superado por el mieloma múltiple y el osteosarcoma. El 75% son lesiones primarias y el 25% restante pertenecen a categorías especiales, entre las que se cuentan las variantes anatomopatológicas y las formas secundarias. Un condrosarcoma secundario es aquel que aparece en una lesión cartilaginosa benigna preexistente, entre las que se incluyen el osteocondroma solitario, la osteocondromatosis múltiple, el encondroma, las diferentes encondromatosis y la condromatosis sinovial primaria. La incidencia de la transformación maligna es muy variable en función del tipo de lesión. En este trabajo se discuten e ilustran las diferentes formas de condrosarcomas secundarios, poniendo un especial énfasis en los hallazgos radiológicos que deben alertar y que permiten al radiólogo tener un papel central en el diagnóstico, manejo y seguimiento de estos pacientes (AU)

Chondrosarcomas are malignant bone tumors originating in cartilage. Chondrosarcoma is the third most common malignant bone tumor after multiple myeloma and osteosarcoma. About 75% of chondrosarcomas are primary lesions. The remaining 25% belong to special categories such as histologic variants and secondary forms. A secondary chondrosarcoma is one that appears in a pre-existing benign chondral lesion; the different types of secondary chondrosarcomas include solitary osteochondroma, multiple osteochondromatosis, enchondroma, the different types of enchondromatosis, and primary synovial chondromatosis. The incidence of this malignant transformation varies widely in function of the type of lesion. In this article, we discuss and illustrate the different types of secondary chondrosarcomas, placing special emphasis on the imaging findings that should alert to these lesions and give radiologists a key role in the diagnosis, management, and follow-up of these patients (AU)

Prospective evaluation of visual outcomes with three presbyopia-correcting intraocular lenses following cataract surgery.

PURPOSE: To compare the visual acuity and quality of vision achieved with three widely-used intraocular lenses (IOLs) in subjects with bilateral cataracts. PATIENTS AND METHODS: This three-arm, parallel, prospective, partially masked, single-surgeon study randomized 78 subjects to receive bilateral Crystalens® Advanced Optics (AO) accommodating IOLs, AcrySof® IQ ReSTOR® +3.0 multifocal IOLs, or TECNIS® Multifocal IOLs. Examinations were assessed through days 120 to 180. RESULTS: The Crystalens AO group had statistically significantly better monocular and binocular, high-contrast (HC) and low-contrast (LC) uncorrected intermediate visual acuity, HC and LC distance-corrected intermediate visual acuity, and significantly fewer monocular and binocular halos and starbursts than did the ReSTOR and TECNIS groups. Monocular and binocular, HC and LC uncorrected near visual acuity exhibited no significant differences among the three lenses. For monocular and binocular HC distance-corrected near visual acuity, the Crystalens AO performed significantly better than the TECNIS and was not significantly different from the ReSTOR. For monocular and binocular LC distance-corrected near visual acuity, the Crystalens AO performed significantly better than both the ReSTOR and the TECNIS. Contrast sensitivity was clinically similar between groups. The Crystalens AO produced statistically fewer halos and starbursts. CONCLUSION: All three IOLs had excellent uncorrected acuity results at all distances and had good safety, confirming the established safety and effectiveness of these IOLs. Distance and near vision were similar between all three IOLs, and the Crystalens AO provided statistically significantly better intermediate vision.

Imaging of humic substance macromolecular structures in water and soils

Humic substances (HSs) are the natural organic polyelectrolytes formed from the biochemical weathering of plant and animal remains. Their macromolecular structure and chemistry determine their role in biogeochemical processes. In situ spectromicroscopic evidence showed that the HS macromolecular structures (size and shape) vary as a function of HS origin (soil versus fluvial), solution chemistry, and the associated mineralogy. The HSs do not simply form coils in acidic or strong electrolyte solutions and elongated structures in dilute alkaline solutions. The macromolecular structural changes of HSs are likely to modify contaminant solubility, biotransformation, and the carbon cycle in soils and sediments.

Characterization of Metal Complexation in Multiligand Systems with Lanthanide Luminescence.

The effectiveness of an Eu3+ luminescence technique to describe metal complexation reactions in humic substances was evaluated. The molecular uncertainties intrinsic to humic substances were circumvented by using polyacrylic acid (PAA) and polyvinylsulfonic acid (PVS) as probes. An adequate determination of the Eu3+-citrate affinity constant suggested that this technique could potentially be used to characterize metal binding reactions in polyelectrolytes. Various mixtures of PAA and PVS were then evaluated. The commonly adopted assumption of a single metal binding environment in those systems proved ineffective and resulted in a misleading representation of the Eu-PAA binding isotherm. Our evidence indicates that prior knowledge about the number of binding environments, as well as their relative contribution to the overall sorption, is needed to describe metal binding on humic substances appropriately through this approach. The effect of metal competition on Eu3+ binding by a mixed polymer system (1:1 PAA:PVS) was also ascertained. The affinity series obtained (Cu2+ > Pb2+ >> Cd2+ >/= Co2+ congruent with Mg2+ congruent with Ni2+ > Ca2+) was similar to that frequently observed in humic substances, which reinforces the utility of these polymers as their surrogates in metal sorption studies. Copyright 1998 Academic Press.