RESUMEN
OBJECTIVE: To describe 4 T MRI techniques in imaging chondrocalcinosis within the knee and examine the results together with those demonstrated using three-dimensional (3D) computed tomography, conventional radiography, and arthroscopy. DESIGN AND PATIENTS: From a larger clinical imaging study of early osteoarthritis, knee arthroscopy patients were imaged using high-field MRI and high-resolution 3D CT prior to their surgery. Retrospective review of the imaging data diagnosed three patients with chondrocalcinosis. Fat-suppressed 3D spoiled gradient (3D SPGR) and two-dimensional fat-suppressed fast spin echo (FSE) imaging was performed at 4 T. The MR images, multi-planar reformatted CT (MPR-CT) and maximum intensity projection CT (MIP-CT) images, and radiographs were examined by a musculoskeletal radiologist for the presence and location of chondrocalcinosis. The findings from arthroscopy were also included. RESULTS: MRI showed 16 sites of punctate hypointense regions from 18 articular surfaces and five of six menisci with similar signal characteristics. Both meniscal chondrocalcinosis and meniscal tears were clearly visible using the 3D SPGR sequence. Only three sites were demonstrated to have calcification using MPR-CT and MIP-CT revealed an additional three. In articular cartilage surfaces showing surface disruption, arthroscopy demonstrated 11 sites with crystal deposition. Arthroscopy also revealed five menisci with calcification present. CONCLUSION: Our preliminary findings suggest that imaging chondrocalcinosis using spoiled gradient 4 T MRI is superior and complementary to the other imaging modalities in the detection of crystal deposition in both articular cartilage and menisci.
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Enfermedades de los Cartílagos/diagnóstico , Condrocalcinosis/diagnóstico , Articulación de la Rodilla/patología , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Artroscopía , Femenino , Humanos , Imagenología Tridimensional , Articulación de la Rodilla/diagnóstico por imagen , Masculino , Meniscos Tibiales/diagnóstico por imagen , Meniscos Tibiales/patología , Persona de Mediana Edad , Estudios Retrospectivos , Tomografía Computarizada por Rayos XRESUMEN
Knowledge of human blood-flow waveforms is required for in vitro investigations and numerical modelling. Parameters of interest include: velocity and flow waveform shapes, inter- and intra-subject variability and frequency content. We characterized the blood-velocity waveforms in the left and right common carotid arteries (CCAs) of 17 normal volunteers (24 to 34 years), analysing 3560 cardiac cycles in total. Instantaneous peak-velocity (Vpeak) measurements were obtained using pulsed-Doppler ultrasound with simultaneous collection of ECG data. An archetypal Vpeak waveform was created using velocity and timing parameters at waveform feature points. We report the following timing (post-R-wave) and peak-velocity parameters: cardiac interbeat interval (T(RR)) = 0.917 s (intra-subject standard deviation = +/- 0.045 s); cycle-averaged peak-velocity (V(CYC)) = 38.8 cm s(-1) (+/-1.5 cm s(-1)); maximum systolic Vpeak = 108.2 cm s(-1) (+/-3.8 cm s(-1)) at 0.152 s (+/-0.008 s); dicrotic notch Vpeak = 19.4 cm s(-1) (+/-2.9 cm s(-1)) at 0.398 s (+/-0.007 s). Frequency components below 12 Hz constituted 95% of the amplitude spectrum. Flow waveforms were computed from Vpeak by analytical solution of Womersley flow conditions (derived mean flow = 6.0 ml s(-1)). We propose that realistic, pseudo-random flow waveform sequences can be generated for experimental studies by varying, from cycle to cycle, only T(RR) and V(CYC) of a single archetypal waveform.
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Arterias Carótidas/diagnóstico por imagen , Ultrasonografía Doppler de Pulso , Adulto , Velocidad del Flujo Sanguíneo , Electrocardiografía , Femenino , Análisis de Fourier , Pruebas de Función Cardíaca , Frecuencia Cardíaca , Humanos , MasculinoRESUMEN
The skin of the skh-1 mouse after ultraviolet B (280-320 nm, UVB) irradiation shows the pathological changes typical of sunburn damage: spongiosis (edematous spaces) around some cells, necrosis of keratinocytes, giving rise to sunburn cells, inflammatory infiltration of polymorphonuclear leucocytes, etc. In our previous study, these were accompanied by erythema, increased skin sensitivity, and edematous swelling. The topical application of tocopherol acetate (TA) immediately after the UVB exposure decreased these changes. In this paper, multiple measurements of the skin thickness were made at different locations along the magnetic resonance imaging (MRI) cross-sectional image of the skin. This permits effects to be quantified with (if desired) the contralateral half of the back serving as an internal control, either exposed (positive control) or unexposed (negative control). Topical application of TA resulted in an increase in the concentration of free tocopherol in the skin. No qualitative differences in ultrastructural appearance of the UVB-irradiated, TA-treated skin could be discerned by careful examination. In vivo high resolution video microscopy of blood flow in venules of the irradiated mouse ear revealed a large (tenfold) but not statistically significant decrease in stationary lymphocytes adhering to the venule walls. The delaying of the application of TA up to 8 hours after the termination of UVB irradiation still offered statistically significant protection as did immediate application of 5% TA in diluent Myritol 318 (Delios S, Henkel).
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Protectores contra Radiación/administración & dosificación , Piel/efectos de los fármacos , Piel/efectos de la radiación , Quemadura Solar/prevención & control , Vitamina E/análogos & derivados , alfa-Tocoferol/análogos & derivados , Administración Tópica , Animales , Relación Dosis-Respuesta a Droga , Imagen por Resonancia Magnética , Masculino , Ratones , Ratones Pelados , Microscopía Electrónica , Traumatismos Experimentales por Radiación/tratamiento farmacológico , Traumatismos Experimentales por Radiación/patología , Traumatismos Experimentales por Radiación/prevención & control , Protectores contra Radiación/uso terapéutico , Piel/patología , Piel/ultraestructura , Fenómenos Fisiológicos de la Piel , Quemadura Solar/tratamiento farmacológico , Quemadura Solar/patología , Factores de Tiempo , Tocoferoles , Rayos Ultravioleta , Vitamina E/administración & dosificación , Vitamina E/uso terapéuticoRESUMEN
Gadolinium-DTPA enhanced magnetic resonance (MR) imaging has been used to demonstrate uterine vascular changes during ovoimplantation and artificially induced decidualization in rats. Evans blue dye and Gd-DTPA were injected i.v. into rats 10 h after unilateral decidualization was induced by injection of sesame oil into the lumen of one uterine horn. Animals were killed various times later and uteri were removed, T1-weighted proton imaging was performed, and mean image intensities for stimulated and control uterine horns were calculated by computer-assisted image analysis. Macroscopic bluing confined to stimulated horns was apparent 5 min after tracer injection and increased in intensity until the experiment was terminated at 320 min. Analysis of MR images showed that mean image intensity of control horns did not change significantly at any time after injection of the Gd-DTPA and Evans blue whereas mean image intensity of stimulated horns increased significantly by 5 min after injection, peaked at 20 min, and returned to values not different from controls by 320 min. T1-weighted images of day 6 pregnant rats injected with Gd-DTPA and Evans blue revealed patterns of image enhancement that matched those of macroscopic bluing. Uterine concentrations of radioactivity after injection of 153Gd-DTPA indicated that increased extracellular fluid volume (ECFV) produces the image enhancement of stimulated horns since the tracer permeates the extracellular fluid of both horns. Gd-DTPA-enhanced MR imaging of uteri after deciduogenic stimulation revealed significant image enhancement for stimulated horns at both 9 and 27 h after stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)
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Vasos Sanguíneos/anatomía & histología , Implantación del Embrión , Gadolinio , Imagen por Resonancia Magnética/métodos , Compuestos Organometálicos , Ácido Pentético , Útero/irrigación sanguínea , Animales , Medios de Contraste , Azul de Evans , Femenino , Gadolinio DTPA , Embarazo , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
Exposure of the skin of the back of skh-1 hairless mice to UVB (310 nm peak) irradiation at doses of 0.115-0.23 J/cm2 results after 24-48 h in an erythema which can be quantified using an erythema meter, providing a useful model of sunburn. Application of pure d-alpha-tocopherol acetate, a thick oil, to the skin immediately following the exposure to UVB significantly reduces the increase in erythema index, by 40-55%. At the lower dose (0.115 J/cm2), skin thickness (associated with edematous swelling of the sunburned skin) was measured by a novel non-invasive technique not previously reported for this purpose--magnetic resonance imaging (MRI). In two experiments the UVB-induced increase in skin thickness was significantly reduced at 24 hr by 29 and 54%, and at 48 hr by 26 and 61%. After 8 days the untreated irradiated mouse skin still showed a significant increase in thickness (24%) compared to the untreated unirradiated control, while the treated irradiated control was not significantly thicker than the unexposed control. Skin sensitivity was tested using a modification of the technique of esthesiometry, by observing rapid avoidance responses of the mouse to a pressure of 0.96 g/cm2 exerted by applying to the skin the tip of a nylon esthesiometer fiber extended to 60 mm in length. The untreated irradiated mice were more sensitive (p less than 0.07, Wilcoxon test) than the treated irradiated mice, and also significantly different from the untreated unirradiated control mice (p less than 0.04, Wilcoxon test), but the treated irradiated mice were not significantly differently sensitive when compared to the unirradiated controls (p less than 0.32). Taken together these data indicate that the erythema, edema, and skin sensitivity commonly associated with UVB-induced sunburn are significantly reduced by topical application of tocopherol acetate even after the exposure has occurred. This observation suggests that treatment of sunburn may be possible even after the irradiation has stopped, by a derivative of d-alpha-tocopherol which is stable to autooxidation.