Enrique Mollá

Cognitive impairment: classification by 1H magnetic resonance spectroscopy

1H magnetic resonance spectroscopy (MRS) allows accurate and non‐invasive in vivo metabolic study, and is a useful tool for the diagnosis of different forms of dementias. Cognitive impairment pathologies have been almost exclusively studied with MRS by comparison with healthy without a global comparison amongst Alzheimer disease (AD), vascular dementia, mild cognitive impairment (MCI) and major depression patients with cognitive impairment. Whereas decrease of N‐acetylaspartate (NAA) and increase myo‐Inositol (mI) at different brain locations by 1H MRS are common features of AD, Choline (Cho) alterations have been inconclusive. In our study, 64 patients with cognitive impairment were evaluated by 1H MRS using two echo times (31 and 136 ms). There were statistical differences between dementia (AD and vascular dementia) and non‐dementia (MCI and depression) spectra at posterior cingulate gyrus. Cho/Cr, mI/Cr and NAA/Cr have been valuables for the differentiation amongst the different cognitive impairment entities. NAA/mI provides the best area under the ROC curve with the highest sensitivity (82.5%) and specificity (72.7%) in diagnosing AD. NAA/mI and mI/Cr ratios differed amongst the four cognitive impairment degenerative pathologies. Metabolic MRS differences found amongst patients with cognitive impairment entities can be useful to differentiate between AD, vascular dementia, MCI and depression.

MR imaging of baker cysts—prevalence and relation to internal derangements of the knee

Rationale and objectives: To evaluate the prevalence of popliteal cysts in patients studied with magnetic resonance (MR) imaging. Cyst presence and volume will be related to other internal derangement of the knee.Materials and methods: Three hundred and eighty-two consecutive patients with a MR study of the knee were included. Images were obtained in the three spatial orthogonal planes and evaluated through consensus. Four categories were established for the Baker cyst and synovial fluid (absence, minimum, moderate and massive), and the presence of meniscal, cruciate ligaments and cartilage lesions were recorded. Statistical analysis was carried out with bivariate analysis (χ2 of Pearson and Gamma tests).Results: From the 382 patients, 145 had Baker cysts (38.0%). Cyst content was minimum in 99, moderate in 34 and massive in 12. Joint effusion was observed in 269 patients (70.4%), being minimal in 140 patients, moderate in 119 and massive in ten. Meniscal lesions were observed in 195 patients (51%), while 58 patients (15%) had a cruciate ligament lesion. Baker cyst has a statistically significant direct relationship with the presence and quantity of synovial fluid (P=0.002) and with the presence and type of meniscal lesion (P=0.01) but not with cruciate ligaments or cartilage lesions.Conclusions: The prevalence of Baker cysts in MR studies of the knee is high. Its presence and volume are related to the quantity of synovial fluid, and to the presence and severity of meniscal lesions.

Relationship between low back pain, disability, MR imaging findings and health care provider

ObjectiveTo determine the association between the self-report of pain and disability and findings on lumbar MR images, and to compare two different health care providers in Spanish patients with low back pain (LBP).DesignCross-sectionalMaterial and methodsA total of 278 patients, 137 men and 141 women aged 44±14 years submitted with low back pain (LBP) were studied. One hundred and nine patients were from the National Health System (NHS) and 169 from private practice. Patients with previous discitis, surgery, neoplasm or traumatic episodes were excluded. Every patient completed a disability questionnaire with six core items, providing a score of disability from 2 to 28. All patients had sagittal spin-echo T1 and turbo spin-echo T2, axial proton-density and MR myelography weighted images. MR images of the two most affected disc levels were read, offering an MR imaging score from 0 to 30.ResultsPatients with a combination of LBP and sciatica showed the highest levels of disability (p=0.002). MR imaging scores only correlated with pain interference with normal work (p=0.04), but not with other disability questions. Patients from the NHS showed greater disability scores than private ones (p=0.001) and higher MR imaging scores (p=0.01).ConclusionIn patients with LBP, MR imaging only correlates with pain interference with work but not with other disability questions. Differences are found between private and NHS patients, the latter being more physically affected.

Utilidad de la mielografía mediante resonancia magnética en el diagnóstico de las enfermedades de la columna vertebral

To evaluate the utility of myelography obtained with MR imaging (MR-myelography) as a complementary tool in patients studied with a conventional MR examination of the spine. 275 consecutive patients were included. All of them were studied with MR-myelography in 2 planes, coronal and sagittal, with a turbo spin-echo single-shot technique, as a complement to a conventional MR study of the spine; 130 were males and 145 women, with ages ranging from 20 to 71 years (mean, 45 years). The analyzed variables were age, sex, vertebral segment studied, alteration of the dural sac, intradural nerve roots, emergent roots, and presence of intradural lesions, meningeal cysts, and spinal stenosis. The added value of MR-myelography regarding conventional MR was categorized. MR-myelography obtained new information in 88 cases (32%), being considered irrelevant information in 42 cases and relevant in 46 cases (16.7% of all cases) (amputations of the emergent roots and alterations of the intradural roots). MR-myelography did not contribute to any type of additional information to the conventional MR study in 187 cases (68% of all studies). MR-myelography is a rapid acquisition technique that supplements the conventional MR study of the spine, contributing with relevant new information in the analysis of the spine diseases 16.7% of cases.

Magnetic resonance myelography evaluation of the lumbar spine end plates and intervertebral disks.

Purpose: To evaluate the value of magnetic resonance (MR) myelography in the evaluation of intervertebral disk and end‐plate degenerative changes in the lumbar spine. Material and Methods: Conventional MR and MR myelography examinations were performed in 150 consecutive patients (69 F and 81 M, mean age 45±15 years, range 18–89). Sagittal T1 and T2‐weighted TSE images were compared to MR myelography obtained with a multishot‐TSE‐T2‐weighted sequence (4000/250/fat suppression). Coronal, sagittal, and both oblique MR myelography projections were obtained. Image analysis was carried out independently by two radiologists who categorized lumbar disks into normal, degenerated, or edematous; and vertebral end plates into normal, edematous, or with fatty changes. The proportions were statistically compared at every lumbar intervertebral level. Results: There was good agreement in the classification of disk disease (Kappa: 0.8–0.9). MRI detected a larger number of disk degeneration and end‐plate fatty metamorphosis, while the MR myelography technique depicted a larger number of edematous disks and end plates. Conclusion: MR myelography was of limited value in detecting the same vertebral end‐plate changes observed in MRI, although with similar findings in disk disease. However, the higher detection of edema changes by MR myelography should be analyzed prospectively, as it could be more sensitive than conventional MR sequences.

MR-myelography as an adjunct to the MR examination of the degenerative spine.

Our objective was to analyse the usefulness of single-slice MR-myelography images as a complementary test to conventional MR of the spine in patients with clinically suspected degenerative spine disease. A prospective analysis of 1022 consecutive patients studied with conventional MR and MR-myelography (four acquisitions: one coronal plane, one sagittal plane, and two oblique lateral, right and left planes) examinations was performed. Conventional MR and MR-myelography studies were classified as positive when morphological or structural alterations were noted. Positive MR-myelography information was also categorized as relevant if findings were considered important and radiologically significative to the final diagnosis (either by increasing the radiologists confidence in the diagnosis or because the findings were not observed in the conventional study). Other positive findings were considered non- relevant. There were 62% cases considered positive in the MR-myelography examination. Of them, 3% revealed no alterations on the conventional MR examination. Of the negative MR-myelography studies, 75% had a positive conventional MR examination. Considered as diagnostic techniques, their Kappa concordance was poor. However, MR-myelography complemented the information obtained with the conventional MR examination of the spine, this information being relevant to the final MR diagnosis in 22% of the total number of cases. The contribution of MR-myelography was not different in the three spinal levels. In conclusion, MR-myelography complements the information obtained with conventional MR in a large number of cases.

Comparison of different injection forms in CT examination of the upper abdomen.

AbstractBackground: The optimal technique for administration of intravenous contrast medium in computed tomography (CT) remains controversial. Therefore, we analyzed the influence of variable-rate injection protocols. Methods: A double-blind, parallel-group study was conducted in 60 patients studied with the same helical CT contrast-enhanced protocol. Patients were randomly distributed into three groups: monophasic (123 mL at 2.5 mL/s), biphasic (123 mL, 60 mL at 1.5 mL/s and then 63 mL at 2.5 mL/s), and sigmoid (0.6 mL/s ending at 2.5 mL/s). Contrast-enhancement efficacy was evaluated by attenuation coefficient measurements. Results: The monophasic injection protocol produced a statistically higher liver, inferior vena cava, and portal enhancement than did the low–high biphasic and sigmoid protocols. The biphasic protocol produced a statistically higher enhancement in the superior aorta. The enhancement obtained with the monophasic protocol was always higher than or equal to those obtained with the biphasic protocol in all measurement protocols except in the superior aorta and the aortic bifurcation. Conclusions: A monophasic injection produces better parenchymal and venous enhancement. When arterial enhancement is important, a low–high biphasic protocol can be used. A sigmoid protocol, with the parameters used in our series, is significantly less effective.

Formas de presentación de las masas intraarticulares

Objetivo Las tumoraciones intraarticulares son relativamente raras y sus caracteristicas en resonancia magnetica (RM) poco conocidas. Nuestro objetivo en este trabajo ha sido valorar la presentacion y los hallazgos de imagen en RM para las diferentes formas histologicas en una serie de 22 pacientes. Material y metodos Revisamos los hallazgos de imagen en RM de 22 masas intraarticulares (18 en la rodilla, dos en tobillo y dos en hom-bro). Las variables estudiadas fueron: calcificaciones, edema, morfolo-gia, metahemoglobina, hemosiderina, homogeneidad, margenes, alte-raciones oseas, intensidad de senal en T1, intensidad de senal en T2/STIR, presentacion clinica y edad. Las relaciones estadisticas se es-tablecieron con las pruebas de χ2 y de ANOVA (Student-Newman-Keuls). Resultados Los tumores intraarticulares se distribuyen en 14 (63,6%) sinovitis villonodular pigmentada (SVNP), tres (13,6%) he-mangiomas, tres (13,6%) sarcomas sinoviales y dos (9,1%) condrosar-comas. Se encontraron relaciones estadisticamente significativas entre los tipos histologicos de tumor y las calcificaciones (p = 0,004), irregulares en condrosarcomas y flebolito en hemangiomas; la forma (p = 0,007), serpiginosa en los hemangiomas y oval en la SVNP focal; las areas de hemosiderina (p = 0,002), de la SVNP y el sarcoma sinovial; la presentacion clinica (p = 0,003), con alteraciones cutaneas en los he-mangiomas; y la edad (p = 0,04), siendo mas jovenes los pacientes con hemangiomas (media, 21 anos) y mayores los pacientes con sinovio-sarcomas (media, 56 anos). Conclusion En las tumoraciones intraarticulares la presencia de calcificaciones, la morfologia del tumor, la presencia de hemosiderina, la edad del paciente y la presentacion clinica son datos estadisticamen-te diferentes en funcion del tipo histologico.

Mapas de resonancia magnética functional obtenidos con PC

Objetivos: El estudio de resonancia magnetica funcional (RMf) tiene una especial relevancia en el analisis de diversas activaciones cerebrales. En este trabajo se describe el desarrollo de un programa informatico para PC que analiza estas imagenes para obtener mapas de activacion funcional de una forma sencilla. Material y Metodos: Los mapas de activacion se basan en las diferencias temporales de oxihemoglobina en un plano tomografico. Para detectar estas diferencias se comparan las intensidades registradas repetidamente durante dos estados distintos del cerebro, control y activacion. Los experimentos se han realizado en un equipo de RM de 1,5 Teslas. Para comprobar el correcto funcionamiento del programa se han realizado estudios de RMf en cuatro sujetos sanos (12 cortes contiguos, 80 imagenes por corte cada 3,1 segundos, 960 imagenes totales). Todas las imagenes se transfirieron a un PC. El procesamiento de las imagenes se hizo pixel a pixel dentro de cada secuencia, obteniendose una curva de intensidad/tiempo. El analisis mediante metodos estadisticos (t de Student y correlacion cruzada) permite decidir la activacion de cada pixel. En la preparacion de las imagenes se uso filtrado espacial, filtrado temporal, correccion de la linea base, normalizacion y segmentacion del parenquima. En el posprocesado del resultado se uso la eliminacion de pixeles aislados, superposicion de una imagen anatomica de mayor resolucion espacial y el filtrado anti- aliasing. Resultados: La aplicacion ( Xfun 1.0 , Valencia) se ha desarrollado en el entorno Microsoft Visual C++ 5.0 Developer Studio para Windows NT Workstation. En un ejemplo representativo el programa tardo 8,2 segundos para calcular y presentar los resultados de un studio completo (12 mapas funcionales). En los experimentos de activacion motora y visual se observo la activacion correspondiente a regions proximas al surco central del hemisferio contralateral a la mano que ejercia la accion y en la corteza occipital. Discusion: Si bien existen programas que calculan mapas de activacion, el desarrollo de un programa para PC en entorno Windows tiene unas caracteristicas clave para su utilizacion rutinaria: facilidad de manejo y alta capacidad de computo. La aplicacion desarrollada es capaz de discriminar cuales son las zonas del cerebro que se activan como respuesta a un estimulo de las que no se modifican.