[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to evaluate whether single-voxel (1)H MRS could add useful information to conventional MRI in the preoperative characterisation of the type and grade of brain tumours. MRI and MRS examinations from a prospective cohort of 40 consecutive patients were analysed double blind by radiologists and spectroscopists before the histological diagnosis was known. The spectroscopists had only the MR spectra, whereas the radiologists had both the MR images and basic clinical details (age, sex and presenting symptoms). Then, the radiologists and spectroscopists exchanged their predictions and re-evaluated their initial opinions, taking into account the new evidence. Spectroscopists used four different systems of analysis for (1)H MRS data, and the efficacy of each of these methods was also evaluated. Information extracted from (1)H MRS significantly improved the radiologists' MRI-based characterisation of grade IV tumours (glioblastomas, metastases, medulloblastomas and lymphomas) in the cohort [area under the curve (AUC) in the MRI re-evaluation 0.93 versus AUC in the MRI evaluation 0.85], and also of the less malignant glial tumours (AUC in the MRI re-evaluation 0.93 versus AUC in the MRI evaluation 0.81). One of the MRS analysis systems used, the INTERPRET (International Network for Pattern Recognition of Tumours Using Magnetic Resonance) decision support system, outperformed the others, as well as being better than the MRI evaluation for the characterisation of grade III astrocytomas. Thus, preoperative MRS data improve the radiologists' performance in diagnosing grade IV tumours and, for those of grade II-III, MRS data help them to recognise the glial lineage. Even in cases in which their diagnoses were not improved, the provision of MRS data to the radiologists had no negative influence on their predictions.
NMR in Biomedicine 09/2011; 25(4):661-73. · 3.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Traumatic vertebral artery dissection is not often seen by forensic pathologists, and cases investigated are scarce in the forensic literature. We present the case of a 40-year-old woman cyclist who was struck by a car while wearing a helmet, and was neurologically near normal immediately thereafter at Emergency. She presented 48 h later with acute right hemiparesis, decreasing level of consciousness, and unsteadiness. CT revealed massive cerebellar infarction. CT angiography was normal. The patient died in coma 7 days after injury and autopsy revealed bilateral edematous cerebellar infarction and bilateral vertebral artery dissection. Rotational neck injury and mural tear in the wall of the Atlantic parts of both vertebral arteries is suggested as the possible mechanism of the arterial injury. Head and neck injuries are reported as a precipitating cause of vertebral artery injury. The possible influence of trauma may be further underestimated if longer intervals between vessel dissection and ischemia occur. The current case illustrates that "talk-and-die" syndrome may be due to occult vertebral artery dissection, possibly bilateral. In forensic cases of delayed death after mild trauma to the head and neck, the vertebral arteries should be examined for the cause of death.
Forensic science international 07/2011; 214(1-3):e12-5. · 2.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: There is a large range of survival times in patients with HGA that can only be partially explained by histologic grade and clinical aspects. This study aims to retrospectively assess the predictive value of single-voxel (1)H-MRS regarding survival in HGA.
Pretreatment (1)H-MRS in 187 patients with HGA produced 180 spectra at STE (30 ms) and 182 at LTE (136 ms). Patients were dichotomized into 2 groups according to survival better or worse than the median. The spectra of the 2 groups were compared using the Mann-Whitney U test. The points on the spectrum with the most significant differences were selected for discriminating patients with good and poor prognosis. Thresholds were defined with ROC curves, and survival was analyzed by using the Kaplan-Meier method and the Cox proportional hazards model.
Four points on the spectrum showed the most significant differences: 0.98 and 3.67 ppm at STE; and 0.98 and 1.25 ppm at LTE (P between <.001 and .011). These points were useful for stratifying 2 prognostic groups (P between <.001 and .003, Kaplan-Meier). The Cox forward stepwise model selected 3 spectroscopic variables: the intensity values of the points 3.67 ppm at STE (hazard ratio, 2.132; 95% CI, 1.504-3.023), 0.98 ppm at LTE (hazard ratio, 0.499; 95% CI, 0.339-0.736), and 1.25 ppm at LTE (hazard ratio, 0.574; 95% CI, 0.368-0.897).
(1)H-MRS is of value in predicting the length of survival in patients with HGA and could be used to stratify prognostic groups.
American Journal of Neuroradiology 10/2010; 32(1):74-80. · 3.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to assess the usefulness of proton MR spectroscopy in the diagnosis of intraventricular tumours. Fifty-two intraventricular tumours pertaining to 16 different tumour types were derived from our database. All cases had single-voxel proton MR spectroscopy performed at TE at both 30 and 136 ms at 1.5 T. The Mann-Whitney U test was used to search for the most discriminative datapoints each tumour type. Characteristic trends were found for some groups: high Glx and Ala in meningiomas (p < 0.001 and p < 0.01, respectively), high mobile lipids in metastasis (p < 0.001), high Cho in PNET (p < 0.001), high mI + Gly in ependymoma (p < 0.001), high NAC (p < 0.01) in the absence of the normal brain parenchyma pattern in colloid cysts, and high mI/Gly and Ala in central neurocytoma. Proton MR spectroscopy provides additional metabolic information that could be useful in the diagnosis of intraventricular brain tumors.
European Radiology 03/2009; 19(8):2049-59. · 4.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: La muerte súbita es una de las principales causas de mortalidad en pacientes epilépticos. Se define por su presentación repentina e inesperada, no traumática, con o sin evidencia de crisis, sin que el examen postmortem revele hallazgos anatómicos o toxicológicos como causa de la muerte. En este sentido, los hallazgos de autopsia suelen ser inespecíficos y por lo que respecta al examen neuropatológico, son raros los casos en los que se puede demostrar la presencia de lesiones encefálicas. En este trabajo, presentamos el caso de un varón de 29 años de edad, con antecedentes de enfermedad epiléptica, que falleció de forma súbita e inesperada mientras dormía. El estudio neuropatológico reveló la presencia de anomalías cerebrales en ambos hemisferios que consistían en trastornos de la sulcación y de la migración neuronal. Se realiza la descripción macroscópica de estas malformaciones congénitas, las cuales con frecuencia se manifiestan clínicamente en forma de crisis comiciales.
[Show abstract][Hide abstract] ABSTRACT: Delayed postanoxic encephalopathy (DPE) is a rare condition that presents after apparent recovery from acute cerebral anoxia. DPE, which consists of cognitive and neuropsychiatric deficits, appears between one and three weeks after cerebral anoxia. We present a patient with DPE secondary to acute cocaine and heroin intoxication with typical cranial MRI changes. The clinical improvement of the patient could be related to the improvement in white matter lesions despite the characteristics of the ADC map.
[Show abstract][Hide abstract] ABSTRACT: Despite considerable literature on the functional anatomy of the hominoid upper limb, there are no quantitative approaches relating to bone design and the resulting muscular-activity enhancement. The purpose of this study is to quantitatively analyze the relationship between the rotational efficiency of the pronator teres muscle and the design of the skeletal structures on which it acts. Using conventional scan images of a human forearm for three rotational positions, this study develops an original biomechanical model that defines rotational efficiency as a mathematical function expressing a geometrical relationship between the origin and insertion muscular sites. The results show that this parameter varies throughout the entire pronation range, being maximal when the forearm lies around its functional position. Moreover, the rotational-efficiency formula allows us to demonstrate, by several simulation conditions, that an improvement in pronation efficiency is derived from a large shaft radius curvature, a large humeral medial epicondyle, and a more proximal pronator teres radial attachment. The fact that forearm pronation efficiency can be inferred, even quantified, throughout the entire rotational range, by applying the biomechanical model developed here allows us to undertake anatomical approaches in the field of Evolutionary Anthropology, to interpret more precisely how skeletal design is related to upper-limb function in extant and fossil primate taxa.
American Journal of Physical Anthropology 04/2008; 135(3):293-300. · 2.48 Impact Factor