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Biomedical subjects

J Capellades

Publications and source records attributed to J Capellades.

At least 19 recordsLinked to original sources
PubMed2002

Agreement between CSF flow dynamics in MRI and ICP monitoring in the diagnosis of normal pressure hydrocephalus. Sensitivity and specificity of CSF dynamics to predict outcome.

OBJECTIVES: The aims of the study were 1) to assess the degree of agreement between CSF flow dynamics determined by MR and ICP monitoring in the diagnosis of NPH, and 2) to determine the sensitivity and specificity of CSF flow dynamics studied by MR in predicting improvement after shunting. PATIENTS AND METHODS: A prospective study was carried out in 35 consecutive patients with suspected NPH. CSF velocity (Phase Contrast) through the aqueduct was determined in sagittal plane. Patients were classified as "normal" or hyperdynamic in comparison with a control group of 27 healthy volunteers. Continuous extradural ICP monitoring was performed for at least 72 hours and patients were classified as having active, compensated, or ex-vacuo hydrocephalus. Patients with active or compensated hydrocephalus were shunted. RESULTS: The degree of agreement between MR dynamics and ICP monitoring was 82%. Sensitivity of CSF velocity was 90% and specificity was 50%. CONCLUSIONS: The degree of agreement between ICP monitoring and CSF velocity is high. High CSF velocity through the aqueduct is a good predictor of improvement after surgery. However, patients with normal velocity in MR required additional tests before a diagnosis of NPH is ruled out.

Aged↗
PubMed2002

Use of 201Tl SPECT imaging to assess the response to therapy in patients with high grade gliomas.

PURPOSE: To assess the potential role of 201Tl single photon emission tomography (201-Thallium SPECT) when compared to other imaging modalities in the evaluation of the response to therapy in high grade gliomas. MATERIALS AND METHODS: Twenty patients with histologically proved high grade glioma have been included: 15 with glioblastoma (GBM), 3 with anaplastic astrocytoma (AA) and 2 with anaplastic oligoastrocytoma (AOA). Patients were assessed by 201Tl SPECT, computed tomography (CT) and magnetic resonance imaging (MRI) at (a) either at the moment of maximum response to first line chemotherapy, or after the completion of radiotherapy and chemotherapy if post-surgical residual disease was present, and (b) after the completion of second line chemotherapy if disease persisted, or either a relapse or disease progression was confirmed. Final response was evaluated according to the McDonald criteria, and by comparing SPECT, CT and MRI results. RESULTS: According to the McDonald criteria, clinical response after first line chemotherapy was 5 partial response, 7 stable disease and 8 progressive disease. Evaluation by 201Tl SPECT was in agreement with such criteria in nearly all patients (90%). MRI findings closely agreed with the clinical follow-up. CT findings clearly differed from those observed by SPECT and MRI. After second line therapy, 10 patients progressed, 3 had stable disease and 7 had partial response. 201Tl SPECT agreed with the clinical status in 89% cases, whereas MRI and, specially CT, fared significantly lower. CONCLUSION: Compared to conventional neuroimaging, 201Tl SPECT added valuable information in the assessment of the response to therapy in our patient population; whenever findings were not conclusive and in the case of disagreement between CT and MRI findings.

Adult↗
PubMed2002

[Diffusion-weighted magnetic resonance in deep cerebral venous thrombosis].

Changes in the apparent diffusion coefficient (ADC) are well established in acute ischemic stroke of arterial origin. However, ADC behaviour and its prognostic significance in cerebral venous thrombosis (CVT) are not fully understood. Diffusion-weighted imaging (DWI) findings in a 34-year old woman with deep cerebral venous thrombosis are described. Recent literature concerning DWI and cerebral venous thrombosis is also reviewed. A MRI performed within 7 hours from onset revealed hyperintensities in deep grey matter bilaterally (FLAIR/T2), without changes in ADC maps, suggesting vasogenic edema. After anticoagulation a new MRA disclosed complete recanalization of venous thrombosis. Despite her good clinical outcome the MRI showed hemorrhagic lesions suggesting venous infarct. Lesions detected in acute CVT with DWI may have normal ADC values. There is no good correlation between the acute ADC values and clinical and radiological evolution. The prognostic value of ADC in the acute phase of CVT remains unsettled.

Adult↗
PubMed2000

Magnetic resonance anatomic study of iliocava junction and left iliac vein positions related to L5-S1 disc.

STUDY DESIGN: An in vivo anatomic study analyzing the venous anatomy in the lumbosacral area was performed. OBJECTIVES: To obtain in vivo data concerning iliocava junction and left common iliac vein positions at L5-S1. SUMMARY OF BACKGROUND DATA: The left common iliac vein and the iliocava junction are at risk during L5-S1 anterior lumbar interbody fusion. Anatomic studies have demonstrated great interindividual variability in this vascular anatomy. METHODS: Magnetic resonance angiography was used to study 134 patients. Image processing was carried out with maximum intensity projection algorithm and the maximum intensity projection and addition algorithm. Iliocava junction position was measured in the maximum intensity projection and addition image. Four groups of junction position were established: very high, high, low, and very low. The left common iliac vein position was measured in axial magnetic resonance images, and three groups were established: lateral, intermediate, and medial. To describe the operative window delimited by the venous structures at L5-S1, the study population was classified into 12 configurations by combining junction position and vein position values. RESULTS: Very high lateral included 3.76% of the patients, high lateral 48.12%, high intermediate 10.53%, high medial 0.75%, low lateral 15.04%, low intermediate 4.51%, low medial 6.77%, very low lateral 0.75%, very low intermediate 2.26%, and very low medial 7.52%. Medial vein position was significantly more frequent in men. CONCLUSIONS: In 18.05% of the study population, the venous structures overlapped the center of the L5-S1 disc, reducing the operative window.

Adolescent↗
PubMed2000

Vertebral artery occlusion after acute cervical spine trauma.

STUDY DESIGN: A retrospective study of vertebral artery injury diagnosed during the last 6 years in our institution. OBJECTIVES: To determine the clinical and radiologic features of vertebral artery injury. SUMMARY OF BACKGROUND DATA: Extracranial occlusion of the vertebral artery associated with cervical spine fracture is uncommon and can cause serious and even fatal neurologic deficit due to back lifting and cerebellar infarction. Magnetic resonance imaging and magnetic resonance angiography are extremely helpful in the examination of acute injuries of the cervical spine. METHODS: Magnetic resonance imaging and magnetic resonance angiography were performed at the time of injury. RESULTS: The authors reviewed six patients with cervical spine fractures who were diagnosed with a unilateral occlusion of the vertebral artery by means of magnetic resonance imaging/magnetic resonance angiography. One patient had signs of vertebrobasilar insufficiency and another with complete cord lesion had cerebellar and back lifting infarctions. Surgical anterior spinal fusion was performed in five patients, and one was treated by traction and orthosis. At the time of discharge, five patients had no vertebrobasilar symptoms, and the patient who experienced vertebrobasilar territory infarctions showed no progression of the neurologic damage. CONCLUSIONS: Vertebral artery injury should be suspected in cervical trauma patients with facet joint dislocation or transverse foramen fracture. Magnetic resonance imaging/magnetic resonance angiography is a helpful test to rule out vascular injury. Vertebral artery injury affects the extracranial segment at the same level as the cervical fracture. This is a retrospective review that did not permit drawing conclusions about the effects of early surgical stabilization in the treatment of cervical spine injuries with associated vertebral artery injury; however, surgical stabilization may avoid propagation and embolization of the clot located at the site of the lesion.

Adolescent↗
PubMed2000

Isolated demyelinating syndromes: comparison of different MR imaging criteria to predict conversion to clinically definite multiple sclerosis.

BACKGROUND AND PURPOSE: Various authors have developed criteria to classify MR imaging findings that suggest the possibility of multiple sclerosis. The purpose of this study was to evaluate and compare the capacity of three sets of MR imaging criteria for predicting the conversion of isolated demyelinating syndromes to clinically definite multiple sclerosis. METHODS: Seventy patients with clinically isolated neurologic symptoms suggestive of multiple sclerosis were prospectively studied with MR imaging. The MR imaging findings were evaluated by two independent neuroradiologists who were blinded to clinical follow-up data. Based on the clinical outcome at follow-up (presence of a second attack that established clinically definite multiple sclerosis), the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the criteria proposed by Paty et al, Fazekas et al, and Barkhof et al were calculated. RESULTS: Clinically definite multiple sclerosis developed in 22 (31%) patients after a mean follow-up time of 28.3 months. The criteria proposed by Paty et al and those proposed by Fazekas et al showed identical results: sensitivity, 86%; specificity, 54%; accuracy, 64%; positive predictive value, 46%; and negative predictive value, 89%. The criteria proposed by Barkhof et al showed the following: sensitivity, 73%; specificity, 73%; accuracy, 73%; positive predictive value, 55%; and negative predictive value, 85%. CONCLUSION: The four dichotomized MR imaging parameters proposed by Barkhof et al are more specific and accurate than the criteria proposed by Paty et al or Fazekas et al for predicting conversion to clinically definite multiple sclerosis.

Adult↗
PubMed1999

Spontaneous ventriculostomy: report of three cases revealed by flow-sensitive phase-contrast cine MR imaging.

Spontaneous ventriculostomy is a rare condition that occurs with the spontaneous rupture of a ventricle, resulting in a communication between the ventricular system and the subarachnoid space. Three cases of spontaneous ventriculostomy through the floor of the third ventricle that occurred in cases of chronic obstructive hydrocephalus are presented. The communication was identified via flow-sensitive phase-contrast cine MR imaging. Spontaneous ventriculostomy is probably a result of a rupture of the normally thin membrane that forms the floor of the third ventricle and, with long-standing obstructive hydrocephalus, creates an internal drainage pathway that spontaneously compensates for the hydrocephalus.

Adolescent↗
PubMed1999

Radiologic findings in two cases of acute Schmörl's nodes.

We describe two cases of atypical acute Schmörl's nodes, one benign, the other on a tumoral vertebra. In both cases, MR imaging showed a decreased vertebral T1 signal and a slightly increased T2 signal. These signal intensities are indistinguishable from tumoral disease or inflammatory lesions. The identification of endplate defects or intranuclear cleft bending of the disk by either CT or MR may be helpful for the correct diagnosis of acute Schmörl's nodes.

Adult↗
PubMed1999

Lumbar extradural hemangiomas: report of three cases.

The CT, MR, and histologic findings of three patients with surgically proved lumbar extradural cavernous and arteriovenous hemangiomas are reported. All three patients suffered from radicular and low back pain that disappeared completely or nearly so after total surgical excision. In each case, neuroimaging studies showed a well-defined ventrally located extradural mass with no bone involvement. On MR images, all lesions were homogeneous and isointense on noncontrast T1-weighted images and hyperintense on T2-weighted images relative to the intervertebral disk. Homogeneous enhancement was seen in one of the two cases in which contrast-enhanced T1-weighted images were obtained. Purely extradural hemangiomas should be included in the differential diagnosis of lumbar extradural soft-tissue lesions. Features that may help to distinguish this entity from the more common extruded disk herniation or neurogenic tumors are its homogeneous high signal intensity on T2-weighted images, ovoid shape, and lack of anatomic relationship with the adjacent intervertebral disk or exiting nerve root.

Adolescent↗
PubMed1998

31Phosphorus magnetic resonance spectroscopy in the assessment of head and neck tumors.

PURPOSE: 31Phosphorus magnetic resonance spectroscopy (31P-MRS) provides biochemical information in a noninvasive way. The aim of this work was: (a) to characterize the 31P spectrum of advanced head and neck tumors, and (b) to evaluate the spectral changes after treatment and to correlate them with the pathologic response. METHODS AND MATERIALS: A total of 20 patients diagnosed with advanced head and neck tumors and 7 healthy controls participated in the study. The tumor mass and its contralateral side were studied by means of 31P-MRS before and after treatment. Neck muscles of a control group were also studied. RESULTS: Tumors presented ratios of phosphomonoesters (PME), phosphodiesters (PDE), and inorganic phosphate (Pi) with respect to the adenosine triphosphate (ATP), significantly higher and a PCr (phosphocreatine)/ATP ratio lower than the neck muscle of volunteers or the contralateral side. The PDE/ATP and PME/ATP ratio values obtained before therapy were similar, independent of the later response to treatment. However, when there was a complete response, the ratios measured after treatment were decreased. CONCLUSION: These results show the existence of significant differences between the 31phosphorus spectrum of tumors and neck muscle, but also between the tumors and their contralateral sides. Moreover, 31P-MRS is able to detect metabolic changes after a complete response. These results suggest that 31P-MRS would be useful in the evaluation of the clinical response of head and neck tumors.

Adenosine Triphosphate↗
PubMed1998

[Value of cranial MRI in the follow-up of dural sinus thrombosis].

INTRODUCTION: At the present time it is well established that cranial magnetic resonance (MR) is the imaging technique of choice for diagnosis of thrombosis of the dural sinuses. However, few studies have been done to evaluate its role in follow-up in this cerebrovascular disorder. OBJECTIVE: To assess the alterations in resonance signal in follow-up of patients with thrombosis of the dural sinuses and the clinical correlation of this. MATERIAL AND METHODS: We reviewed the clinical histories of 12 patients diagnosed on cranial MR as having thrombosis of the dural sinuses; 8 cases were also seen again six months later. The cranial MR study was done using a 1.5 or 1.0 T superconductive apparatus to do measured spin-echo sequences (SE) in T1 and T2 in sagittal, transverse and coronal planes. The time elapsed between diagnosis on MR and clinical diagnosis was between 24 hours and 6 months. RESULTS: All patients had stronger resonance signals in T1 and T2 indicating a subacute phase of the thrombosis (oxidative conversion of deoxyhaemoglobin to methoxyhaemoglobin) and complete absence of blood flow in the sinuses. The eight patients seen again after six months were found to be normal on neurological. On cranial MR partial recanalization was seen in 5 of these (62%). CONCLUSION: Changes in the resonance signal persist for a long time both with and without signs of recanalization. This finding does not affect the medium term clinical course.

Adult↗
PubMed1996

[Cerebral proton spectroscopy of people infected with the human immunodeficiency virus].

BACKGROUND: This article presents a combined magnetic resonance imaging and proton spectroscopy protocol (MRI/1H-MRS) applied to study the brain of human immunodeficiency virus (HIV) infected patients. The spectroscopic results were compared with clinical and radiological parameters. PATIENTS AND METHODS: The proton spectra of 57 HIV patients and 20 control subjects were obtained from a volume of interest of 8 cm3 located in the parietooccipital region of the brain that did not include any focal lesion. The resonance areas due to N-acetyl aspartate (NAA), creatine (Cr) and choline (Cho) were obtained. The MRI exam allowed us to determine the presence of focal or diffuse lesions and the degree of atrophy. Finally, the clinical exploration included the performance of a Mini-Mental test. The NAA/Cr, NAA/Cho and Cho/Cr ratios were correlated with clinical characteristics, the result of the Mini-Mental test, the presence of lesions and the degree of atrophy. RESULTS: There were altered spectral patterns in a volume of the brain that did not contain any focal lesion. The decrease in the NAA/Cr or NAA/Cho ratios was significative when considering the presence of atrophy, the existence of signs of cognitive deficiencies or the diagnosis of AIDS-dementia complex. CONCLUSIONS: The spectral changes found in the present study suggest the existence of neuronal lesions that would be due to the HIV-infection. A combined MRI/1H-MRS study may provide a more complete information about the neurological impairment by HIV and could constitute a marker of AIDS-dementia complex.

Adult↗
PubMed1996

A multicenter proton magnetic resonance spectroscopy study of neurological complications of AIDS.

Human immunodeficiency virus (HIV) infection as seen in Europe and the United States has predominantly been contracted through male homosexual sex or intravenous drug abuse. In infected subjects, the brain is frequently affected both clinically and neuropathologically. The aim of this multicenter study has been to evaluate the value of single-voxel proton magnetic resonance spectroscopy (MRS) in the assessment of the neurological complications of acquired immunodeficiency syndrome (AIDS). MRS (voxel size = 8 ml, TR/TE = 1600/135 msec) was performed in 137 HIV-1-seropositive patients and 64 healthy controls without risk factors at three clinical MR sites operating at 1.5 T. The first result of this multicenter trial is that good reproducibility of results among participating sites was found. This demonstrates the reliability and robustness of MRS in the study of in vivo brain metabolism. In HIV patients, there was no significant correlation between metabolite ratios of brain detected by MRS and CDC grouping of patients or CD4 count. In contrast, the variations of brain metabolite ratios (NA/Cr, NA/Cho, and Cho/Cr) were related to the occurrence of encephalopathy, brain atrophy, or diffuse white matter lesions. There was no significant difference in brain metabolites between male homosexual AIDS patients and male intravenous drug user AIDS patients, whatever their neurological status (neurosymptomatic or neuroasymptomatic). Thus, the mode of transmission of HIV infection does not appear to affect the cerebral changes observed in the proton spectra from AIDS patients. Because of its ease of implementation and high information content, single-voxel proton MRS is likely to play a significant role in the evaluation of HIV-related encephalopathies.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Diffusion-weighted magnetic resonance in the diagnosis of acute subcortical infarcts].

INTRODUCTION: The diagnostic efficacy of radiological studies in acute subcortical infarcts is limited by the low sensitivity of conventional computerized tomography (CT) and magnetic resonance (MR) in detecting small-sized infarcts, and the difficulty in differentiating acute from chronic lesions. Diffusion-weighted MR (DMR) has shown great sensitivity and specificity in the detection of small vessel ischemic lesions during the acute phase. OBJECTIVE: To determine the diagnostic value of DMR in the study of patients with subcortical infarcts during the acute phase. PATIENTS AND METHODS: We made a prospective analysis of 100 consecutive patients with a clinical diagnosis of subcortical infarct. In all cases MR examination was done within the first 10 days (average 3.9 days) following onset, using conventional and diffusion-weighted sequences. RESULTS: In all cases the DMR showed the presence of ischemic lesions which explained, at least partly, the clinical features of the stroke. In 42 patients (42%) the DMR gave relevant information for diagnosis, as compared with the conventional MR studies, by confirming the presence of an ischemic lesion responsible for the clinical picture. The percentage rose to 50% when the examination was done within the first two days. CONCLUSIONS: DMR gives useful information in a high percentage of patients with acute subcortical infarcts. This is due to its great sensitivity in the detection of acute lesions of small size, and capacity to distinguish acute from chronic lesions.

Acute Disease↗
PubMedDate not supplied

[Eosinophilic cystitis. Apropos of a case].

We report a case of eosinophilic cystitis (EC) in an elderly patient who had previously undergone transurethral resection of a bladder tumor which is the reason why this diagnosis was not taken into consideration and was discovered by the pathologist in a fragment whose intraoperative diagnosis had been that of tumor recurrence. We describe the radiologic features of this disease entity and its similarity to other malignant conditions. Because of the foregoing, a differential diagnosis--both clinical as well as radiologic--must be made.

Aged↗