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PubMed2004

The cost of living in purgatory's shadow.

A 40-year-old alcoholic man developed Wernicke-Korsakoff syndrome. His examination showed ophthalmoplegia, ataxia and memory difficulties. His cranial magnetic resonance imaging scan showed increased signal in the paraventricular regions of the thalamus on T-2 weighted, diffusion and axial fluid-attenuated inversion recovery sequences consistent with the syndrome. The ophthalmoplegia resolved with thiamine administration; however, his memory did not improve.

Adult↗
PubMed2005

[Brainstem injury diagnosed by MRI. An epidemiologic and prognostic reappraisal].

INTRODUCTION AND OBJECTIVES: CT-scan allows emergency surgical evaluation of head injury lesions, but does not offer a comprehensive diagnosis of the resulting brain injuries. Magnetic Resonance Imaging (MRI) can complete the evaluation of head injury, particularly in the brain stem. We attempted to estimate the frequency of traumatic primary brain stem injuries MATERIAL AND METHODS: Thirty patients with moderate or severe head injury (GCS < or = 13) underwent a MRI study during the first two weeks after trauma. In order to exclude old patients with previous ischemic lesions unrelated to the head trauma, only young patients (16-40 years-old) were included. Patients with cranial surgery were also eliminated from the study. Based on previous studies, the FLAIR (8000/120/T. Inversion 2200mseg) sequence was selected. RESULTS: Brain stem injuries were detected in 26.6% of the patients; this was confirmed by two independent radiologists. Six patients had hyperintense lesions compatible with diffuse axonal damage, and two others showed hemorrhagic lesions. These findings were directly related to a specific neurological deficit in four patients; while in the remaining, unspecific consciousness disturbances were noted. CONCLUSIONS: We believe that the FLAIR sequence demonstrate a type of traumatic brain stem injury (probably corresponding to diffuse axonal injury) that is more frequent and less severe in terms of prognosis than those classically described in previous CT scan studies.

Adolescent↗
PubMed2005

Mitochondrial encephalomyopathy with lactic acidosis and stroke (MELAS).

Mitochondrial disorders are an uncommon, but important, cause of stroke-like clinical and imaging presentations in individuals under the age of 45 years. We present a 31-year-old man with a 4-year history of migraine-like headaches, type 2 diabetes mellitus, seizures, and hearing loss. Magnetic resonance imaging revealed multiple hyperintensities on T2 and fluid-attenuated inversion recovery sequences. An exhaustive work-up for vasculitis including brain biopsy was performed. Mitochondrial DNA testing revealed the A3243G substitution associated with the mitochondrial encephalomyopathy with lactic acidosis and stroke syndrome. In this case review we briefly discuss the signs and symptoms, frequency, pathophysiology, and prognosis of this disorder.

Acidosis, Lactic↗
PubMed2006

MR imaging of the brain in patients cured of acute lymphoblastic leukemia--the value of gradient echo imaging.

BACKGROUND AND PURPOSE: Hemosiderin and white matter lesions are 2 of the most common neurologic complications found on MR imaging that may be related to cranial irradiation and intrathecal methotrexate (MTX) therapy in childhood acute lymphoblastic leukemia (ALL). We evaluated the brains of patients previously treated for ALL with cranial irradiation and intrathecal MTX with MR imaging and tested the hypothesis that these patients have more MR evidence of central nervous system (CNS) injury than control patients who are in complete remission following systemic chemotherapy without cranial irradiation. METHODS AND MATERIALS: ALL patients recruited from a pediatric cancer center data base were examined at 1.5T by using T1-weighted, T2-weighted, gradient echo (GE), and fluid-attenuated inversion recovery sequences. Patients treated in childhood for solid extracranial neoplasms were used as controls. RESULTS: Lesions consistent with old hemorrhage were detected in 23 (55%) of the ALL patients and in none of the control patients (P <.001). Of the 62 hemorrhages detected on the GE images, only 9 (15%) were shown on T2-weighted images. White matter abnormalities were found in 2 ALL patients (5%) and one control patient (5%). Old infarcts were seen in 2 ALL patients (10%). CONCLUSION: Cerebral hemorrhages related to radiation-induced vascular malformations, most of which are asymptomatic, are much more common in survivors of childhood ALL than previously thought. GE sequencing is more sensitive in detecting hemorrhagic lesions than T2-weighted sequencing and is to be included in imaging protocols for follow-up study of patients after cerebral radiation therapy.

Adolescent↗
PubMed2005

Kyphoplasty for vertebral compression fracture via a uni-pedicular approach.

BACKGROUND: Percutaneous kyphoplasty using a bone expander polymer device, such as percutaneous vertebroplasty and balloon kyphoplasty, is a therapeutic intervention for painful osteoporotic vertebral body compression fractures. Typically the procedure involves placement of bilateral Sky Bone Expanders in the fractured vertebral body via a transpedicular approach. We describe performance of "SKy"phoplasty using the Disc-O-Tech Sky Bone Expander (Disc-O-Tech Medical Technologies, Herzliya, Israel, and Monroe Township, New Jersey) via a unilateral transpedicular approach. The advantage of a unilateral approach is that it reduces the risks associated with large-bore needle placement. These risks include pedicle fracture, medial transgression of the pedicle or transgression into the spinal canal, nerve injury, cement leakage along the cannula tract, and spinal epidural hematoma. Additionally, using a unilateral approach reduces operative time and costs. CASE ILLUSTRATION: A 68-year-old man with osteoporosis presented with severe upper back pain which occurred following a fall. The pain was reproducible on palpation of the L1 spinous process. A lumbar spine magnetic resonance imaging (MRI) with STIR (short tau inversion recovery) sequence demonstrated an acute L1 vertebral body compression fracture. A L1 "SKy"phoplasty was performed using a single Sky Bone Expander polymer device via a unilateral transpedicular approach. The patient reported immediate relief of pain after the procedure. He denied any residual back pain at his follow-up visit. He was able to resume his normal activities including walking, which had been inhibited by pain prior to the procedure. CONCLUSION: "SKy"phoplasty can be performed using a single Sky Bone Expander via a unilateral pedicular approach. The key is a medial needle trajectory with a final Sky Bone Expander position in the midline of the vertebral body.

Journal Article↗
PubMed2004

Balloon kyphoplasty for vertebral compression fracture using a unilateral balloon tamp via a uni-pedicular approach: technical note.

OBJECTIVE: Percutaneous balloon kyphoplasty, like percutaneous vertebroplasty is a therapeutic intervention for painful osteoporotic vertebral body compression fracture. The procedure involves placement of bilateral inflatable balloon tamps in the fractured vertebral body via a bilateral transpedicular or bilateral extra-pedicular approach. We describe performance of balloon kyphoplasty using a unilateral, single, balloon tamp via a unilateral transpedicular approach. The advantages of a unilateral approach are reducing the risk, albeit low, of pedicle fracture, medial transgression of the pedicle and/or transgression into the spinal canal, nerve injury, cement extravasation along the cannula tract, and spinal epidural hematoma. Additionally, operative and anesthesia time is reduced, as well as the costs of balloon tamps, cannulas, and needles. CASE ILLUSTRATION: An 83-year-old woman with osteoporosis presented with severe lower thoracic back pain which occurred when she bent over to lift a heavy box. The pain was reproducible on palpation of the T-11 spinous process. A spine MRI with STIR (short tau inversion recovery) sequence demonstrated a subacute T-11 vertebral body compression fracture with associated edema. A T-11 balloon kyphoplasty was performed using a unilateral inflatable balloon tamp via a unilateral transpedicular approach. The patient reported immediate relief of pain and improvement of visual analog score (VAS) for pain from preoperative 10 to postoperative 2. She was able to ambulate postoperatively whereas preoperatively she was inhibited by pain. CONCLUSION: Balloon kyphoplasty can be performed using a unilateral balloon tamp via a unilateral pedicular approach. The key is a medial needle trajectory with a final balloon position in the midline of the vertebral body.

Journal Article↗
PubMed2006

Scrub typhus-associated acute disseminated encephalomyelitis.

BACKGROUND: Acute disseminated encephalomyelitis (ADEM) is a monophasic demyelinating disease of the central nervous system, typically occurring after infections or vaccinations. To our knowledge, scrub typhus has not been described in association with ADEM. CASE REPORT: A 77-year-old man was admitted with fever, convulsions and an altered level of consciousness. On neurological examination, the patient was stuporous and had nuchal rigidity and left hemiparesis. A generalized tonic-clonic seizure was observed. Serum and cerebrospinal fluid samples were positive for anti-Orientia tsutsugamushi antibody. Despite a 10-day course of parenteral minocycline, his clinical condition deteriorated. Serial cranial magnetic resonance images demonstrated progressively extensive areas of signal hyperintensity on conventional T2-weighted and fluid attenuated inversion recovery sequence images, mainly affecting the periventricular white matter. After administration of intravenous high-dose corticosteroids, the patient had limited improvement. CONCLUSIONS: This is the first identifiable case of ADEM temporally associated with scrub typhus alone.

Aged↗
PubMed1991

Tissue characterization of intracranial tumors by MR imaging. In vivo evaluation of T1- and T2-relaxation behavior at 1.5 T.

The main purpose of this in vivo study was to provide a detailed description of the T1- and T2-relaxation processes in intracranial tumors at 1.5 T. A total of 100 patients were investigated. Optimal experimental conditions were carefully observed, including the use of long TR values. T1 determination was based on a partial saturation inversion recovery sequence covering 12 or 6 data points. T2 determination involved a multiple spin echo sequence with 32 echoes. Calculations included biexponential analysis of the 12-point T1 data and all T2 data obtained. The results were evaluated in accordance with histopathology. The T1- and the T2-relaxation times of the prevailing tumor types were significantly different (p less than 0.0005). However, biologic scatter and overlap between tumor types were considerable. In particular, no discrimination between benign and malignant tumor growth was possible. Biexponential evaluation did not increase the specificity, although a biexponential relaxation behavior was recognized in 37% of the T2 curves. The results indicate that tissue heterogeneity is responsible for most of the scatter in the relaxation times. It is concluded that tissue characterization by MR imaging, based solely on relaxation time measurements, seems to be of no value in the differentiation of intracranial tumors.

Adolescent↗
PubMed1991

Nickel-doped agarose gel phantoms in MR imaging.

A method for the production of a tissue-mimicking phantom material for MR imaging is described. The material consists of a nickel-doped agarose gel. The T1 and T2 values of the gel can be varied independently by changing the relative amounts of nickel and agarose. Practically any T1 and T2 combination of clinical interest can be obtained. The long-term stability was studied and found to be good. The relaxation times were estimated using an MR analyzer. The accuracy and the reproducibility of these measurements were evaluated and found to be reassuring. Gel phantoms were also scanned in an MR unit. The signal strength of an inversion recovery sequence was evaluated using the gel phantoms in order to verify their usefulness. These measurements were compared to theory with good agreement. Furthermore, tissue-equivalent phantoms were made. Gels resembling gray matter, white matter, and CSF were scanned. Comparisons with clinical in vivo scans, as well as calculated levels were made. It is anticipated that the gel phantoms described here will be useful in quality assurance as well as in pulse sequence optimization.

Gels↗
PubMed1990

[A case of foreign-body granuloma].

A 24-year-old male patient was admitted to our Ryukyu University Hospital, complaining of visual disturbance. He had had partial removal of a suprasellar region tumor in another hospital one year before the admission. Microscopical findings had shown two cell patterns of germinoma in the first operation. Following it, the patient received irradiation with a total dose of 54Gy. The tumor completely disappeared after these procedures. On this admission, plain CT scan revealed an isodensity mass in the suprasellar cistern extending to the right side of the third ventricle, which was enhanced homogeneously. In MRI, the mass showed low intensity in the T1-weighted inversion recovery sequence, and heterogeneously, high intensity in the T2-weighted spin echo sequence. By bifrontal craniotomy, the tumor was removed. Histologically, it consisted of granuloma containing fine cotton fibers. MRI findings of intracranial foreign-body granuloma were discussed.

Adult↗
PubMed1990

MR imaging of experimental intramuscular hemorrhage at 0.02 T. Contrast enhancement with Gd-DOTA.

Intramuscular hemorrhage was induced by injecting autologous blood into the paraspinal muscle of 8 rabbits. In order to evaluate the time-dependent changes of hemorrhage observed on MRI, the animals were imaged at different stages of blood resolution at 0.02 tesla (T), and control examined with ultrasound using a 7.5 MHz linear transducer. Six inversion recovery sequences (TR = 1,000 ms. TE = 30 ms, and TI = 18, 48, 148, 201, 302, and 398 ms) were used for the in vivo calculation of T1 relaxation times. IR 1,000 (398)/30 imaging was performed before and after the Gd-DOTA administration. The hemorrhage was evident on MR images throughout the study, especially on the T2 weighted (SE 1,000/100) images. MRI showed the healing lesion longer than ultrasound. The T1 relaxation time increased during the time of resolution. Lesions on days 4 to 7 enhanced in intensity after the injection of Gd-DOTA.

Animals↗
PubMed1990

[Usefulness and limitations of neuroradiologic tests (CT, US, MRI) in periventricular leukomalacia].

Sixteen young patients, with clinical and radiological signs of periventricular leukomalacia (PVL), were investigated with MR imaging. Twelve of them were investigated with US in the perinatal period. The extant 4 patients, older than the others, had a clinical history of PVL. US scans were capable of yielding precise information about the anatomical features of PVL in both the acute and the middle phases. The lesions appeared as hyperechoic areas which subsequently turned to anechoic cavities. MR imaging and CT scans did not present any particular advantage over US scans in the acute phase, but they did detect periventricular damage when the patient was 6-7 months old. MR imaging was superior to CT in detecting the delayed myelination of white matter. Inversion-recovery sequences gave more anatomical details to distinguish normal from abnormal white matter. Spin-echo proton-density images detected periventricular gliosis, which appeared as persistent hyperintense areas. CT might be useful in the acute phase, after US detection of hyperechoic intraparenchymal areas, for it allowed purely ischemic lesions to be distinguished from hemorrhagic ones.

Adolescent↗
PubMed1990

Pelizaeus-Merzbacher disease. Contribution of magnetic resonance imaging to an early diagnosis.

The lesions of the cerebral white matter which characterize Pelizaeus-Merzbacher disease are classically observed at pathological examination. An early diagnosis can now be obtained by magnetic resonance imaging (MRI). In an eutrophic first son born at term, stridor, nystagmus-like eye movements and axial hypotonia were noted immediately after birth and pyramidal signs appeared at 2 months, the only extra-clinical finding at that age being prolonged latencies of evoked visual potentials. An MRI exploration, performed at 3 months, showed that compared with the grey matter the white matter emitted a low-intensity signal on the T1-weighted sequence and a high-intensity signal on the T2-weighted sequence (signal inversion), such diffuse and symmetrical MRI abnormalities being typical of dysmyelination. When combined with suggestive clinical signs, these abnormalities confirm the diagnosis of Pelizaeus-Merzbacher disease, even in the absence of a familial history, and make it possible to warn the parents of the poor prognosis and the risk of recurrence among future sons.

Brain↗
PubMed1990

Anatomical study of the temporal lobe. Correlations with nuclear magnetic resonance.

Following a brief review of embryogenesis and phylogenesis, the different anatomical structures of the temporal lobe of the brain are described. This lobe has 4 surfaces: lateral, inferomedial, superomedial and superior. The first 2 surfaces, visible on the lateral and inferior aspects of the cerebral hemisphere, are composed of 5 temporal gyri. The superomedial and superior surfaces do not show and must be made visible by a digital or instrumental manipulation. The hippocampal formation, surrounded by the temporal horn of the lateral ventricle medially, the choroid and transverse fissures laterally and the amygdaloid complex anteriorly, forms the superomedial surface and represents the "rhincendephalic" part of the temporal lobe. The superolateral surface, which is the superior surface of the first temporal gyrus, is buried deeply in the fissure of Sylvius and is divided into 3 parts: the planum polare, the gyri of Heschl and the planum temporale. Two categories of fibres are present in the white matter of the temporal lobe: projection fibres (acoustic radiation, optic radiation, temporo-pontine tract, temporo-thalamic fasciculus) and association fibres (cingulum, anterior longitudinal, uncinate, superior occipitofrontal, superior longitudinal fasciculi). The anatomical temporal lobe exploration by MRI was carried out with inversion-recovery sequences performed in all three dimensions. The authors describe the advantages and limitations of MRI and indicate the most appropriate plane(s) for the study of the various temporal structures, with emphasis on coronal on coronal and sagittal sections.

Adult↗
PubMed1989

[Heterotopia of the cerebral cortex: a comparison of CT and MRT].

Heterotopic grey matter is a rare cause of seizures. While lesions appear suspicious on CT because of equidensity to cortex, MR imaging can establish the diagnosis by demonstrating same signal intensity of heterotopia and grey matter on T1- and T2-weighted as well as inversion-recovery sequences.

Cerebral Cortex↗
PubMed1988

Correlative investigations of craniospinal anatomy and pathology with computed tomography, magnetic resonance imaging and cryomicrotomy.

A correlative computed tomographic-anatomic method was applied to multiplanar anatomic studies. The method was particularly valuable for comparative anatomic investigations of complex regions of the central nervous system. The description of CT and MR anatomy in this thesis is based either on direct CT-anatomic correlation of the same specimen, or on indirect MR-anatomic correlation with cryosectional images from cadavers. In sagittal partial saturation MR images with short repetition times, the pituitary fossa in 41 normal volunteers appeared inhomogeneous. A postero-inferiorly located high intensity signal correlated with an intrasellar fat pad in sagittal cryosectional images. The height of the pituitary gland in 38 normal volunteers was usually less than 8 mm and its upper surface was flat or concave. The cavernous sinus anatomy was studied in coronal and axial MR planes in seven normal volunteers and 15 patients in correlation with cryosectional images. The intracavernous cranial nerves were best shown in the coronal plane, in partial saturation and inversion recovery sequences and displayed as foci of high signals intensity. MR signs of a parasellar mass included obliteration of intracavernous venous spaces, displacement of the intracavernous portion of the internal carotid artery and bulging of the lateral wall of the cavernous sinus. The topographic anatomy of the cervical neuroforamina was investigated in axial, sagittal, coronal and oblique planes in a correlative CT-anatomic investigation in 19 specimens. In four normal volunteers, the surface coil MR images of the cervical neuroforamina were correlated with cryosectional images. Surface coil MR images in a plane perpendicular to the cervical nerve roots allowed to determine their relationship to intraforaminal structures and the boundaries of the foramen. The dorsal and ventral nerve roots were demonstrated with both CT and MRI. They were located in the lower half of the foramen at and below the intervertebral disc space. The dorsal nerve roots were in contact with the superior articular process. The ventral nerve roots abutted the uncinate process and the inferior portion of the foramen. In a biomechanical cervical spinal trauma study, experimental fractures were studied with CT in axial and sagittal planes. Sagittal anatomic images showed the fractures and soft tissue injuries. Non-displaced and horizontal fractures were generally difficult to detect on axial CT scans alone. In two pathologic spine specimens CT scans in axial, sagittal and coronal planes were compared with reformatted scans and cryosectional images. Direct CT images revealed four cervical spinal fractures whereas the reformatted images only showed one displaced pedicle fracture.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

[A case of calcified intracranial tuberculoma presenting unique MRI findings].

A 41-year-old male patient was admitted in our Ryukyu University Hospital complaining of parosmia. He had a history of miliary tuberculosis 21 years ago. Neurologically he showed left anosmia and hyperreflexia of the right upper extremity. Plain skull X-P and CT scan revealed a calcified mass, 25mm in diameter, at the left frontal base. In MRI, the mass showed isointensity using the T1 weighted inversion recovery sequence and heterogenously low intensity using the T2 weighted spin echo sequence. Surgery was performed by bifrontal craniotomy. Then the tumor was removed totally including two coexisting small tumors. Histologically, they consisted of calcified caseous tissue and thick collagen capsule, suggesting old calcified tuberculomas. Postoperative course was uneventful and did not result in meningitis. Antituberculous therapy of streptomycin, isoniazid and rifampin was given for 2 weeks, started on the operative day. MRI findings were presented in detail and the guideline of antituberculous therapy to the tuberculoma was discussed.

Adult↗
PubMed1986

Magnetic resonance imaging of the ligaments and menisci of the knee.

Although the technique is still developing and the data are preliminary, MRI will likely be the best noninvasive method for evaluating the ligaments and menisci of the knee. It can provide valuable and accurate information, especially in the acutely injured knee. The presence, extent, and exact location of cruciate ligament disruption can be visualized. This is useful in patients in whom the clinical diagnosis is uncertain and provides valuable information in preoperative planning. Equally important is the ability of MRI to provide diagnostic information about associated injuries to the collateral ligaments, capsule, menisci, articular cartilage, and subchondral bone. Proper pulse sequence selection is important. T2-weighted spin-echo sequences are best for visualizing injuries to the ligaments and menisci, and T1-weighted sequences (inversion-recovery or spin-echo with a short TR and a short TE) are more helpful in evaluating cartilaginous and bony abnormalities.

Arthroscopy↗