MR of staphylococcal myelitis of the cervical spinal cord.

A homogeneously enhancing cervical cord lesion and multiple ring-enhancing brain lesions were detected with MR imaging in a 41-year-old woman with a staphylococcal septicemia. The brain and spinal cord lesions diminished in size after antibiotic therapy. Although no biopsy was performed, we believe, on the basis of the clinical outcome, that the spinal cord lesion represented a bacterial myelitis and that the lesion was prevented from developing into an abscess by early antibiotic therapy.

Cystic meningiomas: MR characteristics and surgical correlations.

PURPOSE: To describe the MR appearance of cystic meningiomas, and to correlate the MR appearance with the surgical and neuropathologic findings. METHODS: Eight patients with cysts associated with meningiomas were studied on a 1.5-T MR system. Unenhanced sagittal T1- and axial T2-weighted images were obtained in all patients. Axial and coronal gadopentetate dimeglumine-enhanced T1-weighted spin-echo images were obtained in seven patients. Additional sagittal T1-weighted spin-echo contrast-enhanced images were obtained in four patients. RESULTS: The cystic components were intratumoral and eccentric in two cases, intraparenchymal in one case, and extraparenchymal (trapped cerebrospinal fluid) in five cases. Cyst wall enhancement was present in two of seven cases performed with intravenous gadopentetate dimeglumine. There was no correlation between cyst signal intensity and cyst content. A preoperative diagnosis of cystic meningioma was possible in all eight cases. CONCLUSIONS: MR demonstrates the extradural location of the tumor and its cystic component, correlates well with the surgical presentation and the neuropathologic results, and allows the preoperative diagnosis of cystic meningioma based on the MR findings. Division into three types of cysts aids the neurosurgeon, who must decide whether total resection is feasible. To obtain total resection and reduce the risk of recurrence with an intratumoral cyst, the surgeon must ensure that the plane of resection is in fact between the thin enhancing membrane of the tumor cyst and the adjacent arachnoid. In cases in which the cyst is trapped cerebrospinal fluid or intraparenchymal in location, the cyst wall adjacent to or within the brain parenchyma is not included in the resection.

Tanycytomas: a newly characterized hypothalamic-suprasellar and ventricular tumor.

We report five cases of tumors occurring in three children and in two adults. The tumors had unusual histomorphology and a mixture of ependymal and piloid-like astrocytic features and a myxoid stroma similar to myxopapillary ependymomas. MR imaging in three of the cases showed aggressive, intensely enhancing partially cystic hypothalamic-suprasellar masses near midline and near the floor of the third ventricle. In the three pediatric cases, the tumor encased the circle of Willis. This newly characterized tumor, the tanycytoma, has neoplastic cells with histomorphologic and ultrastructural characteristics similar to those of the tanycyte.

Acute internal jugular vein thrombosis associated with pseudoabscess of the retropharyngeal space.

We present four patients in whom evidence of edema or a pseudomass in the retropharyngeal space was found on CT scans obtained after thrombosis of the internal jugular vein. The clinical condition of one patient led to surgery, which documented the sterility of the retropharyngeal space despite the CT appearance of an inflammatory process. The CT findings, which are confusing initially, are found to be typical in retrospect.

Giant cervical epidural veins after craniectomy for head trauma.

Markedly dilated cervical epidural veins and right upper extremity weakness developed in a 43-year-old man 4 months after contralateral craniectomy for head trauma. After cranioplasty, his symptoms improved markedly and the size of the veins returned to normal. These findings suggest that enlarged cervical epidural veins may occur without an underlying vascular lesion and that upper extremity weakness may occasionally be attributable to spinal cord venous stasis.

The Sturge-Weber syndrome: comparison of MR and CT characteristics.

Four patients with Sturge-Weber syndrome were evaluated with CT and MR. MR demonstrated the characteristic features of the disease: cerebral atrophy (four patients), ipsilateral bone and sinus hypertrophy (three), ocular findings (one), intracranial calcification (four), prominent deep venous system (three), and enlarged choroid plexus (two). CT demonstrated the following: cerebral atrophy (four), ipsilateral bone and sinus hypertrophy (three), calcification (four), gyral enhancement (two), prominent deep venous system (two), and enlarged choroid plexuses (three). The features of Sturge-Weber syndrome were visualized equally well with MR and CT with the exception of intracranial calcification. Conventional spin-echo MR revealed fewer calcifications, and those visualized appeared smaller than with CT. Gradient-echo acquisition sequences were more effective in the detection of intracranial calcification.

Dynamic computed tomography: intracranial applications.

Rapid sequential computed tomography of the brain after the bolus injection of contrast material provides invaluable information as to the characteristic blood flow of intracranial lesions in a noninvasive manner. Plotted dynamic curves permit accurate diagnosis of particularly difficult cases of infarcts and neoplasms. Dynamic computed tomographic (CT) scanning has become a part of the CT work-up for infarcts, which has allowed their earlier demonstration, detected as areas of hypoperfusion not clearly evident on an initial conventional CT study. Quantitative assessment of vasogenic edema and hypoperfusion are helpful in establishing the diagnosis of infarction and neoplasia. Orbital and parasellar neoplasms can be distinguished accurately from vascular lesions. Dynamic CT studies complemented conventional film screen arteriography in the evaluation of three cases of intracavernous internal carotid artery aneurysm, defining thrombus formation and wall thickness and thus influencing the therapeutic approach. In addition, this modality is useful in differentiating jugular fossa neoplasm from vascular malformation. This review elaborates on the technique involved in dynamic CT scanning and the subsequent results.

Magnetic resonance of intracranial epidermoids.

The magnetic resonance images of seven patients with biopsy-proven epidermoids were evaluated. The epidermoids were hypointense on T1-weighted images. Intermediate density images revealed the tumors to be heterogeneous in signal intensity consisting of areas of hypo- and isointensity. Signal intensity on T2-weighted images was hyperintense and inhomogeneous in all but one case. CT performed in five patients demonstrated the tumors to be well-defined hypodense lesions without contrast enhancement.

Congenital hypopituitarism as part of suprasellar dysplasia. A case report.

Congenital hypopituitarism may be due to hypothalamic failure. The case presented below belonged to this category. In addition, the demonstration of absent septum pellucidum placed this case in the category of suprasellar dysplasia. The patient was 21 years old, with primary amenorrhea and lack of development of secondary sex characteristics. The laboratory findings confirmed the diagnosis of hypothyroidism, hypocortisolism, hypogonadotropism, hyperprolactinemia and normal growth hormone. Stimulation studies revealed a subnormal response of cortisol to adrenocorticotrophic hormone stimulation, subnormal response of follicle stimulating hormone and luteinizing hormone to gonadotropin releasing hormone stimulation, normal response of prolactin to thyrotropin releasing hormone stimulation and exaggerated response of thyroid stimulating hormone to thyrotropin releasing hormone stimulation. The patient was treated with thyroid supplementation. Magnetic resonance imaging showed a hypoplastic infundibulum, ectopic neurohypophysis, small anterior pituitary gland and absent septum pellucidum. Congenital hypopituitarism may be part of a large spectrum of midline brain abnormalities.

Cerebral venous thrombosis. Demonstration with magnetic resonance angiography.

Three patients with cerebral venous thrombosis (CVT) were imaged with magnetic resonance angiography (MRA). Initial spin-echo magnetic resonance (MR) demonstrated acute or subacute thrombosis in all patients. The presence of thrombosis was confirmed with MRA. Repeat MRA in the three patients revealed partial recanalization in one and almost complete recanalization in two patients. The etiology of CVT is reviewed, and the advantages of MRA are compared with conventional MR imaging and computed tomography in the evaluation of CVT.

Pneumorachis and pneumocephalus caused by pneumothorax and multiple thoracic vertebral fractures.

Pneumorachis, or air within the spinal canal, has rarely been described, particularly in conjunction with thoracic trauma. We report a case of pneumorachis and pneumocephalus in a patient with a tension pneumothorax and multiple closed thoracic spinal fractures.

High resolution MR technique in the diagnosis of mesial temporal sclerosis. Correlative MRI and pathological features.

Mesial temporal sclerosis, otherwise known as hippocampal sclerosis, is the most common entity associated with medically intractable temporal lobe epilepsy. The neuronal loss and gliosis of the hippocampus that is pathologically characteristic of this disorder is thought to serve as an epileptogenic substrate. Accurate identification and localization of this pathology is crucial before surgery is considered to potentially cure medically intractable seizures. Magnetic resonance imaging plays a central role in the presurgical work-up. We present a 44-year-old man with a history of intractable partial complex seizures secondary to right-sided mesial temporal sclerosis and discuss the magnetic resonance imaging findings utilizing a high resolution technique.

MR of post traumatic spinal cord lesions. Unexpected improvement of hemorrhagic lesions.

Fifteen patients who sustained spinal cord trauma were evaluated by MR within 72 hours of injury. Nine patients had hemorrhagic and six had nonhemorrhagic traumatic spinal cord lesions. Three patients with hemorrhagic and all six patients with nonhemorrhagic lesions showed some degree of neurological improvement on follow-up examinations. In two of the three patients with hemorrhagic lesions who improved, the hemorrhage was extensive. This supports the observation that hemorrhagic lesions are not always associated with a poor clinical outcome.

Pituitary gland. Variable signal intensities on MRI. A pictorial essay.

The anterior pituitary gland may exhibit high signal on T1-weighted (T1w) images and/or low signal on T2-weighted (T2w) images in several normal and pathological states. High T1w signal may be seen in normal fetuses, neonates, and in pregnant and postpartum women. It may also occur in Rathke's cleft cyst, craniopharyngioma, subacute hemorrhage, manganese deposition, melanoma, dermoid, and lipoma. Low T2w signal may be seen in hemorrhage, calcification, cystic lesion, hemochromatosis, melanoma, and vascular lesions. These are described and illustrated.

Gradient echo imaging of the lumbar spine.

Journal articles have presented pro and con views of gradient recalled echo (GRE) imaging of the lumbar spine, while it has been illustrated in textbooks that have advanced its diagnostic applicability. This paper reappraises GRE in light of evolving MRI technology. The conspicuity of anatomic structures on axial T1-weighted (T1W) spin-echo (SE) images were matched with T2 GRE images in 55 patients referred for evaluation of low back pain. Disc herniations were hyperintense on GRE images and readily separable from hypointense spondylophytes.

Temporomandibular joint chondrosarcoma: CT demonstration.

Chondrosarcoma of the temporomandibular joint is a rare lesion. A 49-year-old woman presented with painless left preauricular swelling. Computed tomography demonstrated a soft tissue mass in the left temporomandibular joint with extraarticular extension along the mandibular ramus. Calcification was present in the extraarticular component.

Magnetic resonance imaging of cerebrospinal fluid leak and tamponade effect of blood patch in postdural puncture headache.

This prospective study examined the efficacy of magnetic resonance imaging (MRI) in visualizing cerebrospinal fluid (CSF) leak in patients with postdural puncture headache (PDPH) and determining the spread of the blood patch in the epidural space and the extent of tamponade on the thecal sac. After obtaining institutional review board approval, five patients with symptomatic PDPH after 3 days of failed conservative treatment were included in this study. MRI using proton density (PD) and T2-weighted imaging was performed on all patients and CSF flow studies were done on one patient. All patients received 20 mL of blood in the epidural space. They remained supine for 45 min, and repeat MRI studies were performed. Extent of the spread of blood in the epidural space was measured. A visual analog scale of 0-10 was used to evaluate the headache. All patients had severe postural headache with nausea/vomiting. Preblood patch MRI showed extrathecal CSF and hemosiderosis indicating the site of dural puncture in four patients. The postprocedure MRI demonstrated the blood patch as a large extradural collection with anterior displacement of the thecal sac, the mean spread being 4.6 intervertebral spaces. The tamponade effect of the blood patch was observed on PD, T2-weighted, and CSF flow images. All patients experienced immediate resolution of their symptoms. This study suggests that using MRI, the site of the CSF leak, the tamponade effect of the blood patch, and its spread in the epidural space can be documented.