Cardiac-triggered and segmented two-dimensional MR angiography of peripheral arterial occlusive disease. A pictorial essay.

Magnetic resonance (MR) angiography has been shown to be an important technique to image the vasculature of the lower extremities. The two-dimensional (2D) time-of-flight technique has evolved as the standard method of MR angiography used to examine patients with peripheral arterial occlusive disease (PAOD). There is evidence that cardiac triggering substantially improves the quality of 2D time-of-flight angiography. In this pictorial essay, we describe PAOD, show the results of this nonintrusive angiographic technique, and provide a current overview of the interventional and surgical management of PAOD.

Contrast-enhanced breast MRI for cancer detection using a commercially available system--a perspective.

The diagnosis and treatment of breast cancer are dependent upon early detection of the disease by physical examination and mammography. Although mammography is a relatively good and cost-effective method of early breast cancer detection, there are some inherent weaknesses associated with this imaging modality that limit its sensitivity and specificity. Contrast-enhanced MRI of the breasts provides the additional capability to answer questions raised or unanswered with conventional imaging methods. This paper reviews contrast-enhanced breast MRI interpretation guidelines and patient preselection criteria for diagnostic problem cases. Technical aspects using a commercially available three-dimensional (3D) spoiled gradient-echo technique are discussed.

Fenestration of the internal carotid artery: a rare mass of the hypotympanum associated with persistence of the stapedial artery.

A 61-year-old woman was examined because of unilateral nonpulsatile tinnitus involving the right ear. CT scanning showed a soft-tissue mass in the hypotypanum. Angiographically, the mass was identified as a fenestrated or duplicated internal carotid artery associated with persistence of the stapedial artery. Embryologic considerations are discussed.

Magnetic resonance imaging of cauda equina syndrome in ankylosing spondylitis: a case report.

A case of ankylosing spondylitis associated with massive dural ectasia is presented. Computed tomography and magnetic resonance imaging characteristics are shown, and possible causes are discussed.

Alteration of serum pituitary hormone levels in postmenopausal women with stroke.

BACKGROUND AND PURPOSE: The aim of this study was to determine if circulating levels of pituitary hormones are altered by stroke and, if so, whether these alterations offer insight into specific neurochemical pathways in the region of the central nervous system injury. METHODS: Twenty-eight consecutive postmenopausal women undergoing computed tomographic imaging of the brain for evaluation of clinical evidence of stroke underwent blood sampling for determination of serum levels of luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, triiodothyronine, prolactin, estradiol, and sex hormone--binding globulin. RESULTS: In stroke involving the caudate, serum levels of luteinizing hormone and follicle-stimulating hormone were reduced to 16% and 24% of concentrations found in those with stroke outside of the basal ganglia (p < 0.03 and p < 0.01, respectively). Levels of estradiol, sex hormone-binding globulin, thyroid-stimulating hormone, and prolactin were similar in all stroke groups. Nonspecific biochemical effects of stress that might influence hormone concentrations were assessed by measurement of serum triiodothyronine, the level of which is a sensitive biochemical correlate of disease severity. These levels were not different between stroke groups. CONCLUSIONS: Stroke involving the caudate nucleus may interrupt neurotransmitter pathways involved in control of secretion of gonadotropins. Peripheral levels of these hormones may serve as a marker for central neurochemical disturbances associated with stroke in specific brain regions.

Clinical-radiographic correlations within the first five hours of cerebral infarction.

Fifty patients, ages 54-79, with ischemic hemispheric strokes productive of hemiparesis, at a minimum, underwent standardized neurological evaluations, computed tomographic scanning and cerebral angiography (N = 38) or carotid ultrasound (N = 12) within 5 h of onset. A second scan was performed at 5-7 days. Clinical scores were not associated with a history of, or the presence of: hypertension, smoking or cardiac disease, including atrial fibrillation, nor with severe internal carotid artery stenosis or occlusion. Clinical scores were adversely affected by early scan abnormalities (especially mass effect), lesion size, intracranial arterial occlusions, elevated serum glucose levels and the subsequent development of hemorrhagic infarction. Glucose levels correlated with infarct size and the development of hemorrhagic infarction. Delayed intracranial arterial filling and collateral flow were associated with reduced infarct size but did not confer clinical protection. We believe that combining the initial glucose level and scan results has prognostic significance, and early angiography is valuable in characterizing infarct etiology and assessing clinical severity.

Computed tomographic-angiographic findings within the first five hours of cerebral infarction.

BACKGROUND AND PURPOSE: Modern management of acute stroke necessitates early diagnosis. To this end, we sought to delineate the radiographic features of focal hemispheric infarction within 5 hours of ictus. METHODS: Fifty patients, ages 54-79, with ischemic strokes productive of at least hemiparesis underwent computed tomographic scanning and cerebral angiography (n = 38) or carotid ultrasound (n = 12). Radiographic lesions were characterized for location, size, and pathophysiology. RESULTS: Acute abnormalities, hypodensity, and mass effect were seen in 56% of scans and confirmed on a second scan 5-7 days later. Intracranial angiographic abnormalities occurred in 61% of patients: arterial occlusions in 45% and delayed arterial filling in 16%. Hemorrhagic infarctions occurred in 26% of second scans and were associated with mass effect (100%) and arterial occlusions (89%). Infarcts with hemorrhagic transformation were larger on both scans than those without (p = 0.001). Of four patients with infarctions in watershed territories on the scans, two had middle cerebral artery occlusions on angiography, thereby questioning the specificity of such scan lesions to low-flow states. CONCLUSIONS: We conclude that cerebral infarctions are often visible on early scans, but their locations may not be etiologically determinative. The infarcts associated with intracranial arterial occlusions (45%) were of thromboembolic origin, but, given current controversies as to the pathophysiology of lacunar and watershed infarctions, we cannot ascertain the etiology in the remainder. These findings are relevant to the new stroke therapies that require administration in the first hours after infarction.

Stroke in children.

Childhood stroke, although similar to adult stroke, is characterized by congenital and genetic causes. The evaluation and treatment of the child with stroke requires special considerations. Currently, drug therapy is untested and as a result, therapeutic interventions are problematic. Platelet antagonists are rational prophylactically; warfarin probably has a role in preventing cardiogenic embolus in the older child. However, chronic anticoagulation in the toddler is dangerous due to frequent trauma and is therefore relatively contraindicated. Vascular malformations are surgically repaired but alternative therapies, including radiation and embolization, may be used for inoperable lesions. Aneurysms are primarily surgical lesions. Newer imaging modalities will clarify the pathophysiologic picture and improve treatment.

Computerized volume measurement of brain structure.

Morphometric analysis of brain structures recently has become a main focus of interest in studies of some neuropsychiatric diseases. Limitations in imaging and mensuration methodology that is available currently for quantitative measurement of anatomic structures have prompted the development of a computerized system to study brain morphometry. A menudriven semi-automated computer system has been developed to assess in vivo brain morphometry using three-dimensional (3-D) magnetic resonance (MR), gradient echo, contiguous images of the whole brain. Accuracy of the system was tested with phantoms creating white on black contrast to simulate the brain tissue surrounded by subarachnoid cerebrospinal fluid (CSF), and a second set of phantoms creating black on white contrast to simulate the ventricular system in the brain tissue. The first set of phantoms was composed of three water-filled balloons (spherical, elliptical, and multiform) and a fresh postmortem brain. The second set of phantoms consisted of three rods of different diameters from a simple geometric plexiglass rod phantom and a life size cast of a human ventricular phantom. System accuracy was generally within 2.0% of the true volumes. System reliability was evaluated in three patient populations; 12 patients with Alzheimer's disease, nine with schizophrenia and nine healthy controls age-matched to the patients with Alzheimer's disease. Two independent observers measured the ventricular systems of these patients. Reliability of the system was addressed by the correlation between the two sets of measurements. For the sample as a whole, and each of the subgroups, the correlation between the two observers was 0.99. This system compares favorably with other morphometric methods reported.

CT sialography: utilising acinar filling.

The technique of computed tomographic sialography (CTS) has been demonstrated to be valuable in the diagnosis of masses of the major salivary glands. Forty-one CT sialograms were performed in 35 patients using acinar glandular filling with oily contrast material. Twenty-two mass lesions and seven cases of inflammatory disease were identified. There were two instances of mild parotitis following the procedure. CTS performed with this technique was found to be a safe, accurate method for evaluating salivary gland masses.

Avulsion of the spinous processes caused by infant abuse.

In infants who are victims of abuse, fractures of the thoracic and lumbar spinous processes are likely to be the result of violent shaking. While initial radiographs may appear normal, subsequent studies may reveal extensive ossification within the adjacent soft tissues. These abnormalities are subtle and easily overlooked, in part explaining the rarity of such reports in the literature. The authors recommend that lateral views of the vertebral column be obtained whenever infant abuse is suspected.

Neurosyphilis presenting as a focal mass lesion: a case report.

A patient with subacute aphasia and hemiparesis was found to have a low density white matter lesion with mass effect on the computed tomographic (CT) scan. Serological examination and biopsy established the diagnosis of paretic neurosyphilis. This CT appearance has not previously been described in cases of neurosyphilis. Neurosyphilis should be considered as a potentially treatable cause of a cerebral mass lesion.

Focal cerebral ischemia distal to a cerebral aneurysm in hereditary hemorrhagic telangiectasia.

Neurologic complications in patients with Hereditary Hemorrhagic Telangiectasia (HHT) occur as a consequence of a variety of vascular malformations. One type of intracranial malformation, saccular aneurysm, has recently been appreciated as a potential source of ischemic cerebrovascular disease on the basis of aneurysm to artery emboli. We report a patient with HHT and an unruptured saccular intracranial aneurysm presenting with ischemic vascular events.

The subarachnoid spaces in children: normal variations in size.

Intra- and extraventricular subarachnoid spaces in children were studied by high-resolution computed tomography. Scans were reviewed of 34 patients who were selected as highly likely to have normal scans. Sizes of the ventricular system and the seven extraventricular subarachnoid compartments were analyzed and graded on a subjective scale from 0 (not visible) to 4 (markedly enlarged). Data were also analyzed by age group (greater or less than 2 years of age). The subarachnoid spaces were found to be both larger and more variable in size before the age of 2 years and to be quite uniform thereafter. Based on these findings, it is inadvisable to base specific diagnoses during the first 2 years of life solely upon modest enlargement of the subarachnoid spaces.

Glioblastoma of the cerebellum. Computed tomographic and pathologic considerations.

Cerebellar glioblastoma is a brain malignancy that is often difficult to distinguish from metastatic disease in the elderly before biopsy. The clinical course and computed tomographic appearance of four patients with multiform glioblastoma of the cerebellum are presented and correlated with other reports in the literature. The appearance of a cerebellar hemispheric lesion with little mass effect is described, and the pathology of the tumor is reviewed.

Low-dose metrizamide cisternography with pluridirectional tomography: a useful adjunct to computed tomographic cisternography.

The use of stereotactic necrotizing proton beam irradiation for treatment of pituitary adenoma has prompted the use of computed tomographic cisternography (CTC) as an adjunct to intravenous enhanced computed tomographic (CT) scanning. A technique for obtaining sagittal pluridirectional tomographic sections prior to coronal and axial CTC is outlined. Experience with 19 cases is described.

Metrizamide sagittal tomography: adjunct to CT cisternography of the sellar region.

A total of 30 patients with pituitary adenoma was studied by sagittal polytomography en route to coronal and axial computed tomography (CT) cisternography after a low FDA-approved dose of 6 ml of 170 mg I/ml metrizamide via lumbar injection. The requirement for defining the relation of the optic nerves and chiasm to the intrasellar contents or suprasellar mass before proton beam irradiation or certain surgical approaches was satisfied. Pneumoencephalography as a supplemental procedure to CT and CT cisternography was replaced. The concomitant elimination of conventional sellar polytomography and pneumoencephalography results in decreased total radiation exposure and a more comfortable, expeditious workup.