Sydenham Chorea: magnetic resonance imaging reveals permanent basal ganglia injury

We report the case of a 26-year-old man with diffuse esophageal leiomyomatosis involving the trachea. The tumor was resected by total esophagectomy and partial resection of the trachea and the left main bronchus. The tracheobronchial defect was repaired with a free forearm skin graft with satisfactory outcome. This approach offers good long-term prospects.     

Single photon emission computed tomography-EEG relations in temporal lobe epilepsy

The role of single photon emission computed tomography (SPECT) as an independent confirmation test in presurgical evaluation of medically intractable temporal lobe epilepsy has not been critically investigated. Because spreading ictal discharges may cause a concomitant increase of cerebral blood flow in remote cerebral regions, a careful analysis of peri-injection EEG patterns and their relation to ictal SPECT may be important in evaluating the reliability of ictal SPECT. Both interictal and ictal EEG and SPECT were reviewed in 19 patients with temporal lobe epilepsy who achieved a successful seizure outcome after surgery. Patients were divided into unitemporal and bitemporal groups according to the lateralization of interictal epileptiform discharges (IED). Ictal EEG features were classified into lateralized and nonlateralized groups. The concordance between SPECT and EEG lateralizations was examined in each patient and correlated to the documented epileptogenic temporal lobe. Interictal SPECT correctly lateralized in eight of nine patients with unitemporal IED and in five of 10 patients with bitemporal IED. Ictal SPECT was highly concordant with the peri-injection ictal EEG but correctly lateralized the epileptogenic region in only 11 of 19 patients. When both pre- and postinjection EEG epochs lateralized ipsilaterally, all ictal SPECT images showed concordant lateralization. If pre- and postinjection EEG epochs were either different in lateralization or nonlateralization, ictal SPECT images often showed complex patterns of cerebral perfusion with a high incidence of false lateralization. Interictal SPECT was more sensitive and reliable in patients with unitemporal IED than in patients with bitemporal IEDs. Ictal SPECT was closely related with peri-injection EEG epochs but with frequent false lateralization. The role of ictal SPECT as an independent confirmation test in presurgical evaluation should be reappraised.     

Single photon emission computed tomography scanning in childhood systemic lupus erythematosus

Chromosomal abnormalities are thought to be a major contributor to the genetic risks of infertility treatment by intracytoplasmic sperm injection (ICSI). Apart from abnormalities arising de novo, abnormal karyotypes in pregnancies conceived through assisted reproductive technology may be directly derived from predisposing parental aberrations. In a prospective study we have analysed the chromosomes of 868 male and female patients prior to planned ICSI treatment. A total of 33 aberrant karyotypes was diagnosed, corresponding to an abnormality rate of 7.6% per couple or 3.8% per individual studied. Even though male factor infertility was twice as common as female factor infertility in this cohort, 24 of the chromosomal abnormalities were found among the women. Low-level mosaicism for numerical sex chromosome anomalies was diagnosed in 20 individuals, and one patient had the triple X karyotype. With respect to structural chromosomal anomalies, we found six reciprocal and three Robertsonian translocations, two paracentric inversions and one marker chromosome. Many of the aberrations that we diagnosed could be classified as carrying only a small to moderate reproductive risk. Given the high rate of abnormal karyotypes among the female subjects, we suggest that not only the males, but both partners should be routinely karyotyped prior to ICSI.     

Single photon emission computed tomography scanning in neuropsychiatric systemic lupus erythematosus

Percutaneous tracheostomy is being used increasingly in the intensive care unit and endoscopic control of this procedure affords an improved level of safety. Training in such new minimal access techniques can be a significant risk factor in patient outcome. Surgical simulation provides training which minimizes this risk. We present a method of training in percutaneous endoscopic tracheostomy using a simulation model based on animal tissue. Our experience with this model is reported.     

Cerebral fat embolism studied by magnetic resonance imaging, transcranial Doppler sonography, and single photon emission computed tomography: case report

Cerebral fat embolism syndrome is an uncommon complication of trauma. We present a patient who developed cerebral fat embolism syndrome secondary to long-bone fractures. Although computed tomography of the brain failed to show any intracranial lesion, magnetic resonance imaging (MRI) detected scattered, high-signal-intensity lesions on T2-weighted images. 99mTc-d, 1-hexamethyl-propylene amine oxine single photon emission computed tomography (99mTc-HMPAO SPECT) and transcranial Doppler sonography (TCD) demonstrated low cerebral blood flow in the acute stage. MRI, 99mTc-HMPAO SPECT, and TCD correlated well with the clinical course of cerebral fat embolism syndrome.     

Computed tomographic and magnetic resonance imaging of chronic odontoid fractures

STUDY DESIGN: The analysis of the imaging characteristics found in chronic odontoid fractures. OBJECTIVES: To determine the efficacy of computed tomography and magnetic resonance imaging in diagnosing a chronic odontoid fracture. SUMMARY OF BACKGROUND DATA: Radiographic examination of the cervical spine is intrinsic to the evaluation of all patients with blunt trauma. Injury to the craniocervical junction constitutes 19-25% of all cervical spine fractures. At the authors' trauma center computed tomography is routinely used instead of the open-mouth odontoid radiograph to facilitate cervical spine evaluation. This practice has increased the detection of fractures that are unrecognized in plain radiography, and has, at the same time, raised questions about the age and significance of these fractures. METHODS: Radiography, computed tomography, and magnetic resonance imaging studies were performed on three patients who came to the emergency department with odontoid fractures. Two patients had a history of severe trauma, and one had a history inconsistent with an acute odontoid fracture. One patient also had a technetium Tc 99m methylene dihydroxyphosphonate bone scan. The studies were obtained to determine the age of the fractures. RESULTS: All three patients were determined to have chronic odontoid fractures. This diagnosis was facilitated by the use of computed tomographic and magnetic resonance imaging. Computed tomography showed increased sclerosis in the proximal fracture fragment in all cases and well-corticated fracture edges in one patient. Magnetic resonance images showed normal bone marrow or bone sclerosis in the odontoid process. Soft tissue edema was absent. A bone scan was not useful in resolving this issue. CONCLUSION: Computed tomography and magnetic resonance imaging can be useful in determining the chronicity of an odontoid fracture.     

Assessment of cerebral blood flow reserve using functional magnetic resonance imaging

Imaging of activated brain areas based on changes of blood deoxyhemoglobin levels is now possible with MRI. Acetazolamide (ACZ) increases cerebral blood flow (CBF) without changing cerebral oxygen consumption; this results in signal changes observed in gradient echo MR images from the areas with an increase in CBF. We assessed signal changes after ACZ application in seven healthy subjects with a conventional 1.5-T MRI scanner. The susceptibility-sensitized three-dimensional fast low-angle shot (FLASH) sequence was used to visualize signal changes induced by ACZ. We analyzed anatomic localization of different ranges of detected signal changes. ACZ caused significant signal changes in the gray matter and at the edge of the cerebral cortex, the latter corresponding to draining surface veins. No significant differences were seen among different brain areas within the same slice. Using the maximal intensity projection technique, we were able to partially separate signal changes originating in draining veins from signal originating in the gray matter microvasculature. Signal changes from the microvessels reflect cerebrovascular reserve. Blood-oxygen-level-dependent (BOLD) based MRI can evaluate CBF reserve with high spatial and temporal resolution. To assess cerebrovascular reserve, it is necessary to separate signal changes originating in large vessels from signal from brain microvasculature.     

Quantification of optic nerve blood flow changes using magnetic resonance imaging

PURPOSE: To evaluate the possibilities of magnetic resonance imaging (MRI) for quantification of pharmacologically induced changes in optic nerve microcirculation. METHOD: T2-weighted MRI sequences were used to image the eye, optic nerve, and frontal cortex in rats. Two sets of control images before and one set during Gd (DTPA) infusion were recorded. Blood flow values for two regions of the optic nerve (an anterior part, including the optic nerve head, and a more posterior part) and the frontal cortex were calculated by image analysis from the change in signal intensity, as already reported for cerebral blood flow. For each rat, a control experiment before drug administration and a second experiment 30 minutes after subcutaneous injection of either placebo (n = 7), timolol (n = 7), or SDZ GLC-756, a dopamine D-1 antagonist and D-2 agonist (n = 7), were carried out in a double-blind fashion. RESULTS: Mean basal blood flow values were found between 29.4 and 45.6 ml/100 g per minute in the anterior part of the optic nerve, 38.3 and 42.9 ml/100 g per minute in the posterior part of the optic nerve, and 68.0 and 75.0 ml/100 g per minute in the frontal cortex. Placebo and timolol did not cause significant changes. SDZ GLC-756 significantly increased blood flow by 238% +/- 65% in the anterior part and by 87% +/- 40% in the posterior part of the optic nerve. CONCLUSIONS: These results suggest that MRI provides quantification of optic nerve blood flow and that dopaminergic substances increase optic nerve blood flow.     

Diagnostic neuroimaging: computed tomography and magnetic resonance imaging

BACKGROUND: Computed tomography (CT) and magnetic resonance imaging (MR) are commonly used neuroimaging modalities for patients with signs or symptoms of neuro-ophthalmic disorders. Understanding the technology and clinical uses of these modalities is vital in patient management. METHODS/RESULTS: Basic instrument design and technology are presented together with a discussion of indications and contraindications to the use of these imaging techniques. Case reports are presented to illustrate the usefulness in diagnosis of orbital and neuro-ophthalmic disease. CONCLUSIONS: A basic knowledge of CT and MR helps the optometrist correlate imaging with clinical signs and symptoms of disease. This understanding also results in more effective communication with other health care providers and patients.     

Torsion of an accessory hepatic lobe in a child: ultrasound, computed tomographic, and magnetic resonance imaging findings

A case of acute epigastric pain resulting from torsion of an accessory hepatic lobe is reported. Sonographic, computerized tomographic, and magnetic resonance findings are illustrated and the surgical management is discussed.     

Changes in cerebral blood flow and oxygen metabolism related to magnetic resonance imaging white matter hyperintensities in Alzheimer's disease

We studied changes in cerebral perfusion and oxygen metabolism to elucidate the pathophysiological nature and clinical significance of white matter hyperintensities in Alzheimer's disease (AD). METHODS: Sixteen AD patients (age 71.6 +/- 3.1 yr) whose T2-weighted MR images showed white matter hyperintensities, and 16 age-matched AD patients (age 71.0 +/- 4.3 yr) without white matter hyperintensities were compared. Regional cerebral blood flow (CBF), oxygen metabolism (CMRO2) and oxygen extraction fraction (OEF) were measured by using (15)O steady-state method and PET. RESULTS: There was no significant difference in cognitive impairment between the two groups. Compared to the patients without white matter hyperintensities, those with them had significantly low CBF values and significantly high OEF values in all cortical and white matter regions. However, there were no significant differences in CMRO2 values between the two groups. Severity of white matter hyperintensities correlated with the mean cortical and mean white matter OEF. CONCLUSION: In AD patients, white matter hyperintensities on T2-weighted MR images represent ischemic changes in which oxygen metabolism and function are fairly compensated. These changes are not disease-specific but are age-associated coincidences, as in normal aging with or without vascular risk factors.     

Altered cortical blood flow in HIV-seropositive individuals with and without dementia: a single photon emission computed tomography study

OBJECTIVE: To quantitatively demonstrate the pattern of cerebral perfusion abnormalities in HIV-1-infected individuals described as 'patchiness' or inhomogeneity in previous qualitative emission tomographic imaging studies. DESIGN: We aimed to create a quantitative measure of inhomogeneity in HIV-infected individuals. High-frequency variance in cortical profiles is an indication of inhomogeneity in the distribution of radiotracer in the cerebral cortex. Therefore, the study analysis was designed to enable the estimation of variance frequencies in cortical profiles. METHODS: Regional cerebral blood flow was examined in nine mildly demented and 10 cognitively normal HIV-1-seropositive individuals and eight seronegative normal controls using single photon emission computed tomography with the radiotracer [I-123]-N-isopropyl-p-iodoamphetamine. Quantitative analysis was performed using circumferential profiles of cerebral cortical perfusion. Fourier transform power spectra of the profiles were examined as an index of patchiness in tracer distribution. RESULTS: Normal controls were characterized by strong middle frequency and weak high-frequency power. Both HIV-1-infected groups showed a significant power shift from middle to high frequencies. CONCLUSIONS: Increased high-frequency variations in both HIV-1-infected groups indicates diffuse cortical perfusion changes compared with normal controls. This study suggests that there are cerebral bloodflow abnormalities in HIV-1-infected individuals both with and without clinically severe dementia.     

Impact of exercise single-photon emission computed tomographic imaging on appropriateness of coronary revascularization

This study examined the predictors of early coronary revascularization in 816 patients with chest pain syndromes who had coronary artery disease by angiography and exercise single-photon emission computed tomography (SPECT) thallium imaging. Multivariate analysis of clinical, stress, nuclear, and catheterization variables revealed the presence of SPECT reversibility as the most powerful predictor (chi-square = 43) of early revascularization.     

Quantitative proton magnetic resonance spectroscopy of the basal ganglia in patients with affective disorders

We have retrospectively reviewed 53 cases (62 hips) with a diagnosis of slipped capital wedge epiphysis. After admission to our Hospital, a skin longitudinal traction was applied for 2 weeks, All patients were treated afterward with pinning in situ without manipulation in the operating room. Group A (31 hips) consisted of patients treated with smooth K wires and group B (31 hips) of patients treated with cannulated screws. We found a high incidence of pin penetration in group A (27 hips), whereas there was just one case in group B. Physical closure was considered when 75% of proximal growth plate disappeared in the frog lateral view and both groups showed similar values (7 months). Chondrolysis was observed in just three cases in group A, and one case had an avascular necrosis. Few complications were observed compared with the high rate of pin penetration, and we suggest that preoperative traction may be a relevant factor contributing to the low incidence of avascular necrosis (1.6%).     

Temporal lobe abnormalities in dementia and depression: a study using high resolution single photon emission tomography and magnetic resonance imaging

OBJECTIVES: Perfusion SPECT and MRI were used to test the hypothesis that late onset depression is associated with brain abnormalities. METHODS: Forty depressed patients (DSM-III-R major depressive episode, not demented at two year follow up) were recruited who were either drug free, or on a stable dose of antidepressants for at least three weeks, as well as 22 demented patients (DSM-IIIR and NINCDS/ADRDA criteria for probable Alzheimer's disease). Patients were imaged at rest with a high resolution single slice 12 detector head scanner (SME-Neuro 900) and the cerebral perfusion marker 99mTc-exametazime (HM-PAO). Temporal lobe templates were fitted with brains pitched by 20 degrees-30 degrees. A subgroup of 41 patients (22 depressed) were also scanned using a Siemens Magnetron 1.0 Tesla magnetic resonance imager, using a FLAIR imaging sequence for the assessment of white matter hyperintensities, and a Turbo FLASH sequence for the measurement of medial temporal lobe width. RESULTS: Demented patients showed reduced perfusion, particularly in the left temporoparietal cortex. In these regions of interest, patients with late onset depression tended to have perfusion values intermediate between patients with early onset depression and demented patients. Differences in changes in white matter between demented and early and late onset depressive patients did not reach conventional levels of significance. Temporal lobe width differed between demented and depressed patients, but not between early and late onset depressed patients. Perfusion and temporal lobe width were not associated, but reductions of perfusion were associated with periventricular white matter changes. Mini mental state examination scores were associated with temporal perfusion in demented patients and with changes in deep white matter in depressed patients. Finally, severity of depressive symptoms was associated with decreased perfusion in frontotemporal and basal ganglia regions of interest. CONCLUSION: A cumulative effect of duration of illness on regional cerebral perfusion could not be confirmed. Late onset depression may show more abnormalities of deep white matter and of left temporoparietal perfusion than early onset depression, but the underlying pathology remains to be established.     

Multifunctional magnetic resonance imaging of cerebrovascular disease

Over the last few years magnetic resonance imaging (MRI) has developed into a multipurpose imaging technique. In addition to anatomical information, data can be obtained on perfusion, metabolism and imaging of the vascular anatomy. Especially in the field of neuroradiology the possibilities for obtaining multifunctional information from combined MR examinations are promising. In particular, stroke or stroke-related research benefits from these developments. This article reviews the current status and the potential of newly developed MR techniques with regard to the intracranial hemodynamic changes in patients with severe stenosis or occlusion of the internal carotid artery. The combination of MR angiography, perfusion-weighted MRI and MR spectroscopic imaging seems especially useful in the management of the individual patient.     

Cine magnetic resonance imaging study of blood flow and wall motion of the aortic arch

The aortic arch has 3D distortions in the transverse arch in the axial view, and we previously reported that this distortion is a risk factor in the pathogenesis of arch aneurysms. In this study, we evaluated blood flow and movement of the aortic arch. In 10 healthy young volunteers, ECG-gated cine magnetic resonance imaging was carried out in the axial plane of the transverse arch, the coronal plane of the ascending arch, and the long axial plane along the entire arch. 1. Left anterolateral movements around the midpoint of the transverse arch in the systolic phase were observed in all of the men (6.3 +/- 1.59 mm) and women (4.8 +/- 0.73 mm). 2. A jet flow was detected in the systolic phase along the right side of the aortic wall. At the top of the plane, this jet flow turned to the left in a clockwise rotation in the anterior view. 3. In the long axial plane, a turbulent flow in the systolic phase was observed distal to the left subclavian arterial orifice in 6 of the 7 cases. In conclusion, this turbulent flow and left anterolateral wall motion of the transverse arch are due to anatomical three-dimensional distortion of the transverse arch. We propose that these phenomena may be important risk factors in the pathogenesis of arch aneurysms.