Assessing lumbar paraspinal muscle cross-sectional area and fat composition with T1 versus T2-weighted magnetic resonance imaging: Reliability and concurrent validity.

PURPOSE: Studies using magnetic resonance imaging to assess lumbar multifidus cross-sectional area frequently utilize T1 or T2-weighted sequences, but seldom provide the rationale for their sequence choice. However, technical considerations between their acquisition protocols could impact on the ability to assess lumbar multifidus anatomy or its fat/muscle distinction. Our objectives were to examine the concurrent validity of lumbar multifidus morphology measures of T2 compared to T1-weighted sequences, and to assess the reliability of repeated lumbar multifidus measures. METHODS: The lumbar multifidus total cross-sectional area of 45 patients was measured bilaterally at L4 and L5, with histogram analysis determining the muscle/fat threshold values per muscle. Images were later re-randomized and re-assessed for intra-rater reliability. Matched images were visually rated for consistency of outlining between both image sequences. Bland-Altman bias, limits of agreement, and plots were calculated for differences in total cross-sectional area and percentage fat between and within sequences, and intra-rater reliability analysed. RESULTS: T1-weighted total cross-sectional area measures were systematically larger than T2 (0.2 cm2), with limits of agreement <±10% at both spinal levels. For percentage fat, no systematic bias occurred, but limits of agreement approached ±15%. Visually, muscle outlining was consistent between sequences, with substantial mismatches occurring in <5% of cases. Intra-rater reliability was excellent (ICC: 0.981-0.998); with bias and limits of agreement less than 1% and ±5%, respectively. CONCLUSION: Total cross-sectional area measures and outlining of muscle boundaries were consistent between sequences, and intra-rater reliability for total cross-sectional area and percentage fat was high indicating that either MRI sequence could be used interchangeably for this purpose. However, further studies comparing the accuracy of various methods for distinguishing fat from muscle are recommended.

'No-reflow' after acute myocardial infarction: direct visualisation of microvascular obstruction by gadolinium-enhanced CMR.

Cardiovascular magnetic resonance is considered the standard imaging modality in clinical trials to monitor patients after acute myocardial infarction. However, limited data are available with respect to infarct size, presence and extent of microvascular injury (MVO) and changes over time, in relation to cardiac function in optimally treated patients. In the current study we prospectively investigate the change of infarct size over time, and the incidence and significance of MVO in a uniform, optimally treated patient group after AMI. (Neth Heart J 2008;16:179-81.).

Presentation and course of AIDS dementia complex: 10 years of follow-up in Amsterdam, The Netherlands.

OBJECTIVE: To assess the clinical presentation and course of the AIDS dementia complex (ADC). DESIGN: Retrospective study of a consecutive series of symptomatic HIV-1-infected patients [Centers for Disease Control and Prevention (CDC) stages IVA, B, C and D] evaluated for neurological symptoms between 1982 and 1992. SETTING: An academic referral centre for AIDS. PATIENTS: A total of 536 symptomatic HIV-1-infected patients evaluated for neurological symptoms between 1982 and 1992. INTERVENTIONS: Zidovudine treatment, which was introduced in The Netherlands on 1 May 1987 for patients with severe symptoms of HIV infection (CDC stages IVA, B, C and D). MAIN OUTCOME MEASURES: Diagnosis of ADC and CD4 cell count, clinical features, neuropsychological abnormalities, computed tomography (CT) and magnetic resonance imaging (MRI) abnormalities, cerebrospinal fluid (CSF) findings and course in patients with ADC. RESULTS: ADC was diagnosed in 40 out of 536 (7.5%) immunosuppressed, neurologically symptomatic HIV-1-infected patients in CDC stage IV, and was the AIDS-defining illness in six. The mean CD4 cell count of the 40 patients with ADC was 109 x 10(6)/l. Neuropsychological abnormalities in 15 out of 17 patients tested were in accordance with subcortical dementia. On CT scan of the brain, 70% showed no or only mild cortical atrophy. MRI was more sensitive than CT scan for detecting white matter abnormalities (73 versus 35%; P = 0.02). CSF examination showed mononuclear pleocytosis in 25%, protein level increase in 55%, and HIV-1 p24 core protein in 38% (13 out of 34). The mean survival was 6.7 months in the 40 ADC patients, but 4 months in 20 patients who had never used zidovudine, compared with 14.8 months in 10 patients who started zidovudine after they were classified as having ADC (P < 0.001). Three of these 10 patients improved remarkably, and two slightly, after starting zidovudine. ADC developed after discontinuation of zidovudine in nine patients. Only one patient developed ADC while receiving 600 mg zidovudine. CONCLUSIONS: MRI is more sensitive than CT for detecting white matter abnormalities. To date, there is no specific or sensitive CSF marker for ADC. Zidovudine may improve symptoms and prolong survival in patients with ADC, which rarely developed with continued zidovudine use in our study.

Hereditary cerebral hemorrhage with amyloidosis-Dutch type. Clinical and computed tomographic analysis of 24 cases.

Clinical and computed tomographic findings in 24 patients with hereditary cerebral hemorrhage with amyloidosis-Dutch type were reviewed. The common initial symptoms were headache and vomiting. Computed tomographic scans showed 50 hypodense and 49 hyperdense cortical lesions and in 20 patients the scans also showed generalized white matter hypodensity. Impairment of consciousness was related to the size of the hemorrhagic lesion. Dementia, seen in 11 patients, was related to the duration of the disease and the number of focal lesions on the computed tomographic scans, but not to the presence of white matter hypodensity. It is concluded that in hereditary cerebral hemorrhage with amyloidosis-Dutch type, lobar hemorrhages account predominantly for the acute clinical syndromes. The hemorrhages often have an irregular shape and are responsible for progression of the symptoms after an acute onset. Furthermore, cerebral amyloid angiopathy leads to a generalized abnormality of the white matter, probably due to chronic hypoperfusion.

Toxic leukoencephalopathy after inhalation of poisoned heroin: MR findings.

Retrospective MR studies of four patients with neurologic symptoms after inhalation of contaminated heroin vapor revealed extensive, typically symmetrical lesions in the white matter of the cerebrum, cerebellum, and midbrain. Selective involvement of the corticospinal tract, the solitary tract, and the lemniscus medialis also has been found.

Remote expert consultation for MRI procedures by means of teleradiology.

From April 1992 to January 1993, radiology expert opinion for MRI procedures was offered by means of teleradiology. The experiment was carried out in addition to an existing service of a mobile MRI unit. MRI images were sent by means of teleradiology via regular telephone lines from the mobile MRI unit to an academic hospital, which served as expert consultation centre. During this period, 43 requests for expert opinions were performed. This article describes the clinical effects of these expert opinions, and the technical and organisational requirements to perform teleradiology in daily clinical practice.

Spinal subarachnoid hemorrhage due to a filum terminale ependymoma.

We present a case of spinal subarachnoid hemorrhage due to an ependymoma of the filum terminale in a 23-year-old male. Clinical signs indicating a spinal origin of the subarachnoid hemorrhage are discussed. Subarachnoid hemorrhages are only rarely caused by an intraspinal tumor, most of which are located in the cauda equina. Our findings in this case proved the value of MRI examination in tumors of the cauda equina.

Intracerebral uptake of Tc-99m labeled antimelanoma antibodies.

A patient with an intraocular tumor showed accumulation of Tc-99m labeled antimelanoma antibodies in the head. This was not due to a metastatic lesion but proved to be a benign intracranial osteoma. The reasons for this false-positive result are discussed.

[Progressive multifocal leukoencephalopathy in AIDS]. / Progressieve multifocale leuko-encefalopathie bij AIDS.

This study was carried out to determine clinical features, abnormalities on CT scan and MRI, and course in patients with HIV-I-related progressive multifocal leukoencephalopathy (PML). There were 14 patients with a presumptive diagnosis of PML among 500 HIV-I infected patients with neurological complaints, examined between September 1982 and May 1991 in the University Medical Centre in Amsterdam by a neurologist. In these 14 patients clinical features, imaging abnormalities and course of the disease were analysed retrospectively. All patients presented with progressive focal neurological abnormalities. Cerebrospinal fluid analysis revealed aspecific abnormalities in 5/13 patients. CT scanning of the brain showed hypodense areas in the white matter, without mass effect and with contrast enhancing in only one patient. MR Imaging of the brain showed high signal intensity areas in white matter and in gray matter (10/13), without mass effect, and with contrast enhancement in two. Specimens for neuropathological examination were obtained from 7 patients; in all these cases the diagnosis of PML was confirmed. In patients with AIDS a presumptive diagnosis of PML can be based on clinical features, brain imaging abnormalities and course. However neuropathological confirmation remains the gold standard. Usually the course in these patients was steadily progressive. Most patients died within one year.

A double-blind, comparative study of gadodiamide injection and gadopentetate dimeglumine in MRI of the central nervous system.

Seventy-nine patients with known or suspected central nervous system lesions were studied with MRI in a phase III double-blind study. Forty were given gadopentetate dimeglumine (Gd-DTPA) and 39 gadodiamide injection (Gd-DTPA BMA), a new low-osmolar nonionic contrast enhancing medium. The dosage was 0.1 mmol/kg body weight, corresponding to 0.2 ml/kg. Spin-echo sequences were performed before and immediately after injection. The safety and efficacy of the two contrast media were assessed. No changes were observed in blood pressure, heart rate or neurological status. Five adverse effects (two episodes of headaches, two of nausea and one of dizziness) were reported by 2 patients who received gadodiamide injection and 1 who received gadopentetate dimeglumine. All events were mild and their relationship to the contrast media was uncertain. For both contrast media statistically significant changes in serum iron were observed 24 h after injection. More than 70% of the patients had abnormal findings on MRI, and in 56% of these contrast enhancement of the abnormal structure or lesion was seen. Contrast enhancement provided the diagnosis in about 50%, changed it in 40% and increased diagnostic confidence in 95%.

Rheumatoid arthritis with vertical atlanto-axial subluxation complicated by hydrocephalus.

The present report describes a patient with rheumatoid arthritis and vertical atlanto-axial subluxation who developed hydrocephalus with high intraventricular pressure and neuropsychiatric abnormalities. The vertical atlanto-axial subluxation and hydrocephalus were visualized by magnetic resonance imaging, which clearly demonstrated the basilar impression by the dens and ventricular enlargement. The patient recovered completely after ventriculo-cardial drainage.

Magnetic resonance imaging in the evaluation of patients with rheumatoid arthritis and subluxations of the cervical spine.

We used magnetic resonance imaging (MRI) to examine 21 patients with rheumatoid arthritis and vertebral subluxations of the cervical spine, in whom neurologic symptoms and signs indicated spinal cord compression. Based on neurologic signs, the patients were assigned to 1 of 3 classes: class I, no objective signs of cervical myelopathy (9 patients); class II, only 1 objective sign of cervical myelopathy (4 patients); or class III, 2 or more objective signs of cervical myelopathy (8 patients). Atlantoaxial subluxation (20 patients) and subluxations below C2 (6 patients) were detected equally well by MRI and radiography. MRI revealed physical distortion of the spinal cord in all class III patients with compressive myelopathy. This distortion was found less frequently in class II and class I patients (3 patients), and the difference was statistically significant (P less than 0.005, class III versus class I and class II). No correlation was found between the vertebral dislocation (measured in millimeters) on plain radiographs and the presence of cord distortion on MRI. Myelography in class III patients showed that passage of contrast medium was blocked at the same level as the cord distortion seen on MRI. These findings suggest that MRI can serve as a useful, noninvasive procedure in the diagnosis and management of rheumatoid arthritis patients in whom compressive cervical myelopathy is suspected.

Gadolinium-DTPA enhanced magnetic resonance imaging of bone cysts in patients with rheumatoid arthritis.

OBJECTIVES: To examine the contents of intraosseous cysts in patients with rheumatoid arthritis (RA) through the signal intensity characteristics on gadolinium-DTPA (Gd-DTPA) enhanced magnetic resonance imaging. METHODS: The hand or foot joints of nine patients with the cystic form of RA (where the initial radiological abnormality consisted of intraosseous cysts without erosions) were imaged before and after intravenous administration of Gd-DTPA. A 0.6 unit, T1 weighted spin echo and T2* weighted gradient echo were used to obtain images in at least two perpendicular planes. RESULTS: Most cysts showed a low signal intensity on the non-enhanced T1 weighted (spin echo) images and a high signal intensity on the T2* weighted (gradient echo) images, consistent with a fluid content. No cyst showed an enhancement of signal intensity on the T1 weighted images after intravenous administration of Gd-DTPA, whereas synovium hyperplasia at the site of bony erosions did show an increased signal intensity after Gd-DTPA. Magnetic resonance imaging detected more cysts (as small as 2 mm) than plain films, and the cysts were located truly intraosseously. In six patients no other joint abnormalities were identified by magnetic resonance imaging; the three other patients also showed, after Gd-DTPA administration, an enhanced synovium at the site of bony erosions. CONCLUSIONS: It is suggested that intraosseous bone cysts in patients with RA do not contain hyperaemic synovial proliferation. The bone cysts in patients with the cystic form of RA may be the only joint abnormality.

Methotrexate induced brain necrosis and severe leukoencephalopathy due to disconnection of an Ommaya device.

A 63-year old woman with breast carcinoma developed leucoencephalopathy and local brain necrosis after intraparenchymal infusion of methotrexate. This iatrogenic condition was caused by drain disconnection of the Ommaya device (bore hole type). The diagnosis of this rare complication of an Ommaya device was based on multiplanar MR-imaging. The case is discussed with regard to the complications of intraventricular chemotherapy by means of an Ommaya reservoir.