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.).

Comparison of sonography and magnetic resonance imaging for the diagnosis of partial tears of finger extensor tendons in rheumatoid arthritis.

OBJECTIVE: Finger extensor tenosynovitis in rheumatoid arthritis (RA) may lead to partial and eventually to complete tendon tears. The aim of this study was to investigate the diagnostic value of sonography (SG) and/or magnetic resonance imaging (MRI) to visualize partial tendon tears. METHODS: Twenty-one RA patients with finger extensor tenosynovitis for more than 12 months underwent SG, MRI and surgical inspection, the latter being the gold standard. RESULTS: For partial tears, sensitivity and specificity were 0.27 and 0.83 for MRI, and 0.33 and 0.89 for SG, respectively. Positive and negative predictive values were 0.35 and 0.78 for MRI, and 0.50 and 0.80 for SG, respectively. Accuracy was 0.69 for MRI and 0.75 for SG. CONCLUSION: For visualization of partial finger extensor tendon tears in RA patients, SG performs slightly better than MRI, but both techniques are at present not sensitive enough to be used in daily practice.

Sonography and magnetic resonance imaging equivalent for the assessment of full-thickness rotator cuff tears.

OBJECTIVE: To investigate the diagnostic value of sonography (SG) and magnetic resonance imaging (MRI) in the assessment of full-thickness rotator cuff tears (RCTs). METHODS: Twenty-one consecutive, otherwise healthy patients with noninflammatory unilateral chronic (>3 months) shoulder complaints due to a possible full-thickness RCT were studied (9 women and 12 men, mean +/- SD age 56 +/- 12). According to standardized procedures, SG was performed by both a radiologist and a rheumatologist, and MRI was evaluated by 2 radiologists. All assessors were blinded to the patient's diagnosis. Within 3 weeks after SG and MRI, arthroscopy was performed. SG, MRI, and arthroscopy results were scored as negative or positive for the presence of a full-thickness RCT. The result of surgical inspection was used as the "gold standard." RESULTS: For full-thickness RCTs, the sensitivity was 0.81 for SG and 0.81 for MRI. The specificity was 0.94 for SG and 0.88 for MRI. The positive predictive value was 0.96 for SG and 0.91 for MRI. The negative predictive value was 0.77 for SG and 0.74 for MRI. Accuracy was 0.86 for SG and 0.83 for MRI. CONCLUSION: Full-thickness RCTs can be identified accurately by both SG and MRI. Because of its low cost and because it can be performed in the rheumatology unit, SG seems to be a promising diagnostic tool for use by the rheumatologist.

Cortical lesions in multiple sclerosis.

Although previous studies have shown that the lesions of multiple sclerosis may involve the cerebral cortex, there is little published research on the prevalence and distribution of such lesions. Using neuropathological techniques and MRI, a series of studies has been undertaken in order to assess this, in particular to identify their relationship to cortical veins. A serial MRI study showed that the use of gadolinium proffered an increase in cortical lesion detection of 140% and showed that 26% of active lesions arose within or adjacent to the cortex. In a post-mortem study, MRI under-reported lesions subsequently analysed neuropathologically, particularly those arising within the cortex. In a further 12 cases examined, 478 cortical lesions were identified, of which 372 also involved the subcortical white matter. Seven different lesion types were identified; the majority arose within the territory of the principal cortical veins, whilst the remaining quarter arose within the territory of the small branch or superficial veins. Small cortical lesions are common in multiple sclerosis and are under-reported by MRI. Investigation of the cortical venous supply shows how such lesions may arise, and why the majority also involve the underlying white matter.

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.

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.

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.

Angiotropic intravascular large-cell lymphoma with massive cerebral extension.

Angiotropic intravascular large-cell lymphoma (AILL) is a rare, generally fatal disease characterised by a multifocal proliferation of neoplastic mononuclear cells within small blood vessels. The diagnosis of a patient was made at necropsy. The malignant cells had infiltrated the periventricular areas of the brain.

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.

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.

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%.

White matter lesions on magnetic resonance imaging in clinically diagnosed Alzheimer's disease. Evidence for heterogeneity.

In a prospective magnetic resonance imaging (MRI) study we evaluated the prevalence and severity of white matter changes in 29 patients with Alzheimer's Disease (AD) and 24 age-matched healthy elderly, all without cerebrovascular risk factors. The AD patients were divided into two groups according to age at onset of symptoms, one with presenile onset AD (n = 13) and one with senile onset AD (n = 16), who were matched for dementia severity. Signal hyperintensities were rated using a semiquantitative scoring method, separately in the periventricular region (PVH) and in the lobar white matter (WMH), as well as in the basal ganglia (BGH) and in the infratentorial region (ITFH). Cortical atrophy as a parameter of grey matter involvement was rated on a 0 (absent) to 3 (severe) scale. We found PVH, WMH and BGH scores to be significantly higher in senile onset AD patients than in age-matched controls. By means of multiple linear logistic regression we found that PVH, WMH and BGH scores were significantly dependent on the diagnosis of senile onset AD, while the PVH score also showed a significant age dependency. Cortical atrophy did not differ significantly between presenile onset AD and senile onset AD patients. These results indicate that presenile onset AD and senile onset AD patients differ with respect to white matter involvement, but not with respect to grey matter involvement on MRI. Since cerebrovascular risk factors were excluded these findings may indicate that senile onset AD patients display more small vessel involvement (arteriolosclerosis) than presenile onset AD patients, suggesting additional (microvascular) factors for the dementia syndrome in senile onset AD. Our data lend support to the growing body of evidence that AD is heterogeneous, consisting of at least two types. Based on our findings two forms can be distinguished: (i) a 'pure' form of the disease, usually with early disease onset, and no more white matter changes than normal for age; (ii) a 'mixed' form, usually with disease onset later in life, and showing more white matter changes on MRI than normal for age.