Cumulative Dose of Macrocyclic Gadolinium-Based Contrast Agent Improves Detection of Enhancing Lesions in Patients with Multiple Sclerosis.

BACKGROUND AND PURPOSE: Gadolinium-enhanced MR imaging is currently the reference standard for detecting active inflammatory lesions in patients with multiple sclerosis. The sensitivity of MR imaging for this purpose may vary according to the physicochemical characteristics of the contrast agent used and the acquisition strategy. The purpose of this study was to compare detection of gadolinium-enhancing lesions or active disease following a single or cumulative dose of a macrocyclic gadolinium-based contrast agent with different image acquisition delays in patients with clinically isolated syndrome or relapsing multiple sclerosis. MATERIALS AND METHODS: All patients received a first dose (0.1 mmol/kg) of gadobutrol and, 20 minutes later, a second dose (0.1 mmol/kg), with a cumulative dose of 0.2 mmol/kg. Two contrast-enhanced T1-weighted sequences were performed at 5 and 15 minutes after the first contrast administration, and 2 additional T1-weighted sequences at 5 and 15 minutes after the second contrast administration with a 3T magnet. RESULTS: One hundred fifteen patients were considered evaluable. A significantly larger number of lesions were detected in scans obtained at 5 and 15 minutes after the second contrast injection compared with scans obtained at 5 and 15 minutes after the first injection (P < .001). The number of patients with active lesions on MR imaging was significantly higher after the second dose administration (52.0%, first dose versus 59.2%, second dose; P < .001). CONCLUSIONS: Cumulative dosing of a macrocyclic gadolinium-based contrast agent increases detection of enhancing lesions and patients with active lesions. These data could be considered in the design of MR imaging protocols aimed at detecting active multiple sclerosis lesions.

Comparison between gadolinium-enhanced 2D T1-weighted gradient-echo and spin-echo sequences in the detection of active multiple sclerosis lesions on 3.0T MRI.

OBJECTIVES: To compare the sensitivity of enhancing multiple sclerosis (MS) lesions in gadolinium-enhanced 2D T1-weighted gradient-echo (GRE) and spin-echo (SE) sequences, and to assess the influence of visual conspicuity and laterality on detection of these lesions. METHODS: One hundred MS patients underwent 3.0T brain MRI including gadolinium-enhanced 2D T1-weighted GRE and SE sequences. The two sets of contrast-enhanced scans were evaluated in random fashion by three experienced readers. Lesion conspicuity was assessed by the image contrast ratio (CR) and contrast-to-noise ratio (CNR). The intracranial region was divided into four quadrants and the impact of lesion location on detection was assessed in each slice. RESULTS: Six hundred and seven gadolinium-enhancing MS lesions were identified. GRE images were more sensitive for lesion detection (0.828) than SE images (0.767). Lesions showed a higher CR in SE than in GRE images, whereas the CNR was higher in GRE than SE. Most misclassifications occurred in the right posterior quadrant. CONCLUSIONS: The gadolinium-enhanced 2D T1-weighted GRE sequence at 3.0T MRI enables detection of enhancing MS lesions with higher sensitivity and better lesion conspicuity than 2D T1-weighted SE. Hence, we propose the use of gadolinium-enhanced GRE sequences rather than SE sequences for routine scanning of MS patients at 3.0T. KEY POINTS: • 2D SE and GRE sequences are useful for detecting active MS lesions. • Which of these sequences is more sensitive at high field remains uncertain. • GRE sequence showed better sensitivity for detecting active MS lesions than SE. • We propose GRE sequence for detecting active MS lesions at 3.0T.

Reproducibilidad de la valoración cualitativa de la atrofia del lóbulo temporal por RM / Reproducibility of qualitative assessments of temporal lobe atrophy in MRI studies

Objetivo: Determinar la reproducibilidad de la escala visual de Scheltens para establecer la atrofia del lóbulo temporal medial. Material y métodos: Reunimos 25 pacientes con diagnóstico clínico de enfermedad de Alzheimer leve o deterioro cognitivo leve (DCL) y 25 sujetos sin deterioro cognitivo. Todos fueron estudiados con RM 1,5 Tesla utilizando secuencias de inversión recuperación ponderadas en T1 en el plano coronal. Cinco neurorradiólogos fueron entrenados para aplicar la escala de Scheltens y analizaron las imágenes. Se utilizó el coeficiente de correlación intraclase para valorar el grado de acuerdo inter e intraobservadores. Resultados: El 80% de los pacientes con deterioro cognitivo leve o enfermedad de Alzheimer obtuvieron puntuaciones entre 2 a 4, mientras que 21 de los 25 controles sanos (84%) fueron puntuados entre 0-1. La concordancia entre observadores fue consistentemente mayor de 0,82, con un intervalo de confianza del 95% (0,7-0,9). La concordancia intraobservador varió entre 0,82 y 0,87, con un intervalo de confianza del 95% (0,56-0,93). Conclusión: La clasificación de Scheltens es un método reproducible entre observadores, lo que apoya su uso en la práctica clínica (AU)

Objective: To determine the reproducibility of the Scheltens visual rating scale in establishing atrophy of the medial temporal lobe. Material and methods: We used coronal T1-weighted inversion recovery sequences on a 1.5 Tesla MRI scanner to study 25 patients with clinically diagnosed Alzheimer's disease or mild cognitive decline and 25 subjects without cognitive decline. Five neuroradiologists trained to apply the Scheltens visual rating scale analyzed the images. We used the interclass correlation coefficient to evaluate interrater and intrarater agreement. Results: Raters scored 20 (80%) of the 25 patients with mild cognitive decline or Alzheimer's disease between 2 and 4; by contrast, they scored 21 (84%) of the 25 subjects without cognitive decline between 0 and 1. The interrater agreement was consistently greater than 0.82, with a 95% confidence interval of (0.7-0.9). The intrarater agreement ranged from 0.82 to 0.87, with a 95% confidence interval of (0.56-0.93). Conclusion: The Scheltens visual rating scale is reproducible among observers, and this finding supports its use in clinical practice (AU)

Reproducibility of qualitative assessments of temporal lobe atrophy in MRI studies.

OBJECTIVE: To determine the reproducibility of the Scheltens visual rating scale in establishing atrophy of the medial temporal lobe. MATERIAL AND METHODS: We used coronal T1-weighted inversion recovery sequences on a 1.5 Tesla MRI scanner to study 25 patients with clinically diagnosed Alzheimer's disease or mild cognitive decline and 25 subjects without cognitive decline. Five neuroradiologists trained to apply the Scheltens visual rating scale analyzed the images. We used the interclass correlation coefficient to evaluate interrater and intrarater agreement. RESULTS: Raters scored 20 (80%) of the 25 patients with mild cognitive decline or Alzheimer's disease between 2 and 4; by contrast, they scored 21 (84%) of the 25 subjects without cognitive decline between 0 and 1. The interrater agreement was consistently greater than 0.82, with a 95% confidence interval of (0.7-0.9). The intrarater agreement ranged from 0.82 to 0.87, with a 95% confidence interval of (0.56-0.93). CONCLUSION: The Scheltens visual rating scale is reproducible among observers, and this finding supports its use in clinical practice.

Brainstem lesions in clinically isolated syndromes.

BACKGROUND: Number of baseline lesions has been shown to predict future attacks and disability in clinically isolated syndromes (CIS). OBJECTIVE: To investigate the role of baseline infratentorial lesions in long-term prognosis. METHODS: Subjects were included in a prospective cohort of patients with CIS. Patients underwent brain MRI within 3 months after CIS onset. Number and location of lesions at baseline were prospectively studied. Retrospective scan analysis was conducted to specifically look at number and location of infratentorial lesions. We analyzed the time to a second attack and to reach EDSS 3.0. RESULTS: We included 246 patients with CIS followed for a median of 7.7 years. Patients with infratentorial lesions had both a higher risk of conversion (71.4% vs 29.6%; hazard ratio [HR] 3.3; 95% confidence interval [CI] 2.2-4.8; p < 0.001) and of developing disability (32.5% vs 12.4%; HR 2.4; 95% CI 1.3-4.3; p = 0.003). Presence of at least one cerebellar lesion was associated with an increased risk of conversion (HR 2.4; 95% CI 1.3-4.5; p = 0.007). Presence of at least one brainstem lesion increased both the risk of conversion (HR 2.9; 95% CI 1.7-5.0; p < 0.001) and disability (HR 2.5; 95% CI 1.1-5.4; p = 0.026). Broken down into number of lesions, the presence of infratentorial lesions increased both the risk of conversion (83% vs 61%) (HR 22.3; 95% CI 9.7-51.1; p < 0.001) and of reaching EDSS 3.0 (40% vs 19%) (HR 3.2; 95% CI 1.3-7.4; p = 0.008) only in patients with 9 or more lesions. CONCLUSIONS: Presence of infratentorial lesions increases the risk for disability. Brainstem rather than cerebellar lesions may be responsible for poor prognosis.