Sensitivity of delayed gadolinium-enhanced MRI in multiple sclerosis

Use of gadolinium-based contrast agents in multiple sclerosis: a review by the ESMRMB-GREC and ESNR Multiple Sclerosis Working Group

Magnetic resonance imaging (MRI) is the most sensitive technique for detecting inflammatory demyelinating lesions in multiple sclerosis (MS) and plays a crucial role in diagnosis and monitoring treatment effectiveness, and for predicting the disease course. In clinical practice, detection of MS lesions is mainly based on T2-weighted and contrast-enhanced T1-weighted sequences. Contrast-enhancing lesions (CEL) on T1-weighted sequences are related to (sub)acute inflammation, while new or enlarging T2 lesions reflect the permanent footprint from a previous acute inflammatory demyelinating event. These two types of MRI features provide redundant information, at least in regular monitoring of the disease. Due to the concern of gadolinium deposition after repetitive injections of gadolinium-based contrast agents (GBCAs), scientific organizations and regulatory agencies in Europe and North America have proposed that these contrast agents should be administered only if clinically necessary. In this article, we provide data on the mode of action of GBCAs in MS, the indications of the use of these agents in clinical practice, their value in MS for diagnostic, prognostic, and monitoring purposes, and their use in specific populations (children, pregnant women, and breast-feeders). We discuss imaging strategies that achieve the highest sensitivity for detecting CELs in compliance with the safety regulations established by different regulatory agencies. Finally, we will briefly discuss some alternatives to the use of GBCA for detecting blood-brain barrier disruption in MS lesions. CLINICAL RELEVANCE STATEMENT: Although use of GBCA at diagnostic workup of suspected MS is highly valuable for diagnostic and prognostic purposes, their use in routine monitoring is not mandatory and must be reduced, as detection of disease activity can be based on the identification of new or enlarging lesions on T2-weighted images. KEY POINTS: • Both the EMA and the FDA state that the use of GBCA in medicine should be restricted to clinical scenarios in which the additional information offered by the contrast agent is required. • The use of GBCA is generally recommended in the diagnostic workup in subjects with suspected MS and is generally not necessary for routine monitoring in clinical practice. • Alternative MRI-based approaches for detecting acute focal inflammatory MS lesions are not yet ready to be used in clinical practice.

Interval between contrast administration and T1-weighted MRI for cerebral adrenoleukodystrophy: a single-case observation

In adrenoleukodystrophy (ALD), contrast enhancement (CE) is a disease activity marker, but there is uncertainty about the optimal delay, if any, between contrast injection and magnetic resonance imaging (MRI) acquisition to avoid false-negative results. We acquired axial two-dimensional (2D) and three-dimensional (3D) T1-weighted gradient-echo every 6 min from 0 to 36 min after contrast administration (gadobutrol 0.1 mmol/kg) in an ALD patient with enlarging white matter lesions and progressive neuropsychological symptoms, using a 3-T magnet. The image signal over time was qualitatively assessed and measured in two regions of interest. On 3D sequences, no definite CE was appreciated, whereas on 2D sequences, CE was noticed after 6 min and definitely evident after 12 min, when 73% of the maximum signal intensity was measured. In ALD subjects, contrast-enhanced 2D T1-weighted gradient-echo sequences acquired at least 10 min after contrast injection may be considered to reduce false negative results.Relevance statementOur report is the first attempt to find an optimal delay between contrast administration and T1-weighted acquisition in cALD patients in order to correctly detect disease activity and avoid false negative results.Key points• The optimal time between contrast injection and image acquisition for MRI of adrenoleukodystrophy is unknown.• Contrast enhancement predicts adrenoleukodystrophy progression and could help patient's selection for the therapy.• We acquired two post-contrast T1-GRE-2D/3D sequences several times to find the best injection-time.• T1-weighted 2D GRE resulted more sensitive than T1-weighted 3D GRE even after long intervals from injection.• A delay of about 10 min may minimize false negatives.

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.

Time-delayed contrast-enhanced MRI improves detection of brain metastases and apparent treatment volumes

OBJECTIVE

Contrast-enhanced MRI is the preeminent diagnostic test for brain metastasis (BM). Detection of BMs for stereotactic radiosurgery (SRS) planning may improve with a time delay following administration of a high-relaxivity agent for 1.5-T and 3-T imaging systems. Metastasis detection with time-delayed MRI was evaluated in this study.

METHODS

Fifty-three volumetric MRI studies from 38 patients undergoing SRS for BMs were evaluated. All studies used 0.1-mmol/kg gadobenate dimeglumine (MultiHance; Bracco Diagnostics) immediately after injection, followed by 2 more axial T1-weighted sequences after 5-minute intervals (final image acquisition commenced 15 minutes after contrast injection). Two studies were motion limited and excluded. Two hundred eighty-seven BMs were identified. The studies were randomized and examined separately by 3 radiologists, who were blinded to the temporal sequence. Each radiologist recorded the number of BMs detected per scan. A Wilcoxon signed-rank test compared BM numbers between scans. One radiologist determined the scan on which BMs were best defined. All confirmed, visible tumors were contoured using iPlan RT treatment planning software on each of the 3 MRI data sets. A linear mixed model was used to analyze volume changes.

RESULTS

The interclass correlations for Scans 1, 2, and 3 were 0.7392, 0.7951, and 0.7290, respectively, demonstrating excellent interrater reliability. At least 1 new lesion was detected in the second scan as compared with the first in 35.3% of subjects (95% CI 22.4%-49.9%). The increase in BM numbers between Scans 1 and 2 ranged from 1 to 10. At least 1 new lesion was detected in the third scan as compared with the second in 21.6% of subjects (95% CI 11.3%-35.3%). The increase in BM numbers between Scans 2 and 3 ranged from 1 to 9. Between Scans 1 and 3, additional tumors were seen on 43.1% of scans (increase ranged from 1 to 14). The median increase in tumor number for all comparisons was 1. There was a significant increase in number of BMs detected from Scan 1 to Scan 2 (p < 0.0367) and from Scan 1 to Scan 3 (p < 0.0264). In 34 of the 51 subjects (66.7%), the radiologist selected the third scan as the one providing the clearest tumor definition. There was an average 25.4% increase in BM volume between Scans 1 and 2 (p < 0.0001) and a 9% increase in BM volume between Scans 2 and 3 (p = 0.0001).

CONCLUSIONS

In patients who are being prepared for SRS of BMs, delayed MRI after contrast injection revealed more targets that needed treatment. In addition, apparent treatment volumes increased with a time delay. To avoid missing tumors that could be treated at the time of planned SRS and resultant "treatment failures," the authors recommend that postcontrast MR images be acquired between 10 and 15 minutes after injection in patients undergoing SRS for treatment of BMs.

Evidence-based guidelines: MAGNIMS consensus guidelines on the use of MRI in multiple sclerosis-clinical implementation in the diagnostic process

The clinical use of MRI in patients with multiple sclerosis (MS) has advanced markedly over the past few years. Technical improvements and continuously emerging data from clinical trials and observational studies have contributed to the enhanced performance of this tool for achieving a prompt diagnosis in patients with MS. The aim of this article is to provide guidelines for the implementation of MRI of the brain and spinal cord in the diagnosis of patients who are suspected of having MS. These guidelines are based on an extensive review of the recent literature, as well as on the personal experience of the members of the MAGNIMS (Magnetic Resonance Imaging in MS) network. We address the indications, timing, coverage, reporting and interpretation of MRI studies in patients with suspected MS. Our recommendations are intended to help radiologists and neurologists standardize and optimize the use of MRI in clinical practice for the diagnosis of MS.

MRI in multiple sclerosis: an intra-individual, randomized and multicentric comparison of gadobutrol with gadoterate meglumine at 3 T

OBJECTIVES

To compare contrast effects of gadobutrol with gadoterate meglumine for brain MRI in multiple sclerosis (MS) in a multicentre, randomized, prospective, intraindividual study at 3 T.

METHODS

Institutional review board approval was obtained. Patients with known or suspected active MS lesions were included. Two identical MRIs were performed using randomized contrast agent order. Four post-contrast T1 sequences were acquired (start time points 0, 3, 6 and 9 min). If no enhancing lesion was present in first MRI, second MRI was cancelled. Quantitative (number and signal intensity of enhancing lesions) and qualitative parameters (time points of first and all lesions enhancing; subjective preference regarding contrast enhancement and lesion delineation; global preference) were evaluated blinded.

RESULTS

Seventy-four patients (male, 26; mean age, 35 years) were enrolled in three centres. In 45 patients enhancing lesions were found. Number of enhancing lesions increased over time for both contrast agents without significant difference (median 2 for both). Lesions signal intensity was significantly higher for gadobutrol (p < 0.05 at time points 3, 6 and 9 min). Subjective preference rating showed non-significant tendency in favour of gadobutrol.

CONCLUSION

Both gadobutrol and gadoterate meglumine can be used for imaging of acute inflammatory MS lesions. However, gadobutrol generates higher lesion SI.

KEY POINTS

Contrast-enhanced MRI plays a key role in the management of multiple sclerosis. Different gadolinium-based contrast agents are available. Number of visibly enhancing lesions increases over time after contrast injection. Gadobutrol and gadoterate meglumine do not differ in number of visible lesions. Gadobutrol generates higher signal intensity than gadoterate meglumine.

Evaluation of plaque detection and optimum time of enhancement in acute attack multiple sclerosis after contrast injection

BACKGROUND

Magnetic resonance imaging (MRI) is important in the early diagnosis of novel or relapsing multiple sclerosis (MS). In addition, the optimal MRI protocol plays an important role in detecting MS plaques.

PURPOSE

To find the best time to detect MS plaques on MRI after Gadobutrol injection.

MATERIAL AND METHODS

Sixty-two relapsing-remitting type MS patients, (56 women, 6 men) with the mean age of 31 ± 7 years were enrolled into this study. The patients underwent T1-weighted MRI scan without contrast agents. Subsequently, Gadobutrol was injected (0.1 mmol/kg) and MRI scanning was repeated after 30 s, 5, 10, 15, and 30 min of Gadobutrol injection. The size, signal intensity, and enhancement pattern were determined for each plaque by contrast-enhanced T1-weighted images.

RESULTS

Enhancing plaques were seen in 42 out of 62 patients. The mean number of enhancing plaques was 4 ± 8 plaques after 30 s of contrast injection. This figure increased to 7 ± 13 plaques after 15 min and 6 ± 10 plaques after 30 min. The signal intensity and size of plaques increased progressively, and the maximum signal intensity and plaque size were seen after 30 min (P < 0.001).

CONCLUSION

The maximum number of enhancing plaques in MS patients was detected 15 min after contrast agent administration and the size and signal intensity of the lesions also increased remarkably at this time.

Feasibility of imaging myelin lesions in multiple sclerosis

The goal of this study was to provide a feasibility assessment for PET imaging of multiple sclerosis (MS) lesions based on their decreased myelin content relative to the surrounding normal-appearing brain tissue. The imaging agent evaluated for this purpose is a molecule that binds strongly and specifically to myelin basic protein. Physiology-based pharmacokinetic modeling combined with PET image simulation applied to a brain model was used to examine whether such an agent would allow the differentiation of artificial lesions 4–10 mm in diameter from the surrounding normal-looking white and gray matter. Furthermore, we examined how changes in agent properties, model parameters, and experimental conditions can influence imageability, identifying a set of conditions under which imaging of MS lesions might be feasible. Based on our results, we concluded that PET imaging has the potential to become a useful complementary method to MRI for MS diagnosis and therapy monitoring.

Fat-saturated post gadolinium T1 imaging of the brain in multiple sclerosis

BACKGROUND

Magnetic resonance imaging (MRI) is of vital importance in the diagnosis and follow-up of patients with multiple sclerosis (MS). Imaging sequences better demonstrating enhancing lesions can help in detecting active MS plaques.

PURPOSE

To evaluate the role of fat-saturated gadolinium-enhanced T1-weighted (T1W) images of the brain in MS and to assess the benefit of performing this additional sequence in the detection of enhancing lesions.

MATERIAL AND METHODS

In a prospective study over a six-month period, 70 consecutive patients with clinically diagnosed MS were enrolled. These constituted 14 male and 56 female patients between the ages of 21 and 44 years. All the patients underwent brain MRIs on a 1.5 Tesla Magnet. Gadolinium-enhanced T1 images with and without fat saturation were compared and results were recorded and analyzed using a conspicuity score and McNemar test.

RESULTS

There were a total of 157 lesions detected in 70 patients on post-contrast T1W fat-saturated images compared with 139 lesions seen on the post-contrast T1W fast spin-echo (FSE) images. This was because 18 of the lesions (11.5%) were only seen on the fat-saturated images. In addition, 15 lesions were more conspicuous on the fat saturation sequence (9.5%). The total conspicuity score obtained, including all the lesions, was 2.24 +/-0.60 (SD). Using the two-tailed McNemar test for quantitative analysis, the P value obtained was <0.0001.

CONCLUSION

T1W fat-saturated gadolinium-enhanced images show better lesion enhancement than T1W images without fat saturation.

Diagnostic value of contrast-enhanced fluid-attenuated inversion-recovery and delayed contrast-enhanced brain MRI in multiple sclerosis

RATIONALE AND OBJECTIVES

In brain MRI of multiple sclerosis (MS) patients, enhancement of the lesions is usually evaluated in early contrast-enhanced T1-weighted images (CE-T1WI). The objective of this study is to determine the sensitivity of contrast-enhanced fluid-attenuated-inversion-recovery (CE-FLAIR) and delayed contrast-enhanced MRI in evaluation of MS brain lesions.

MATERIALS AND METHODS

Brain MRI examination including early and delayed CE-T1WI and early and delayed CE-FLAIR images was performed for 46 patients with clinically definite MS disease. Number, size, location, degree, and pattern of enhancement of the enhanced lesions in each sequence were recorded separately.

RESULTS

A total number of 87 enhanced lesions was detected in 30 patients. Early CE-T1WI could detect only 63 lesions (72.4% of total) in 24 patients, while delayed CE-T1WI and early and delayed CE-FLAIR images showed 85 (97.7%), 84 (96.6%), and 81 (93.1%) lesions in 28, 28, and 26 patients, respectively. A greater degree of enhancement and larger lesion size were observed in the additional sequences compared with the early CE-T1WI.

CONCLUSIONS

The sensitivity of early CE-T1WI for the detection of enhanced MS lesions is significantly lower than that for other additional sequences. Delayed CE-FLAIR images could not add significant information to other sequences. Therefore, early CE-FLAIR and delayed CE-T1WI brain MRI can be considered as part of the evaluation of MS patients, especially if, despite clinically suspected active disease, no enhanced lesion is found in the routine CE-T1WI.

Magnetic resonance imaging at 3.0 tesla detects more lesions in acute optic neuritis than at 1.5 tesla

OBJECTIVE

We sought to assess whether magnetic resonance imaging (MRI) at 3.0 T detects more brain lesions in acute optic neuritis (ON) than MRI at 1.5 T.

MATERIALS AND METHODS

Twenty-eight patients with acute ON were scanned at both field-strengths using fast-fluid-attenuated inversion recovery (FLAIR), proton density and T2-weighted turbo spin echo, and T1-weighted spin echo after contrast. In addition, magnetization-prepared rapid acquisition gradient echo (MPRAGE) was obtained after contrast at 3.0 T. Lesion number and volumes were assessed by an observer blind to patient identity and field strength.

RESULTS

Scans at 3.0 T showed a significantly increase in number of lesions detected on FLAIR images (P = 0.002) relative to scanning at 1.5 T. MPRAGE proved to be suitable for detecting enhancing lesions in ON.

CONCLUSION

The MRI protocol at 3.0 T was more sensitive to hyperintense brain lesions in ON than the standard MRI protocol at 1.5 T.

Enhanced magnetic resonance imaging in multiple sclerosis

Gadolinium-enhanced magnetic resonance imaging (MRI) is very sensitive in the detection of active lesions of multiple sclerosis (MS) and has become a valuable tool to monitor the evolution of the disease either natural or modified by treatment. In the past few years, several studies, on the one hand, have assessed several ways to increase the sensitivity of enhanced MRI to disease activity and, on the other, have investigated in vivo the nature and evolution of enhancing lesions using different non-conventional MR techniques to better define the relationship between enhancement and tissue loss in MS. The present review is a summary of these studies whose results are discussed in the context of MS clinical trial planning and monitoring. Multiple Sclerosis (2000) 6 320 - 326

A comparison of the sensitivity of MRI after double- and triple-dose Gd-DTPA for detecting enhancing lesions in multiple sclerosis

We compared the number and volume of enhancing lesions detected in patients with multiple sclerosis (MS) seen on post-contrast T(1)-weighted scans obtained after the injection of different gadolinium-DTPA (Gd) doses. Enhanced magnetic resonance imaging (MRI) scans were obtained from 16 patients with relapsing remitting or secondary progressive MS on two different occasions separated by an interval of approximately 24 h. On the first occasion, enhanced scans were obtained 15 min after the injection of a double dose of Gd (0.2 mmol/Kg), on the second 15 min after the injection of a triple dose (0.3 mmol/Kg) of Gd. Scans were assessed by consensus in a random order by two observers unaware of the dose of Gd used. We counted the same 30 enhancing lesions on both double dose and triple dose scans from 9 patients. The mean (SD) volumes of enhancing lesions were 1.7 (2.7) mL on double dose and 1.9 (3.4) mL on triple-dose scans. This difference was not statistically significant. This study demonstrated that double dose of Gd has a sensitivity for detecting MS activity similar to that of a triple dose, with the advantage of a significant cost saving.

Linomide in the treatment of multiple sclerosis: MRI results from prematurely terminated phase-III trials

Due to an unexpected increase in serious cardiovascular events in MS patients treated with Linomide, a synthetic immunomodulator, two phase-III multinational relapsing remitting (RR) and secondary progressive (SP) MS trials had to be discontinued. MRI results of 413 patients who participated for at least 3 months were analysed. Patients received placebo, 2.5 or 5 mg Linomide. Scans were performed at pre-enrolment, month 3 and termination. The number and volume of enhancing lesions (ELV), and the number of active scans were evaluated. At month 3, the decrease in the number of enhancing lesions in the placebo group was 11%, compared with 15% in the 2.5 mg group (P=0.027) and 23% in the 5 mg group (P=0.057). Using the percentage of active scans as outcome parameter, the odds ratio for improvement between placebo and 2.5 mg group was 1.62 (P=0.14); between placebo and 5 mg Linomide group 3.58 (P=0.003). At termination, a rebound effect was noted in the 2.5 mg group (P=0.01). Analysis of the ELV showed no significant difference between placebo and treatment groups. Although Linomide has unacceptable side effects, it seems to have a modest effect on MS disease activity, as measured by MRI. Multiple Sclerosis (2000) 6, 99 - 104

MRI evolution of new MS lesions enhancing after different doses of gadolinium

OBJECTIVE

To investigate the evolution of multiple sclerosis (MS) lesions enhancing after single dose (SD) or triple dose (TD) of gadolinium-DTPA (Gd).

MATERIAL AND METHODS

For 3 months, 30 relapsing-remitting MS patients underwent 2 monthly MRI sessions, consisting of Gd-enhanced T1-weighted scans, after SD (i.e., 0.1 mmol/kg) in one session and TD (i.e., 0.3 mmol/kg) in the other. New enhancing lesions on month 1 and month 2 follow-up scans were studied and for them any persistence of enhancement was evaluated on the scans obtained the next month.

RESULTS

In all, 151 lesions enhancing after both SD and TD and 91 lesions enhancing only after TD entered the analysis. After 1 month, for the 151 lesions enhancing after both SD and TD, 73 (48%) were not enhancing, 50 (33%) were still enhancing after both SD and TD and 28 (19%) were enhancing only after TD. For the 91 lesions enhancing only after TD, 61 (67%; P<0.005) were not enhancing, 16 (18%; P<0.01) were still enhancing only after TD and 14 (15%; P=NS) showed enhancement after both SD and TD.

CONCLUSION

Enhancing lesions in patients with MS are heterogeneous. Those enhancing only after TD of Gd are characterized by a milder and shorter opening of the blood-brain barrier.

A longitudinal brain MRI study comparing the sensitivities of the conventional and a newer approach for detecting active lesions in multiple sclerosis

Monthly dual-echo spin-echo (SE) and enhanced magnetic resonance imaging (MRI) after the injection of a standard dose (SD) of gadolinium (Gd) is the conventional approach to monitor short-term disease activity in multiple sclerosis (MS). In this study, the sensitivity of this approach in detecting active lesions in MS was compared with that of monthly fast fluid attenuated inversion recovery (FLAIR) scans associated with enhanced MRI after the injection of a triple dose (TD) of Gd. Thirteen patients with relapsing-remitting MS entered the study. Monthly MRI scans were obtained on four occasions in two separate sessions (interval between 12 and 24 h). In one session, dual-echo conventional SE and SD Tl-weighted scans were obtained; in the other, fast-FLAIR and TD Tl-weighted scans. The order of the two sessions was randomized. Three observers counted the number of active lesions detected by each of the two approaches. One hundred and four active lesions were detected by the conventional approach and 199 by the newer approach (average increase per patient = 75%, range = 0-325%). The mean number of active lesions per month per patient was 2.0 for the conventional approach and 3.8 for the new approach (P = 0.004). Scans with active lesions were 34/52 (65%) with the conventional approach and 37/52 (71%) with the new approach. Our data indicate that the combined use of monthly fast-FLAIR and TD enhanced Tl-weighted scans increases the number of active lesions detected on serial MRI scans from patients with MS.

A preliminary study comparing the sensitivity of serial monthly enhanced MRI after standard and triple dose gadolinium-DTPA for monitoring disease activity in primary progressive multiple sclerosis

We performed this study to evaluate and compare the numbers of total and new enhancing lesions detected on serial monthly brain magnetic resonance imaging (MRI) after the injection of a standard dose (SD) and a triple dose (TD) of gadolinium-DTPA (Gd) in patients with primary progressive multiple sclerosis (PPMS). Every 4 weeks for 3 months and in two separate sessions, MRI scans were obtained from 5 patients with PPMS, 5 (early) and 20 minutes (delayed) after SD (0.1 mmol/kg) or TD (0.3 mmol/kg) Gd injection. In 2 patients, T1-weighted scans with a magnetization transfer pulse (MT) after SD and TD injection were also obtained. There were 13 enhancing lesions (5 of which were new) on the early SD scans, 15 (5 new) on the delayed SD scans, 17 (6 new) on the early TD scans and 18 (7 new) on the delayed TD scans. TD MRI scans detected more enhancing lesions than SD scans in 3 patients (two of them were those with the lowest disability). The application of the MT pulse did not change the numbers of enhancing lesions seen after the injection of SD and TD of Gd in the remaining two patients. No side effects were reported and no significant changes in blood test parameters were found throughout the study. Our results suggest that serial monthly TD MRI, delayed scanning, MT T1-weighted scans or their combination, although safe, have a limited role for monitoring disease evolution in patients with PPMS.