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|Year : 2021 | Volume
| Issue : 2 | Page : 394-396
Role of Double Inversion Recovery Sequence in Neuro-imaging on 3 Tesla MRI
Shilpa Kulkarni1, Makarand M Kulkarni2, Aparna Patankar3, Apurva Watve4
1 Consultant Ophthalmologist, Department of Ophthalmology, Bhartiya Arogya Nidhi Hospital, Mumbai, India
2 Ex-Consultant Radiologist, Department of Radiology, Lilavati Hospital and research center, Mumbai, India
3 Resident Radiology, Lilavati Hospital and Research Center, Mumbai, India
4 Research Fellow, Research Department, Lilavati Hospital and Research Center, Mumbai, India
|Date of Submission||14-Jul-2019|
|Date of Decision||13-May-2019|
|Date of Acceptance||01-Sep-2019|
|Date of Web Publication||24-Apr-2021|
302, EMP73, Thakur Villege Kandiwali East Mumbai 400 101, Maharashtra
Source of Support: None, Conflict of Interest: None
Double Inversion Recovery (DIR) is a robust sequence designed to suppress fat and water signals using two 180° inversion pulses to produce prominent gray matter contrast with high spatial resolution. It has proven to be more sensitive in delineating white matter signal abnormalities than conventional MR techniques. In our study, the highest image contrast with lesion load was observed using DIR over FLAIR and T2 weighted imaging. DIR is evidently valuable for the detection of demyelinating lesions observed in multiple sclerosis (MS), malignancies, epileptogenic foci, and cortical anomalies. Hence this pictorial review is intended to assess the diagnostic efficacy of DIR modality in clinical Neuro-imaging.
Keywords: Double inversion recovery, fluid attenuated inversion recovery, neuro-imagingKey Messages: 3D Double inversion recovery is a robust sequence in detecting cortical and juxta-cortical demyelinating plaques.
|How to cite this article:|
Kulkarni S, Kulkarni MM, Patankar A, Watve A. Role of Double Inversion Recovery Sequence in Neuro-imaging on 3 Tesla MRI. Neurol India 2021;69:394-6
Inversion recovery (IR) sequences were introduced to selectively null the signals obtained from different tissues to generate heavy T1 or T2 weighted images based on the appropriate selection of inversion interval (TI). The classic examples of IR pulse sequence are: Short TI Inversion Recovery (STIR) which is applied to suppress fat signals and Fluid Attenuated Inversion Recovery (FLAIR) sequence for suppression of fluids. These IR sequences are originally spin echo pulse sequences that utilize 180° RF pulse to invert the longitudinal magnetization (Mz) to its negative value (-Mz). Depending upon T1 relaxation times, different tissues (gray matter, white matter, fats, and fluids) regain the longitudinal magnetization at different times. The application of 90° spin echo readout pulse at a time when longitudinal magnetization reaches the null point leads to suppression of the signals from that specific tissue generating a contrast.
DIR is a combination of two inversion pulses designed to simultaneously nullify signals from white matter and CSF by applying 90° pulses at different times during the recovery phase. On the application of 180° preparatory pulse, the magnetization of gray and white matter having shorter T1, as compared to CSF, recover almost completely while CSF takes longer time and recovers only a fraction of its equilibrium magnetization. In order to nullify white matter, second 180° inversion pulse is applied in such a way that white matter and CSF magnetization equally passes through the null point simultaneously. Following 90° excitation pulse, the gray matter having the longest T1 produces a prominent contrast with high spatial resolution. 3D DIR has an advantage over 2D having non-selective pulses which invert the CSF signals and reduce unsuppressed CSF flow artifacts that arise from neighboring slices into the imaging slice during the long TI period. Thus, a uniform signal is achieved across the volume of interest in the brain. This high-resolution 3D DIR technique has proven to hold an important clinical application in the delineation of various CNS disorders. The current pictorial review is an attempt to evaluate the diagnostic relevance and the applicability of DIR in clinical pathologies and its superiority over conventional MR imaging techniques.
Clinical applications in neuro-imaging
- Cortical/subcortical lesions in MS: The conventional MRI sequences are not sensitive enough for the cortical lesions. These cortical lesions may contribute to cognitive impairment in MS patients. DIR has a prime advantage in detecting cortical lesions with high lesion-to-background and gray-to-white matter contrast., There is a very high contrast ratio of the lesions on DIR as compared to FLAIR and T2 weighted images [Figure 1]. The contrast ratio is defined as (SI1-SI2/SI1 + SI2), where SI1 is the signal intensity of lesion and SI2 is the signal intensity of background white matter.
Identification of the lesions involving gray matter or at the junction of the gray and white matter remains challenging due to anatomical limitation using currently available sequences. DIR sequence has overcome this limitation with a significant gain in the detection of the lesions in Juxtacortical region on DIR as compared to T2 and FLAIR sequences, [Figure 2]. In our experience of 30 patients of multiple sclerosis, there is a 16.48% relative gain in the detection of cortical and juxtacortical lesions on DIR as compared to FLAIR which is statistically significant (P = 0.039).
The deep white matter lesions are also better appreciated with a little gain in lesion detection on DIR [Figure 3]. In our series, the DIR shows a relative gain of 8.57% as compared to FLAIR for deep white matter lesions. However, this is not statistically significant (P = 0.083).
- Spinal cord lesions: DIR helps in delineating white matter lesions with more effective contrast both in brain and spine. However, the superiority of DIR over T2 weighted sequence is seen only in the cervical spinal cord. In comparison with T2 weighted imaging, DIR stands out in the identification of demyelinating plaques situated adjacent to CSF by suppressing signals from CSF and providing better visualization [Figure 4].
- Cortical dysplasia: As DIR excels in depicting anomalies located at the boundaries of gray-white matter; it has been mainly used in the diagnosis of pediatric epileptogenic abnormalities such as focal cortical dysplasia, mesial temporal sclerosis and other tumorous lesions., A recent study reported that DIR has sensitivity from 50-88%, while specificity from 67-91% in detecting focal cortical dysplasia. Therefore the inclusion of high contrast resolution DIR sequence in routine MRI protocols for the detection of the cortical lesions would improve diagnostic accuracy [Figure 5]. However, due to poor SNR, the sequence is relatively inferior to 3 D MP-RAGE which is a T1 weighted sequence.
- Hippocampal sclerosis: Preferentially, DIR is used to detect gray matter abnormalities as it selectively suppresses CSF and white matter signals improving the intensity of the contrast. DIR has been observed to produce higher contrast-to-noise ratio (CNR) compared to conventional MRI sequences in Hippocampal sclerosis,, [Figure 6].
- Demyelination of Optic nerves: Recently, Wang et al. has explored the role of 3D DIR imaging in the early differential diagnostic and prognostic evaluation of Neuromyelitis Optica (NMO) and observed that the relative signal intensity of DIR was significantly higher than that of T2 weighted and FLAIR. To best of our knowledge, the role of DIR in the identification of MS lesions in optic nerve has not been studied in the literature so far. In our experience, there is a relative gain in the number of lesions on DIR as compared to FLAIR. Optic nerve lesions are thus better visualized on DIR with improved contrast and sensitivity [Figure 7].
|Figure 1: T2 (a), FLAIR (b) and DIR (c) Sequences in a patient with multiple sclerosis showing high detection rate and better delineation of cortical demyelinating lesion in left frontal and bilateral parietal lobes (open arrows)|
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|Figure 2: T2(a), FLAIR (b) and DIR (c) sequence showing increased detection of juxta-cortical lesions in DIR sequence in bilateral frontal lobes(arrows)|
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|Figure 3: T2(a),FLAIR (b) and DIR (c) sequence showing better contrast ratio in deep white matter lesions in bilateral frontal and parietal white matter (arrows)|
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|Figure 4: T2, FLAIR and DIR sequence of cervical spinal cord showing better lesion delineation on DIR sequence|
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|Figure 5: FLAIR (a) and DIR (b) sequence in case of transmental cortical dysplasia(open arrows), in the right frontal lobe|
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|Figure 6: T1 inversion recovery (a), T2 (b) and DIR (c)showing right hippocampal sclerosis (open arrows)|
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|Figure 7: Oblique coronal reconstruction of 3D FLAIR (a) and 3D DIR (b) sequence showing demyelination plaque in the right optic nerve (open arrows)|
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| » Conclusion|| |
DIR has proven its superiority over conventional techniques in detecting lesions with higher sensitivity and contrast especially in gray matter region and at the junction of gray-white matter that was demanding for other conventional MRI techniques. There is a 16.48% relative gain in the detection of cortical and juxtacortical lesions on DIR as compared to FLAIR. The role of 3D DIR as a diagnostic tool has emerged in recent years as it has been used in clinical set up for detection of abnormalities in MS, epilepsy, Alzheimer's and cortical dysplasia. Various studies have bolstered the utility of DIR in clinical manifestation of CNS pathologies encompassing inflammation, infection, tumors and vascular abnormalities. Although having a disadvantage of longer scanning time as compared to 2D DIR, this highly advanced 3D imaging technique with non-selective inversion pulses to suppress CSF and white matter signals is capable of producing high-resolution images with improved contrast. Considering its potential to delineate the CNS aberrations, more efforts should be invested to optimize the applicability of DIR as a diagnostic modality in clinical practice. The sequence has a limitation of poor signal to noise ratio and is susceptible to CSF pulsations artifact. This is more pronounced in posterior Fossa.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| » References|| |
Redpath TW, Smith FW. Technical note: Use of a double inversion recovery pulse sequence to image selectively gray or white brain matter. Br J Radiol 1994;67:1258-63.
Saranathan M, Worters PW, Rettmann DW, Winegar B, Becker J. Physics for clinicians: Fluid-attenuated inversion recovery (FLAIR) and double inversion recovery (DIR) Imaging. J Magn Reson Imaging 2017;46:1590-600.
Simon B, Schmidt S, Lukas C, Gieseke J, Träber F, Knol DL, et al
. Improved in vivo
detection of cortical lesions in multiple sclerosis using double inversion recovery MR imaging at 3 Tesla. Eur. Radiol 2010;20:1675-83.
Calabrese M, De Stefano N, Atzori M, Bernardi V, Mattisi I, Barachino L, et al
. Detection of cortical inflammatory lesions by double inversion recovery magnetic resonance imaging in patients with multiple sclerosis. Arch Neurol 2007;64:1416-22.
Wattjes MP, Lutterbey GG, Gieseke J, Traber F, Klotz L, Schmidt S, et al
. Double inversion recovery brain imaging at 3T: Diagnostic value in the detection of multiple sclerosis lesions. AJNR 2007;28:54-9.
Nelson F, Poonawalla AH, Hou P, Huang F, Wolinsky JS, Narayana PA. Improved identification of intracortical lesions in multiple sclerosis with phase-sensitive inversion recovery in combination with fast double inversion recovery MR imaging. AJNR 2007;28:1645-9.
Priatna A, Park J, Chen C-I, Mar S, Sheline Y, Benzinger T. Detection of white matter disease in the brain and spine using double inversion recovery SPACE at 3 Tesla. Proc Intl Soc Mag Reson Med 2008;16:3501.
Soares BP, Porter SG, Saindane AM, Dehkharghani S, Desai NK. Utility of double inversion recovery MRI in pediatric epilepsy. Br J Radiol 2016;89:20150325.
Wong-Kisiel LC, Britton JW, Witte RJ, Kelly-Williams KM, Kotsenas AL, Krecke KN, et al
. Double inversion recovery magnetic resonance imaging in identifying focal cortical dysplasia. Pediatr Neurol 2016;61:87-93.
Li Q, Zhang Q, Sun H, Zhang Y, Bai R. Double inversion recovery magnetic resonance imaging at 3 T: Diagnostic value in hippocampal sclerosis. J Comput Assist Tomogr 2011;35:290-3.
Wang Y, Yan H, Ding Q, Mao C, Shen Y, Wang G. 3D-DIR for early differential diagnostic and prognostic evaluation of NMO. Exp Ther Med 2016;12:1464-8.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]