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|LETTERS TO EDITOR
|Year : 2019 | Volume
| Issue : 2 | Page : 573-574
Diagnostically useful MRI artifact – India ink artifact
Venkatraman Indiran1, V Sivakumar2
1 Department of Radiodiagnosis, Sree Balaji Medical College and Hospital, Chromepet, Chennai, India
2 Department of Radiodiagnosis, Meenakshi Medical College Hospital and Research Institute, Kanchipuram, Tamil Nadu, India
|Date of Web Publication||13-May-2019|
Dr. Venkatraman Indiran
Department of Radiodiagnosis, Sree Balaji Medical College and Hospital, 7 Works Road, Chromepet, Chennai - 600 044, Tamil Nadu
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Indiran V, Sivakumar V. Diagnostically useful MRI artifact – India ink artifact. Neurol India 2019;67:573-4
A 2-year old female child presented with a history of seizure, for which she underwent magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the brain. There was a small nodular T1-hyperintense lesion measuring ~4 × 3 mm in the left cerebellopontine angle abutting the vestibulocochlear nerve [Figure 1]. Unfortunately, the technologist had not added a fat-saturated T1-weighted sequence to the study, which could have unequivocally confirmed the fatty nature of the lesion. Fortunately, the lesion showed a black boundary/India ink artifact around the lesion on the source images of time-of-flight (TOF) MRA [Figure 2], which confirmed the fatty nature of the lesion prompting the diagnosis of a lipoma.
|Figure 1: Axial T1 weighted image shows a small nodular T1 hyperintense lesion measuring ~ 4 × 3 mm in the left cerebellopontine angle abutting the vestibulocochlear nerve (white arrow)|
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|Figure 2: Axial TOF MRA source image shows a small nearly isointense lesion with black boundary/India ink artifact around the lesion in the left cerebellopontine angle (white arrow)|
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The India ink artifact is a chemical shift artifact normally seen as a dark line or ink-like boundary around the periphery of a structure on gradient echo image or opposed-phase images. It represents a signal loss in voxels containing both fat and water components, as fat and water spins which are out of phase cancel each other. It is also known as the black boundary, India-ink etching, bounce point, or phase cancellation artifact. The differential diagnoses of a T1-hyperintense foci include a dermoid, melanin deposits, a thrombosed berry aneurysm, calcifications, proteinaceous cysts, and a white epidermoid. In their large review for intracranial lipomas, Kemmling et al., deduced that the dark fringe (India ink artifact) in the periphery of T1-weighted hyperintense lesions is characteristic of a lipoma on TOF source images and helps to avoid potential diagnostic pitfalls like diagnosing a thrombosed aneurysm. Though MRI artifacts usually cause a diagnostic confusion or hinder the image quality, they may sometimes help in establishing the diagnosis, as evidenced above. India ink artifact can be used to confirm the presence of fat in a structure or a lesion and can substitute for fat-saturated T1-weighted images.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]