|Year : 2018 | Volume
| Issue : 1 | Page : 284-285
Authors' Reply: Arterial spin labeling: Clarifying the apparent contradiction
Sona A Pungavkar1, Rishi Awasthi2
1 Department of Radiology, Global Hospitals, Mumbai, S.L. Raheja - Fortis Associate Hospital, Mumbai, Maharashtra, India
2 Wipro GE Healthcare, Bengalaru, Karnataka, India
|Date of Web Publication||11-Jan-2018|
Dr. Sona A Pungavkar
Department of Radiology, Global Hospitals, Mumbai, Maharashtra
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Pungavkar SA, Awasthi R. Authors' Reply: Arterial spin labeling: Clarifying the apparent contradiction. Neurol India 2018;66:284-5
The apparent contradiction between our study  and that of Patel et al., regarding signal-to-noise ratio, lower temporal and spatial resolution and greater susceptibility artefact from the metallic hardware, blood, large vessels and air interfaces  arises from the fact that different vendors have variability in the pulse sequence used for arterial spin labeling (ASL). We performed our study on a 3T scanner with a 19-element coil, which has a decent signal-to-noise ratio. The vendor-provided ASL sequence is a fast spin echo (FSE) based readout, hence our observations viz a viz dynamic susceptibility contrast (DSC) perfusion is that ASL has less susceptibility artifact. The labeling technique used also plays an important role in the quality/accuracy of the generated cerebral blood flow (CBF) maps; in our case, pseudo-continuous labeling was used which gives better signal-to –noise ratio (SNR) and labeling efficiency as compared to pulsed or continuous labeling.
Another important point is the availability of approved clinical sequences for wider reach among clinicians and radiologists as compared to the research prototype sequences. Since ASL is very new to the clinical arena with variability in type of acquisition among different vendors, it will take some time to gain acceptance. Our observations suggest that it can be useful in different pathologies with just-a-few-minutes time penalty. Being a non-contrast based imaging, the sequence can be performed in any patient who is undergoing a magnetic resonance (MR) exam.
The utility of superselective ASL appears to be exciting; however, we do not have any experience in the utilization of this technique as it is not available for clinical use on our scanner.
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Conflicts of interest
There are no conflicts of interest.
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