2315. Novel Application of Conventional Diffusion Weighted Imaging of the Brain as an Imaging Screening Tool for the Diagnosis of Anemia
Authors * Denotes Presenting Author
  1. Kavya Kaushik *; Manipal Hospital, HAL Old Airport Road
  2. Ullas Acharya; Manipal Hospital, HAL Old Airport Road
  3. Balasubramanyam Shankar; Manipal Hospital, HAL Old Airport Road
To assess the significance of increased clival and calvarial bone marrow signal intensity (SI) on diffusion weighted imaging (DWI) in identifying anemia in patients who undergo routine MRI Brain for various neurological indications.

Materials and Methods:
This is a retrospective study in which a total of 84 subjects were selected by random sampling out of all the patients who underwent MRI Brain for various clinical indications. Those subjects who had any known malignancies were excluded. The DWI SI and Apparent Diffusion Coefficient (ADC) values were measured at the basal ganglia (putamen), clivus and calvarium (parietal bone) in each subject. The SI of clivus and parietal bone was normalised with respect to the basal ganglia. Demographic and clinical parameters, namely Hemoglobin (Hb) levels and Red cell distribution width (RDW) were recorded.

Out of a total of 84 subjects, 43 were male and 41 female. Out of this, 30 subjects were identified to have anemia. The mean basal ganglia normalised DWI SI at the clivus and calvarium were significantly higher in anemic subjects as compared to non anemic subjects. Analysis showed that increased clival SI on DWI had sensitivity (Sn) of 90.3% and specificity (Sp) of 79.2% for the detection of anemia with Hb and a Sn of 90.9% and Sp of 82.4% for the detection of anemia with RDW. It also showed that increased calvarial (parietal) SI on DWI had Sn of 80% and Sp of 72.2% for the detection of anemia with Hb and a Sn of 87.5% and Sp of 78.8% for the detection of anemia with RDW. ADC values showed greater variation in standard deviation in subjects without anemia as opposed to those with anemia, however, there was no significant correlation between ADC values of both clivus and parietal bone and Hb or RDW. Clival SI and Hb levels were found to be moderately negatively correlated, r(82) = -.66, p < 0.00001. Similarly, clival SI and RDW were found to be moderately positively correlated, r(82) = .65, p < 0.00001. Calvarial SI and Hb levels showed significant but weak negative correlation, r(82) = -.47, p < 0.00001. Similarly, calvarial SI and RDW showed significant but weak positive correlation, r(82) = .48, p < 0.00001.

Our study shows a high Sn and Sp for the detection of anemia from increased clival and calvarial DWI SI. Clival DWI SI has higher Sn than calvarial (parietal) DWI SI, indicating clival SI changes are more commonly seen. RDW correlation for anemia increases the Sp of the test. There is significant correlation between the marrow SI and presence of anemia, possibly indicating reconversion of the fatty yellow marrow to cellular red marrow. Low Hb levels and RDW affect the visibility of red marrow on DWI. Anemia is a very prevalent condition in developing countries and is known to have adversities. DWI is a norm in any neurological MRI. Therefore, this imaging sequence can have a novel application as a screening tool for anemia in patients who undergo MRI for various other reasons and prompt further evaluation, especially in subclinical cases, thereby aiding in appropriate clinical management and avert possible complications.