Table 20 The use of novel imaging techniques for prediction of shunt response in iNPH
Study | Sample size | Radiological methodology | Cutoff level | Image specification | Image plane | Main reported outcomes |
|---|---|---|---|---|---|---|
Aoki et al. [4] | n = 34 | •Exact-low-resolution-brain-electromagnetic-tomography. A type of approach to EEG which can localize electrical activity. Normalized power variance (NPV) calculated | •Prediction score = log (beta eLORETA-NPV) + 1.49 •If number is positive, it predicts patient will respond to shunt | •19-electrode EEG system •Analysis was computed for five frequency bands in high convexity areas.: •delta (1.5–4.0 Hz), •theta (4.5–7.0 Hz), •alpha (7.5–13.0 Hz), •beta (13.5–29.5 Hz), •gamma (30.0–59.5 Hz) | •N/A | •positive predictive value of 61.1% (11/18) and negative predictive value of 75.0% (12/16) |
Jurcoane et al. [25] | n = 12 | •Fractional anisotropy, mean diffusivity, radial diffusivity, axial diffusivity and magnetization transfer ratio | •a decrease of > 1% in axial diffusivity | •Diffuse tensor imaging using echo-planar sequence | •Corticospinal tract and the superior lateral fascicle | •Decrease of > 1% in axial diffusivity could differentiate between SR and SNR with a sensitivity of 87.5% and a specificity of 75% to predict SR |
Chen et al. [8] | n = 28 | •Magnetic resonance spectroscopy (MRS): N-acetyl aspartate/ creatine ratio change at the anterior, middle, and posterior Centrum Semiovale white matter (CSWM) in both sides. Average was taken of those 6 | •N/A | •1.5-T MRI. T1/T2 and FLAIR in axial section. MRS using the with default chemical shift imaging method | •Transverse, sagittal and coronal | •NAA/Cre strongly correlated with rCBF (p < 0.001) and scores < 1.5 in anterior CSWM were found in all 23 patients with more than gait symptoms •NAA/Cre not significantly correlated with CRC (p = 0.635) •There was no significant correlation with clinical response, although in the 5 SNR, NAA/Cre was < 0.8 in at least 2 regions •There was a weak correlation between NAA/Cre and the NPH scale (R2 = 0.332, p < 0.1) |
Agerskov et al. [3] | n = 20 | •Apparent diffusion coefficients in 6 regions; 3 within upper part of the mesencephalon and 3 located 6 mm caudally in the pons | •N/A | •1.5 T Gyroscan MRI. ADC maps calculated using Transverse DWI. FLAIR sequence was used to draw 6 ROIs in two regions to map the ADC onto | •All sequences angulated parallel to the callosal plane | •There was no significant difference in ADC between SR and SNR groups •Mesencephalon: SR: 800 (IQR 750–821); SNR: 775 (IQR 753–828) •Pons: SR: 772 (IQR 738–813); SNR: 760 (IQR 721–798) •NB there was a post-operative increase in ADC in the mesencephalon and pons in responders |
Wu et al. [61] | n = 41 | •Volumetric analysis using Automatic whole-brain segmentation. Brain split into 283 ROIs. 5 levels of granularity were produced, depending on number of ROIs in each image. 7, 19, 54, 137, and 283 for levels 1–5 respectively | •N/A | •High-resolution T1-weighted MRI using MPRAGE sequence. Multi-atlas algorithm was used to segment the brain | •Sagittal | •Level 5 could not be used for statistical reasons •The correlation between the predictive model at each level and the ground truth for the Tinetti score were r = 0.55, 0.56, 0.76, and 0.80 at levels 1, 2, 3, and 4. For MMSE it was r = 0.85, 0.86, 0.87, and 0.88 at levels 1, 2, 3, and 4, respectively. When the predictive model only had the volumetric analysis as input, the r values at levels 1–4 were 0.53, 0.53, 0.77, and 0.75 for Tinetti and 0.61, 0.75, 0.69, and 0.83 for MMSE •Areas strongly which related to Tinetti score were ventricle and sulci, especially right parietal and frontal sulci and bilateral inferior left ventricle (a strong predictor) •Areas which strongly related to MMSE score were cortical gyri and white matter e.g., left angular gyrus, right cuneus, left fornix/stria terminalis, and left anterior deep white matter |
Kuchcinski et al. [31] | n = 38 | •Automated sulcal morphometry used to assess the size of the sulcal opening of 10 sulci. Two ratios between 4 different sulci were also calculated: Lateral/intraparietal and Calcarine/cingulate | •N/A | •3 T MR scanner Magnetization-Prepared Rapid Gradient-Echo 3D T1 sequence. Morphometry was performed using BrainVISA software | •Sagittal | •The lateral and superior temporal sulci were significantly correlated with score improvement r = 0.42, p-0.02; r = 0.38, p = 0.03 respectively •NB interesting when used to compare with population (healthy controls and cognitive dementia caused by vascular accidents, calcarine/cingulate ratio (AUC = 0.94; 95% CI: 0.89,0.99) was the most discriminative sulci, and a cutoff of 0.95 had sensitivity 96.8% and specificity 83.3% |