CBV maps reconstructed and converted according the (A) TT and (B) CBT paths on the same side of the fourth vertebrae in patients aged 26–100 years, with the total CBV marked on the map.

CBV maps reconstructed and converted according the (A) TT and (B) CBT paths on the same side of the fourth vertebrae in patients aged 26–100 years, with the total CBV marked on the map.</p

(A) and (B) display drilled surface images reconstructed from rods placed to represent the area traversed by a screw according to the TT and CBT paths in the fourth vertebrae of the same section and the converted CBV map.

(A) and (B) display drilled surface images reconstructed from rods placed to represent the area traversed by a screw according to the TT and CBT paths in the fourth vertebrae of the same section and the converted CBV map.</p

Rod location in the area traversed by a screw and the corresponding reconstructed drilled surface image.

Rod location in the area traversed by a screw and the corresponding reconstructed drilled surface image.</p

S1 Data -

Intraoperative navigation systems have been widely applied in spinal fusion surgery to improve the implantation accuracy of spinal screws using orthogonal tomographic and surface-rendering imaging. However, these images contain limited anatomical information and no information on bone volume contact by the implanted screw, which has been proven to affect the stability of implanted screws. This study proposed a novel drilled surface imaging technique that displays anatomical integration properties to calculate the contact bone volume (CBV) of the screws implanted along an implantation trajectory. A cylinder was used to represent the area traversed by the screws, which was manually rotated and translated to a predetermined implantation trajectory according to a vertebra model obtained using computed tomography (CT) image volumes. The drilled surface image was reconstructed by interpolating the CT numbers at the predefined sampling points on the cylinder surface. The anatomical integration property and CBV of the screw implanted along the transpedicular trajectory (TT) and cortical bone trajectory (CBT) were evaluated and compared. The drilled surface image fully revealed the contact anatomical structure of the screw under the trajectories, improving the understanding of the anatomical integration of the screw and surrounding tissues. On average, the CBV of the CBT was 30% greater than that of the TT. The proposed drilled surface image may be applied in preoperative planning and integrated into intraoperative navigation systems to evaluate the anatomical integration and degree of bone contact of the screw implanted along a trajectory.</div

Fig 6 -

(A) Relationship between total CBV of the TT and CBT paths on the same side of the fourth vertebrae. (B) Relationship between implantation depth of the TT and CBT paths on the same side of the fourth vertebrae.</p

Relationship between age and total CBV in both the TT and CBT paths on both sides of the fourth vertebrae.

Relationship between age and total CBV in both the TT and CBT paths on both sides of the fourth vertebrae.</p

Fig 1 -

(A) Cylinder placed along the CBT path. (B) coronal and (C) sagittal CT images of a lumbar spine labeled with sampling points redefined from the coordinates of postdisplacement cylindrical mesh model vertexes.</p

Calculating air volume fractions from computed tomography images for chronic obstructive pulmonary disease diagnosis - Fig 4

(a) CT images of the foams with slice thicknesses of 0.47, 0.94, 1.88, 2.82, and 4.7 mm with addressed mean CT numbers of the foams. (b) PU volume fraction maps calculated from (a) using the TCM with an air–PU submaterial pair. The white circle in (a) indicates the location of the ROI for the calculation of the mean CT numbers.</p

Image_1_Effects of Hemodynamic Response Function Selection on Rat fMRI Statistical Analyses.pdf

The selection of the appropriate hemodynamic response function (HRF) for signal modeling in functional magnetic resonance imaging (fMRI) is important. Although the use of the boxcar-shaped hemodynamic response function (BHRF) and canonical hemodynamic response (CHRF) has gained increasing popularity in rodent fMRI studies, whether the selected HRF affects the results of rodent fMRI has not been fully elucidated. Here we investigated the signal change and t-statistic sensitivities of BHRF, CHRF, and impulse response function (IRF). The effect of HRF selection on different tasks was analyzed by using data collected from two groups of rats receiving either 3 mA whisker pad or 3 mA forepaw electrical stimulations (n = 10 for each group). Under whisker pad stimulation with large blood-oxygen-level dependent (BOLD) signal change (4.31 ± 0.42%), BHRF significantly underestimated signal changes (P 0.05). Under forepaw stimulation with small BOLD signal change (1.71 ± 0.34%), different HRFs provided insignificantly different t-statistics (P > 0.05). Therefore, the selected HRF can influence data analysis in rodent fMRI experiments with large BOLD responses but not in those with small BOLD responses.</p

Block diagrams that represents the evaluation procedure of the (a) phantom and (b) patient studies performed in this study.

Block diagrams that represents the evaluation procedure of the (a) phantom and (b) patient studies performed in this study.</p