The Use of Intraoperative CT Hounsfield Unit Values for the Assessment of Bone Quality in Patients Undergoing Lumbar Interbody Fusion

Abstract

Study Design Retrospective Cohort Study Objective To evaluate the accuracy of intraoperatively measured computed tomography (CT) Hounsfield unit (HU) values by comparison with preoperative CT HU values and to compare the radiation exposure between preoperative and intraoperative CT scans. Methods HU values of lumbar vertebrae were measured and compared between preoperative and intraoperative CT scans in patients undergoing lumbar interbody fusion. In patient group one, Canon CT scanners were used preoperatively and the AIRO CT scanner was used intraoperatively. In patient group two, Canon CT scanners were used preoperatively and the O-arm Cone Beam CT (CBCT) scanner was used intraoperatively. In a subgroup analysis of patient group one, radiation by means of CT Dose Index (CTDI) was compared between Canon and AIRO CT scanners. Results In the first patient group, a total of 250 vertebrae were analysed in 74 patients showing a strong Pearson correlation of >.94 between pre- and intraoperative HU values. Bland-Altman analysis indicated consistency and equivalence with a bias of 3.9 and 95% limits of agreement from −27.17 to 34.97 when comparing all pre- and intraoperative HU values of L1–5. In the second patient group, a total of 27 vertebrae were analysed in 10 patients showing weak Pearson correlation and Bland-Altman analysis indicated no equivalence. CTDI did not differ between Canon and AIRO CT scanners. Conclusion Correct and reliable CT HU measurement as mandatory key factor for the intraoperative assessment of bone quality and robotic-assisted surgery is feasible with intraoperative AIRO CT imaging without increase of radiation exposure.

Decompression with or without fusion in degenerative adjacent segment stenosis after lumbar fusions

“…A total of 86.5% of patients suffered from a proximal adjacent ) and a Mentally Health Component Summary Score (MSC) of 30.9 (18.4-44.9) of the study population. Mood state analysis showed a median of ADS-K depression score of 16 (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Concerning radiographical determined parameters, the two groups showed no significant differences.…”

“…Disc heights and diameters of spinal canals were measured in preoperative MRI scans. For osteoporosis assessment, hounsfield units (HUs) of adjacent vertebral body were determined in preoperative CT-scans with 1 mm slices [14]. Therefore, an oval region of interest was placed over axial image of the vertebral body of the adjacent corporal body.…”

Characteristics and Comparisons of Morphometric Measurements and Computed Tomography Hounsfield Unit Values of C2 Laminae for Translaminar Screw Placement Between Patients With and Without Basilar Invagination

“…[20][21][22] Moreover, HU measured at a region of interest (ROI) of the screw trajectory presents the approximate BMD and correlates strongly with insertion torque and implant stability in vitro and in vivo studies. [23][24][25][26] Furthermore, Han et al 27 demonstrated that HU values on C2-3 segments indicate a more reliable BMD level than those on C4-7 segments, and HU values of cervical CT provided reliable information regardless of measured sections, age, sex, and degree of degeneration. Therefore, the BMD, insertion torque, and implant stability of translaminar screw can be approximately compared between patients with and without BI using the HU values measured on C2 laminae.…”