Reviewing the MRI images of 2400 patients will not violate the rights of the patients. After the discussion by the institutional review board, consent forms were not required. The 30 volunteers gave informed consent to participate, and the study was approved by institutional review board of Foshan Fosun Chancheng Hospital (No. KY2022002). We collected patients who underwent lumbar MRIs at our center from April 2018 to April 2022. Exclusion criteria were as follows: 1) injection of MRI contrast material; 2) known oncologic patients; 3) traumatic vertebral injuries; 4) known or suspected demyelinating disease; 5) presence of relevant image artifacts.
VBQ in Non-OVCF patients
Patients presenting for low back pain, lumbar disc herniation, or lumbar spinal stenosis were included. Patients with long-term corticospinal, parathyroid, diabetes, and fractures were excluded.
We only counted patients aged 20–80 years. It is because fewer than 200 people aged over 80 met the criteria. Moreover, there has been a significant selection bias when conducting random screening because of the high proportion of chronic diseases. Therefore, we only counted up to age 80. Two hundred patients (100 males and 100 females) in each age group who had received 3.0T and 1.5T magnetic resonance scans of the Lumbar Spine were randomly selected at a 10-year stratification.
To evaluate the impact of MRI parameters on VBQ, we recruited 30 healthy adults aged 25 to 30 to receive multiple lumbar MRI using different parameters at our institution. The records of identified patients were screened to identify a history of congenital spine abnormalities, in-born bone metabolic disease, history of cancer, history of osteomyelitis, history of disseminated infection, history of chronic liver or kidney disease, or history of glucocorticoid use. Patients meeting any of these criteria were excluded from the healthy cohort.
VBQ in OVCF patients
Patients with nonviolent and low-energy spinal compression fractures who had been followed up in our hospital for more than two years were included, and patients with vertebral fractures caused by severe violence and pathological fracture were excluded.
Demographic information, including age, sex, body mass index (BMI), and parameters of MRI, were collected.
Parameters of MRI
The 1.5T and 3.0T magnetic resonance systems in this study are both from Siemens (Magnetom Sonata Maestro Class, Siemens Medical Solutions, Erlangen, Germany). The imaging protocol of 1.5T sagittal T1-weighted spin-echo sequence: Repetition time (TR) = 645 ms; Echo time (TE) = 11 ms; slice thickness = 4 mm; squared field of view = 280 mm. Among 1200 patients, the bandwidth of more than ten patients was 35.36 kHz (158 patients), 36.06 kHz (100 patients), 37.03 kHz (120 patients), and 43.31 kHz (791 patients). Other frequencies used included 41.22 kHz (8 patients); 39.28 kHz (7 patients), 33.28 kHz (7 patients), 33.01 kHz (7 patients), and 32.2 kHz (2 patients).
The imaging protocol of 3.0T sagittal T1-weighted spin-echo sequence: TR = 550 ms; slice thickness = 4 mm; squared field of view = 280 mm. The combination of echo time and bandwidth frequency is: 56 kHz/9.4 ms (7 patients); 58 kHz/9.4 ms (9 patients); 64 kHz/9.4 ms (450 patients); 67.25 kHz/9.5 ms (10 patients); 69.5 kHz/9.5 ms (322 patients); 76.75 kHz/9.5 ms (402 patients).
Method of measuring VBQ
VBQ score was calculated using a non-contrast, T1-weighted MRI of the Lumbar Spine. First, mid-sagittal slices were used to measure the median signal intensity (SI) of the trabecular bone of the L1 through L4 vertebral bodies, as shown in Figure. Next, for patients with abnormalities that prevented region-of-interest (ROI) measurement on the midsagittal slice (e.g., hemangioma, venous plexus, scoliotic changes, fracture, bone marrow edema), parasagittal slices were used to have SIs accurately reflect inner medullary portions of bone. Finally, in cases where abnormalities invaded all sagittal slices of the vertebral body, this level was excluded from the calculation, and the VBQ was determined using only the remaining vertebrae.
The median value of L1 − L4 vertebral bodies is then determined and divided by the SI of the adjacent cerebrospinal fluid (CSF) to give a relative vertebral body SI: the VBQ (Fig. 1). The SI of CSF was pegged to the median SI within an ROI placed at the level of L3 to allow for standardization of this step. In cases where L3 CSF space was obstructed entirely by descending nerve roots, CSF ROI was placed at the level of L2 or L4.
![](data:image/png;base64,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)
While calculating VBQ, we placed no restrictions on MRI field strength or scanner manufacturer. All VBQ measurements were made by two independent reviewers blinded to clinical outcomes. VBQ values used in the statistical analysis represent the average of the values calculated by the two reviewers. A third reviewer was used in cases where the scores differed by more than 10%, and the value used for analysis was the average of the two closest VBQ measurements.
Statistical analysis
All data were gathered using Microsoft Excel (Redmond, WA, USA) and then analyzed using Prism version 9.0 for Mac (GraphPad Software Inc., San Diego, California, USA). Descriptive statistics constituted mean and standard deviation for continuous variables and proportions for dichotomous and categorical variables. The univariable analysis included a two-tailed Student t-test for continuous variables and a chi-square analysis for categorical variables. The multivariable model was analyzed using logistic regression and included all clinically relevant variables.