Sonography of the Spine and Spinal Cord

A Three-Dimensional Morphological Assessment for Evaluating Pre- and Postsurgery in Cervical Laminoplasty

OBJECTIVE

The efficacy of medical treatments and the changes in radiologic imaging before and after treatment have consistently remained pivotal factors. This is particularly critical for surgical procedures, where precise evaluation of disparities pre and postsurgery or the accuracy of implantation is paramount. Based on three-dimensional morphological interests, we provide an automatic quantification evaluation method that delivers an evident base for assessing the outcomes of a widely employed surgical technique, cervical laminoplasty.

METHODS

The sample study included patients who underwent cervical laminoplasty for cervical spondylotic myelopathy/ossification of the longitudinal ligament. We present a superimposition method that facilitates a unique and precise assessment between pre and postsurgery. The degree of expansion was evaluated by the canal volume increase and canal expansion rate after surgery.

RESULTS

There were 31 patients with 112 vertebral segments measured. The target cervical's pre and postoperative canal areas were 122.63 ± 30.34 and 196.50 ± 37.10 mm2, respectively (P < 0.001). The average cervical canal expansion rate was 64.42%. The expansion effect of C5 cervical laminoplasty was the maximum (71.01%), and the canal volume of other segments expanded by approximately 60%. The functional outcomes demonstrated significant improvements in symptoms.

CONCLUSIONS

The quantification evaluation method can be utilized for any morphology changes before and after laminoplasty, as it does not lead to errors or variations from different inspection machines or human factors. The automatic method delivers an evident base for assessing the outcomes of a widely employed surgical technique.

Determination of the normal conus medullaris level in term infants: the role of MRI in early infancy

OBJECTIVE

This study aimed to explore the migration process of the conus medullaris (CM) in early infancy using infant MRI and to evaluate the application of MRI for locating the infant CM level.

METHODS

The authors retrospectively analyzed the CM level on the lumbosacral MR images of 26 term infants aged < 3 months who were classified into three groups according to age. The authors numbered the CM level in each patient and analyzed the range and average of the CM level of the cohort. The authors studied the linear correlation between CM level and postnatal days with linear regression analysis, 1-way ANOVA, and the least significant difference test.

RESULTS

The CM level ranged from the superior border of the L1 vertebra to the top third of the L3 vertebra. About 96.2% of infants had CM higher than the superior border of the L3 vertebra. On average, CM was located between the L1-2 intervertebral disc and the inferior border of the L2 vertebra (mean ± SD score 1.64 ± 1.14). The three groups had no significant statistical difference in CM level (F = 1.071 and p = 0.359; groups 1 and 2, p = 0.408; groups 1 and 3, p = 0.170; groups 2 and 3, p = 0.755). CM level had no linear regression correlation with postnatal days within the first month (r2 = 0.061, F = 0.654, p = 0.438) or within the first 3 months (r2 = 0.002, F = 0.056, p = 0.816).

CONCLUSIONS

The CM level reaches the normal adult level by birth in term infants and does not ascend during childhood. On average, the CM was between the L1-2 intervertebral disc and the inferior border of the L2 vertebra in term infants. Considering the possibility of physiologically low-lying CM, the authors agree that normal CM is located above the L3 level in term infants and CM at the L3 level could be equivocal and should be investigated with other clinical data. The study data suggest that MRI is an accurate and valuable method for determining the CM level in term infants.