Table 3 –
Summary of pathologies, interventions, and findings for 11 studies investigating elastography in patients with conditions other than intracranial tumors
| Author, year | Pathology (n) | Surgery | Elasticity results | Conclusions |
|---|---|---|---|---|
| Al-Habib et al., 2021 [31] | Degenerative disease (10), tumors (6), trauma (3), infection (1), syndromic (4), tethered cord (1) | Laminectomy or corpectomy | Spinal cord: Compressed group - 93.8 kPa, decompressed group - 9.35 kPa. Dura: compressed group - 121.8 kPa, decompressed group - 29.8 kPa | Compression significantly increases stiffness of spinal cord and dura mater. Elasticity is significantly reduced following decompression. |
| Chan et al., 2014 [9] | MRI-negative epilepsy (1) | Resection of FCD | YM: Lesion - 74.7 kPA; gray matter - 36.2 kPa; white matter - 20.8 kPa | USE can identify MRI-negative and ultrasound-negative epileptogenic lesions. Histology confirmed type 11b focal cortical dysplasia. |
| Dirrichs et al., 2019 [10] | Hydrocephalus/increased ICP (56), controls (110) | Invasive ventricular drainage | YM: Hydrocephalus – 21.8 kPa, controls – 14.1 kPa | Increased stiffness in hydrocephalus, correlation between ICP measurements and SWE |
| Freimann et al., 2012 [35] | NPH (20) | CSF drainage, VP shunting | Shear elasticity: before shunt – 2.24 kPa, after shunt – 2.26 kPa; connectivity parameter: before shunt – 0.26, after shunt – 0.28 | Viscoelastic parameters lower in NPH than healthy controls; elasticity did not change after shunt treatment but connectivity parameter returned to normal. |
| Mathon et al., 2019 [32] | Epilepsy (28) | Epileptogenic zone resection | Lesion/normal brain stiffness ratio: MRI- FCD – 2.8 kPa, MRI+ FCD – 3.9 kPa; SWE sensitivity: 93% | SWE improves intraoperative detection of epileptogenic lesions and can detect FCD not visible on B-mode US. |
| Mathon et al., 2021 [33] | FCD (18): MRI- FCD (8), MRI+ FCD (10) | FCD resection | FCD/normal brain stiffness ratio: MRI- FCD – 2.2 kPa, MRI+ FCD – 3.6 kPa; SWE sensitivity: 78% | SWE outperforms B-mode US in intraoperative FCD detection, detected 60% of MRI- FCD |
| Olivero et al., 2016 [12] | Hydrocephalus (1) | Shunt drainage | MRE: 1.62 kPa (normal ~ 3.0 kPa) | Observed extremely low brain tissue stiffness in low pressure hydrocephalus, even after shunt treatment |
| Perry et al., 2017 [36] | Idiopathic NPH (10) | VP shunt placement | MRE (vs healthy control): Cerebrum – 2.64 (higher), occipital – 2.97 (higher), parietal – 2.63 (higher), periventricular – 1.74 (lower) | Abnormal brain stiffness correlates with symptoms. Postoperative improvement associated with increased deep gray matter stiffness, and failure associated with increased temporal stiffness. |
| Prada et al., 2020 [34] | Type IIb FCD of right frontal lobe (4) | FCD resection | Qualitative results only; FCD mean stiffness similar to adjacent healthy brain | Dysplastic foci contain heterogenous stiffness; neither elastography nor contrast-enhanced US superior to B-mode US in identifying boundaries. |
| Solamen et al., 2021 [37] | NPH (22) | Lumbar drain placement | Increased stiffness in cerebral and periventricular regions (p=0.01) | NPH drain responders showed initial increase followed by a later decrease, suggesting mechanical changes from drainage. |
| Vergari et al., 2020 [11] | AIS (25) | Fusion | Shear wave speed: AIS – 4.0 m/s, controls – 3.1 m/s, AIS patients 1 year after treatment – 3.3 m/s | Significant differences between AIS and healthy discs, which normalizes 1 year after treatment. |
AIS – adolescent idiopathic scoliosis; FCD – Focal Cortical Dysplasia; MRI – Magnetic Resonance Imaging; NA – not applicable NPH – normal pressure hydrocephalus; SWE – shear-wave elastography; US – ultrasound; VP – ventriculoperitoneal shunting; YM – Young’s Modulus