Non-inferiority of a non-gadolinium-enhanced magnetic resonance imaging follow-up protocol for isolated optic pathway gliomas

Abstract OBJECTIVE: Intramedullary spinal cord arteriovenous malformations (AVMs) have an unfavorable natural history that characteristically involves myelopathy secondary to progressive ischemia and/or recurrent hemorrhage. Although some lesions can be managed successfully with embolization and surgery, AVM size, location, and angioarchitecture precludes treatment in many circumstances. Given the poor outlook for such patients, and building on the successful experience with radiosurgical ablation of cerebral AVMs, our group at Stanford University has used CyberKnife (Accuray, Inc., Sunnyvale, CA) stereotactic radiosurgery (SRS) to treat selected spinal cord AVMs since 1997. In this article, we retrospectively analyze our preliminary experience with this technique. METHODS: Fifteen patients with intramedullary spinal cord AVMs (nine cervical, three thoracic, and three conus medullaris) were treated by image-guided SRS between 1997 and 2005. SRS was delivered in two to five sessions with an average marginal dose of 20.5 Gy. The biologically effective dose used in individual patients was escalated gradually over the course of this study. Clinical and magnetic resonance imaging follow-up were carried out annually, and spinal angiography was repeated at 3 years. RESULTS: After a mean follow-up period of 27.9 months (range, 3–59 mo), six of the seven patients who were more than 3 years from SRS had significant reductions in AVM volumes on interim magnetic resonance imaging examinations. In four of the five patients who underwent postoperative spinal angiography, persistent AVM was confirmed, albeit reduced in size. One patient demonstrated complete angiographic obliteration of a conus medullaris AVM 26 months after radiosurgery. There was no evidence of further hemorrhage after CyberKnife treatment or neurological deterioration attributable to SRS. CONCLUSION: This description of CyberKnife radiosurgical ablation demonstrates its feasibility and apparent safety for selected intramedullary spinal cord AVMs. Additional experience is necessary to ascertain the optimal radiosurgical dose and ultimate efficacy of this technique.

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Magnetic Resonance Imaging T2* Mapping of the Talar Dome and Subtalar Joint Cartilage 3 Years After Anterior Talofibular Ligament Repair or Reconstruction in Chronic Lateral Ankle Instability

The American Journal of Sports Medicine ◽

10.1177/0363546520982240 ◽

2021 ◽

Vol 49 (3) ◽

pp. 737-746

Author(s):

Yiwen Hu ◽

Yuyang Zhang ◽

Qianru Li ◽

Yuxue Xie ◽

Rong Lu ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Ankle Instability ◽

Anterior Talofibular Ligament ◽

Resonance Imaging ◽

Talar Dome ◽

Lateral Ankle ◽

Chronic Lateral Ankle Instability ◽

Lateral Ankle Instability

Background: Cartilage degeneration is a common issue in patients with chronic lateral ankle instability. However, there are limited studies regarding the effectiveness of lateral ligament surgery on preventing talar and subtalar joint cartilage from further degenerative changes. Purpose: To longitudinally evaluate talar and subtalar cartilage compositional changes using magnetic resonance imaging T2* mapping in anatomic anterior talofibular ligament (ATFL)–repaired and ATFL-reconstructed ankles and to compare them with measures in asymptomatic controls. Study Design: Cohort study; Level of evidence, 3. Methods: Between January 2015 and December 2016, patients with chronic lateral ankle instability who underwent anatomic ATFL repair (n = 19) and reconstruction (n = 20) were prospectively recruited. Patients underwent 3.0-T magnetic resonance imaging at baseline and 3-year follow-up. As asymptomatic controls, 21 healthy volunteers were recruited and underwent imaging at baseline. Talar dome cartilage was divided into (1) medial anterior, central, and posterior and (2) lateral anterior, central, and posterior. Posterior subtalar cartilage was divided into (1) central talus and calcaneus and (2) lateral talus and calcaneus. Ankle function was assessed using the American Orthopaedic Foot & Ankle Society scores. Results: There were significant increases in T2* values in medial and lateral posterior and central talus cartilage from baseline to 3-year follow-up in patients who underwent repair. T2* values were significantly higher in ATFL-repaired ankles at follow-up for all cartilage regions of interest, except medial and lateral anterior and lateral central, compared with those in healthy controls. From baseline to 3-year follow-up, ATFL-reconstructed ankles had a significant increase in T2* values in lateral central and posterior cartilage. T2* values in ATFL-reconstructed ankles at follow-up were elevated in all cartilage regions of interest, except medial and lateral anterior, compared with those in healthy controls. ATFL-repaired ankles showed a greater decrease of T2* values from baseline to follow-up in lateral calcaneus cartilage than did ATFL-reconstructed ankles ( P = .031). No significant differences in American Orthopaedic Foot & Ankle Society score were found between repair and reconstruction procedures (mean ± SD, 19.11 ± 7.45 vs 16.85 ± 6.24; P = .311). Conclusion: Neither anatomic ATFL repair nor reconstruction could prevent the progression of talar dome and posterior subtalar cartilage degeneration; however, ankle function and activity levels were not affected over a short period. Patients who underwent ATFL repair exhibited lower T2* values in the lateral calcaneus cartilage than did those who underwent reconstruction.

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