{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T14:07:55Z","timestamp":1791986875689,"version":"4.4.0"},"reference-count":18,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2020,5]]},"abstract":"<jats:sec><jats:title>OBJECTIVE<\/jats:title><jats:p>Skull density ratio (SDR) assesses the transparency of the skull to ultrasound. Magnetic resonance\u2013guided focused ultrasound (MRgFUS) thalamotomy in essential tremor (ET) patients with a lower SDR may be less effective, and the risk for complications may be increased. To address these questions, the authors analyzed clinical outcomes of MRgFUS thalamotomy based on SDRs.<\/jats:p><\/jats:sec><jats:sec><jats:title>METHODS<\/jats:title><jats:p>In 189 patients, 3 outcomes were correlated with SDRs. Efficacy was based on improvement in Clinical Rating Scale for Tremor (CRST) scores 1 year after MRgFUS. Procedural efficiency was determined by the ease of achieving a peak voxel temperature of 54\u00b0C. Safety was based on the rate of the most severe procedure-related adverse event. SDRs were categorized at thresholds of 0.45 and 0.40, selected based on published criteria.<\/jats:p><\/jats:sec><jats:sec><jats:title>RESULTS<\/jats:title><jats:p>Of 189 patients, 53 (28%) had an SDR &lt; 0.45 and 20 (11%) had an SDR &lt; 0.40. There was no significant difference in improvement in CRST scores between those with an SDR \u2265 0.45 (58% \u00b1 24%), 0.40 \u2264 SDR &lt; 0.45 (i.e., SDR \u2265 0.40 but &lt; 0.45) (63% \u00b1 27%), and SDR &lt; 0.40 (49% \u00b1 28%; p = 0.0744). Target temperature was achieved more often in those with an SDR \u2265 0.45 (p &lt; 0.001). Rates of adverse events were lower in the groups with an SDR &lt; 0.45 (p = 0.013), with no severe adverse events in these groups.<\/jats:p><\/jats:sec><jats:sec><jats:title>CONCLUSIONS<\/jats:title><jats:p>MRgFUS treatment of ET can be effectively and safely performed in patients with an SDR &lt; 0.45 and an SDR &lt; 0.40, although the procedure is more efficient when SDR \u2265 0.45.<\/jats:p><\/jats:sec>","DOI":"10.3171\/2019.2.jns183517","type":"journal-article","created":{"date-parts":[[2019,4,27]],"date-time":"2019-04-27T07:20:04Z","timestamp":1556349604000},"page":"1392-1397","source":"Crossref","is-referenced-by-count":86,"title":["Impact of skull density ratio on efficacy and safety of magnetic resonance\u2013guided focused ultrasound treatment of essential tremor"],"prefix":"10.3171","volume":"132","author":[{"given":"Marissa","family":"D\u2019Souza","sequence":"first","affiliation":[{"name":"Departments of Neurosurgery and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kevin S.","family":"Chen","sequence":"additional","affiliation":[{"name":"Departments of Neurosurgery and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jarrett","family":"Rosenberg","sequence":"additional","affiliation":[{"name":"Radiology, Stanford University School of Medicine, Stanford, California;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"W. 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