{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,4]],"date-time":"2026-10-04T12:32:24Z","timestamp":1791117144186,"version":"4.1.0"},"reference-count":16,"publisher":"Wiley","issue":"4","license":[{"start":{"date-parts":[[2005,11,17]],"date-time":"2005-11-17T00:00:00Z","timestamp":1132185600000},"content-version":"vor","delay-in-days":3061,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Magnetic Resonance Imaging"],"published-print":{"date-parts":[[1997,7]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Temporal changes in respiration could influence navigator\u2010echo (NE)\u2010gated MR coronary angiography (MRCA), but systematic investigation of the effects of such variations and how to limit them has not been performed. We addressed these issues by studying the influence of time in the magnet on diaphragm position and respiratory patterns using NE diaphragm monitoring in volunteers and a phantom model. NE diaphragm monitoring was performed at .5 T in 10 subjects over a total period of 35 minutes. The end\u2010expiratory position was sustained for longer (1.1 vs .4 seconds, <jats:italic>P<\/jats:italic> &lt; .001) and with greater position stability (SD 1.9 vs 5.9 mm, <jats:italic>P<\/jats:italic> = .01) than the end\u2010inspiratory position. Drift of the end\u2010expiratory position occurred over time, causing a fall in scan efficiency (44\u201328%, <jats:italic>P<\/jats:italic> = .01). Up\u2010drift of the end\u2010expiratory position was most common. Loss of scan efficiency was worse with up\u2010drift because of loss of the end\u2010expiratory pause from the NE window (up\u2010drift 10% mm<jats:sup>\u22121<\/jats:sup>, down\u2010drift 7% mm<jats:sup>\u22121<\/jats:sup>, both <jats:italic>P<\/jats:italic> = .03). Scan efficiency also was reduced during sleep (to a nadir of 0%), secondary to loss of the end\u2010expiratory pause, periodic breathing with oscillating end\u2010expiratory position, and periods of apnea. The phantom model used actual diaphragm traces to evaluate the artifact resulting from diaphragm motion during acquisition. Artifact was considerably reduced by NE adaptive motion correction compared with NE gating alone (ghosting ratio 2.0 vs 2.8, <jats:italic>P<\/jats:italic> &lt; .01). Artifact also was significantly reduced with up\u2010drift if scan efficiency was maintained above 35% (<jats:italic>P<\/jats:italic> = .05). For optimal NE\u2010gated MRCA, the following features are important: the NE window should be placed around the end\u2010expiratory position; subjects should not sleep; scan efficiency should be monitored and the NE window should be repositioned if scan efficiency falls below 35%; and adaptive motion correction should be used.<\/jats:p>","DOI":"10.1002\/jmri.1880070404","type":"journal-article","created":{"date-parts":[[2007,3,15]],"date-time":"2007-03-15T22:33:10Z","timestamp":1173997990000},"page":"629-636","source":"Crossref","is-referenced-by-count":166,"title":["MR navigator\u2010echo monitoring of temporal changes in diaphragm position: Implications for MR coronary angiography"],"prefix":"10.1002","volume":"7","author":[{"given":"Andrew M.","family":"Taylor","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Permi","family":"Jhooti","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Frank","family":"Wiesmann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennifer","family":"Keegan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David N.","family":"Firmin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dudley J.","family":"Pennell","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2005,11,17]]},"reference":[{"key":"e_1_2_1_2_2","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.87.1.94"},{"key":"e_1_2_1_3_2","doi-asserted-by":"publisher","DOI":"10.1136\/hrt.70.4.315"},{"key":"e_1_2_1_4_2","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1910330118"},{"key":"e_1_2_1_5_2","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1910300416"},{"key":"e_1_2_1_6_2","doi-asserted-by":"publisher","DOI":"10.1148\/radiology.198.1.8539406"},{"key":"e_1_2_1_7_2","first-page":"450","volume-title":"Proceedings of the 4th annual meeting of the International Society for Magnetic Resonance in Medicine","author":"McConnell MV","year":"1996"},{"key":"e_1_2_1_8_2","first-page":"177","volume-title":"Proceedings of the 4th annual meeting of the International Society for Magnetic Resonance in Medicine","author":"Danias PG","year":"1996"},{"key":"e_1_2_1_9_2","first-page":"175","volume-title":"Proceedings of the 4th annual meeting of the International Society for Magnetic Resonance in Medicine","author":"Wang Y","year":"1996"},{"key":"e_1_2_1_10_2","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1954.sp005099"},{"key":"e_1_2_1_11_2","first-page":"758","article-title":"Assessment of hepatic respiratory excursion","volume":"13","author":"Weiss PH","year":"1972","journal-title":"J Nucl Med"},{"key":"e_1_2_1_12_2","doi-asserted-by":"publisher","DOI":"10.1259\/0007-1285-67-803-1096"},{"key":"e_1_2_1_13_2","doi-asserted-by":"publisher","DOI":"10.1148\/radiology.194.3.7862995"},{"key":"e_1_2_1_14_2","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1910230118"},{"key":"e_1_2_1_15_2","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1910330517"},{"key":"e_1_2_1_16_2","first-page":"1718","article-title":"Upward creep of the heart: a frequent source of false\u2010positive reversible defects during Thallium 201 stress redistribution SPECT","volume":"30","author":"Friedman J","year":"1989","journal-title":"J Nucl Med"},{"key":"e_1_2_1_17_2","first-page":"3","article-title":"Respiration and wakefulness in man","volume":"59","author":"B\u00fclow K","year":"1963","journal-title":"Acta Physiol Scand"}],"container-title":["Journal of Magnetic Resonance Imaging"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fjmri.1880070404","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/jmri.1880070404","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,28]],"date-time":"2023-10-28T09:07:28Z","timestamp":1698484048000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/jmri.1880070404"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1997,7]]},"references-count":16,"journal-issue":{"issue":"4","published-print":{"date-parts":[[1997,7]]}},"alternative-id":["10.1002\/jmri.1880070404"],"URL":"https:\/\/doi.org\/10.1002\/jmri.1880070404","archive":["Portico"],"relation":{},"ISSN":["1053-1807","1522-2586"],"issn-type":[{"value":"1053-1807","type":"print"},{"value":"1522-2586","type":"electronic"}],"subject":[],"published":{"date-parts":[[1997,7]]}}}