吉岡 哲志

A 320-detector-row multislice computed tomography (320-MSCT) scanner can acquire a volume data set covering a maximum range of 16 cm and can generate axial images 0.5-mm thick at 0.5-mm intervals. Three-dimensional (3D) images reconstructed from the thin axial slices include multiplanar reconstruction and 3D-CT. Single-phase 3D images are reconstructed from 0.175-s data, and multiphase 3D images are created in 29 phases at intervals of 0.1 s. Continuous replay of these 3D images produces four-dimensional moving images. In order to determine the feasibility of the morphologic and kinematic analyses of swallowing using 320-MSCT, single- phase volume scanning was performed on three patients and multiphase volume scanning was performed on one healthy volunteer. The single-phase 3D images clearly and accurately showed the structures involved in swallowing, and the multiphase 3D images were able to show the oral stage to the early esophageal stage of swallowing, allowing a kinematic analysis of swallowing. We developed a reclining chair that allows scanning to be performed with the subject in a semisitting position, which makes swallowing evaluation by 320-MSCT applicable not only to research on healthy swallowing but also to the clinical examination of dysphagia patients. © 2010 Springer Science+Business Media, LLC.

320列面検出器型CT(ADCT)を用いた嚥下機能評価の初期経験を報告した。延髄梗塞による咽頭麻痺患者2例を対象とした。2例とも検査者の合図に合わせた挺舌発声が可能で、発声時撮影を行うことができた。歯からの金属アーチファクトを認めたが、モーションアーチファクトはなく、良好な3次元画像を作成できた。次に健常成人4例を対象として正常嚥下動態画像を作成した。全例、検査者の合図に合わせて嚥下を開始し、315秒の撮影時間内で嚥下を終了することができた。時相を合わせた任意のタイミングでのMPRおよび3D-CT像が作成可能であった。3D-CT像の連続再生により、4次元の嚥下動態画像が作成された。

320列高速多列面検出器CTを小児の気管支異物の診断に使用した。本機は0.5 mm&middot;320列の面検出器が，1回転あたり最速0.35秒で回転し，最大160 mm幅を1回転のみで撮像することが可能である。そのため画像内の全部分に時相差がなく，また連続回転により時間的に連続する立体画像データを得ることが可能である (4DCT) 。<br>対象は，気管支異物を強く疑った幼児4名である。機器は東芝Aquilion ONE^&reg;を使用し，多断面再構成像 (MPR) および三次元再構成画像 (3DCT) を作成した。予め観察した1呼吸分の連続4DCT動画も作成した。<br>本機により，薬物睡眠無しでの超短時間での撮影が可能であった。静止画においては，従来回避不可能だった，呼吸や心拍動に伴うモーションアーチファクトが完全に消失したため，画像の連続性や末梢気管支の描出能が飛躍的に改善した。そのため微細・複数の異物の診断の確実性が非常に高まった。4DCTでは，動的な観察により異物介在部位や肺の生理学的な状況を視覚的に解りやすく画像化した。すなわち，肺の機能診断にもCTが応用できた。被曝量は，認容できる量であった。<br>本機は新しい肺気管支領域の画像評価ツールとして非常に期待できる。

【はじめに・目的】耳管形態, 特に各年齢期での違いを検討することで, 耳管機能異常に起因する疾患の病態を明らかにできる可能性がある. われわれはCTを利用し, ヒト生体における耳管計測を行ってきたが, 今回さらに測定値を年齢ごとに比較検討した.<br>【方法・対象】対象は成人48耳, 小児31耳 (7歳未満23耳). CTデータ上にそれぞれ設定した基準点座標を元に, 各部の長さ, 径, 角度を計測した.<br>【結果】標本で生じるゆがみ・縮みは発生せず, 離れた位置の距離や角度の計測が可能であった. 7歳未満の幼児群と7歳以上の学童成人群を比較すると, 骨部長, 軟骨部長, 耳管全長のすべてにおいて乳幼児群よりも学童成人群で長くなっており, 咽頭口も乳幼児群よりも学童成人群で大きい結果であった. 骨部と軟骨部のなす角は学童成人群でより鋭角となった. 耳管を正面・側面から見た場合においても, 軟骨部が成長と共に有意差を持ってより急峻となり, その結果, 骨部と軟骨部がなす角度がより鋭角へと変化した.<br>【考察・まとめ】CTによる耳管測定方法は, 従来の標本による測定法に代替しうる有用な測定方法と考えられた. 小児耳管の立体解剖学的特徴を, ヒト生体において初めて証明した. これらの耳管の年齢変化は, いずれも小児の耳管機能が未熟であることを検証, 示唆するものであった. 本手法は多くの生体標本を利用した精密な計測を可能にし, 耳管形態に関する基礎的・臨床的研究の有益な手法となりうるものであった.

1992年に当大学に口唇口蓋裂センターが開設されて以来,2006年4月までに600例以上の口唇口蓋裂患者が当センターを受診し,そのうち382例が当教室の鼻咽腔閉鎖機能検査外来を受診した.その内,30例に著明な鼻咽腔閉鎖不全のため咽頭弁形成術が施行された.咽頭弁形成術は高度のいびきや睡眠呼吸障害を来し,最悪,睡眠時の呼吸停止という生命的危機に係わる重大な状況に陥る危険性が否定できない.一方で,小児の場合,高度の口蓋扁桃肥大による睡眠呼吸障害は扁桃摘出術のよい適応であるが,術後,正常児でも開鼻声を来すことがある.咽頭弁形成が施行された症例の中から,特殊症例として,著明な口蓋扁桃肥大を合併していた4症例に対して,口蓋扁桃摘出術を同時に併用して良好な成績を得たが,相反する両手術を併用する場合には,その適応についての十分な検討と,保護者への術前説明に特段の注意を払わなければならないと考える.

Morphological aberration of the Eustachian tube is a significant factor of various middle ear diseases.<BR>Traditionally, cadaveric specimens have been used for studies on the morphology of Eustachian tubes.However, this approach was not too efficient, as samples were limited in number as they were difficult to obtain, and biological conditions were not reflected due to rigor mortis and atrophy during specimen preparation.<BR>We thus decided to use Multi-Slice CT (MSCT) to perform 3-D anatomic measurements of the Eustachiantube. MSCT has benefits of isotropy and high resolution, and it is useful in preparing images of any plane.<BR>Forty-eight adults were studied. For the purpose of measurement, various anatomic indices were carefullyand precisely defined to identify each area on the image. Calculations based on each coordinate value enabledthe measurement of length, diameter and angle of the Eustachian tube of normal adults.<BR>Therefore, measurements of the Eustachian tube, which were traditionally difficult as it is located in the deeppart of the cranium, were simplified in many specimens.<BR>Mean value of total length was 39. 2&plusmn;3. 2 mm, cartilage part length of the tube 30.0&plusmn;2.7mm and bony part9.2&plusmn;1.6mm. Mean values of diameter of tympanic orifice were 5.2&times;3.2mm, and pharyngeal orifice 9.7&times;4.4mm. Mean value of angle between bony part and cartilage part was 160.9-13.6 degrees.<BR>This approach to anatomic measurement is expected to contribute greatly to investigation on various middleear diseases.

われわれは、海水浴中にサーフボードが頸部を打撃したことによる、9歳女児の喉頭の外傷の一例の治療を経験した。初診時、彼女の声帯は声帯の裂傷が原因で左右とも中央で癒着し横隔膜症を来していた。われわれは、直達喉頭鏡を用い声帯の癒着を切離し、声帯の辺縁を縫合してraw surfaceを被覆することにより、低侵襲手術でありながら声帯の再癒着を防ぎ得た。術後から運動に伴う呼吸障害は改善し、嗄声も軽減、十分な大きさの音声を獲得できた。

Using high-resolution isotropic volume data obtained by 0.5mm, 4-row multislice CT, cross-sectional observation of the auditory ossicles is possible from any desired direction without difficulty in high-resolution multiplanar reconstruction (HR-MPR) images, also distortion-free three-dimensional images of the ossicles are generated in three-dimensional CT (3D-CT) images. We measured angles of fifty normal ossicles relative to the reference plane, which has been defined as a plane through the bilateral infraorbital margins to the middle portion of the external auditory canal. Based on the results of angle measurement, four optimal sections of the ossicles for efficient viewing to the ossicular chain were identified. To understand the position of the angle measurement and the four sections, the ossicles and the reference plane were reconstructed in the 3D-CT images.<BR>As the result of observation of the ossicles and the reference plane, the malleus was parallel to the incudal long process and perpendicular to the reference plane. As the results of angle measurement, the mean angle of the tympanic portion of the facial nerve relative to the reference plane in the sagittal plane was found to be 17&deg;, and the mean angle of the stapedial crura relative to the reference plane in the sagittal plane was found to be 6&deg;. The mean angle of the stapes relative to the reference plane in the coronal plane was 44&deg;, and the mean angle of the incudal long process relative to the stapes in the coronal plane was 89&deg;. In 80% of ears, the stapes extended straight from the incudal long process.<BR>Image reconstruction technique for viewing four sections of the ossicles was investigated. Firstly, the image of the malleal head and the incudal short process was identified in the axial plane. Secondly, an image of the malleus along the malleal manubrium was reconstructed in the coronal plane. Thirdly, the image of the incudal long process was seen immediately behind the malleus image. Finally, an image of the stapes was reconstructed in the image of the incudal long process. During sequential reconstruction of the four planes, it was possible to observe the entire auditory ossicular chain from the malleal manubrium attached to the tympanic membrane to the stapedial foot plate embedded in the oval window. This technique is considered to be a useful new imaging technique for observing the ossicles due to its reproducibility.

Twenty-four children with a cleft palate who were evaluated as veropharyngeally incompetent underwent pharyngeal flap construction because of speech therapy failure. Veropharyngeal competence and general health conditions were assessed more than one year after pharyngeal flap construction in 9 of the 24 children. Their veropharyngeal incompetence had completely healed, and they had no sleep apnea, athough they had exhibited mild snoring postoperatively. Their height and body weight development were not disturbed by pharyngeal flap construction.

We demonstrated high-resolution multiplanner reformation (MPR) and 3-dimentional CT (3D-CT) imaging of Eustachian tube (ET) using a 1-mm, 8-row multislice CT scanner.<BR>CT scans were performed in 5 normal adult volunteers during quiet breathing and the Valsalva maneuver.<BR>Bony portion of ET was clearly detected on MPR, however cartilaginous portion of the ET was still elusive during quiet breathing scan.<BR>MPR and 3D-CT images during Valsalva maneuver improved visualization of cartilaginous portion of the ET and surrounding soft tissues including cartilage, muscle and fat.<BR>Imaging of the ET obtained by multislice CT during the Valsalva maneuver can propose further investigation for various middle ear disorders.

44歳男.耳下腺に発生した悪性筋上皮腫で,組織学的に腫瘍細胞は明細胞型と形質細胞型が主体で,充実性胞巣内に著明な扁平上皮化生を伴い,周囲への浸潤傾向が認められた.免疫染色では腫瘍細胞はcytokeratin,S-100蛋白,vimentinに陽性像を呈していた