【正文】 R(ratio of contrast/noise) in patients before and after chemothrapy, contrasting to materials in clinic and pathology. Materials and methods Thirtyeight patients, with acute leukemia were examined. Twentyfive patients served as remission group. As control group ,35 healthy volunteers were performed MR examination with identical methods. Serial MR studies include observation of MRI character and measurement of T1 value and CNR in all patients. Result Of all 38 cases of acute leukemia at the time of diagnosis pare with control group: Hypointense signal in T1WI by welldistribute were found in lumbosacral vertebral, iliac, and femur approaching. Isointense signal in T2WI was found in all cases we done. The signal intensity in T1WI tended to normal in all 25 remission cases of acute leukemia. Isointense signal also found in T2WI in remission cases. The difference of T1 value in lumber, CNR in lumber/subcutaneous fat and femur/subcutaneous fat, B% in blood and marrow were significant (P) among groups of diagnosis and control, diagnosis and remission。急性白血病骨髓MRI定性和定量診斷價值摘要 目的：通過觀察急性白血病治療前后骨髓的MRI表現(xiàn)和T1及對比度噪聲比（CNR）的測定，對照臨床、病理資料，探討急性白血病骨髓MRI定性和定量診斷價值。結論：急性白血病的ＭＲＩ檢查為一種無創(chuàng)性方法，MRI表現(xiàn)具有一定的特征性，在估計病情的嚴重程度及治療效果的評價簡便實用，為避免多次重復骨髓穿刺檢查以及全面觀察急性白血病骨髓浸潤范圍和程度有著重要的臨床意義。本研究旨在結合本地的病例特點，采用大病例組，探討急性淋巴細胞性白血?。ˋLL）和急性髓細胞性白血?。ˋML）的MRI表現(xiàn)，并與臨床、病理聯(lián)系，系統(tǒng)而深入進行定性和定量的研究，以期使MRI成為診斷本病和觀察其療效的一種重要手段。層厚5mm，層距1mm，矩陣180256。評價外周血B%、骨髓B%、腰椎T1值、腰椎/皮下脂肪CNR之間的線性相關統(tǒng)計。②化療緩解組25例：所有椎體、髂骨、股骨頭、股骨大轉子及骨干均表現(xiàn)為不同程度的信號增高，達完全緩解者（21例）比部分緩解者（4例）更接近相應的正常骨髓信號。二、急性白血病定量測定 急性白血病治療前組、化療緩解組和正常對照組的外周血B%、骨髓B%、腰椎T1值、腰椎/皮下脂肪CNR、股骨骨髓/皮下脂肪CNR的測定結果及比較分析見表1。 177。 急性白血病治療前組骨髓B%與腰椎T1值、骨髓B%與腰椎/皮下脂肪CNR、血B%與腰椎T1值、血B%與腰/皮脂CNR、腰椎T1值與腰椎/皮下脂肪CNR的相關性分析，見表2。,不同性別腰椎T1值的差異無顯著性（P）。T2WI像上，紅黃骨髓信號強度相差不大。白血病細胞可呈片狀、團塊狀或彌散浸潤，則可造成骨髓MRI信號不均勻或均勻降低。）（P）。 %），外周血B%也大于25%（177。腰椎T1值與腰椎/皮下脂肪CNR呈直線相關（P）。15 /