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亨氏單位（英語：Hounsfield unit，縮寫：HU），為亨氏量表（Hounsfield scale）阻射率的數量尺度單位，命名自X射線電腦斷層掃描的發明人高弗雷·豪斯費爾德（Godfrey Newbold Hounsfield）。亨氏單位常用於X射線電腦斷層掃描，因此又稱為CT值（CT number）。
定義
亨氏單位為其所測量之介質的線性衰減係數的線性映射，其定義將蒸餾水與空氣在標準溫度與標準壓力下的阻射率分別設為0 HU和-1,000 HU。因此，在線性衰減係數介於平均值間的體素中，其亨氏單位為：[1]
其中 與 分別為水與空氣的線性衰減係數。[2]
由於空氣的線性衰減係數趨近於0，一個HU的變化相當於水線性衰減係數0.1%的變化。[2]
原理
由於X射線電腦斷層掃描的功能在於將生物（主要是陸上生物，如人類）的體內結構成像化，因此採納上述標準作為所有介質的參照依據。[2]
人體內各介質的亨氏單位值
亨氏單位僅適用於常見的雙能電腦斷層掃描（dual-energy CT scan），而不適用於錐狀射束電腦斷層掃描（cone beam CT scan）。[3]
| 介質 |
亨氏單位
|
| 空氣
|
−1,000
|
| 脂肪
|
−120至−90[4]
|
| 造影劑電腦斷層掃描下的軟組織
|
+100至+300
|
| 骨骼 |
鬆質骨 |
+300至+400[5]
|
| 密質骨 |
+1,800至+1,900[5]
|
| 頭部外傷 |
前數小時 |
+75至+100[6]
|
| 3日後 |
+65至+85[6]
|
| 10-14日後 |
+35至+40[7]
|
| 其他血液 |
非凝血 |
+13[8]至+50[9]
|
| 凝血 |
+50[10]至+75[8][10]
|
| 胸腔積液 |
漏出液 |
+2至+15 [11]
|
| 滲出液 |
+4至+33[11]
|
| 其他體液 |
乳糜
|
−30[12]
|
| 水
|
0
|
| 尿液
|
−5至+15[4]
|
| 膽汁
|
−5至+15[4]
|
| 腦脊液
|
+15
|
| 膿瘍/膿
|
0[13]至+20[14] 或 +40[14]至+45[13]
|
| 黏液
|
0[15] - 130[16]（超過70HU時進入高衰減）[17][18]
|
| 薄壁組織 |
肺
|
−700至−600[19]
|
| 腎
|
+20至+45[4]
|
| 肝
|
60 ± 6[20]
|
| 淋巴結
|
+10至+20[21]
|
| 肌肉
|
+35至+55[4]
|
| 胸腺
|
+20至+40（兒童）[22]
|
| +20至+120（成人）[22]
|
| 白質
|
+20至+30
|
| 灰質
|
+37至+45
|
| 膽結石 |
膽固醇石 |
+30至+100[23]
|
| 色素性膽結石 |
+90至+120[23]
|
| 異物[24]
|
一般窗戶玻璃 |
+500
|
| 鋁、瀝青、車窗玻璃、玻璃瓶與其他石類 |
+2,100至+2,300
|
| 石灰岩 |
+2,800
|
| 銅 |
+14,000
|
| 銀 |
+17,000
|
| 鋼 |
+20,000
|
| 金、鋼與黃銅 |
+30,000（可測量之上限）
|
| 耳垢 |
<0
|
亨氏單位常用於辨識腫瘤，以腎上腺腺瘤為例，當該腫瘤的阻射率小於10 HU，則其脂肪成分偏高，代表該腫瘤有較大機率為良性腫瘤[25]。
參見
參考資料
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- ^ 2.0 2.1 2.2 DenOtter, Tami; Schubert, Johanna. Hounsfield Unit. 美國國家衛生院. 2020-05-11 [2020-12-20]. （原始内容存档于2021-12-06） （英语）.
- ^ De Vos, W.; Casselman, J.; Swennen, G.R.J. Cone-beam computerized tomography (CBCT) imaging of the oral and maxillofacial region: A systematic review of the literature. International Journal of Oral and Maxillofacial Surgery. 2009-06, 38 (6): 609–625. PMID 19464146. doi:10.1016/j.ijom.2009.02.028.
- ^ 4.0 4.1 4.2 4.3 4.4 Page 83 in: Herbert Lepor. Prostatic Diseases. W.B. Saunders Company. 2000. ISBN 9780721674162.
- ^ 5.0 5.1 Birur, NPraveen; Patrick, Sanjana; Gurushanth, Keerthi; Raghavan, AShubhasini; Gurudath, Shubha. Comparison of gray values of cone-beam computed tomography with hounsfield units of multislice computed tomography: An in vitro study. Indian Journal of Dental Research. 2017年, 28 (1): 66–70. ISSN 0970-9290. PMID 28393820. doi:10.4103/ijdr.IJDR_415_16.
- ^ 6.0 6.1 Fig 3 in: Rao, Murali Gundu. Dating of Early Subdural Haematoma: A Correlative Clinico-Radiological Study. Journal of Clinical and Diagnostic Research. 2016, 10 (4): HC01–5. ISSN 2249-782X. PMC 4866129
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- ^ Dr Rohit Sharma; A.Prof Frank Gaillard. Subdural haemorrhage. Radiopaedia. [2018-08-14]. （原始内容存档于2011-03-23）.
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- ^ page 20.17 in: F W Wright. Radiology of the Chest and Related Conditions. CRC Press. 2001. ISBN 9780415281416.
- ^ 10.0 10.1 page 17 in: Dr. Avital Fast; Dorith Goldsher. Navigating the Adult Spine: Bridging Clinical Practice and Neuroradiology. Demos Medical Publishing. 2006. ISBN 9781934559741.
- ^ 11.0 11.1 Cullu, Nesat; Kalemci, Serdar; Karakas, Omer; Eser, Irfan; Yalcin, Funda; Boyaci, Fatma Nurefsan; Karakas, Ekrem. Efficacy of CT in diagnosis of transudates and exudates in patients with pleural effusion. Diagnostic and Interventional Radiology. 2013, 20 (2): 116–20. ISSN 1305-3825. PMC 4463296 . PMID 24100060. doi:10.5152/dir.2013.13066.
- ^ Page 342 in: Luca Saba; Jasjit S. Suri. Multi-Detector CT Imaging: Principles, Head, Neck, and Vascular Systems, Volume 1. CRC Press. 2013. ISBN 9781439893845.
- ^ 13.0 13.1 P. Sanchez de Medina Alba; C. Santos Montón; N. Calvo; K. El Karzazi; T. González de la Huebra Labrador; R. Corrales; N. Alegre Borge; Salamanca/ES. Liver abscesses: where do they come from?A review of the main types of liver abscesses and the correlation between their causes and the radiologic findings. ECR 2014. 2014 [2020-12-17]. doi:10.1594/ecr2014/C-1927. （原始内容存档于2019-01-12）.
- ^ 14.0 14.1 Sasaki, Toru; Miyata, Rie; Hatai, Yoshiho; Makita, Kohzoh; Tsunoda, Koichi. Hounsfield unit values of retropharyngeal abscess-like lesions seen in Kawasaki disease. Acta Oto-Laryngologica. 2014, 134 (4): 437–440. ISSN 0001-6489. PMID 24512428. doi:10.3109/00016489.2013.878475.
- ^ K SAGGAR, A AHLUWALIA; P SANDHU, V KALIA. Mucocoele Of The Appendix (PDF). Ind J Radiol Imag. 2006, 16 (2). [失效連結]
- ^ Gaeta, Michele; Vinci, Sergio; Minutoli, Fabio; Mazziotti, Silvio; Ascenti, Giorgio; Salamone, Ignazio; Lamberto, Salvatore; Blandino, Alfredo. CT and MRI findings of mucin-containing tumors and pseudotumors of the thorax: pictorial review. European Radiology. 2001, 12 (1): 181–189. ISSN 0938-7994. PMID 11868096. doi:10.1007/s003300100934.
- ^ Subash S Phuyal; Mandeep Kumar MK Garg; Ritesh R Agarwal; Pankaj P Gupta; Arunaloke A Chakrabarti; Manavjit Singh MS Sandhu; Niranjan N Khandelwal. High-Attenuation Mucus Impaction in Patients With Allergic Bronchopulmonary Aspergillosis: Objective Criteria on High-Resolution Computed Tomography and Correlation With Serologic Parameters. Current Problems in Diagnostic Radiology. 2015-09-02.
- ^ Agarwal, Ritesh; Sehgal, Inderpaul Singh; Dhooria, Sahajal; Aggarwal, Ashutosh. Radiologic Criteria for the Diagnosis of High-Attenuation Mucus in Allergic Bronchopulmonary Aspergillosis. Chest. 2016, 149 (4): 1109–1110. ISSN 0012-3692. PMID 27055707. doi:10.1016/j.chest.2015.12.043.
- ^ Page 379 in: Ella A. Kazerooni; Barry H. Gross. Cardiopulmonary Imaging 4. Lippincott Williams & Wilkins. 2004. ISBN 9780781736558.
- ^ page 210 in: Erwin Kuntz; Hans-Dieter Kuntz. Hepatology, Principles and Practice: History, Morphology, Biochemistry, Diagnostics, Clinic, Therapy. Springer Science & Business Media. 2006. ISBN 9783540289777.
- ^ Page 58 in: G. Maatman. High-Resolution Computed Tomography of the Paranasal Sinuses and Pharynx and Related Regions: Impact of CT identification on diagnosis and patient management. Volume 12 of Series in Radiology. Springer Science & Business Media. 2012. ISBN 9789400942776.
- ^ 22.0 22.1 Page 488 （页面存档备份，存于互联网档案馆） in: Jean-Claude Givel; Marco Merlini; David B. Clarke; Michael Dusmet. Surgery of the Thymus: Pathology, Associated Disorders and Surgical Technique. Springer Science & Business Media. 2012. ISBN 9783642710766.
- ^ 23.0 23.1 Rambow A, Staritz M, Wosiewitz U, Mildenburger P, Thelen M, Meyer zum Büschenfelde KH. Analysis of radiolucent gallstones by computed tomography for in vivo estimation of stone components. Eur J Clin Invest. 1990, 20 (4): 475–8. PMID 2121509. doi:10.1111/j.1365-2362.1990.tb01887.x.
- ^ Bolliger, Stephan A.; Oesterhelweg, Lars; Spendlove, Danny; Ross, Steffen; Thali, Michael J. Is Differentiation of Frequently Encountered Foreign Bodies in Corpses Possible by Hounsfield Density Measurement?. Journal of Forensic Sciences. 2009, 54 (5): 1119–1122. ISSN 0022-1198. PMID 19627414. doi:10.1111/j.1556-4029.2009.01100.x.
- ^ Perry J Horwich. Adrenal Adenoma Imaging. 2011-04-21 [2020-12-19] （英语）.
參考書籍
- Feeman, Timothy G. The Mathematics of Medical Imaging: A Beginner's Guide. Springer Undergraduate Texts in Mathematics and Technology. Springer. 2010. ISBN 978-0387927114.
外部連結
Information related to 亨氏單位 |
