20.電腦斷層檢查中發現某一物質在120kVp之線性衰減係數為0.132 cm-1，它可能是何種物質？（水在120kVp之 線性衰減係數為0.180 cm-1）
(A)脂肪
(B)空氣
(C)血液
(D)骨骼

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統計： A(2189), B(190), C(330), D(75), E(0) #2183154

詳解 (共 3 筆)

#3772163
(A)脂肪：-100 ☞ 最相近 ...

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#3777789


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#4071820

[ ( μ.tissue – μ.water ) / μ.water ] * 1000

[ ( 0.132 - 0.18 ) / 0.18 ] * 1000 = -266 (最接近脂肪HU -120 ~ -90)

SubstanceHU
Air−1000
Fat−120 to −90[2]
Soft tissue on contrast CT+100 to +300
BoneCancellous+300 to +400[3]
Cortical+1800 to +1900[3]
Subdural hematomaFirst hours+75 to +100[4]
After 3 days+65 to +85[4]
After 10-14 days+35 to +40[5]
Other bloodUnclotted+13[6] to +50[7]
Clotted+50[8] to +75[6][8]
Pleural effusionTransudate+2 to +15 [9]
Exudate+4 to +33[9]
Other fluidsChyle−30[10]
Water0
Urine-5 to +15[2]
Bile-5 to +15[2]
CSF+15
Abscess / Pus0[11] or +20[12], to +40[12] or +45[11]
Mucus0[13] - 130[14] ("high attenuating" at over 70 HU)[15][16]
ParenchymaLung-700 to −600[17]
Kidney+20 to +45[2]
Liver60 ± 6[18]
Lymph nodes+10 to +20[19]
Muscle+35 to +55[2]
Thymus
  • +20 to +40 in children[20]
  • +20 to +120 in adolescents[20]
White matter+20 to +30
Grey matter+37 to +45
GallstoneCholesterol stone+30 to +100[21]
Bilirubin stone+90 to +120[21]
Foreign body[22]Windowpane glass+500
Aluminum, tarmac, car window glass, bottle glass, and other rocks+2,100 to +2,300
Limestone+2,800
Copper+14,000
Silver+17,000
Steel+20,000
Gold, steel, and brass+30,000 (upper measurable limit)
Earwax<0

r.f. https://en.wikipedia.org/wiki/Hounsfield_scale#cite_note-Lepor2000-2 

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私人筆記 (共 2 筆)

私人筆記#3963576
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(0.132-0.18)/0.18*10...
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私人筆記#6448185
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