before mid-term Flashcards
Atlantoaxial instability - flexion
C1, C2位移太大（移動前後的角度差太多了），超出正常頭部移動距離變化的範疇，推測C1, C2結構不太穩定。
Atlantoaxial instability: distance between c1 and c2 too short
which lesion causes actue paralysis?
從本案例可知，骨刺和filling defect（有可能直接導致癱瘓）區域相聚蠻遠的，也就是說骨刺並不會直接導致急性癱瘓
PS Spondylosis deformans：
- 會在脊椎骨和脊椎骨中間增生贅骨（vertebral osteophytes）
- 也會有骨刺(spurs or complete boney brideges)增生，因為是往腹側或側邊長，
- 大部分不會有顯著臨床症狀（因為沒壓迫到neural canal），也就是說骨刺不會是讓他站不起來或急性癱瘓的原因，頂多在影像上出顯著變化，回去吃止痛藥就好
.Which statement is incorrect?
a. High contrast is related to having very few shades on a film.
b. Compared to fluid, bone has higher photoelectric effect. When X-rays strike bone tissue, there are more X-rays pass through and expose to the film, result in the higher radiopacity.
c. One determining factor of high contrast is a result of low KvP.
d. High-energy X-rays can change the photoelectric effect of body parts, therefore decrease the contrast between tissues of various types.
b. Compared to fluid, bone has higher photoelectric effect. When X-rays strike bone tissue, there are more X-rays pass through and expose to the film, result in the higher radiopacity.
Which statement is incorrect?
a. Improper tube centering has effect on shape distortion.
b. The area of primary interest should be placed close to the X-ray tube to avoid distortion.
c. The purpose of contrast on a radiographic film is to see different structures within the radiograph.
d. Two projections 90 degrees to each other are the general rule of choosing projections when taking radiographs.
b. The area of primary interest should be placed close to the X-ray tube to avoid distortion.
Which statement is incorrect?
a. The charge of the cathode side of the X-ray tube is negative.
b. mA is applied to the cathode to produce electrons.
c. By increasing mA, the electrons are accelerated to higher velocities, therefore producing high-energy X-rays.
d. X-ray beam collimation for radiography is important for patient dose and imaging quality.
c. By increasing mA, the electrons are accelerated to higher velocities, therefore producing high-energy X-rays.
CRT>2sec 所代表的臨床意義
- compromised circulation due to cold, shock, cardiovascular disease, anemia. 循環問題、貧血、休克
正常狗貓呼吸、心跳 、體溫的參考值範圍
Dog puppy__Cat
呼吸 10-30/min 15-35/min 20-40/min
心跳 60-120/min 150-220/min 120-180/min
體溫 38.0-39.0℃ 37-38℃ 38.5-39.0℃
7 color of mucous membrane 所代表的臨床意義與可能的原因
how to increase constrast in X-ray?
what kinds of tissue suitable for a high contrast and low contrast respectively?
Decreasing kVp can increases the contrast
但同時，整體都會變得更黑，這時候可以降低mAs
- 高對比度的組織
- Ex. 肺臟
- 胸腔：5種物質有4種（空氣、脂肪、軟組織、骨頭），本來對比度就大，因此要降低對比度才能有更好的成像
- 方法：高kVp+低mAs
- 高kVp：X光能量增加->吸收變少->穿透變多->對比變小
- 低mAs：時間短->減少運動而造成片子的模糊程度（因為呼吸時胸腔會運動）
- Ex. 肺臟
- 低對比度的組織
- Ex. 腹腔
- 腹腔：幾乎都是軟組織和少量空氣，本來對比度就小，因此要增加對比度才能有更好的成像
- 方法：低kVP+高mAs
- 高mAs：吸收到一定程度->對比度增加
- Ex. 腹腔
window：center & width為什麼？
不同組織需要的window有什麼不一樣
定義：
- Window center (WC)：window的中心，例如想看脂肪的會就會訂-100為WC
- Window width (WW) ：window的範圍，越寬可以同時判讀越多種組織；越窄則可以越精細地呈現組織細節 (tissue contrast)
舉例：同一張CT圖在不同window下可以凸顯不同的細節
- Bone window: 凸顯骨頭，觀察皮質骨cortical bone厚薄（白）與骨髓（骨小梁混合脂肪，CT number稍低），因此需要看的window稍大（骨頭＆脂肪）
- Soft tissue window：凸顯肌群、脂肪, so the WW is small
2 types of signal intensity of MRI
- *T1-Weighted T2-Weighted**
- *脂肪Fat** 偏白（訊號強hyperintensity） 偏黑 (intermediate intensity)
- *水Fluid** 偏黑 (hypointensity) 偏白（訊號強hyperintensity）
- lesser curvature
- greater curvature
- cecum
- transverse colon
- cecum
- left kidney
- ascending colon
left kidney
intussuception
coiled spring (enema
enlarged spleen
enlarged liver
(rib突出太多了
enlarged liver
PS this is a lymphosarcoma case
Rt. kidney
