1071207-超音波原理與操作技巧

超音波原理與操作技巧 高雄醫學大學 內科部 肝膽胰內科 高雄市立大同醫院 內科 謝明彥

超音波檢查迅速上手秘訣 了解超音波基本原理 對檢查部位之解剖學有基本認識 要有立體空間想像力 熟悉儀器常用控制鍵之操作方式 先找正常人做練習，熟悉檢查部位之所謂正常影像，祇有 熟悉何謂正常才有可能看出所謂不正常。 • 超音波檢查是相當operator-dependent的，不要有先入為 主的想法，否則會愈看愈像、心想事成，真的有異常的地 方不會因你探頭切入角度不同就看不到也不會跑掉，等一 下再回頭檢查看是否仍在，記得要照你常規檢查步驟依序 檢查完以防因一直看第一個異常而漏掉其他異常

• • • • •

常用字 echogenicity (misspelled as echogenecity)： 音波回音性 echoic：回音性的 hyperechoic： 高音波回音性 hypoechoic： 低音波回音性 isoechoic： 等超音波回音性 anechoic (nonechoic, unechoic)：無回聲的；無反響的如液 體 reverberation (交混回響，混響，餘響) echogenicity: 如 bowel gas造成之dirty shadowing acoustic shadow：音波被如stone、rib等鈣化物整個阻擋導 致下方無法顯像 posterior enhancement: 如cyst下方音波加強情形

Equipments : B-mode real-time ultrasound : Duplex-pulsed Doppler ultrasound : Continuous wave Doppler ultrasound : Color Doppler ultrasound : Power Doppler ultrasound : Contrast-enhanced color Doppler and power Doppler ultrasound : 3D ultrasound

Transducer

Target

•Doppler ultrasound成像原理和一般B-mode ultrasound不同 •B-mode ultrasound成像原理是將反射波直接回收成像，

由於音波在組織中之傳導速度為已知： time X 探測波

time 2X target

回收反射波轉成影像

•Doppler ultrasound成像原理是將反射波頻率相對於探測波頻 率之改變(relative change in the returned ultrasound frequency)轉成我們可判讀之資料

Attenuation of ultrasonic intensity in body (1) Acoustic absorption : strong in all biological tissue and is mainly due to the transformation of ultrasonic energy into thermal energy : At the frequencies used in diagnostics Acoustic absorption is : very low in fluid media : intermediate in soft tissue : very high in bone and gas

Attenuation of ultrasonic intensity in body (1) absorption (2) divergence of the beam • scattering and reflection by small discontinuities and mode conversion .. The energy is divided into vibrations in several different directions, each having a different velocity of propagation.

• The acoustic intensity decreases as the inverse of the square of the distance. This attenuation is known as attenuation due to divergence of the beam, or “diffraction loss”.

Propagation across interfaces : Normal incidence.. For incidence of a wave over a theoretically plane surface, along the direction of the perpendicular to the surface.

B-mode US 垂直target時 影像最清晰

Medium 1 Medium 2

: Oblique incidence.. The wave is deflected if the velocity in medium 1 is different from velocity in medium 2. 這就是為什麼剛開始站在岸 邊用魚叉叉魚時常摃龜的原 因！

Medium 1

Medium 2

Choice of frequency 探頭頻率越高，影像越清晰但所能探測深度越淺！ : Abdomen.. 1.5-3.75 MHz : Breast and thyroid.. 5-10 MHz : Heart.. 2-3.75 MHz : Newborns.. 5-7 MHz : Brain.. 1-2.25 MHz : Eye.. 10 MHz and over

Focussing of ultrasonic beam : In the near zone the beam is approximately cylindrical; in the far zone it is conical and diverges. : It is possible to focus the ultrasonic beam so that the beam is formed at a slightly shorter distance from the transmitter face, compared with a non-focussed beam and with less divergence within a certain range of distances. : The width of such a beam will then however increase with respect to the nonfocussed beam, but at greater distances which are no longer useful for echographic examination.

近探頭

Focus

遠離探頭 以下就糊掉了

一格一公分

Gain control • Gain: 【無線電】增益，放大，增量 • 調整gain之目的在使影像能更清楚呈現與最小背景干擾 • B-mode: 將gain強度調愈高，螢幕影像愈亮，反之愈暗 • Doppler US: : gain強度調愈高，Doppler signals表現愈明顯 : 調太高會產生所謂mirroring or crosstalk signals : 調太低會讓Doppler signals無法正確呈現

Gain adjustment: B mode real-time US

Gain adjustment according to depth : B-mode real-time US

probe和skin中間不要有空隙，否則會造 成影像不清晰，只要兩者藉由gel能完全 接觸就ok，不必用probe拼命壓，否則 你會很累病人也會受不了！

Probe Gel Body

Probe

Probe Gel

Gel Body X

Probe Gel

Body X

Body X

Abdominal ultrasonography : 主用於偵測含大量液體或實質器官之病變 : 受限於氣體﹝腸氣﹞、皮下脂肪及骨骼之 干擾 : 胃腸道之病變，除非呈現非常典型之超音 波表徵，否則並不建議以超音波檢查結果 來確立診斷 : 發達之肌肉也易造成檢查時之干擾

Abdominal ultrasonography : 檢查時病人最好已禁食至少 6 小時以上， 否則膽囊之病變可能因食物造成之膽囊收 縮而遺漏。 : 如果要進一步以 Doppler US 偵測器官之 血流變化，檢查時病人禁食至少 8 小時是 必須的，同時在系列追蹤病人器官之血流 變化時，維持固定之檢查姿勢也是必要 的。

Abdominal ultrasonography : 充分漲尿是檢查骨盆器官時所必須的。 : 檢查時病人之姿勢要做必要之改變，從各種 角度觀察，如有必要可用探頭從體表輕壓懷 疑之區域，以探試能否引起局部疼痛或造 成該區域之氣體或液體之移動。

檢查時患者之姿勢須依檢查目的而定 應依欲檢查目的讓受檢者做其可接受之必要變換姿勢以減少 檢查死角 : 一般腹部超音波建議檢查順序 (a) 平躺(liver surface and edge)、右側躺(左腎與脾臟)、平 躺(肝、膽道系統、膽囊、胰臟、腹部血管如腹主動脈及下腔 靜脈)、及左側躺(右腎、肝、膽道系統、膽囊、胰臟、腹部 血管)、平躺 (b) 平躺、左側躺、平躺、右側躺、平躺 : 針對腎臟及腎上腺採平躺、右側躺、左側躺及俯臥 : 胃腸採平躺、右側躺及左側躺

平躺 Liver surface: smooth、irregular or nodulation ，看白線下緣 Liver edge: sharp、dull or round

右側躺 left kidney and spleen (normal A x B < 20 cm2)

右側躺 以spleen影像顆粒粗細做標準 check liver parenchyma是否 coarse 兩者均要以intercostal view掃描， 音波和target要盡量垂直 比較兩者顆粒粗細時要以同深 度來比較，深度不同影像顆粒 粗細會改變

左側躺 Right kidney，GB (wall 0.3 cm after NPO for at least 6 hours) 比較renal cortex 和liver parenchyma之echogenicity是否有bright liver

左側躺 CBD (<= 0.8 cm after NPO，may be dilated after cholecystectomy，要量內徑， 不要將wall也量進去)，portal vein CBD

IVC

portal main trunk

左側躺 CBD, hepatic artery, portal vein

hepatic artery

LT 5 6

RHV

MHV 8

3

U

4

LV

T IVC

7

T: transverse portion of left portal vein; U: umbilical portion of left portal vein; LT: ligamentum teres; LV: ligamentum venosum

1

2

左側躺 /平躺

Liver 8 segments

ĺšłčşş

pancreas

SV

B

N H

T

PMT

SMA A

U

V

Pancreatic duct: body <0.22-0.25 cm A: aorta; SMA: superior mesenteric artery ; SV: splenic vein; PMT: portal main trunk; U: uncinate portion; H: head; N: neck; B: body; T: tail; V: vertebra

平躺 pancreas pancreatic duct

Ligamentum teres

Floating right kidney

Artifact similar to hepatic nodule at longitudinal scanning (arrow) 轉方向scanning就變成hypoechoic patch (arrow head) 注意hypoechoic patch 前有個 hyperechoic line (portal triad之 connective tissue)(curved arrow) ， 此line之干擾導致下面出現 hypoechoic patch

Abdominal ultrasound cross sectional anatomy

Liver 的靜脈系統比較特別: 有分 肝靜脈 hepatic vein system & 肝門靜脈 portal vein system。 看圖可以發現，Liver被3條 hepatic vein分成4份，而 其再根據portal vein 分支我們把它分成8塊。 • 肝門靜脈 (Portal vein system): 超音波下管壁厚亮。 由splenic vein & SMV (上腸繫膜靜脈 superior mesenteric vein) 會合而成， 雖說是靜脈系統，但它的方向是注入肝臟。 • 肝靜脈 (hepatic vein system) 超音波下管壁較薄。它的方向則是 離開肝臟，注入IVC。

http://pocusacademy.com/2016/03/24/sonoanatomy-liverportal-vein-hepatic-vein/ 作者：許哲彰

http://pocusacademy.com/2016/03/24/sonoanatomy-liverportal-vein-hepatic-vein/ 作者：許哲彰

http://pocusacademy.com/2016/03/24/sonoan atomy-liver-portal-vein-hepatic-vein/ 作者：許哲彰

LT 5 6

RHV

MHV 8

3

U

4

LV

T IVC

7

T: transverse portion of left portal vein; U: umbilical portion of left portal vein; LT: ligamentum teres; LV: ligamentum venosum

1

2

http://pocusacademy.com/201 6/03/24/sonoanatomy-liverportal-vein-hepatic-vein/ 作者：許哲彰

LT 5 6

RHV

MHV 8

3

U

4

LV

T IVC

7

T: transverse portion of left portal vein; U: umbilical portion of left portal vein; LT: ligamentum teres; LV: ligamentum venosum

1

2

http://pocusacademy.com/2016/03/24/sonoanatomy-liverportal-vein-hepatic-vein/ 作者：許哲彰

Biliary system （綠色）從肝發出匯合後加上cystic duct 形成 CBD (common bile duct) ; CBD 會和 pancreatic duct （橘色）會合後開口於十二指腸，黃色的是胰臟 pancreas。 CBD 後方會有一條血管 portal vein（藍），也是我們看 CBD的一個landmark.

Portal vein前方除了CBD外還有一管狀結構，那是另一條 血管 hepatic artery (源自celiac trunk) 。

Gallbladder (GB) • Gallbladder 為儲存膽汁之器官，位在肝臟 下緣，而肝臟位置跨右胸下緣至右上腹。所 以我們可以用兩個方向去尋找GB。 • Subcostal: 鎖骨中線和肋骨下緣交界處 • Intercostal: 劍突下方橫移至右腋前線位置 的肋間處

• GB 是善變的： – 1.它並不是固定不動的 – 2.它可以是很多不同方向的 – 3.它可以是不同大小的（進食後膽汁排出則縮小） 所 以我們要在這兩個位置運用tilting, rocking…去“找 ”GB，以及做整體完整的掃描，一般習慣呈現出GB longitudinal scan的影像如下，可分三部分。

• 病患若禁食時間足夠，則可見脹大的GB，成水滴 狀。看見GB後記得要做一下tilting 把整體看過一 遍。正常的膽囊壁，厚度不超過3mm。

Common bile duct (CBD) • 膽道系統匯聚起來，最後的終點就是CBD，他和 pancreatic duct 會合後最後注入十二指腸。有時 候病患上腹痛痛到背後，有可能是CBD內有 stone卡住，但是我們要怎麼去看CBD呢？ • 找到portal vein當作landmark，前方有一和其並 排的管狀結構即可能 是CBD。 • 從pancreas 下手，找到pancreas後，CBD會被 包在 pancreas head位置，有時還可見 pancreatic duct注入CBD。

• GB wall 厚度 < 3mm • Cystic duct 彎彎曲曲又細小，從GB neck 去找，會連接到CBD • CBD 在portal vein前面，寬度 < 7mm • 別把hepatic artery 誤認CBD

http://pocusacademy.com/2016/03/24/sonoanatomy-liverportal-vein-hepatic-vein/ 作者：許哲彰

Pancreas ，splenic vein • Splenic vein is the key / 它躺在Aorta & IVC 上 & 蝌蚪狀。 • Pancreas 躺在splenic vein上 / tail 不容易看到 （spleen & left kidney之間)。 • Pancreas head大約2cm/body 約1cm/tail 約 2cm) 但是range很大 • SMV 和 Splenic vein 會合成portal vein。 • Portal vein是CBD的landmark之一 / Pancreas 也可以是CBD的landmark之一

http://pocusacademy.com/2016/03/24/sono anatomy-liver-portal-vein-hepatic-vein/ 作者：許哲彰

http://pocusacademy.com/2016/03/24/sonoanatomy-liverportal-vein-hepatic-vein/ 作者：許哲彰

http://pocusacademy.com/2016/03/24/sonoanatomy-liverportal-vein-hepatic-vein/ 作者：許哲彰

http://pocusacademy.com/2016/03/24/sonoanatomy-liverportal-vein-hepatic-vein/ 作者：許哲彰

http://pocusacademy.com/2016/03/24/sonoanatomy-liverportal-vein-hepatic-vein/ 作者：許哲彰

S2

S3 S6

S5

S5

S4a S8

S7

S8

S7 RHV

MHV

S5 S8 S6 S7

S7

S4b S5

S4a

R’t Ant

R’t post

S4

http://pocusacademy.com/2016/03/ 24/sonoanatomy-liver-portal-veinhepatic-vein/ 作者：許哲彰

S3 S3

S4 S4 S2 S1

S2

Liver diffuse parenchyma diseases

腹部超音波異常影像介紹 高雄醫學大學 內科部 肝膽胰內科 高雄市立大同醫院 內科 謝明彥

Acute hepatitis : 肝臟之檢查通常是正常，但膽囊壁在肝炎發作之高峰期常有增厚之現象。 : ascites 及/或 pleural effusion..併發症之病人

Chronic hepatitis 及 Liver cirrhosis : surface.. smooth, irregular, nodulation : edge.. sharp, dull, round : parenchyma.. coarse : collateral circulation of portal system : splenomegaly

splenic size

surface and edge

umbilical portion

comparison of parenchyma

Patent paraumbilical vein

LC ascites

collateral circulation

dilated LGV

collateral circulation

Fatty liver : bright liver : blurred vessel : posterior attenuation

Simple cyst : unechoic : no blood flow signal

Hepatic tumor : low periphery of the tumor .. malignancy * bull eye sign, target sign .. vascular invasion : high periphery of the tumor .. hemangioma Vessel displacement can be seen in both malignant and benign tumors.

hemangioma

abscess

low periphery

hypoechoic HCC

Portal vein thrombosis

Portal vein thrombosis

Acute cholecystitis : thickening of gall-bladder wall ( > 0.3 cm), may loss definite three layers of the gall-bladder wall : may presence of low-level echoes in the most dependent portion of the gall-bladder ( pus or sludge) : US Murphyâ&#x20AC;&#x2122;s sign; with or without stone; fluid collection around gallbladder Chronic cholecystitis : thickening of gall-bladder wall; usually with stone; contracted gallbladder Porcelain gall-bladder : strong acoustic shadow in gall- bladder fossa Emphysematous cholecystitis : gas within gall-bladder

Biliary tract infection : 無法由超音波正確診斷或排除, 有擴張之膽管或膽管結石並不代表有 biliary tract infection Biliary tract stone : acoustic shadow; IHD stone.. usually linear type, along with portal vein : with or without dilatation of bile duct : stone in distal common bile duct.. 因腸氣之干擾故不易掃瞄出 Pneumobilia : gas within bile duct; movable Hemobilia : echogenic substance (blood clot) within bile duct, change its echo pattern and shape in the short time period : D.D. with malignant emboli

Gall-bladder stone

Pneumobili a

Gall-bladder stone Meniscus sign

gall-bladder polyp : < 1 cm.. usually observation : > 2 cm.. operation

Cometâ&#x20AC;&#x2122;s tail sign

Cometâ&#x20AC;&#x2122;s tail sign of gallbladder: adenomyomatosis or polyp

polyp

gall-bladder tumor: mass, nodule or diffuse thickening of wall

left IHD

CBD

transverse portion of PV adenomyomatosis

Acute pancreatitis : may be normal in US imaging : hypoechoic and enlarged pancreas ( diffuse or local ) : local fluid collection around pancreas in more severe case : with or without CBD and/or pancreatic duct dilatation and/or stone Chronic pancreatitis : with or without pancreatic duct dilatation and/or stone : with or without enlarged pancreatic head : 由超音波無法直接診斷 Acute / Chronic pancreatitis，有 pancreatic duct dilatation及stone 也祇能強烈懷疑此診斷

Pancreatic duct: body 0.22-0.25 cm A: aorta SMA: superior mesenteric artery SV: splenic vein PMT: portal main trunk U: uncinate portion; H: head; N: neck; B: body; T: tail

dilated pancreatic duct with stones

V: vertebra N

PMT

B

SV

H T

U

A V

SMA

Dilated pancreatic duct

normal kidney

hydronephrosis

renal cyst

right adrenal tumor

accessory spleen

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