【雙語(yǔ)病例】Autosomaldominant polycystic kidney disease 常染色體顯性遺傳多囊腎來(lái)源：雙語(yǔ)學(xué)影像；病例選自《Mayo Clinic Body MRI Case Review》 History47-year-old woman with agenetic disorder
Fig 2.1.1 Coronal SSFSE 
Fig 2.1.2 axial T1WI FSE 
Fig 2.1.3 Axial fat-saturated 2D SSFP images 
Imaging FindingsCoronal SSFSE (Figure 2.1.1) and axial T1-weighted FSE (Figure 2.1.2) images demonstrate in numerable variable-sized cysts throughout the liver and kidneys. Some cysts show high T1-signal intensity. Axial fat-saturated 2D SSFP images (Figure 2.1.3) show similar findings and demonstrate patency of the intrahepatic IVC. 冠狀位SS FSE序列和橫斷位T1WI FSE序列示肝臟及腎臟內(nèi)布滿大量大小不等的囊性病灶,，部分囊于T1WI呈高信號(hào),。橫斷位脂肪抑制2D SSFP圖像示下腔靜脈肝內(nèi)段通暢。
Diagnosis Autosomaldominant polycystic kidney disease 常染色體顯性遺傳多囊腎
CommentADPKD is a relatively common hereditary disorder with a prevalenceestimated between 1 per 300 to 1 per 1,000 persons. It accounts for approximately 8% to 10% of patients with end-stage renal disease in theUnited Statesand Europe.Two separate genetic mutations are responsible for most cases of ADPKD: the PKD1 geneon chromosome 16 (80%-85%) and the PKD2gene on chromosome 4(15%-20%). Renal function is generally well preserved until the fourth through sixth decades of life, when a rapid decline in renal function occurs; chronic renal failure is present in about 50% of patients by age 60 years. More than 90% of ADPKD patients also have hepatic cysts,although often with less severe hepatic involvement. Unlike in the kidneys, it is uncommon for cystic disease to affect hepatic function. Although renal cysts are virtually always present in ADPKD (hence the name),there are a few reports of patients with isolated hepatic cystic disease. 常染色體顯性遺傳多囊腎（ADPKD）是一種常見(jiàn)的遺傳病,，發(fā)病率約1/300~1/1000,。在美國(guó)和歐洲，ADPKD約占全部終末期腎病的8%-10%,。絕大多數(shù)病變與兩個(gè)基因突變有關(guān)：16號(hào)染色體（約占80%-85%）和4號(hào)染色體（約占15%-20%）,。大部分患者腎功能早期正常，約40-60歲時(shí)迅速下降,，60歲的患者中約有一半表現(xiàn)為慢性腎功能衰竭,。超過(guò)90%的ADPKD患者伴有肝臟囊腫，但一般肝臟受累并不嚴(yán)重,，與腎臟相比,，肝臟的囊腫很少影響肝功能。盡管ADPKD經(jīng)常表現(xiàn)為腎臟囊腫,，但也有少量報(bào)道僅有肝囊腫發(fā)生,。
Although the vast majority of examinations performed on PKD patients at our institution areresearch studies, occasionally we are asked to scan a patient for an actual clinical indication that generally falls into 1 of 3 categories: screening relatives of patients with known PKD (this is the“Rolls Royce” of screening examinations—US is a lot cheaper but is less aesthetically pleasing); looking for complications of PKD, including hemorrhagic or infected cysts, to explain new onset of pain; and assessing for compression or occlusion of the IVC in patients with abdominal or lower extremity swelling or for compression of biliary ducts in patients with jaundice. The images can also be used as a road map for surgeons interested in resecting dominant or strategically placed cysts in an attempt to relieve symptoms. 在我們單位，對(duì)于PKD患者有很多種檢查方法,，但通常會(huì)選擇最適合患者的方法,，一般分為3類：患者的親屬中有人確診PKD，該類患者的超聲篩查價(jià)格較低,、圖像美觀程度欠佳,，稱為Rolls Royce篩查；尋找ADPKD的合并癥,，包括囊腫出血或感染,，以解釋患者新近出現(xiàn)的疼痛癥狀；評(píng)估腹部,、下肢水腫病人的下腔靜脈受壓閉塞情況及黃疸病人的膽道受壓情況,。當(dāng)外科醫(yī)生準(zhǔn)備切除主要病灶以緩解癥狀時(shí)，影像學(xué)可以作為路徑支持,。
Because one of the complications of ADPKD is progressive loss of renal function, MRI scans on ADPKD patients are often performed without intravenous contrast. This presents noreal difficulties when looking for a new, large hemorrhagic cyst (high signal intensity on T1-weighted images and low T2-signal intensity in subacute thrombus). Infected cysts aresomewhat more problematic, since rim enhancement after gadolinium administration is the classic diagnostic sign, but high signal intensity (ie, restricted diffusion) on diffusionweighted images with high b values (>600 s/mm2) can be a useful clue. A high b value is necessary to reduce the amount of T2 shine-through so you can distinguish a simple cystfrom an infected one. 由于進(jìn)行性腎功能減低是ADPKD的并發(fā)癥之一,，MRI掃描一般不采用對(duì)比劑增強(qiáng)掃描。發(fā)現(xiàn)較大的新鮮出血的囊腫并不難（亞急性期出血T1WI呈高信號(hào)，T2WI高信號(hào)）,，而囊腫感染則有一定困難,，釓劑增強(qiáng)掃描邊緣環(huán)形強(qiáng)化是典型的影像學(xué)表現(xiàn)。高b值（＞600s/mm2）DWI可以減小T2透射效應(yīng),，所以高b值DWI呈高信號(hào)（彌散受限）可以有助于鑒別單純性囊腫和囊腫伴感染,。
Figure 2.1.4：Axial 2D GRE images 
Axial 2D GRE images (Figure 2.1.4) demonstrate moderate compression of the IVC by adjacent hepatic cysts, but the IVC and the hepatic veins are patent. 橫斷位2D GRE圖像示IVC輕度受壓，但I(xiàn)VC及肝靜脈仍通暢,。
SSFSE and SSFP images are generally preferable to respiratory-triggered or navigator-gated FSE images in PKD patients because these are both fast techniques that provide beautiful visualization of cystic lesions. If, however, you are trying to find a solid lesion among the cysts, an FSE acquisition is probably warranted. Remember that livers are often enlarged in patients with severe hepatic cystic disease, and therefore the acquisition times can become quite substantial. SSFSE和SSFP圖像是快速掃描技術(shù),，對(duì)于PKD患者肝內(nèi)囊性病變的顯示效果較好，優(yōu)于呼吸觸發(fā)或膈肌導(dǎo)航FSE序列,。但如果試圖尋找囊性病變內(nèi)的實(shí)性成分時(shí),，F(xiàn)SE序列則是更好的選擇。需要記住的是,，重度肝臟囊性病變的患者肝臟體積通常很大,，需要的掃描時(shí)間也就會(huì)很長(zhǎng)！
In addition to hepatic cysts, other extrarenal findings associated with ADPKD include a symptomatic pancreatic cysts, cardiac valve disease,colonic diverticula, abdominal wall or inguinal hernias, and cerebral aneurysms. ADPKD的腎外表現(xiàn),，除了肝囊腫外，還包括胰腺囊腫,、心瓣膜病變,、結(jié)腸憩室、腹壁或腹股溝疝,、腦動(dòng)脈瘤,。
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