1、寶石能譜CT臨床應(yīng)用劉士辰寶石CT是超高端CT的一種有別于其他CT的重要功能：1、低劑量，自適應(yīng)性統(tǒng)計迭代算法。2、心臟高分辨模式及SSF（凍結(jié)技術(shù)）3、動態(tài)500排，實現(xiàn)了全臟器的灌注及4D掃描4、能譜，寶石CT的最重要的功能寶石 CT Low Dose口訣：1、相同劑量使用ASIR提高圖像質(zhì)量2、相同圖像質(zhì)量使用ASIR減少劑量寶石心臟高分辨及SSFCase冠脈支架及斑塊LAD- stent支架內(nèi)再阻塞Comparison: HDCT Vs. Non HDCTStent-High Definition ImagingNon CT 750CT 750plaque and stent Non

2、CT 750CT 750104112bpm8291bpm高心率SnapShot Freeze Conventional Recon SnapShot Freeze99-101 bpm Halfscan FBP ReconSnapShot FreezeSnapShot Freeze90-96 bpm Conventional recon SnapShot Freeze SnapShot Freeze78-79 bpm Volume Helical Shuttle (VHS)Use this procedure for prescribing a Volume Helical Shuttle ac

3、quisition. Volume Helical Shuttle (VHS) mode is a repetitive helical scan mode where the table continuously moves back and forth across the prescribed area providing data that has temporal sampling information for each pass. With this temporal sampling information, data can be processed to create ti

4、me resolved CT angiography of the head, neck, and body as well as perfusion studies. Volume Helical Shuttle is different from normal helical imaging in that data is collected during acceleration and deceleration of the table.4D CTA scan range is 110 to 312.5 mm.For perfusion studies, temporal sampli

5、ng should not exceed 3.2 seconds, as there can be error present in the data when processed by CT Perfusion. For perfusion in the head, scan range is 110 to 120 mm. For perfusion in the body, scan range is 110 to 140 mm.Initial reconstruction is limited to 5 mm slice thickness with 10 mm interval. Co

6、ntiguous data at desired slice thickness must be created in Retro Recon.ASiR can be used when acquiring data for 4D CTA.GSI Gemstone Spectral Imaging寶石能譜CT能量(CTE,CT Energy)0電子輸出強度120 kVp60Kev80Kev40Kev20Kev100Kev120Kev 1、能量是X線本身具備的物理特性，也是X線成像的物理基礎(chǔ)； 2、CT可以發(fā)射兩種高低能級的X線，得到兩種不同混合能量圖像，利用計算機成像的原理得到兩種能量級(80

7、和140kV)的圖像信息?；旌夏芰繄D像，能量不均勻，出現(xiàn)硬化偽影CT值誤差大掃描后密度對比固定，組織CT值無法調(diào)整什么是CT能譜？把 x 線能量分開不同的能量用于不同的診斷目的Number 1CT能譜(CT Energy Spectrum, CTES)Photon Energy (keV)0012345x 106140KVP X-ray SpectrumIntensity 20406080100120140Photon Energy (keV)0012345x 106140KVP X-ray SpectrumIntensity 20406080100120140得到40 - 140keV的單能

8、量圖像感興趣區(qū)用能譜曲線去觀察分析明確特定物質(zhì)的特征，進行物質(zhì)分離并測量含量怎么得到CT能譜？把 x 線能量分開不同的能量用于不同的診斷目的Number 2GSI掃描80kV于140kV快速切換不增加掃描時間不增加患者射線劑量GSI后處理（GSI viewer）能譜CT的臨床價值是什么？Number 3單能量圖像能譜曲線物質(zhì)定量與分離123 有效原子序數(shù)4寶石能譜的臨床應(yīng)用提高圖像質(zhì)量檢出等密度或小病灶優(yōu)化動脈成像靜脈成像去除偽影能譜工具1：單能量圖像提高圖像質(zhì)量傳統(tǒng)圖像70keV檢出等密度或小病灶70keV混合能量50keV低keV有助于提高圖像對比度，清晰顯示病灶50Kev低keV有助于提

9、高圖像對比度，清晰顯示病灶常規(guī) CT 圖像能譜CT 圖像DSA肝硬化有沒有癌性結(jié)節(jié)存在？常規(guī)CT圖像栓塞旁腫瘤情況如何？能譜CT圖像 動脈期 門脈期手術(shù)病理證實為胰島素瘤混合能量圖像70Kev圖像50Kev圖像CN1.260.051.340.041.660.06CNR3.720.525.200.589.340.92噪 聲5.790.165.000.137.420.21圖像評分1.440.102.900.102.460.08檢出病灶268枚306枚316枚病變檢出率的比較研究單能量圖像 vs. 混合能量圖像早期腫瘤檢出率比常規(guī)檢查提高25優(yōu)化動脈成像靜脈成像混合能量單能量60keV單能量圖像能夠

10、提高對比度，提高靜脈顯像結(jié)腸癌，常規(guī)圖像少許顯示腫瘤供血動脈，50Kev圖像清晰顯示腫瘤供血，并顯示出腫瘤引流靜脈。動脈期，50Kev圖像觀察，肝動脈、腸系膜上動脈、胃十二指腸動脈及肋間動脈均參加供血，為下一步治療方法的選擇提供了重要依據(jù)。下肢動靜脈右下肢腫脹一周（動脈檢查未見異常）常規(guī)圖像55keV圖像GSI靜脈檢查，常規(guī)圖像血管顯示欠佳，55keV圖像見右下肢深靜脈迂曲，提示曲張近端血流不暢。55keV MPR圖像，見小腿靜脈內(nèi)多發(fā)栓子靜脈期，選擇低Kev清晰顯示靜脈引流血管。去除偽影病史：腦動脈瘤破裂已于3年前行顱內(nèi)彈簧圈植入術(shù)，現(xiàn)突發(fā)昏迷。CT平掃：顯示蛛網(wǎng)膜下腔出血，疑再發(fā)腦動脈瘤破

11、裂？層厚：5mmKv：140mA: 260Rotat: 1s去除金屬偽影由于彈簧圈的金屬偽影影響，普通CT無法發(fā)現(xiàn)被掩蓋的新病灶，診斷困難利用能譜CTA去除金屬偽影，揭示出血原因：動脈瘤再發(fā)后破裂Yellow arrow-coil Red arrow-aneurysmCT動脈造影DSA證實：動脈瘤位于左頸內(nèi)動脈分出左后交通動脈處動脈導(dǎo)管造影未使用MARS使用MARS140Kvp140Kev人股骨頭置換術(shù)后現(xiàn)病史：術(shù)后患者不明原因高熱，臨床懷疑周圍膿腫？CT檢查：通常CT檢查受金屬偽影干擾，無法滿意觀察。能譜MARS技術(shù)，發(fā)現(xiàn)在右側(cè)髖關(guān)節(jié)周圍液性密度影包裹診斷膿腫。穿刺抽液證實。膝關(guān)節(jié)置換術(shù)后G

12、SI+MARS QC圖 70kev 93kev病例 2 M/52Y 右髖關(guān)節(jié)置換術(shù)后1月QC 組 圖 像 140keVMono 組 圖 像 140keVMars 組 圖 像某些特定組織有特定曲線相同組織有相同曲線不同組織結(jié)構(gòu)曲線不同能譜工具2：能譜曲線鑒別診斷錯構(gòu)瘤肺癌 正常肝臟脂肪肝能譜曲線輕度脂肪肝中度脂肪肝重度脂肪肝同源性分析淋巴瘤-同一病人不同部位淋巴結(jié)評估頸部淋巴結(jié)縱隔淋巴結(jié)肺門淋巴結(jié)脾臟淋巴結(jié)同一病人同源腫瘤Kev曲線具有較好的一致性 前列腺癌轉(zhuǎn)移灶684300腎臟透明細胞癌和乳頭狀腎細胞癌物質(zhì)碘定量測定可反映組織或病變的血供特點碘定量能譜工具3：物質(zhì)定量與分離亞段栓塞核醫(yī)學(xué)顯示灌

13、注減低區(qū)常規(guī)CT未見異常能譜碘定量發(fā)現(xiàn)灌注減低區(qū)無栓子肺梗塞臨床資料：女性，77y, DVT。突發(fā)胸部疼痛入院檢查。ROI碘含量mg/cc標準差患側(cè)1.260.98健側(cè)5.172.07 射頻消融術(shù)后 術(shù)前術(shù)后體積變大 術(shù)前碘值：1.030.38 mg/cc術(shù)后碘值：0.30.31 mg/cc病例4 肝癌射頻術(shù)后復(fù)查肝癌射頻術(shù)后復(fù)查，動脈期病灶內(nèi)密度不均，有高密度；門脈期密度降低。有無復(fù)發(fā)不易鑒別。動脈期及門脈期碘基圖像，均未見病灶內(nèi)部碘的沉積，病灶內(nèi)碘測量均接近零。因此考慮射頻術(shù)后效果良好。病灶內(nèi)密度不均考慮液化壞死及出血。痛風(fēng)結(jié)節(jié)融合像 70keV / Uric AcidMD 尿酸像MD 鈣

14、基像物質(zhì)濃度分布圖（尿酸）70keV / VOI臨床價值GSI有助于鑒別痛風(fēng)和假性痛風(fēng)痛風(fēng)由于尿酸結(jié)晶體沉積在人體組織所致假性痛風(fēng)是由于磷酸鈣鹽沉積所致如果在關(guān)節(jié)內(nèi)不進行針刺活檢無法評估尿酸結(jié)晶存在.MD 尿酸鹽成像提示痛風(fēng)或者假性痛風(fēng)存在，并加以鑒別Images Courtesy of Dr. Amy Hara Mayo Clinic, Scottsdale Az物質(zhì)分離像尿酸鈣血管造影像MD Iodine65 keV物質(zhì)分離像碘鈣能譜工具4：有效原子系數(shù)（Effective-Z Value)MD Water image categorized stone as calcium based

15、and effective-z (atomic number) value was around 14 which is suggestive of Calcium oxalate Monohydrate (COM)腎結(jié)石成份鑒別Kidney Stone Characterization70keV Effective_ZEff_Z Histogram70keV Effective_Z70keV Effective_Z70keV Effective_ZMD Water (Calcium)CompositionOccurrenceOn KUBOn CTHUCompositionEff. ZCalc

16、ium Oxalate Monohydrate (COM)40-60 %Radio-opaqueRadio-opaque1700-2800CaC2O414.37Calcium Oxalate Dihydrate (COD)40-60 %Radio-opaqueRadio-opaque1700-2800CaC2O4.2H2O15.36Hydroxyapatite (Calcium phosphate) 20-60%Radio-opaqueRadio-opaque1200-1600Ca5(PO4)3(OH)14.59Brushite2-4%Radio-opaqueRadio-opaque1700-

17、2800CaHPO4.2H2O14.12Uric Acid5-10%Radio- lucentRadio-opaque200-450C5H4N4O3.6.92Struvite5-15%Radio-opaqueRadio-opaque600-1100(NH4)MgPO46H2O)9.72Cystine1-2.5%Mildly OpaqueRadio-opaque600-900C6H12N2O4S211.07結(jié)石分類Calculi TypesEff. Z data courtesy Dr. D Sahani單能量圖像能譜曲線物質(zhì)定量與分離基物質(zhì)圖能譜平臺四大工具123高清晰的圖像去除金屬偽影更好的

18、檢出病變更好顯示病灶內(nèi)部特征能譜曲線可以反應(yīng)組織器官和病變的特點和規(guī)律物質(zhì)定量測定能反映組織或病變的血供特點 有效原子序數(shù)4有效原子序數(shù)能反映組織或病變的物質(zhì)組成CT 120 kVp能譜4大工具總結(jié) 45keV130keV1、單能量2、能譜曲線3、物質(zhì)分離及定量?Fat ( Water )Iodine ( Water)4、有效原子序數(shù)Freedom 寶石CT在心臟中的應(yīng)用 劉士辰CT applicationConventionalAngiography (CA)64 row CCTAIVUS w/ radio-frequency backscatter analysisProspective

19、Validation of Standardized 3-Dimensional, Quantitative Coronary Computed tomographic plaque measurements using radiofrequency backscatter intravascular ultrasound as reference standard in intermediate coronary arterial lesions; Voros, S. et al. JACCCV Intev 2011 3333-21%+104%+39% Calcium blooming le

20、ads to: 104% calcied plaque volume 21% minimal luminal diameter 39% % diameter stenosis Calcified plaque: Atlanta 1 studySECT: 120 kVp40 keV50 keV60 keV70 keV80 keV90 keV100 keV110 keV120 keV130 keV140 keV130 keV120 keV110 keV100 keV90 keV80 keV70 keV60 keV50 keV40 keV40 keV50 keV60 keV70 keV80 keV9

21、0 keV100 keV110 keV120 keV130 keV140 keVDECT: 40keV to 140keVGSI cardiac: Case showing lumen visualization with monochromatic imaging 40 keV50 keV60 keV80 keV70 keV100 keV120 keV140 keVSECT 120 kVpImages Courtesy Dr. Earls Fairfax RadiologyGSI cardiac: Case showing lumen visualization with monochrom

22、atic imaging HAP*(Iodine)Iodine(HAP*)Images Courtesy Dr. Earls Fairfax Radiology*GSI is delivered with a base set of materials from the NIST database and is engineered for the capability to add other material from this database.Currently, HAP is not included on the scanner/viewer as one of the mater

23、ials, but can be loaded by the user following instructions in the GSI Viewer User Manual.Calcium FREEdom:Designed to enhance vessel visualization HU Spectral CurvesMD Scatter PlotsPlaqueLumenCalciumImages Courtesy Dr. Panse, MayoHorizon FREE: GSI cardiac Plaque material composition LAD soft plaque with distal calcium , is there any fatty core inside?Plaque characterizationL1 &L2 look like soft plaque and water concentration are similar. L1 :-61.75HU at 70Kev-7.25*0.1mg/cm3 at iodine concentrat