Liver, Liver Fat, Fibrosis and HCC Screening with DECT

Transcription

1 Liver, Liver Fat, Fibrosis and HCC Screening with DECT Dushyant Sahani, M.D Director of CT Associate Professor of Radiology Massachusetts General Hospital Harvard Medical School

2 Disclosures MGH has research agreement GE Health Care Advisory Board Allena Pharma Dr Sahani Receives Royalties from Elsevier publishing for text book on Abdomen Imaging

3 Chronic Liver Disease NAFLD NASH Management of CLD involves screening for HCC and assessing for risk factors such as steatosis, iron deposition and liver fibrosis to estimate liver function. Imaging is cornerstone for staging, treatment planning and monitoring. Healthy liver Hemochromatosis Hepatitis, Alcohol, other Cirrhosis HCC

4 AASLD 2010 Guidelines for HCC Management Diagnosis of HCC should be based on imaging techniques and/or biopsy

5 Hypervascular Liver Lesions

6 DECT: Improved Detection of HCC on Low kev Images Anzidei M et al. Clin Radiol Sep;70(9): Altenbernd JC et al. Acta Radiol Nov;56(11): Wang Q, Eur J Radiol Oct;83(10): Dai X et al. Eur J Radiol Feb;82(2): Lee JA, et al. Eur J Radiol Apr;82(4):

7 Nodule Characterization in 55 yr-old-man with HBV cirrhosis 140kVp-AP 140kVp-PV 65keV-AP 65keV-PV MD Iodine-AP MD Iodine-PV COLOR -AP Anzidei M et al. Clin Radiol Sep;70(9): Altenbernd JC et al. Acta Radiol Nov;56(11): Wang Q, Eur J Radiol Oct;83(10): Dai X et al. Eur J Radiol Feb;82(2): Lee JA, et al. Eur J Radiol Apr;82(4):

8 DECT approach Material decomposition algorithm Images generated DSDECT Based on projection data (before image reconstruction from high and low-energy sinograms) HU at 80 kv Fat Iodine Measured voxel value Soft tissue Iodine content HU at 140 kv ssdect Two material decomposition Attenuation information of a given material at two different X-ray energies can be mathematically transformed into the amount (concentration) of material pairs that would be necessary to produce the measured attenuation level. 1. Water 2. Iodine 3. Other base pairs (Iodine: calcium) Multi-material decomposition 1. Iodine 2. Fat 2. Bone 3. Fibrosis 5. Soft tissue 6. Blood 7. Air

9 Multi-Material Decomposition (ssdect) Iodine (Zeff=53) Calcium (Zeff=20) Fat (Zeff=5.92) Soft tissue (C=6, H=1, O=8, N=7) The DECT is based on varying behavior of materials when exposed to different x-ray photon energies AIR FAT BLOOD CALCIUM IODINE

10 Liver Fat quantification- CT Dual Energy CT As the kvp increases, the fat attenuation increases Steatotic liver exhibits greater change in attenuation between 80kVp and 140kVp than normal liver Liver Fat Index = HU at 140 kvp - HU at 80 kvp Liver Fat Index >10HU suggests HS >25%

11 Fat quantification Mendonca PR, Lamb P, Sahani DV. A Flexible Method for Multi-Material Decomposition of Dual-Energy CT Images. IEEE Trans Med Imaging Jan;33(1): %fat Fat quantification evidenced moderate fatty infiltration. Mendonca PR, Lamb P, Sahani DV. A Flexible Method for Multi-Material Decomposition of Dual-Energy CT Images. IEEE Trans Med Imaging Jan;33(1): Patino M et al. Radiograhics (in-press) Ma J, Song ZQ, Yan FH. PLoS One Oct 30;9(10):e Hur BY et al J Comput Assist Tomogr Nov-Dec;38(6): Sun T, Lin X, Chen K. Front Biosci (Landmark Ed) Jun 1;19: Fischer MA, Invest Radiol Jun;46(6):351-8.

12 LFQ VUE Original VUE and Liver Fat: CE-DECT Contrast-free phase Arterial phase Portal venous phase Delayed phase Agrawal M et al. RSNA 2013 Agrawal M et al. Radiographics 2015 S. Mendonca et al. IEEE Trans Med Imaging. Jan 2014: 30(1): Patel BN et al. J Comput Assist Tomogr Nov-Dec;37(6):

13 Fat Quantification Mendonca PR, Lamb P, Sahani DV. A Flexible Method for Multi-Material Decomposition of Dual-Energy CT Images. IEEE Trans Med Imaging Jan;33(1): Patino M et al. Radiograhics (in-press) Sun T, Lin X, Chen K. Front Biosci (Landmark Ed) Jun 1;19: Fischer MA, Invest Radiol Jun;46(6):351-8.

14 SECT DECT FAT IMAGES

15 DECT: Fibrosis Quantification DECT also offers the possibility to assess and stage fibrosis through iodine distribution in the liver. Note on a patient with cirrhosis the ability to potentially stratify fibrosis by analyzing iodine trapping at low energies(40-50 KeV). Normal liver, iodine map Spectral HU curve Cirrhosis, iodine map MR Elastography Lv P, Lin X, Gao J, Chen K. Spectral CT: preliminary studies in the liver cirrhosis. Korean J Radiol 2012;13(4):

16 Liver Iodine Quantification: Scan Delay Arterial phase Delayed phase (2 min.) Delayed phase (5 min.) A B C D E F. Quantification and visualization of liver fibrosis with DECT. (

17 Liver Fibrosis: Iodine Retention Histopathology (Ishak score) NIC (mg/ml) on the delayed phase P value No fibrosis (0) ± 0.02 < Mild fibrosis (1-2) ± 0.02 < Severe fibrosis (5-6) ± Patino et al. RSNA 2014 Agarwal SA et al. SAR Howard Stern Award Lamb P, Sahani DV, Fuentes-Orrego JM, Patino M, Ghosh A, Mendonça PR. IEEE Trans Med Imaging Mar;34(3):

18 Reproducibility Iodine Extraction in the Liver Fibrosis Patino M et al. RSNA 2014 Agarwal S et al. SAR 2015

19 DECT Spectrum in CLD 80/140 kv MD Fat MD Water MD Iodine Mono 50KeV Iodine map Spectral HU curve Detect and quantify fat deposition in the liver. Replacement for TUE Iodine distribution in the lesion and liver. Tumor viability. Improve detection of hypervascular lesions. Iodine trapping may serve to stratify liver fibrosis. Spectral HU curve aids lesion enhancement MMD

20 DECT Spectrum in CLD Mono Fat Water Fibrosis Iodine

21 HCC DETECTION STEATOSIS DETECTION FIBROSIS DETECTION STAGING QUANTIFICATION QUANTIFICATION TREATMENT MONITORING TREATMENT MONITORING TREATMENT MONITORING