복부초음파 : 담낭과췌장 Gallbladder & Pancreas Ultrasonography 김정훈 Department of Radiology 1
Interaction of sound with matter (1) 반사 (Reflection) (2) 굴절 (Refraction) (3) 흡수 (Absorption) (4) 산란 (Scattering) 음향저항 (Acoustic Impedance; Z) Z = p v Density of the medium (p) Velocity of US through the medium (v) Acoustic impedance mismatch - The greater acoustic mismatch: Ultrasound reflection Transmittion - Ex: soft tissue / bone, soft tissue / air interfaces (barrier) 2
Ultrasonography (US) Initial screening modality Advantages - Real-time evaluation, Safety, Flexibility, Portability - No radiation hazard - No iodine toxicity Limitations - Operator dependent - Small field of view - Beam interruption by bowel gas & obesity 간, 담낭, 췌장전체를다볼수없는경우가있다 US for pancreatic disease A great challenge 3
초음파실에서 국민 500 명을대상으로 초음파실에서 췌장에대해서. 췌장잘봐주세요? 췌장도잘보이지요? 췌장암이걱정되요. 잘안보여요. 일부만보입니다. 췌장은 CT나 MRI를하셔야보입니다. 숨참으세요 Contents GB Normal Anatomy & Technique disease Pancreas Normal Anatomy & Technique Disease Summary 4
Introduction Fundus Body Infundibulum Hartmann pouch Neck Cystic duct spiral valve of Heister Normal GB Anatomy Normal size - 7 to 10cm length - 3 to 5cm diameter - 50ml volume Normal GB Anatomy Infundibulum (Hartmann s pouch) Cystic duct 5
Normal GB Fasting After Meal GB Wall: Anatomy Wall thickness: < 3mm 1. Mucosa : columnar epi. Lamina propria Muscularis mucosa(-) Submucosa(-) muscle layer perimuscular c.t. layer, serosa mucosa 2. Irregular muscle layer 3. Perimuscular connective tissue layer 4. Serosa 6
High Resolution US Examination Technique Fasting for 6-8 hours (overnight fasting) Probe: 3-5 MHz convex transducer 7-9 MHz convex transducer Scan through whole gallbladder from fundus to neck portion! Recent Technique Harmonic imaging (HI) reverberation artifact, side lobe artifact Noise, contrast resolution Applying to GB with high frequency transducer Narrower beamwidth 7
Probe & Image Techniques HI Contents GB Normal Anatomy & Technique disease Pancreas Normal Anatomy & Technique Disease Summary 8
Gallbladder Stone USG: highly sensitive, specific & accurate Etiology: supersaturation, bile stasis, Obesity, DM, contraceptive, TPN, cirrhosis Cholesterol, pigment(brown, black), mixed Gallbladder Stone Echogenic lesion Posterior shadowing : specific sign Mobile except adherent 9
Basic US Findings (1) (2) (3) Cyst Hemangioma Calcification Porcelain Gallbladder Emphysematous cholecystitis 10
Acute Cholecystitis An acute inflammation of the gallbladder that in 90% of cases, is caused by gallstones US Findings Large, distended GB GB stones (+/-: Acalculous cholecystitis) US Murphy sign: High specificity (> 90%) GB wall thickening (> 4mm) striated pattern Sludge or Internal Echo Pericholecystic Fluid Acute Cholecystitis Striated Wall Thickening 11
GB Polyps Pathologic classification of GB polyps Cholesterol polyp 12
Adenoma : neoplastic polyp Tubular adenoma Gallbladder Polyp Risk factor of adenoma for malignancy 1 >50 yrs 2 Single, sessile 3 >1cm, size 4 Stone 5 Interval growth 13
Gallbladder Cancer: T Staging perimuscular c.t. layer, serosa muscle layer mucosa T2 pt2 Papillary and nodular tumor pt2 14
HRUS = EUS HRUS T1a Pathology pt1a EUS T1a Contents GB Normal Anatomy & Technique disease Pancreas Normal Anatomy & Technique Disease Summary 15
Normal anatomy of pancreas Retroperioneal organ Anterior pararenal space Duodenal 2 nd portion ~ splenic hilum Courtesy of olymphus 16
Normal US Findings: Pancreatic duct Well-visible at the body portion Anechoic structure with hyperechoic wall At US: 2.1mm (head) / 1.6mm (tail), < 2 mm Increased diameter with aging F/34 Incidental pancreatic mass on US 진단은? (1) Pancreatic cancer (2) Mucinous cystic tumor (3) Serous cystic tumor (4) IPMN (intraductal papillary mucinous neoplasm) (5) None of above 17
F/34 Incidental pancreatic mass on US 진단은? 6-8 hr NPO Scan Technique Empty stomach (food, air) Decrease air in small bowel and colon 3-5MHz convex transducer Wide FOV Easy to avoid air 18
Scan Technique Supine position Respiration control Compression to displace bowel Full inspiration with the liver as sonic window Semi-erect position: avoiding stomach & T-colon gas Lt. Oblique coronal: for pancreas tail Water ingestion (300~500cc) LAO with stomach as sonic window Right lateral decubitus Water in antrum, air in fundus Scan Technique Pancreas tail Through spleen Rt lateral decubitus after water ingestion 19
Scan Technique Supine position Respiration control (inspiration vs expiration) Compression vs Noncompression Conventional vs Harmonic technique Scan Technique 20
Scan Technique_compression Scan Technique_Non compression 21
Scan Technique_poor window Contents GB Normal Anatomy & Technique disease Pancreas Normal Anatomy & Technique Disease Summary 22
1. Solid 2. Cystic Pancreatic Cancer Ductal cell adenocarcinoma (>90%) Variant of ductal adenocarcinoma NET (Neuroendocrine tumor) SPN (Solid psudopapillary neoplasm) Metastasis Serous cystic tumor Mucinous cystic tumor Intraductal papillary mucinous neoplasm(ipmn) Ductal Adenocarcinoma 90-95% of pancreatic malignancy Overall 5-Yr sur.: 2-3% Surgical resection offers the only potential chance of cure < 20% Advanced stage : 65% at Dx - No capsule, abundant lymphatics, meta. (liver, LN,peritoneum) Early detection is important 23
중요암 5 년생존율 Risk Factors of Pancreatic Cancer Pancreatitis 5.1 Pancreatitis, chronic 13.3 Pancreatitis, hereditary 69.0 Pancreatitis, tropical 100 Diabetes 1.82-2.0 Family Hx 1.8 Obesity 1.2-1.6 Tabacco 1.2-1.7 Alcohol 1.2 Occupational exposure 1.1-1.6 Evidence from recent meta-analyses, pooled analyses and systematic reviews of risk factors for pancreatic cancer Dig Dis 2010;28:645 656 24
Problems of Screening for Pancreas Target: High risk group Tools US CT EUS MRI CA 19-9 - Sen: 67-92% - Spe: 68-92% PP: Inflammation Cholangitis Stage 1: 50% K-ras Pancreatitis Pancreatitis, chronic Pancreatitis, hereditary Pancreatitis, tropical Diabetes Family Hx Obesity Tabacco Alcohol Occupational exposure IPMN Ductal Adenocarcinoma-US Primary screening method Low sensitivity - Poor sonic window: gas & obesity - Small tumor size, tumor location US findings Hypoechoic mass Pancreatic duct dilatation Double duct sign 25
US, 2014-04-22 2015-01-07 Ductal Adenocarcinoma 26
Early detection of pancreatic Ca. Pan Ca = 39 Control = 10244 June 1990, P-duct, 7 mm Sep 1992 Early sign of pancreatic Ca. P-duct dilatation> 2mm Screening for Pancreas: US Pancreatic cyst at CT and MRI from 2008 to 2013 (n=1018) US before CT and MRI (n=580): detection of cyst (n=284, 49%) US after CT and MRI (n=910): detection of cyst (n=785, 86%) Unpublished Data 27
Summary The Role of US in GB disease Important screening exam Detection and characterization of a lesion Preoperative staging for resectability High Resolution US Probe: 3-5 MHz convex & Highest frequency (>7 MHz) Image: Fundamental & Harmonic imaging Different position & Respiration control US for Pancreatic disease is a great challenge US scan Techniques Supine position Respiration control (inspiration vs expiration) Compression Conventional vs Harmonic technique Pancreatic adenocarcinoma: No screening method 가장중요한것 : 관심 Early sign is P-duct dilatation> 2mm 28