Liver MRI (eBook)

Foreword I 8
Foreword II 9
Preface 10
Contents 12
I High-Fluid Content Liver Lesions 15
1 Abscesses – Pyogenic Type 16
2 Biliary Hamartomas (von Meyenberg Complexes) 18
3 Cyst I – Typical Small 20
4 Cyst II – Typical Large with MR-CT Correlation 22
5 Cyst III – Multiple Small Lesions with MR-CT-US Comparison 24
6 Cyst IV – Adult Polycystic Liver Disease 26
7 Cystadenoma / Cystadenocarcinoma 28
8 Hemangioma I – Typical Small 30
9 Hemangioma II – Typical Medium-Sized with Description of Pathology 32
10 Hemangioma III – Typical Giant 34
11 Hemangioma IV – Giant Type with a Large Central Scar 36
12 Hemangioma V – Atypical, Flash-Filling with Perilesional Enhancement 38
13 Hemangioma VI – Multiple with Perilesional Enhancement 40
14 Hemorrhage 42
15 Hemorrhage – Within a Solid Tumor 44
16 Mucinous Metastasis – Mimicking an Hemangioma 46
II Solid Liver Lesions 49
II A Metastases: Colorectal 49
17 Colorectal Metastases I – Typical Lesion 50
18 Colorectal Metastases II – Typical Multiple Lesions 52
19 Colorectal Metastases III – Metastasis Versus Cyst 54
20 Colorectal Metastases IV – Metastasis Versus Hemangiomas 56
21 Liver Metastases V – Large, Mucinous, Mimicking a Primary Liver Lesion 58
22 Colorectal Metastases VI – with Portal Vein and Bile Duct Encasement 60
23 Colorectal Metastases VII – Recurrent Disease Versus RFA Defect 62
II B Metastases: Non-Colorectal 65
24 Breast Carcinoma Liver Metastases 66
25 Kahler’s Disease (Multiple Myeloma) Liver Metastases 68
26 Melanoma Liver Metastases I – Focal Type 70
27 Melanoma Liver Metastases II – Diffuse Type 72
28 Neuroendocrine Tumor I – Typical Liver Metastases 74
29 Neuroendocrine Tumor II – Pancreas Tumor Metastases 76
30 Neuroendocrine Tumor III – Gastrinoma Liver Metastases 78
31 Neuroendocrine Tumor IV – Carcinoid Tumor Liver Metastases 80
32 Neuroendocrine Tumor V – Peritoneal Spread 82
33 Ovarian Tumor Liver Metastases – Mimicking Giant Hemangioma 84
34 Renal Cell Carcinoma Liver Metastasis 86
II C Primary Solid Liver Lesions in Cirrhotic Liver 89
35 Cirrhosis I – Liver Morphology 90
36 Cirrhosis II – Regenerative Nodules and Confluent Fibrosis 92
37 Cirrhosis III – Dysplastic Nodules 94
38 Cirrhosis IV – Dysplastic Nodules – HCC Transition 96
39 Cirrhosis V – Cyst in a Cirrhotic Liver 98
40 Cirrhosis VI – Multiple Cysts in a Cirrhotic Liver 100
41 Cirrhosis VII – Hemangioma in a Cirrhotic Liver 102
42 HCC in Cirrhosis I – Typical Small with Pathologic Correlation 104
43 HCC in Cirrhosis II – Small With and Without a Tumor Capsule 106
44 HCC in Cirrhosis III – Nodule-in-Nodule Appearance 108
45 HCC in Cirrhosis IV – Mosaic Pattern with Pathologic Correlation 110
46 HCC in Cirrhosis V – Typical Large with Mosaic and Capsule 112
47 HCC in Cirrhosis VI – Mosaic Pattern with Fatty Infiltration 114
48 HCC in Cirrhosis VII – Large Growing Lesion with Portal Invasion 116
49 HCC in Cirrhosis VIII – Segmental Diffuse with Portal Vein Thrombosis 118
50 HCC in Cirrhosis IX – Multiple Lesions Growing on Follow-up 120
51 HCC in Cirrhosis X – Capsular Retraction and Suspected Diaphragm Invasion 122
52 HCC in Cirrhosis XI – Diffuse Within the Entire Liver with Portal Vein Thrombosis 124
53 HCC in Cirrhosis XII – With Intrahepatic Bile Duct Dilatation 126
II D Primary Solid Liver Lesions in Non-Cirrhotic Liver 129
54 Focal Nodular Hyperplasia I – Typical with Large Central Scar and Septa 130
55 Focal Nodular Hyperplasia II – Typical with Pathologic Correlation 132
56 Focal Nodular Hyperplasia III – Typical with Follow-up Examination 134
57 Focal Nodular Hyperplasia IV – Multiple FNH Syndrome 136
58 Focal Nodular Hyperplasia V – Fatty FNH with Concurrent Fatty Adenoma 138
59 Focal Nodular Hyperplasia VI – Atypical with T2 Dark Central Scar 140
60 Hepatic Angiomyolipoma – MR-CT Comparison 142
61 Hepatic Lipoma – MR-CT-US Comparison 144
62 Hepatocellular Adenoma I – Typical with Pathologic Correlation 146
63 Hepatocellular Adenoma II – Large Exophytic with Pathologic Correlation 148
64 Hepatocellular Adenoma III – Typical Fat-Containing 150
65 Hepatocellular Adenoma IV – With Large Hemorrhage 152
66 Hepatocellular Adenoma V – Multiple in Fatty Liver (Non-OC-Dependent) 154
67 Hepatocellular Adenoma VI – Multiple in Fatty Liver (OC-Dependent) 156
68 HCC in Non-Cirrhotic Liver I – Small with MR-Pathologic Correlation 158
69 HCC in Non-Cirrhotic Liver II – Large with MR-Pathologic Correlation 160
70 HCC in Non-Cirrhotic Liver III – Large Lesion with Inconclusive CT 162
71 HCC in Non-Cirrhotic Liver IV – Cholangiocellular or Combined Type 164
72 HCC in Non-Cirrhotic Liver V – Central Scar and Capsule Rupture 166
73 HCC in Non-Cirrhotic Liver VI – Capsule with Pathologic Correlation 168
74 HCC in Non-Cirrhotic Liver VII – Very Large with Pathologic Correlation 170
75 HCC in Non-Cirrhotic Liver VIII – Vascular Invasion and Satellite Nodules 172
76 HCC in Non-Cirrhotic Liver IX – Adenoma-Like HCC with Pathologic Correlation 174
77 Intrahepatic Cholangiocarcinoma – With Pathologic Correlation 176
78 Telangiectatic Hepatocellular Lesion 178
III Diffuse (Depositional) Liver Diseases 181
79 Focal Fatty Infiltration Mimicking Metastases 182
80 Focal Fatty Sparing Mimicking Liver Lesions 184
81 Hemosiderosis – Iron Deposition, Acquired Type 186
82 Hemochromatosis – Severe Type 188
83 Hemochromatosis with Solitary HCC 190
84 Hemochromatosis with Multiple HCC 192
85 Thalassemia with Iron Deposition 194
IV Vascular Liver Lesions 197
86 Arterioportal Shunt I – Early Enhancing Lesion in a Cirrhotic Liver 198
87 Arterioportal Shunt II – Early Enhancing Lesion in a Non-Cirrhotic Liver 200
88 Budd-Chiari Syndrome I – Abnormal Enhancement and Intrahepatic Collaterals 202
89 Budd-Chiari Syndrome II – Gradual Deformation of the Liver 204
90 Budd-Chiari Syndrome III – Nodules Mimicking Malignancy 206
91 Hereditary Hemorrhagic Telangiectasia or Rendu-Osler-Weber Disease 208
V Biliary Tree Abnormalities 211
92 Caroli’s Disease I – Intrahepatic with Segmental Changes 212
93 Caroli’s Disease II – Involvement of the Liver and Kidneys 214
94 Cholelithiasis (Gallstones) 216
95 Choledocholithiasis (Bile Duct Stones) 218
96 Gallbladder Carcinoma I – Versus Gallbladder Wall Edema 220
97 Gallbladder Carcinoma II – Hepatoid Type of Adenocarcinoma 222
98 Hilar Cholangiocarcinoma I – Typical 224
99 Hilar Cholangiocarcinoma II – Intrahepatic Mass 226
100 Hilar Cholangiocarcinoma III – Partially Extrahepatic Tumor 228
101 Hilar Cholangiocarcinoma IV – Metal Stent with Interval Growth 230
102 Hilar Cholangiocarcinoma V – Biliary Dilatation Mimicking Klatskin Tumor at CT 232
103 Primary Sclerosing Cholangitis I – Cholangitis and Segmental Atrophy 234
104 Primary Sclerosing Cholangitis II – With Intrahepatic Cholestasis 236
105 Primary Sclerosing Cholangitis III – With Intrahepatic Stones 238
106 Primary Sclerosing Cholangitis IV – With Biliary Cirrhosis 240
107 Primary Sclerosing Cholangitis V – With Intrahepatic Cholangiocarcinoma 242
108 Primary Sclerosing Cholangitis VI – With Hilar Cholangiocarcinoma 244
VI Differential Diagnosis 247
109 T2 Bright Liver Lesions 248
110 T1 Bright Liver Lesions 250
111 T2 Bright Central Scar 252
112 Lesions in Fatty Liver 254
VII Appendices 257
113 Appendix I: MR Imaging Technique and Protocol 258
114 Appendix II: Liver Segmental and Vascular Anatomy 260
Subject Index 263

1 Abscesses – Pyogenic Type (p. 2)

Hepatic abscesses result from an infectious process of bacterial origin associated with destruction of the hepatic parenchyma and stroma in 0.006–2.2% of hospital admissions. Gram-negative bacteria of colonic origin (E. coli, Klebsiella, and Enterobacter) can often be isolated from such abscesses. Pyogenic liver abscesses may result from obstruction of the biliary tract with stasis of bile and bacterial overgrowth, or as a complication of direct biliary tract infection. Hematogenous spread and bacterial seeding of the liver may occur via the portal vein secondary to abdominal infection. Other less common routes are hematogenous and direct perihepatic spread.

MR Imaging Findings

Hepatic abscess presents as a relatively complicated fluid collection, which is composed of central areas with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Particularly, on T2-weighted images the central cavity may show septa and debris. A central fluid-containing cavity is often surrounded by a few millimeters (in most cases: 1–5 mm, in some cases: >,5 mm) of thick inflamed liver parenchyma (wall of the abscess), which most likely contains microabscesses. Perilesional (wedge-shaped) edema may be present. Most abscesses show early persistent enhancement of the wall (Figs. 1.1–1.3A, B). Although in most patients the diagnosis and follow-up is carried out on computed tomography (CT), magnetic resonance (MR) imaging is increasingly being performed on acutely ill patients, therefore, it is important for radiologists to understand the appearance of hepatic abscesses at MR imaging.

Differential Diagnosis

In ambiguous cases, the differential diagnosis may include: (1) metastases (the ring enhancement progresses in a centripetal fashion with a decrease in intensity on delayed images), (2) infected metastases (difficult to differentiate, thicker andmore irregular wall, clinical history important), (3) hepatosplenic candidiasis (multiple lesions <,10 mm in diameter), (4) hydatid cysts (internal septa), (5) echinococcus abscesses (thicker septa and daughter cysts) (Fig. 1.3C, D).

Management

Management options include: (1) percutaneous drainage, (2) open surgical drainage, and (3) antibiotic therapy. Single dominant hepatic abscesswith a large fluid cavity can be treatedwith percutaneous drainage. Treatment should be tailored to each patient.

Literature

1. Mendez RJ, Schiebler ML, Outwater EK, Kressel HY (1994) Hepatic abscesses: MR imaging findings. Radiology 190:431–436
2. Balci CN, Semelka RC, Noone TC, et al. (1999) Pyogenic hepatic abscesses: MRI findings on T1- and T2-weighted and serial gadolinium-enhanced gradient-echo images. J Magn Reson Imaging 9:285–290
3. Perez JAA, Gonzalez JJ, Baldonedo RF, et al. (2001) Clinical course, treatment, and multivariate analysis of risk factors for pyogenic liver abscess. Am J Surg 181:177–186