HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) CME Test (opens in a new window) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hussain, S. M. Articles by de Man, R. A. Search for Related Content PubMed PubMed Citation Articles by Hussain, S. M. Articles by de Man, R. A. Related Collections Magnetic Resonance Imaging Ultrasound Computed Tomography Gastrointestinal Radiology Related Article

Focal Nodular Hyperplasia: Findings at State-of-the-Art MR Imaging, US, CT, and Pathologic Analysis¹

¹ From the Departments of Radiology (S.M.H., E.L.), Surgery (T.T., J.N.M.I.), Pathology (P.E.Z.), and Gastroenterology (S.d.R., R.A.d.M.), Erasmus Medical Center, Dr Molewaterplein 40, 3015 GD Rotterdam, the Netherlands. Recipient of a Certificate of Merit award for an education exhibit at the 2002 RSNA scientific assembly. Received March 6, 2003; revision requested April 22 and received June 9; accepted June 11. All authors have no financial relationships to disclose. Address correspondence to S.M.H. (e-mail: smhussain62@hotmail.com).

View larger version (119K): [in a new window]   Figure 1a.  Gross pathologic and histologic features of classic FNH. (a) Cross section of a resected specimen of classic FNH shows yellowish nodules of variable size (straight black arrows) surrounded by multiple septa (arrowhead) and a central scar (*). The central scar contains large vessels (curved black arrow). Normal liver tissue (white arrow) surrounds the FNH. Note that there is no fibrous capsule at the interface of the lesion and the liver. (b) Photomicrograph (original magnification, x40; hematoxylin-eosin [H-E] stain) shows the interface of the FNH (*), which contains multiple nodules and septa, and the surrounding normal hepatic parenchyma, which contains large vessels (straight arrow) and portal vein tracts with inflammatory infiltrates (curved arrow). (c) Photomicrograph (original magnification, x40; H-E stain) shows a septum (arrow) dividing two neighboring nodules. The septum contains connective tissue and multiple arteries. (d) Photomicrograph (original magnification, x100; H-E stain) shows a typical FNH nodule (*) surrounded by septa. At the interface of the nodule and the septa, ductular proliferation can be seen (arrows).

View larger version (163K): [in a new window]   Figure 1b.  Gross pathologic and histologic features of classic FNH. (a) Cross section of a resected specimen of classic FNH shows yellowish nodules of variable size (straight black arrows) surrounded by multiple septa (arrowhead) and a central scar (*). The central scar contains large vessels (curved black arrow). Normal liver tissue (white arrow) surrounds the FNH. Note that there is no fibrous capsule at the interface of the lesion and the liver. (b) Photomicrograph (original magnification, x40; hematoxylin-eosin [H-E] stain) shows the interface of the FNH (*), which contains multiple nodules and septa, and the surrounding normal hepatic parenchyma, which contains large vessels (straight arrow) and portal vein tracts with inflammatory infiltrates (curved arrow). (c) Photomicrograph (original magnification, x40; H-E stain) shows a septum (arrow) dividing two neighboring nodules. The septum contains connective tissue and multiple arteries. (d) Photomicrograph (original magnification, x100; H-E stain) shows a typical FNH nodule (*) surrounded by septa. At the interface of the nodule and the septa, ductular proliferation can be seen (arrows).

View larger version (155K): [in a new window]   Figure 1c.  Gross pathologic and histologic features of classic FNH. (a) Cross section of a resected specimen of classic FNH shows yellowish nodules of variable size (straight black arrows) surrounded by multiple septa (arrowhead) and a central scar (*). The central scar contains large vessels (curved black arrow). Normal liver tissue (white arrow) surrounds the FNH. Note that there is no fibrous capsule at the interface of the lesion and the liver. (b) Photomicrograph (original magnification, x40; hematoxylin-eosin [H-E] stain) shows the interface of the FNH (*), which contains multiple nodules and septa, and the surrounding normal hepatic parenchyma, which contains large vessels (straight arrow) and portal vein tracts with inflammatory infiltrates (curved arrow). (c) Photomicrograph (original magnification, x40; H-E stain) shows a septum (arrow) dividing two neighboring nodules. The septum contains connective tissue and multiple arteries. (d) Photomicrograph (original magnification, x100; H-E stain) shows a typical FNH nodule (*) surrounded by septa. At the interface of the nodule and the septa, ductular proliferation can be seen (arrows).

View larger version (182K): [in a new window]   Figure 1d.  Gross pathologic and histologic features of classic FNH. (a) Cross section of a resected specimen of classic FNH shows yellowish nodules of variable size (straight black arrows) surrounded by multiple septa (arrowhead) and a central scar (*). The central scar contains large vessels (curved black arrow). Normal liver tissue (white arrow) surrounds the FNH. Note that there is no fibrous capsule at the interface of the lesion and the liver. (b) Photomicrograph (original magnification, x40; hematoxylin-eosin [H-E] stain) shows the interface of the FNH (*), which contains multiple nodules and septa, and the surrounding normal hepatic parenchyma, which contains large vessels (straight arrow) and portal vein tracts with inflammatory infiltrates (curved arrow). (c) Photomicrograph (original magnification, x40; H-E stain) shows a septum (arrow) dividing two neighboring nodules. The septum contains connective tissue and multiple arteries. (d) Photomicrograph (original magnification, x100; H-E stain) shows a typical FNH nodule (*) surrounded by septa. At the interface of the nodule and the septa, ductular proliferation can be seen (arrows).

View larger version (91K): [in a new window]   Figure 2a.  Vascularity of FNH. (a) Drawing of part of an FNH lesion shows a septum that contains connective tissue, a large thick-walled artery and numerous capillaries, and ductular proliferation with inflammatory cells. The rich network of capillaries, which provides arterial blood to the hepatocytes and sinusoids, is responsible for the highly hypervascular nature of most FNH lesions at imaging. The sinusoids drain into veins. The malformed arteries of FNH arise from the hepatic artery, and the vein of FNH eventually drains into the hepatic vein. Note that FNH does not contain portal vessels. (b) Photomicrograph (original magnification, x200; H-E stain) shows a fibrous septum (*) that contains a thick-walled artery (straight solid arrow). Note the ductular proliferation (curved arrow) at the interface of the septum and the parenchyma. The vein (open arrow) is located within the parenchyma. (c) Photomicrograph (original magnification, x400; H-E stain) shows details of the end-artery (dashed line), which is divided into numerous small capillaries that are connected to the sinusoids (straight arrows). Curved arrow = ductular proliferation. (d) Photomicrograph (original magnification, x400; H-E stain) shows details of the vein (open arrow). Note that numerous sinusoids (straight arrows) drain into a venule and eventually into the vein.

View larger version (166K): [in a new window]   Figure 2b.  Vascularity of FNH. (a) Drawing of part of an FNH lesion shows a septum that contains connective tissue, a large thick-walled artery and numerous capillaries, and ductular proliferation with inflammatory cells. The rich network of capillaries, which provides arterial blood to the hepatocytes and sinusoids, is responsible for the highly hypervascular nature of most FNH lesions at imaging. The sinusoids drain into veins. The malformed arteries of FNH arise from the hepatic artery, and the vein of FNH eventually drains into the hepatic vein. Note that FNH does not contain portal vessels. (b) Photomicrograph (original magnification, x200; H-E stain) shows a fibrous septum (*) that contains a thick-walled artery (straight solid arrow). Note the ductular proliferation (curved arrow) at the interface of the septum and the parenchyma. The vein (open arrow) is located within the parenchyma. (c) Photomicrograph (original magnification, x400; H-E stain) shows details of the end-artery (dashed line), which is divided into numerous small capillaries that are connected to the sinusoids (straight arrows). Curved arrow = ductular proliferation. (d) Photomicrograph (original magnification, x400; H-E stain) shows details of the vein (open arrow). Note that numerous sinusoids (straight arrows) drain into a venule and eventually into the vein.

View larger version (153K): [in a new window]   Figure 2c.  Vascularity of FNH. (a) Drawing of part of an FNH lesion shows a septum that contains connective tissue, a large thick-walled artery and numerous capillaries, and ductular proliferation with inflammatory cells. The rich network of capillaries, which provides arterial blood to the hepatocytes and sinusoids, is responsible for the highly hypervascular nature of most FNH lesions at imaging. The sinusoids drain into veins. The malformed arteries of FNH arise from the hepatic artery, and the vein of FNH eventually drains into the hepatic vein. Note that FNH does not contain portal vessels. (b) Photomicrograph (original magnification, x200; H-E stain) shows a fibrous septum (*) that contains a thick-walled artery (straight solid arrow). Note the ductular proliferation (curved arrow) at the interface of the septum and the parenchyma. The vein (open arrow) is located within the parenchyma. (c) Photomicrograph (original magnification, x400; H-E stain) shows details of the end-artery (dashed line), which is divided into numerous small capillaries that are connected to the sinusoids (straight arrows). Curved arrow = ductular proliferation. (d) Photomicrograph (original magnification, x400; H-E stain) shows details of the vein (open arrow). Note that numerous sinusoids (straight arrows) drain into a venule and eventually into the vein.

View larger version (159K): [in a new window]   Figure 2d.  Vascularity of FNH. (a) Drawing of part of an FNH lesion shows a septum that contains connective tissue, a large thick-walled artery and numerous capillaries, and ductular proliferation with inflammatory cells. The rich network of capillaries, which provides arterial blood to the hepatocytes and sinusoids, is responsible for the highly hypervascular nature of most FNH lesions at imaging. The sinusoids drain into veins. The malformed arteries of FNH arise from the hepatic artery, and the vein of FNH eventually drains into the hepatic vein. Note that FNH does not contain portal vessels. (b) Photomicrograph (original magnification, x200; H-E stain) shows a fibrous septum (*) that contains a thick-walled artery (straight solid arrow). Note the ductular proliferation (curved arrow) at the interface of the septum and the parenchyma. The vein (open arrow) is located within the parenchyma. (c) Photomicrograph (original magnification, x400; H-E stain) shows details of the end-artery (dashed line), which is divided into numerous small capillaries that are connected to the sinusoids (straight arrows). Curved arrow = ductular proliferation. (d) Photomicrograph (original magnification, x400; H-E stain) shows details of the vein (open arrow). Note that numerous sinusoids (straight arrows) drain into a venule and eventually into the vein.

View larger version (120K): [in a new window]   Figure 3a.  Important tissue components of FNH as shown with specific histologic stains. (a) Photomicrograph (original magnification, x100; elastica van Gieson stain) of a biopsy specimen shows the fibrous septa (straight arrow) and hepatocytes of FNH, which contain steatosis (curved arrow). (b) Photomicrograph (original magnification, x200; CD 34 stain) shows the epithelium of the arteries (straight solid arrow) and capillaries (curved arrow) fading into the sinusoids of FNH (open arrow). (c) Photomicrograph (original magnification, x200; keratine 19 stain) shows ductular proliferation within a short septum of FNH (arrow). (d) Photomicrograph (original magnification, x200; CD 68 stain) shows numerous Kupffer cells lining the sinusoids of FNH (arrows).

View larger version (159K): [in a new window]   Figure 3b.  Important tissue components of FNH as shown with specific histologic stains. (a) Photomicrograph (original magnification, x100; elastica van Gieson stain) of a biopsy specimen shows the fibrous septa (straight arrow) and hepatocytes of FNH, which contain steatosis (curved arrow). (b) Photomicrograph (original magnification, x200; CD 34 stain) shows the epithelium of the arteries (straight solid arrow) and capillaries (curved arrow) fading into the sinusoids of FNH (open arrow). (c) Photomicrograph (original magnification, x200; keratine 19 stain) shows ductular proliferation within a short septum of FNH (arrow). (d) Photomicrograph (original magnification, x200; CD 68 stain) shows numerous Kupffer cells lining the sinusoids of FNH (arrows).

View larger version (164K): [in a new window]   Figure 3c.  Important tissue components of FNH as shown with specific histologic stains. (a) Photomicrograph (original magnification, x100; elastica van Gieson stain) of a biopsy specimen shows the fibrous septa (straight arrow) and hepatocytes of FNH, which contain steatosis (curved arrow). (b) Photomicrograph (original magnification, x200; CD 34 stain) shows the epithelium of the arteries (straight solid arrow) and capillaries (curved arrow) fading into the sinusoids of FNH (open arrow). (c) Photomicrograph (original magnification, x200; keratine 19 stain) shows ductular proliferation within a short septum of FNH (arrow). (d) Photomicrograph (original magnification, x200; CD 68 stain) shows numerous Kupffer cells lining the sinusoids of FNH (arrows).

View larger version (169K): [in a new window]   Figure 3d.  Important tissue components of FNH as shown with specific histologic stains. (a) Photomicrograph (original magnification, x100; elastica van Gieson stain) of a biopsy specimen shows the fibrous septa (straight arrow) and hepatocytes of FNH, which contain steatosis (curved arrow). (b) Photomicrograph (original magnification, x200; CD 34 stain) shows the epithelium of the arteries (straight solid arrow) and capillaries (curved arrow) fading into the sinusoids of FNH (open arrow). (c) Photomicrograph (original magnification, x200; keratine 19 stain) shows ductular proliferation within a short septum of FNH (arrow). (d) Photomicrograph (original magnification, x200; CD 68 stain) shows numerous Kupffer cells lining the sinusoids of FNH (arrows).

View larger version (126K): [in a new window]   Figure 4a.  Gross pathologic and histologic features of nonclassic FNH. (a) Cross section of a fixed resected specimen shows a nonclassic FNH (*). The lesion contains neither prominent septa nor a central scar. Normal liver tissue surrounds the FNH without a fibrous capsule. (b) Photomicrograph (original magnification, x200; H-E stain) of the FNH shows a short septum containing a small amount of connective tissue and ductular proliferation. (Fig 3c shows ductular proliferation in the same slide.) (c) Photomicrograph (original magnification, x200; H-E stain) of a specimen from another patient shows a small area of FNH containing monotonous hepatocytes (*), an appearance that resembles that of adenoma and suggests a mixed type of FNH. (d) Photomicrograph (original magnification, x200; H-E stain) of a specimen from another patient shows telangiectatic FNH, which is composed of a relatively short septum (straight arrow) and atrophic hepatocytes with wider sinusoids than those normally present in classic FNH (curved arrow).

View larger version (153K): [in a new window]   Figure 4b.  Gross pathologic and histologic features of nonclassic FNH. (a) Cross section of a fixed resected specimen shows a nonclassic FNH (*). The lesion contains neither prominent septa nor a central scar. Normal liver tissue surrounds the FNH without a fibrous capsule. (b) Photomicrograph (original magnification, x200; H-E stain) of the FNH shows a short septum containing a small amount of connective tissue and ductular proliferation. (Fig 3c shows ductular proliferation in the same slide.) (c) Photomicrograph (original magnification, x200; H-E stain) of a specimen from another patient shows a small area of FNH containing monotonous hepatocytes (*), an appearance that resembles that of adenoma and suggests a mixed type of FNH. (d) Photomicrograph (original magnification, x200; H-E stain) of a specimen from another patient shows telangiectatic FNH, which is composed of a relatively short septum (straight arrow) and atrophic hepatocytes with wider sinusoids than those normally present in classic FNH (curved arrow).

View larger version (173K): [in a new window]   Figure 4c.  Gross pathologic and histologic features of nonclassic FNH. (a) Cross section of a fixed resected specimen shows a nonclassic FNH (*). The lesion contains neither prominent septa nor a central scar. Normal liver tissue surrounds the FNH without a fibrous capsule. (b) Photomicrograph (original magnification, x200; H-E stain) of the FNH shows a short septum containing a small amount of connective tissue and ductular proliferation. (Fig 3c shows ductular proliferation in the same slide.) (c) Photomicrograph (original magnification, x200; H-E stain) of a specimen from another patient shows a small area of FNH containing monotonous hepatocytes (*), an appearance that resembles that of adenoma and suggests a mixed type of FNH. (d) Photomicrograph (original magnification, x200; H-E stain) of a specimen from another patient shows telangiectatic FNH, which is composed of a relatively short septum (straight arrow) and atrophic hepatocytes with wider sinusoids than those normally present in classic FNH (curved arrow).

View larger version (158K): [in a new window]   Figure 4d.  Gross pathologic and histologic features of nonclassic FNH. (a) Cross section of a fixed resected specimen shows a nonclassic FNH (*). The lesion contains neither prominent septa nor a central scar. Normal liver tissue surrounds the FNH without a fibrous capsule. (b) Photomicrograph (original magnification, x200; H-E stain) of the FNH shows a short septum containing a small amount of connective tissue and ductular proliferation. (Fig 3c shows ductular proliferation in the same slide.) (c) Photomicrograph (original magnification, x200; H-E stain) of a specimen from another patient shows a small area of FNH containing monotonous hepatocytes (*), an appearance that resembles that of adenoma and suggests a mixed type of FNH. (d) Photomicrograph (original magnification, x200; H-E stain) of a specimen from another patient shows telangiectatic FNH, which is composed of a relatively short septum (straight arrow) and atrophic hepatocytes with wider sinusoids than those normally present in classic FNH (curved arrow).

View larger version (145K): [in a new window]   Figure 5a.  US appearance of FNH. (a) Sagittal US scan shows FNH that is slightly hypoechoic relative to the surrounding liver tissue (arrows) and causes slight distortion of the outer liver contour. (b) Sagittal oblique US scan of another patient shows FNH that is well differentiated from the surrounding liver tissue (arrow). There is a suggestion of radiating septa within the lesion. (c) Axial US scan of another patient shows FNH that is profoundly hypoechoic (arrow) due to diffuse fatty infiltration of the surrounding liver tissue.

View larger version (133K): [in a new window]   Figure 5b.  US appearance of FNH. (a) Sagittal US scan shows FNH that is slightly hypoechoic relative to the surrounding liver tissue (arrows) and causes slight distortion of the outer liver contour. (b) Sagittal oblique US scan of another patient shows FNH that is well differentiated from the surrounding liver tissue (arrow). There is a suggestion of radiating septa within the lesion. (c) Axial US scan of another patient shows FNH that is profoundly hypoechoic (arrow) due to diffuse fatty infiltration of the surrounding liver tissue.

View larger version (108K): [in a new window]   Figure 5c.  US appearance of FNH. (a) Sagittal US scan shows FNH that is slightly hypoechoic relative to the surrounding liver tissue (arrows) and causes slight distortion of the outer liver contour. (b) Sagittal oblique US scan of another patient shows FNH that is well differentiated from the surrounding liver tissue (arrow). There is a suggestion of radiating septa within the lesion. (c) Axial US scan of another patient shows FNH that is profoundly hypoechoic (arrow) due to diffuse fatty infiltration of the surrounding liver tissue.

View larger version (129K): [in a new window]   Figure 6a.  CT appearance of typical FNH with pathologic correlation. (a) Precontrast CT image shows a large lesion (straight arrow) that is only slightly hypoattenuating relative to the surrounding liver tissue. Within the lesion, a central scar (curved arrow) can be seen. (b) Contrast-enhanced CT image obtained during the arterial phase shows intense homogeneous enhancement of the lesion (straight arrow), except for the central scar (curved arrow). (c) Contrast-enhanced CT image obtained during the portal phase shows that the lesion (straight arrow) has become isoattenuating relative to the liver. The central scar (curved arrow) has not yet fully enhanced. (d) Photomicrograph (original magnification, x200; H-E stain) of a biopsy specimen shows classic FNH composed of nodules (*) surrounded by septa (straight arrow), which contain ductular proliferation, inflammatory infiltrates, connective tissue, and large vessels (curved arrow).

View larger version (151K): [in a new window]   Figure 6b.  CT appearance of typical FNH with pathologic correlation. (a) Precontrast CT image shows a large lesion (straight arrow) that is only slightly hypoattenuating relative to the surrounding liver tissue. Within the lesion, a central scar (curved arrow) can be seen. (b) Contrast-enhanced CT image obtained during the arterial phase shows intense homogeneous enhancement of the lesion (straight arrow), except for the central scar (curved arrow). (c) Contrast-enhanced CT image obtained during the portal phase shows that the lesion (straight arrow) has become isoattenuating relative to the liver. The central scar (curved arrow) has not yet fully enhanced. (d) Photomicrograph (original magnification, x200; H-E stain) of a biopsy specimen shows classic FNH composed of nodules (*) surrounded by septa (straight arrow), which contain ductular proliferation, inflammatory infiltrates, connective tissue, and large vessels (curved arrow).

View larger version (136K): [in a new window]   Figure 6c.  CT appearance of typical FNH with pathologic correlation. (a) Precontrast CT image shows a large lesion (straight arrow) that is only slightly hypoattenuating relative to the surrounding liver tissue. Within the lesion, a central scar (curved arrow) can be seen. (b) Contrast-enhanced CT image obtained during the arterial phase shows intense homogeneous enhancement of the lesion (straight arrow), except for the central scar (curved arrow). (c) Contrast-enhanced CT image obtained during the portal phase shows that the lesion (straight arrow) has become isoattenuating relative to the liver. The central scar (curved arrow) has not yet fully enhanced. (d) Photomicrograph (original magnification, x200; H-E stain) of a biopsy specimen shows classic FNH composed of nodules (*) surrounded by septa (straight arrow), which contain ductular proliferation, inflammatory infiltrates, connective tissue, and large vessels (curved arrow).

View larger version (173K): [in a new window]   Figure 6d.  CT appearance of typical FNH with pathologic correlation. (a) Precontrast CT image shows a large lesion (straight arrow) that is only slightly hypoattenuating relative to the surrounding liver tissue. Within the lesion, a central scar (curved arrow) can be seen. (b) Contrast-enhanced CT image obtained during the arterial phase shows intense homogeneous enhancement of the lesion (straight arrow), except for the central scar (curved arrow). (c) Contrast-enhanced CT image obtained during the portal phase shows that the lesion (straight arrow) has become isoattenuating relative to the liver. The central scar (curved arrow) has not yet fully enhanced. (d) Photomicrograph (original magnification, x200; H-E stain) of a biopsy specimen shows classic FNH composed of nodules (*) surrounded by septa (straight arrow), which contain ductular proliferation, inflammatory infiltrates, connective tissue, and large vessels (curved arrow).

View larger version (122K): [in a new window]   Figure 7a.  MR imaging appearance of typical FNH. (a) Axial T2-weighted single-shot fast spin-echo (SE) image shows a large FNH lesion (straight arrow) that is isointense relative to the surrounding liver parenchyma. The central scar (curved arrow) has slightly higher signal intensity than the lesion. (b) Axial gadolinium-enhanced 2D T1-weighted GRE image obtained during the arterial phase shows intense homogeneous enhancement of the entire lesion (straight arrow), except for the central scar (curved arrow). (c) Axial gadolinium-enhanced 2D T1-weighted GRE image obtained during the portal phase shows that the lesion (straight arrow) has become isointense relative to the surrounding liver parenchyma, and the central scar (curved arrow) has enhanced.

View larger version (126K): [in a new window]   Figure 7b.  MR imaging appearance of typical FNH. (a) Axial T2-weighted single-shot fast spin-echo (SE) image shows a large FNH lesion (straight arrow) that is isointense relative to the surrounding liver parenchyma. The central scar (curved arrow) has slightly higher signal intensity than the lesion. (b) Axial gadolinium-enhanced 2D T1-weighted GRE image obtained during the arterial phase shows intense homogeneous enhancement of the entire lesion (straight arrow), except for the central scar (curved arrow). (c) Axial gadolinium-enhanced 2D T1-weighted GRE image obtained during the portal phase shows that the lesion (straight arrow) has become isointense relative to the surrounding liver parenchyma, and the central scar (curved arrow) has enhanced.

View larger version (114K): [in a new window]   Figure 7c.  MR imaging appearance of typical FNH. (a) Axial T2-weighted single-shot fast spin-echo (SE) image shows a large FNH lesion (straight arrow) that is isointense relative to the surrounding liver parenchyma. The central scar (curved arrow) has slightly higher signal intensity than the lesion. (b) Axial gadolinium-enhanced 2D T1-weighted GRE image obtained during the arterial phase shows intense homogeneous enhancement of the entire lesion (straight arrow), except for the central scar (curved arrow). (c) Axial gadolinium-enhanced 2D T1-weighted GRE image obtained during the portal phase shows that the lesion (straight arrow) has become isointense relative to the surrounding liver parenchyma, and the central scar (curved arrow) has enhanced.

View larger version (141K): [in a new window]   Figure 8a.  Appearance of typical FNH at superparamagnetic iron oxide (ferucarbotran)-enhanced MR imaging. (a) Axial unenhanced T2-weighted fast SE image shows a large FNH lesion (straight arrow) that is isointense relative to the surrounding liver parenchyma. The central scar (curved arrow) has slightly higher signal intensity than the lesion. (b) Axial contrast-enhanced fast SE image shows that the lesion (straight arrow) as well as the liver and spleen have decreased signal intensity due to the uptake of ferucarbotran into Kupffer cells. The central scar (curved arrow) does not contain Kupffer cells and has relatively increased signal intensity.

View larger version (114K): [in a new window]   Figure 8b.  Appearance of typical FNH at superparamagnetic iron oxide (ferucarbotran)-enhanced MR imaging. (a) Axial unenhanced T2-weighted fast SE image shows a large FNH lesion (straight arrow) that is isointense relative to the surrounding liver parenchyma. The central scar (curved arrow) has slightly higher signal intensity than the lesion. (b) Axial contrast-enhanced fast SE image shows that the lesion (straight arrow) as well as the liver and spleen have decreased signal intensity due to the uptake of ferucarbotran into Kupffer cells. The central scar (curved arrow) does not contain Kupffer cells and has relatively increased signal intensity.

View larger version (126K): [in a new window]   Figure 9a.  MR imaging appearance of multiple FNH lesions. (a) Axial gadolinium-enhanced fat-saturated 3D fast GRE image obtained during the arterial phase shows intense homogeneous enhancement of two lesions (arrows). This finding is compatible with FNH. (b) Photomicrograph (original magnification, x200; H-E stain) of a biopsy specimen from one of the lesions shows classic FNH composed of nodules (*) with fatty infiltration (open arrow). Septa (curved arrow) surround the nodules and contain ductular proliferation, inflammatory infiltrates, connective tissue, and vessels.

View larger version (139K): [in a new window]   Figure 9b.  MR imaging appearance of multiple FNH lesions. (a) Axial gadolinium-enhanced fat-saturated 3D fast GRE image obtained during the arterial phase shows intense homogeneous enhancement of two lesions (arrows). This finding is compatible with FNH. (b) Photomicrograph (original magnification, x200; H-E stain) of a biopsy specimen from one of the lesions shows classic FNH composed of nodules (*) with fatty infiltration (open arrow). Septa (curved arrow) surround the nodules and contain ductular proliferation, inflammatory infiltrates, connective tissue, and vessels.

View larger version (126K): [in a new window]   Figure 10a.  MR imaging appearance of multiple HCCs in a noncirrhotic liver. (a) Axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the arterial phase shows heterogeneous enhancement of two lesions (arrows). (b) Photomicrograph (original magnification, x100; H-E stain) of a resected specimen from the larger lesion shows an HCC (*) surrounded by a fibrous tumor capsule (arrow).

View larger version (162K): [in a new window]   Figure 10b.  MR imaging appearance of multiple HCCs in a noncirrhotic liver. (a) Axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the arterial phase shows heterogeneous enhancement of two lesions (arrows). (b) Photomicrograph (original magnification, x100; H-E stain) of a resected specimen from the larger lesion shows an HCC (*) surrounded by a fibrous tumor capsule (arrow).

View larger version (111K): [in a new window]   Figure 11a.  MR imaging appearance of an FNH lesion with a prominent pseudocapsule. (a) Axial fat-saturated T2-weighted fast SE image shows a medium-sized FNH lesion (arrow) with a central scar, a pseudocapsule, and septa, all of which are prominent and have high signal intensity. (b) Axial gadolinium-enhanced 3D GRE image obtained during the arterial phase shows intense homogeneous enhancement of the lesion (arrow), except for the central scar and septa. (c) Axial gadolinium-enhanced 3D GRE image obtained during the delayed phase shows enhancement of the central scar as well as the pseudocapsule (arrow).

View larger version (109K): [in a new window]   Figure 11b.  MR imaging appearance of an FNH lesion with a prominent pseudocapsule. (a) Axial fat-saturated T2-weighted fast SE image shows a medium-sized FNH lesion (arrow) with a central scar, a pseudocapsule, and septa, all of which are prominent and have high signal intensity. (b) Axial gadolinium-enhanced 3D GRE image obtained during the arterial phase shows intense homogeneous enhancement of the lesion (arrow), except for the central scar and septa. (c) Axial gadolinium-enhanced 3D GRE image obtained during the delayed phase shows enhancement of the central scar as well as the pseudocapsule (arrow).

View larger version (92K): [in a new window]   Figure 11c.  MR imaging appearance of an FNH lesion with a prominent pseudocapsule. (a) Axial fat-saturated T2-weighted fast SE image shows a medium-sized FNH lesion (arrow) with a central scar, a pseudocapsule, and septa, all of which are prominent and have high signal intensity. (b) Axial gadolinium-enhanced 3D GRE image obtained during the arterial phase shows intense homogeneous enhancement of the lesion (arrow), except for the central scar and septa. (c) Axial gadolinium-enhanced 3D GRE image obtained during the delayed phase shows enhancement of the central scar as well as the pseudocapsule (arrow).

View larger version (110K): [in a new window]   Figure 12a.  MR imaging appearance of an HCC with a tumor capsule in a noncirrhotic liver. (a) Axial fat-saturated T2-weighted fast SE image shows an HCC with predominantly high signal intensity (arrow). Owing to its fibrotic nature, the tumor capsule has low signal intensity on T2-weighted images and therefore is not visible. (b) Axial gadolinium-enhanced 3D GRE image obtained during the arterial phase shows intense, nearly homogeneous enhancement of the lesion (arrow). This appearance may simulate FNH. (c) Axial gadolinium-enhanced 3D GRE image obtained during the delayed phase shows enhancement of the tumor capsule surrounding the lesion (arrow), which demonstrates complete washout.

View larger version (105K): [in a new window]   Figure 12b.  MR imaging appearance of an HCC with a tumor capsule in a noncirrhotic liver. (a) Axial fat-saturated T2-weighted fast SE image shows an HCC with predominantly high signal intensity (arrow). Owing to its fibrotic nature, the tumor capsule has low signal intensity on T2-weighted images and therefore is not visible. (b) Axial gadolinium-enhanced 3D GRE image obtained during the arterial phase shows intense, nearly homogeneous enhancement of the lesion (arrow). This appearance may simulate FNH. (c) Axial gadolinium-enhanced 3D GRE image obtained during the delayed phase shows enhancement of the tumor capsule surrounding the lesion (arrow), which demonstrates complete washout.

View larger version (103K): [in a new window]   Figure 12c.  MR imaging appearance of an HCC with a tumor capsule in a noncirrhotic liver. (a) Axial fat-saturated T2-weighted fast SE image shows an HCC with predominantly high signal intensity (arrow). Owing to its fibrotic nature, the tumor capsule has low signal intensity on T2-weighted images and therefore is not visible. (b) Axial gadolinium-enhanced 3D GRE image obtained during the arterial phase shows intense, nearly homogeneous enhancement of the lesion (arrow). This appearance may simulate FNH. (c) Axial gadolinium-enhanced 3D GRE image obtained during the delayed phase shows enhancement of the tumor capsule surrounding the lesion (arrow), which demonstrates complete washout.

View larger version (112K): [in a new window]   Figure 13a.  MR imaging appearance of an FNH lesion with a prominent central scar. (a) Axial fat-saturated T2-weighted fast SE image shows a large FNH lesion with a prominent central scar (arrow), which has high signal intensity. A pseudocapsule is not visible. (b) Axial gadolinium-enhanced fat-saturated 2D T1-weighted GRE image obtained during the delayed phase shows that the lesion has become isointense relative to the liver and the central scar has enhanced (arrow).

View larger version (111K): [in a new window]   Figure 13b.  MR imaging appearance of an FNH lesion with a prominent central scar. (a) Axial fat-saturated T2-weighted fast SE image shows a large FNH lesion with a prominent central scar (arrow), which has high signal intensity. A pseudocapsule is not visible. (b) Axial gadolinium-enhanced fat-saturated 2D T1-weighted GRE image obtained during the delayed phase shows that the lesion has become isointense relative to the liver and the central scar has enhanced (arrow).

View larger version (114K): [in a new window]   Figure 14a.  MR imaging appearance of a giant hemangioma with a prominent central scar. (a) Axial fat-saturated T2-weighted fast SE image shows a high-signal-intensity giant hemangioma (straight arrow) with a prominent central scar (curved arrow), which has even higher signal intensity than the lesion. Note the smaller hemangioma without a central scar. (b) On an axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the delayed phase, the smaller lesion (arrow) has completely filled in, whereas the central scar within the larger lesion has not enhanced.

View larger version (120K): [in a new window]   Figure 14b.  MR imaging appearance of a giant hemangioma with a prominent central scar. (a) Axial fat-saturated T2-weighted fast SE image shows a high-signal-intensity giant hemangioma (straight arrow) with a prominent central scar (curved arrow), which has even higher signal intensity than the lesion. Note the smaller hemangioma without a central scar. (b) On an axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the delayed phase, the smaller lesion (arrow) has completely filled in, whereas the central scar within the larger lesion has not enhanced.

View larger version (117K): [in a new window]   Figure 15a.  MR imaging appearance of an HCC with a central scar in a patient who was not cirrhotic but who had extremely high levels of -fetoprotein. (a) Axial fat-saturated T2-weighted fast SE image shows a predominantly high-signal-intensity lesion (arrow) with a low-signal-intensity central scar. (b) Axial gadolinium-enhanced fat-saturated 2D T1-weighted GRE image obtained during the delayed phase shows washout of contrast material in most of the lesion and an enhanced tumor capsule (arrow). The central scar remains mainly unenhanced.

View larger version (126K): [in a new window]   Figure 15b.  MR imaging appearance of an HCC with a central scar in a patient who was not cirrhotic but who had extremely high levels of -fetoprotein. (a) Axial fat-saturated T2-weighted fast SE image shows a predominantly high-signal-intensity lesion (arrow) with a low-signal-intensity central scar. (b) Axial gadolinium-enhanced fat-saturated 2D T1-weighted GRE image obtained during the delayed phase shows washout of contrast material in most of the lesion and an enhanced tumor capsule (arrow). The central scar remains mainly unenhanced.

View larger version (164K): [in a new window]   Figure 16a.  MR imaging appearance of an FNH lesion with a low-signal-intensity scar and a pseudocapsule. (a) Axial fat-saturated T2-weighted fast SE image shows a predominantly high-signal-intensity FNH lesion with a spinning wheel appearance due to the presence of radiating septa and a pseudocapsule (arrow). (b) Axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the arterial phase shows intense enhancement of most of the central part of the lesion (arrow). (c) Axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the portal phase shows nearly homogeneous enhancement of the lesion, including the pseudocapsule (arrow). The lesion has becomes nearly isointense relative to the surrounding liver tissue. (d) Axial T2-weighted fast SE image and corresponding photograph of an orange show a striking similarity to the FNH lesion.

View larger version (142K): [in a new window]   Figure 16b.  MR imaging appearance of an FNH lesion with a low-signal-intensity scar and a pseudocapsule. (a) Axial fat-saturated T2-weighted fast SE image shows a predominantly high-signal-intensity FNH lesion with a spinning wheel appearance due to the presence of radiating septa and a pseudocapsule (arrow). (b) Axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the arterial phase shows intense enhancement of most of the central part of the lesion (arrow). (c) Axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the portal phase shows nearly homogeneous enhancement of the lesion, including the pseudocapsule (arrow). The lesion has becomes nearly isointense relative to the surrounding liver tissue. (d) Axial T2-weighted fast SE image and corresponding photograph of an orange show a striking similarity to the FNH lesion.

View larger version (151K): [in a new window]   Figure 16c.  MR imaging appearance of an FNH lesion with a low-signal-intensity scar and a pseudocapsule. (a) Axial fat-saturated T2-weighted fast SE image shows a predominantly high-signal-intensity FNH lesion with a spinning wheel appearance due to the presence of radiating septa and a pseudocapsule (arrow). (b) Axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the arterial phase shows intense enhancement of most of the central part of the lesion (arrow). (c) Axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the portal phase shows nearly homogeneous enhancement of the lesion, including the pseudocapsule (arrow). The lesion has becomes nearly isointense relative to the surrounding liver tissue. (d) Axial T2-weighted fast SE image and corresponding photograph of an orange show a striking similarity to the FNH lesion.

View larger version (84K): [in a new window]   Figure 16d.  MR imaging appearance of an FNH lesion with a low-signal-intensity scar and a pseudocapsule. (a) Axial fat-saturated T2-weighted fast SE image shows a predominantly high-signal-intensity FNH lesion with a spinning wheel appearance due to the presence of radiating septa and a pseudocapsule (arrow). (b) Axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the arterial phase shows intense enhancement of most of the central part of the lesion (arrow). (c) Axial gadolinium-enhanced fat-saturated 3D GRE image obtained during the portal phase shows nearly homogeneous enhancement of the lesion, including the pseudocapsule (arrow). The lesion has becomes nearly isointense relative to the surrounding liver tissue. (d) Axial T2-weighted fast SE image and corresponding photograph of an orange show a striking similarity to the FNH lesion.