Tara C. Noone

Budd‐chiari syndrome: Spectrum of appearances of acute, subacute, and chronic disease with magnetic resonance imaging

The purpose of this study was to describe our collective experience in the magnetic resonance (MR) investigation of patients with proven acute, subacute, and chronic Budd‐Chiari syndrome and to demonstrate the spectrum of appearances on T1‐ and T2‐weighted as well as dynamic post‐gadolinium spoiled gradient‐echo imaging. All patients with proven Budd‐Chiari syndrome who underwent MR examinations between June, 1992 and October, 1998 were included in the study. Fourteen patients were included in the study: four with acute, three with subacute, three with chronic, and four with acute superimposed on either subacute (two) or chronic (two) Budd‐Chiari syndrome. MR imaging features were retrospectively evaluated to determine: a) liver morphology, b) pattern of signal intensity (SI) on T1‐weighted images, c) pattern of SI on T2 weighted images, d) dynamic enhancement characteristics, e) presence or absence of visible venous thrombosis, and f) presence or absence of venous macroscopic collaterals. The MR findings were correlated with surgical, histopathological, and laboratory data to determine imaging characteristics related to the chronicity of the disease process. Hepatic venous thrombosis or absence of hepatic venous flow was demonstrated in all patients in the study. In the four patients with acute Budd‐Chiari syndrome, the liver periphery was moderately low signal on T1 and moderately high signal on T2‐weighted images relative to the central liver; both early and late gadolinium—enhanced images revealed diminished peripheral enhancement. In the three patients with subacute Budd‐Chiari syndrome, the liver periphery was moderately low signal on T1, and moderately high signal on T2‐weighted images, while early and late gadolinium‐enhanced images revealed heterogenously increased enhancement within the liver periphery. In the three patients with chronic Budd‐Chiari syndrome, the SI differences between peripheral and central liver were minimal on T1‐ and T2‐weighted images, and enhancement differences were also minimal. Extensive bridging intrahepatic and capsular venous collaterals were visualized in chronic cases. In the four patients with acute Budd‐Chiari syndrome superimposed on more chronic disease, a combination of gadolinium enhancement patterns was observed on MR images. Enhancement patterns between central and peripheral liver were different for acute, subacute, and chronic Budd‐Chiari syndromes, suggesting differentiation between these phases of the disease process. Application of this pattern approach permitted recognition of acute changes superimposed on more chronic disease. J. Magn. Reson. Imaging 2000;11:44–50.

Cholangiocarcinoma: Spectrum of appearances on mr images using current techniques

This study describes the spectrum of appearances of cholangiocarcinoma on magnetic resonance (MR) sequences, including gadolinium-enhanced, fat-suppressed spoiled gradient echo images and MR cholangiography. Fifteen patients were included in the study. Histologic diagnosis was established in 11 patients by surgical resection (6 patients), percutaneous biopsy (4 patients), and open liver biopsy (1 patient). The final diagnosis was determined by correlation of the MR findings with cholangiographic studies and laboratory studies in 4 patients. MR studies were performed at 1.5 T, and the following sequences were obtained: T1-weighted spoiled gradient echo (SGE), T1-weighted fat-suppressed spin echo or SGE, T2-weighted fat-suppressed conventional or turbo spin echo, MR cholangiography, and gadolinium-enhanced T1-weighted fat-suppressed SGE images. The following determinations were made: tumor location, tumor extent, ductal dilatation, ductal wall thickness, signal intensity, enhancement pattern, and associated findings. Mass-like neoplasms were peripheral (6 patients), hilar (1 patient), and extrahepatic (2 patients). Circumferential tumors were hilar (2 patients) and extrahepatic (4 patients). All peripheral tumors were multifocal. Mass-like tumors were well-defined, rounded, and ranged from 1 to 14 cm in diameter. Circumferential tumors had less well-defined margins and measured from 3 to 15 mm in thickness. All mass-like tumors were moderately hypointense on T1-weighted images and mildly to moderately hyperintense on T2-weighted images. The circumferential tumors were iso- to moderately hypointense on T1-weighted images and iso- to mildly hyperintense on T2-weighted images. Mass-like tumors were generally well shown on non-contrast and immediate gadolinium-enhanced images, whereas circumferential tumors were poorly seen on non-contrast images and best shown on gadolinium-enhanced T1-weighted fat-suppressed images. The degree of enhancement ranged from minimal to intense on immediate gadolinium-enhanced images, with all tumors becoming more homogeneous in signal intensity on images obtained between 1 and 5 min following contrast administration. Tumor-containing lymph nodes greater than or equal to 1 cm in diameter were demonstrated in 11 out of 15 patients (73.3%). These were best shown on T2-weighted fat-suppressed images and gadolinium-enhanced fat-suppressed SGE images. MR cholangiography demonstrated the level of obstruction and degree of dilatation of the proximal biliary system in 5 out of 6 patients who underwent MR cholangiography. The spectrum of appearances of cholangiocarcinoma is demonstrable on MR images. Mass-like tumors are well shown on both pre- and post-gadolinium sequences. Circumferential tumors may cause minimally increased duct wall thickness and are most clearly shown on gadolinium-enhanced fat-suppressed SGE images obtained 1 to 5 min following gadolinium administration.

Pyogenic hepatic abscesses: MRI findings on T1- and T2-weighted and serial gadolinium-enhanced gradient-echo images.

The purpose of this study was to determine the magnetic resonance imaging (MRI) features of pyogenic hepatic abscesses on T1‐weighted, T2‐weighted, and serial gadolinium (Gd)‐enhanced T1‐weighted spoiled gradient‐echo (SGE) images including images acquired in the immediate, intermediate, and late phases of enhancement. The MRI studies of 20 patients with pyogenic liver abscesses were retrospectively reviewed. All patients were examined on 1.5 (n = 19) and 1.0 (n = 1) T MR scanners. MR studies included T1‐weighted, T2‐weighted, and serial Gd‐enhanced SGE images. The following determinations were made: signal intensity of the abscess cavity and perilesional liver tissue, and the presence of internal septations, layering material, or air in the abscess cavity. The pattern of enhancement of the abscess wall, internal septae and peri‐abscess liver were evaluated on serial Gd‐enhanced SGE images. A total of 53 abscesses were observed in the 20 patients. Forty‐eight abscesses were hypointense on T1‐weighted and hyperintense on T2‐weighted images. Internal septations were present in four abscesses. Lower signal intensity material was observed in a dependent location on T2‐weighted images in one abscess. Signal void foci of air located on the nondependent surface was observed in two abscesses. Two other abscesses contained signal void air that occupied the entire abscess cavity, observed on all imaging sequences. On serial gadolinium‐enhanced images, all abscesses revealed early enhancement of the wall, which persisted with negligible change in degree of enhancement or thickness on delayed images. Abscess walls ranged in thickness from 2 to 5 mm. Internal septations ranged in thickness from 2 to 3 mm. Abscess walls and septations were relatively uniform in thickness with no evidence of focal nodularity. Periabscess liver tissue was mildly hypointense on T1‐weighted and mildly hyperintense on T2‐weighted images in 20 lesions, which were either circumferential (n = 12) or wedge‐shaped (n = 8). All these regions enhanced more than the remainder of the liver on immediate post‐gadolinium images and remained relatively hyperintense on late phase images. Periabscess liver parenchyma was isointense on both T1‐ and T2‐weighted images in 18 lesions, and in these lesions wedge‐shaped subsegmental (n = 6) or segmental (n = 12) enhancement was observed on immediate gadolinium‐enhanced images, which faded to isointensity on intermediate phase images. No perilesional signal changes and enhancement difference was observed in 15 lesions. Characteristic features of abscesses include: intense mural enhancement on early gadolinium‐enhanced images, which persists with negligible change in thickness and intensity on later post‐gadolinium images, and the presence of periabscess increased enhancement on immediate post‐gadolinium images. These MRI features may help to distinguish abscesses from other focal liver lesions during differential diagnosis.J. Magn. Reson. Imaging 1999;9:285–290.

Chemotherapy-treated liver metastases mimicking hemangiomas on MR images.

AbstractBackground: To report the observation that chemotherapy-treated liver metastases may mimic the appearance of hemangiomas on T2-weighted and serial postgadolinium gradient-echo magnetic resonance (MR) images. Methods: T2-weighted and serial postgadolinium spoiled gradient-echo images were prospectively and retrospectively analyzed in six patients. All patients had been treated with chemotherapy for a duration of 2–12 months. Histopathologic evaluation of liver lesions was performed in three patients. Results: Twelve lesions that resembled hemangiomas were identified. Lesions were 0.8–5.5 cm in diameter. All were well defined, oval or lobulated, and demonstrated decreased signal intensity on T1-weighted images and increased signal intensity on T2-weighted images. On immediate postgadolinium images, all lesions demonstrated peripheral nodular enhancement, which coalesced on delayed imaging. Final histopathologic diagnoses were as follows: hepatic metastases from colon cancer (two patients), ovarian cancer (two patients), pancreatic islet cell tumor (one patient), and breast cancer (one patient). Conclusions: Metastases treated by chemotherapy may mimic the appearance of hemangiomas on a variety of commonly employed MR techniques. In patients undergoing MR imaging for the evaluation of liver metastases, a history of prior chemotherapy administration and duration should be sought to prevent inaccurate staging and inappropriate therapeutic decision making.

Islet cell tumor of the pancreas associated with tumor thrombus in the portal vein

We report the MR findings of a 70-year-old man with an islet cell tumor that diffusely involved the body of the pancreas associated with enhancing portal vein tumor thrombus and cavernous transformation. The diffusely infiltrative tumor mass was best shown on early post gadolinium spoiled gradient echo. The tumor thrombus enhanced intensely on early post gadolinium images and was also well shown on true FISP (Fast Imaging with Steady State Precession) images. The extent of liver metastases was best shown on fat suppressed T2-weighted images. The most unusual finding was tumor thrombus involving the SMV and portal vein.

Ultrasound and MR findings in acute Budd-Chiari syndrome with histopathologic correlation

This report describes the sonographic and MR appearances of acute Budd-Chiari syndrome (BCS) in a 30-year-old woman. Current imaging techniques including duplex Doppler sonography and dynamic gadolinium-enhanced MRI were employed, and direct histopathologic correlation was made. Duplex Doppler sonography revealed a heterogeneous enlarged liver, no flow in the left and middle hepatic veins, and only trace abnormal flow in the distal-most right hepatic vein. Dynamic serial gadolinium-enhanced, spoiled gradient echo imaging demonstrated early homogeneous enhancement of an enlarged caudate lobe, as well as heterogeneously decreased enhancement of the remainder of the hepatic parenchyma. This differential enhancement pattern persisted on delayed imaging. Patent hepatic veins were not demonstrated on any sequence. Associated findings included hepatomegaly, ascites, and patent portal vasculature. These imaging findings were interpreted as consistent with acute BCS. Within 10 days, the patient underwent orthotopic liver transplantation. Histopathology demonstrated hepatic necrosis and hepatic venous thrombosis consistent with acute BCS.

MRI of normal and abnormal duodenum using Half-Fourier Single-Shot RARE and gadolinium-enhanced spoiled gradient echo sequences.

The objective of this research was two-fold: First, to describe the normal and abnormal MR appearances of the duodenum using combined Half-Fourier Acquisition Single Shot RARE (HASTE) and gadolinium-enhanced standard and fat suppressed spoiled gradient echo (SGE) sequences. The second objective was to assess the ability of these combined sequences to detect and characterize duodenal diseases. MR examinations were performed on fifty consecutive patients with no clinical history of duodenal diseases, who were 1) imaged with HASTE and gadolinium-enhanced standard and fat suppressed SGE sequences and 2) referred to MR examination for reasons other than duodenal diseases, and were reviewed retrospectively to determine the normal MR appearances of the duodenum. A second population of patients with abnormal duodenum who were imaged with the same MR sequences were included in the second part of this study. This population was composed of 20 consecutive patients with subsequently proven duodenal abnormalities, including: malrotation (2), diverticula (4), intussusception (1), sprue (1), polyps (2), neurofibroma (1), lymphoma (1), Zollinger Ellison syndrome (1), metastatic disease (1), Crohns disease (1), and wall thickening and duodenitis (5). Normal measurements of the duodenum are described. Abnormalities of wall thickness and duodenal masses required combined HASTE and gadolinium-enhanced SGE images to evaluate well. Abnormalities of the bowel lumen (e.g., diverticula and intussusception), and developmental variants (e.g., malrotation), were sufficiently visualized on HASTE images alone. Bowel inflammation was best shown on gadolinium-enhanced fat suppressed SGE images. HASTE and gadolinium-enhanced fat suppressed SGE sequences are complementary techniques for the demonstration of normal and abnormal duodenum. The combined use of both sequences allows evaluation of different aspects of bowel diseases; abnormalities of position, lumen, and contents are well shown on HASTE, while inflammation is best shown on gadolinium enhanced fat suppressed SGE, and wall thickening and masses are best evaluated with the combined use of both techniques.

Common occurrence of benign liver lesions in patients with newly diagnosed breast cancer investigated by MRI for suspected liver metastases

The purpose of this study was to determine the prevalence of benign liver lesions in patients with breast cancer who are referred to magnetic resonance (MR) imaging for suspected breast cancer metastases at initial presentation. The original MR imaging reports of consecutive patients with breast cancer were reviewed; these patients had undergone MR imaging at our institution to investigate for suspected breast cancer liver metastases, at initial presentation between April 1993 and May 1998. Determination of the presence of benign and malignant liver lesions in each patient was made, as well as their relative frequencies. Diagnostic accuracy of MR imaging was evaluated by correlation with histologic specimens (5 patients) and imaging follow‐up (27 patients). Thirty‐four patients with newly diagnosed breast carcinoma were evaluated with MR imaging. A total of 11 (32%) of these patients had benign lesions only. Of 21 (62%) total patients who had malignant liver lesions, 19 had breast cancer metastases (2 had coexistent benign lesions), 1 had metastatic carcinoid, and 1 had hepatocellular carcinoma. No liver lesions were detected in two patients (6%). In one patient with biopsy‐proven subcentimeter breast metastases, no focal lesions were shown on MR imaging. No other diagnostic errors in classification of liver lesions by MR imaging occurred, as shown by clinical correlation and imaging follow‐up in all patients. True positive detection of malignant liver lesion was 20/21, true negative was 13/13, false positive was 0/13, and false negative was 1/21, for a sensitivity of 95% and a specificity of 100% for the detection of malignant liver lesions. Benign liver lesions are common in breast cancer patients suspected clinically of having liver metastases. Benign lesions alone were observed in one‐third of our patients. The high diagnostic accuracy of MR imaging in the evaluation of hepatic lesions underscores the value of this technique for baseline investigation of breast cancer patients with clinically suspected liver metastases, particularly patients in whom treatment approaches are dramatically affected by the presence of liver metastases. J. Magn. Reson. Imaging 1999;10:165–169.

Acute and subacute liver-related hemorrhage: MRI findings.

We retrospectively reviewed the MR studies on all patients with liver-related fluid collections compatible with acute or early subacute hemorrhage, who underwent MR imaging at our center between June 1994 and January 1998. All patients had a clinical history of an underlying liver lesion or injury with a duration of symptomatology of less than 5 days. In three patients with only 2-3 days of symptoms, the liver-related hemorrhagic fluid was hypointense on T1-weighted images and markedly hypointense on T2-weighted images relative to liver, consistent with intracellular deoxyhemoglobin. The fluid was relatively homogeneous in signal intensity. In three patients with 3-5 days of symptoms, the majority of liver-related fluid was hyperintense on T1-weighted images and hypointense on T2-weighted images relative to liver, consistent with intracellular methemoglobin. Three of these latter four patients also had fluid collections of varying T1-and T2-weighted signal intensity consistent with blood breakdown products of varying ages. Clinical findings matched the MR findings of acute/early subacute blood in all cases. Our results describe the findings of acute and early subacute liver hemorrhage. The most helpful MR feature of bleeding of recent origin is very low signal intensity of the fluid on T2-weighted imaging.