MRI findings of recurrent hepatocellular carcinoma after liver transplantation: preliminary results.

PURPOSE: To describe the patterns of recurrence and serial magnetic resonance imaging (MRI) features of hepatocellular carcinoma (HCC) after liver transplantation. MATERIALS AND METHODS: All cases of recurrent HCC after transplantation between September 2002 and August 2009 that underwent MRI including precontrast T1, T2-weighted images, and postgadolinium dynamic images were reviewed. On MRI we evaluated the characteristics and patterns of recurrent HCC after transplantation. RESULTS: A total 7 of 76 transplanted patients (four men, three women, age range, 45-63, mean 52.7 years) were included in this study. Four patients (57.1%) were identified to have a pattern of persistent local disease (PLD) near the transplanted liver, hepatorenal space, or suture site within 2.75 years (range, 2-4 years). Two patients showed recurrent HCC in the allograft alone within 5 years. One patient showed an intraperitoneal seeding (IPS) pattern which demonstrated diffuse peritoneal infiltration and thickening within 9 months. The diffuse metastatic disease (DMD) pattern was observed as a late manifestation of PLD and IPS. The most prominent volume of recurrent tumor burden was found in an extrahepatic (5 of 7 patients) compared to an intrahepatic (2 of 7 patients) location. The signal intensities and enhancement patterns did not exhibit change with disease progression. CONCLUSION: We describe four patterns of recurrence of HCC following transplant. The most prominent tumor burden was located in an extrahepatic compared to an intrahepatic location.

Health care systems of developed non-U.S. nations: strengths, weaknesses, and recommendations for the United States--observations from internationally recognized imaging specialists.

OBJECTIVE: The purpose of this article is to survey imaging experts from developed nations on their impression of their own health care system and recommendations for the U.S. health care system as it seeks to enact health care reform. MATERIALS AND METHODS: A survey was sent to individual imaging experts from developed nations requesting information on their health care systems (type of system, strengths, and weaknesses) and their recommendations for the United States. RESULTS: Eighteen respondents from 17 developed nations completed the survey. All respondents reported universal health care coverage: four with government-operated health care, one with mixed government and private insurance-operated health care, 10 with predominantly government run with private insurance supplementation health care, and one with predominantly private insurance with government-operated supplementation health care. The most commonly cited strength was universal health care coverage for all citizens. The most commonly cited weakness was prolonged wait times. Notably absent was concern by the respondent physicians about malpractice litigation. The most commonly cited recommendation was the implementation of a universal health care coverage program. CONCLUSION: In our survey of 18 imaging experts from 17 nations outside the United States, most respondents thought that their nations offered adequate universal health care coverage for their citizens, with the primary drawback of long wait times.

Management of branch-duct intraductal papillary mucinous neoplasms of the pancreas: observation with MR imaging.

PURPOSE: To evaluate the clinical outcomes of conservative management by observation with MRI of patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs). MATERIALS AND METHODS: Twenty-three consecutive patients, who were followed up by MRI with magnetic resonance cholangiopancreatography (MRCP) over a period of more than 9 months after initial MRI examinations, were enrolled in this study. On MRI, number of lesions, the maximum diameter of BD-IPMNs, lesion location, the presence of associated dilatation of main pancreatic duct (MPD), the presence of enhancing mural nodules within the lesion and the presence of interval change were retrospectively reviewed on initial and follow-up MR images in consensus by two radiologists. All patients were evaluated to search for evidence of malignant progression of disease. RESULTS: The follow-up period ranged from 10 to 96 months (mean, 37 months). On initial MRI with MRCP, a total of 39 lesions were found in 23 patients. The maximum diameter of BD-IPMNs ranged between 6 and 32 mm, with a mean of 12 mm. Thirty-four lesions (87%) of 19 patients remained unchanged in the maximum diameter. Five lesions (13%) of four patients showed an increase in the maximum diameter. Enhancing mural nodules were not found in any individual, neither on the initial MRI study nor on the follow-up studies. There was no patient who had evidence of local aggressive growth of tumor or evidence of metastases to distant sites. CONCLUSION: Our study suggests that branch-duct IPMNs without enhancing mural nodules are essentially benign and should be managed nonoperatively through observation by MRI.

MRI findings of rapidly progressive hepatocellular carcinoma.

PURPOSE: The purpose of this study is to determine the magnetic resonance imaging (MRI) and patient characteristics in subjects with hepatocellular carcinoma (HCC) that exhibit rapid progression. MATERIALS AND METHODS: In this unblinded retrospective study, initial and follow up MR images were reviewed, before and after rapid progression of HCC, respectively. Rapid progression was defined as a lesion <3 cm which exhibited >3 cm increase in one year or 2 cm increase in 6 months. Patient characteristics and MRI findings were determined using clinical information from the institution clinical information system and records from the Radiology and Pathology Departments, Hepatology Division and Liver Transplant Service of the Department of Medicine. RESULTS: Seven individuals were identified with HCC that showed rapid progression. Five of the patients had underlying hepatitis C, one had alcoholic hepatitis, and one had immunosuppression due to liver transplantation. On initial MRI, six patients had early intense ring enhancing lesions, which rapidly progressed in size. Five patients died within 6 months, one within 1 year after progression despite treatment. Six of the seven patients also had multiple other liver nodules on initial MRI; those that showed ring enhancement rapidly progressed but those without, did not show rapid progression. CONCLUSION: Patients with rapidly progressive HCC had underlying hepatitis C and intense ring enhancement on initial MRI. This group of patients should be evaluated further to determine if they might benefit from early intervention.

Magnetic resonance angiography visualization of abnormal tumor vasculature in genetically engineered mice.

Previous research on the vasculature of tumor-bearing animals has focused upon the microvasculature. Magnetic resonance angiography (MRA) offers a noninvasive, complementary approach that provides information about larger vessels. Quantitative analysis of MRA images of spontaneous preclinical tumor models has not been previously reported. Eleven TgT121;p53+/- mice, which invariably develop choroid plexus carcinoma (CPC), and nine age-matched healthy controls were imaged using T1, T2, and a high-resolution three-dimensional time-of-flight MRA sequences at 3 T. Tumors and vessels were segmented to determine tumor volume and vascular attributes, including number of terminal branches, vessel count, and the average vessel radii of MRA-visible vessels within the tumor. Differences in the vasculature between tumor-bearing animals and healthy controls were analyzed statistically. Although the spatial resolution of MRA prohibits visualization of capillaries, a high density of intratumor blood vessels was visualized in CPC mice. A significant increase in terminal branch count and vessel count, but not average vessel radius, was observed in CPCs when compared with normal controls. Both terminal branch count and vessel count were highly correlated with tumor volume. This study represents the first MRA analysis of a spontaneous preclinical brain tumor model. Although the spatial resolution of MRA is less than histologic analysis, MRA-obtained vascular attributes provide useful information with full brain coverage. We show that consistent tumor vasculature properties can be determined by MRA. Such methods are critical for developing preclinical therapeutic testing and will help guide the development of human brain tumor analyses.

Effects of interstitial fallopian tube polyps on isthmic tubal diameter.

OBJECTIVE: To study the apparent association between interstitial fallopian tube polyps and isthmic tubal dilatation. DESIGN: Retrospective clinical study. SETTING: Tertiary academic medical center. PATIENT(S): Sixty-five patients with normal hysterosalpingograms and 40 patients with interstitial tubal polyps (25 unilateral and 15 bilateral). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Proximal, medial, and distal isthmic diameters were measured digitally and normalized according to an internal standard. Polyp volumes were measured and divided into four groups according to increasing volume (<2 mm3, 2-5 mm3, 6-12 mm3, >12 mm3). RESULT(S): There was a significant increase in proximal isthmic tubal diameter in patients with interstitial polyps. Mean diameter increased from 0.6 mm to 0.9 mm. There was no significant change in more distal isthmic diameters. Larger polyps tended to be associated with larger luminal diameters. CONCLUSION(S): Interstitial fallopian tube polyps are associated with a significant increase in proximal isthmic luminal diameter as determined on hysterosalpingography. Although these polyps are nonobstructing and thus thought by most investigators not to affect fertility, their association with altered luminal diameter and perhaps altered function might be of clinical interest.

Hemodynamic and permeability changes in posterior reversible encephalopathy syndrome measured by dynamic susceptibility perfusion-weighted MR imaging.

BACKGROUND AND PURPOSE: The physiological mechanism that gives rise to posterior reversible encephalopathy syndrome (PRES) is currently unknown. We sought to better understand the mechanism of the edema formation in PRES and specifically hypothesized that this edema is caused by increased vascular permeability. METHODS: Eight consecutive patients with PRES who had been studied by using perfusion MR imaging were retrospectively identified. Perfusion images were obtained using a gradient-echo echo planar sequence with contrast enhancement. Measures of apparent diffusion coefficient (ADC), cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT) and vascular permeability (K2) were calculated in the affected posterior brain areas and normalized to values obtained in unaffected anterior brain. These values were compared with those found in healthy subjects. RESULTS: Regions of interest within the posterior affected brain indicated a significant increase in ADC values in all but one patient, a significant decrease in CBV and CBF values in all patients with PRES (average 30% of control), variable changes in MTT, and no measurable change in K2. CONCLUSION: The decrease in both CBV and CBF in PRES supports the theory of autoregulatory vasoconstriction; changes in K2 were not detected.