Hepatic Magnetic Resonance Imaging Research Articles

Diagnosis of hepatic nodules 20 mm or smaller in cirrhosis: Prospective validation of the noninvasive diagnostic criteria for hepatocellular carcinoma

This study prospectively evaluates the accuracy of contrast-enhanced ultrasound (CEUS) and dynamic magnetic resonance imaging (MRI) for the diagnosis of nodules 20 mm or smaller detected during ultrasound (US) surveillance. We included 89 patients with cirrhosis [median age, 65 years; male 53, hepatitis C virus 68, Child-Pugh A 80] without prior hepatocellular carcinoma (HCC) in whom US detected a small solitary nodule (mean diameter, 14 mm). Hepatic MRI, CEUS, and fine-needle biopsy (gold standard) (FNB) were performed at baseline. Non-HCC cases were followed (median 23 months) by CEUS/3 months and MRI/6 months. FNB was repeated up to 3 times and on detection of change in aspect/size. Intense arterial contrast uptake followed by washout in the delayed/venous phase was registered as conclusive for HCC. Final diagnoses were: HCC (n = 60), cholangiocarcinoma (n = 1), and benign lesions (regenerative/dysplastic nodule, hemangioma, focal nodular hyperplasia) (n = 28). Sex, cirrhosis cause, liver function, and alpha-fetoprotein (AFP) levels were similar between HCC and non-HCC groups. HCC patients were older and their nodules significantly larger (P < 0.0001). First biopsy was positive in 42 of 60 HCC patients. Sensitivity, specificity, and positive and negative predictive values of conclusive profile were 61.7%, 96.6%, 97.4%, and 54.9%, for MRI, 51.7%, 93.1%, 93.9%, and 50.9%, for CEUS. Values for coincidental conclusive findings in both techniques were 33.3%, 100%, 100%, and 42%. Thus, diagnosis of HCC 20 mm or smaller can be established without a positive biopsy if both CEUS and MRI are conclusive. However, sensitivity of these noninvasive criteria is 33% and, as occurs with biopsy, absence of a conclusive pattern does not rule out malignancy. These results validate the American Association for the Study of Liver Disease (AASLD) guidelines.

Síndrome hereditario de hiperferritinemia y cataratas en una familia española con la mutación A40G (París) en el gen de la L-ferritina (FTL) asociada a la mutación H63D en el gen HFE

The cataract-associated increase in serum ferritin without any other data of iron overload is known since 1995 as hyperferritinemia-cataract syndrome (HHCS). More than 100 families have been described all around the world with this syndrome and more than 30 mutations in the L-ferritin (FTL) gene. We introduce a family from Madrid (Spain), with the disease phenotype and a genotype with the A40G mutation, named Paris, and besides carrier of the H63D mutation of the HFE gene.The proband and his first grade relatives were studied by determining the hemogram, biochemistry, iron metabolism and HFE gene mutations study, as well as by hepatic magnetic resonance imaging and oftalmologic study. Afterwards a molecular study of the coding region for the IRE (iron responsive element) of the FTL gene was done by sequencing.The proband is a male with early cataracts and hyperferritinemia, heterozygous for the H63D and A40G mutations of the HFE and FTL genes, respectively. The mother has the same phenotype (hyperferritinemia and surgery for early cataracts) and genotype (H63D and A40G alleles in heterozygosis). On the other hand, the sister has no cataracts but has hyperferritinemia, is homozygous for H63D and heterozygous for A40G. The father is heterozygous for H63D, but lacks the A40G mutation and the HHCS phenotype.The HHCS must be included in the differential diagnosis of the hyperferritinemias without iron overload. In turn, hyperferritinemia must be ruled out in an early cataract. The only treatment is ophthalmological, and phlebotomies must be avoided in a false hemochromatosis diagnostic when HFE gene mutations are associated, because of the poor tolerance for causing severe anemia.

A physiologically based pharmacokinetic model of vascular–extravascular exchanges during liver carcinogenesis: application to MRI contrast agents

The extraction of physiological parameters by non-invasive imaging techniques such as dynamic magnetic resonance imaging (MRI) or positron emission tomography requires a knowledge of molecular distribution and exchange between microvascularization and extravascular tissues. These phenomena not only depend on the physicochemical characteristics of the injected molecules but also the pathophysiological state of the targeted organ. We developed a five-compartment physiologically based pharmacokinetic model focused on hepatic carcinogenesis and MRI contrast agents. This model includes physical characteristics of the contrast agent, dual specific liver supply, microvessel wall properties and transport parameters that are compatible with hepatocarcinoma development. The evolution of concentrations in the five compartments showed significant differences in the distribution of three molecules (differentiated by their diameters and diffusion coefficients ranging, respectively, from 0.9 to 62 nm and from 68.10(-9) to 47.10(-7) cm(2) s(-1)) in simulated regeneration nodules and dysplastic nodules, as well as in medium- and poorly differentiated hepatocarcinoma. These results are in agreement with known vascular modifications such as arterialization that occur during hepatocarcinogenesis. This model can be used to study the pharmacokinetics of contrast agents and consequently to extract parameters that are characteristic of the tumor development (like permeability), after fitting simulated to in vivo data.

Increased QT variability in young asymptomatic patients with β‐thalassemia major

Despite recent progress in iron chelation therapy, sudden cardiac death due to malignant ventricular arrhythmias remains a vexing, clinical problem in patients with beta-thalassemia major (TM). In this study we assessed whether the major indices of QT variability, emerging tools for risk stratification of sudden cardiac death, differ in young asymptomatic patients with TM and healthy persons. Thirty patients with TM and 30 healthy control subjects underwent a 5-min electrocardiography recording to calculate the following variables: QT variance (QT(v)), QT(v) normalized for mean QT (QTVN) and QT variability index (QTVI). All subjects also underwent a two-dimensional and Doppler echocardiography study and magnetic resonance imaging (MRI) to determine cardiac and hepatic T2* values. No differences were observed in clinical and conventional echo-Doppler findings in healthy control subjects and patients with TM whereas QT(v), QTVN and QTVI values were significantly higher in patients than those in controls (QT(v), P < 0.001; QTVN, P < 0.05 and QTVI, P < 0.001) and cardiac T2* and hepatic MRI T2* values were significantly lower in patients with TM (P < 0.001). The indices of temporal QT variability correlated significantly with MRI data. Young asymptomatic patients with TM have increased cardiac repolarization variability as assessed by QT variability indices, probably due to cardiac iron deposition. These easily assessed, non-invasive markers could be used to identify increased myocardial repolarization lability early in asymptomatic patients with TM.

Small hyperintense hepatic lesions on T1-weighted images in patients with cirrhosis: evaluation with serial MRI and imaging features for clinical benignity

The aim of this study was to evaluate the frequency and magnetic resonance imaging (MRI) features of clinically benign, small (<2 cm) hyperintense hepatic lesions in the cirrhotic liver on T1-weighted MR images seen at serial MRI. This study included 189 patients with cirrhosis, who underwent hepatic MRI more than twice with an interval of at least 12 months. The initial MR images were reviewed for the presence of small hyperintense lesions on T1-weighted images. The size, location and signal intensity on T2-weighted images as well as enhancement patterns of the corresponding lesions were recorded. On the initial T1-weighted MR images, 43 small hyperintense hepatic lesions were detected in 23 (12%) of 189 patients. Twelve (28%) of 43 lesions showed early enhancement and were pathologically diagnosed as hepatocellular carcinoma (HCC) during the follow-up period. Thirty-one (72%) of 43 lesions showed no early enhancement with various signal intensity on T2-weighted images (hyperintensity=4, isointensity=20, hypointensity=7). Among these 31 lesions, 12 showed no interval change, while 11 disappeared (n=10) or decreased in size (n=1). In the remaining eight lesions, seven were diagnosed as HCC on the basis of pathologic confirmation or the interval growth. Small hyperintense hepatic lesions on T1-weighted magnetic resonance (MR) images without early enhancement on the arterial-phase contrast-enhanced dynamic studies in patients with cirrhosis usually showed no interval growth or disappeared during the serial MRI. These lesions with additional findings of iso- or hypointensity on the T2-weighted MR images without "washout effect" on the contrast-enhanced equilibrium-phase images may more frequently be clinically benign or hyperplastic nodules than HCCs.

Dual Gradient-Echo In-Phase and Opposed-Phase Hepatic MR Imaging: A Useful Tool for Evaluating More Than Fatty Infiltration or Fatty Sparing

A T1-weighted gradient-echo in-phase and opposed-phase sequence has become a routine part of every hepatic magnetic resonance (MR) imaging protocol. Although this sequence is primarily used to identify common pathologic conditions, such as diffuse or focal steatosis and focal fatty sparing, it is also helpful in detection of pathologic entities associated with T2* effects owing to the double-echo approach. Thus, pathologic conditions such as hemochromatosis or hemosiderosis can be identified and characterized with a high level of confidence. In cases of iron storage disease, the hepatic parenchymal signal intensity decreases on the image with the longer echo time due to the continued decay of the transverse magnetization. In addition, susceptibility artifacts can be easily detected and characterized with in-phase and opposed-phase MR imaging. Metallic objects demonstrate a larger susceptibility artifact on the image with the second or longer echo time, which is usually the in-phase image. Finally, intrahepatic pneumobilia can be identified with the T1-weighted gradient-echo in-phase and opposed-phase sequence because gas also causes a susceptibility artifact, which is more pronounced on the image with the longer echo time. A complete understanding of both the chemical shift cancellation artifact and the T2* effects of the in-phase and opposed-phase sequence is important for correct interpretation of hepatic MR images.

Correlative Study of Iron Accumulation in Liver, Myocardium, and Pituitary Assessed With MRI in Young Thalassemic Patients

Clinical complications resulting from unevenly iron accumulation in individual organs of patients with beta-thalassemia major can affect both expectancy and quality of life. Magnetic resonance imaging (MRI) offers a quantitative, noninvasive, accurate method for estimating iron levels in various tissues, not easily accessible with other techniques. The aim of this study was to evaluate and correlate the level of iron accumulation in different organs (anterior pituitary, myocardium, and liver) assessed with MRI, in children and young adults with beta-thalassemia major. Thirty children and young adults (13 female and 17 male patients) with homozygous beta-thalassemia, treated conventionally, were studied with hepatic, myocardial, and hypophyseal MRI. For liver and myocardium, we calculated the natural logarithm of the signal-to-air ratio in flash 2-dimensional sequences with electrocardiogram gating, whereas for anterior pituitary, the signal intensity was measured in sagittal T2 sequences. All scans were performed within 3 months. In 13 patients, data regarding liver iron concentrations (LIC) assessed by percutaneous liver biopsy were available. The mean of serum ferritin concentrations for 1 year before scans was calculated for each patient. MRI values in myocardium and liver showed a significant negative correlation to age (r=-0.73 and -0.69, respectively). For pituitary MRI, a linear regression with age was recorded in patients over 14 years of age (r=-0.67), whereas a relatively increased signal intensity reduction was recorded in pubertal subjects. Mean serum ferritin concentrations ranged from 252 to 5872 mug/L with an average of 1525+/-1047 mug/L. No statistical significant correlation was noted between mean ferritin levels versus liver, pituitary, and cardiac MRI values (r=-0.49, -0.28, and -0.1, respectively). Mean LIC values assessed by percutaneous biopsy were 13.76+/-11.6 mg/g of dry tissue. A statistically significant negative correlation was observed between liver MRI readings and LIC determined by biopsy (r=-0.89). None of the 3 organs studied with MRI were significantly correlated to each other. Pituitary to liver MRI values and liver to myocardial MRI values were moderately correlated (r=0.34 and 0.42, respectively). Pituitary MRI was not correlated at all to myocardial MRI (r=-0.001). In conclusion, iron accumulation in thalassemic patients is a procedure progressing with age, which seems to act independently in different organs. MRI represents a reliable, noninvasive method for assessing iron overload in various tissues, non-easily accessible with other techniques. Regular scanning, to recognize preclinically excessive iron deposits and intensified chelation therapy, can prevent serious and fatal complications.

Ultrasound of living donor liver transplantation

Liver transplantation is the most effective treatment for various end-stage liver diseases. Living donor liver transplantation (LDLT) was first developed in Asia due to the severe lack of cadaveric graft in this region. The Liver Transplant Service at Queen Mary Hospital (QMH), Hong Kong, has pioneered the application of LDLT to patients using both left lobe and right lobe grafts. The QMH liver transplant programme is the largest of its kind in China and Southeast Asia.Ultrasound (US) is often employed in the initial work-up of potential donor and recipient of LDLT. It is the imaging technique of choice to assess the early and late complications of LDLT, with colour Doppler ultrasound being the most useful in the evaluation of post-LDLT vascular complications. The use of ultrasound contrast agents improves the visualisation of the hepatic vasculature, possibly delaying or removing the need for more invasive investigations. Intra-operative ultrasound facilitates the determination of the resection plane during donor hepactectomy.Computed tomography (CT) or magnetic resonance imaging (MRI) can be used as the single imaging modality in the evaluation of LDLT candidates.Ultrasound is most useful as the initial screening test in detecting hepatic parenchymal abnormalities, while CT or MRI is the modality of choice in the demonstration of vascular and biliary anatomy of the potential liver donor.Biliary complications are more common in LDLT than in cadaveric liver transplantation. The ductal dilatation, resulting from biliary stricture, is clearly demonstrated by ultrasound. Bilomas can be aspirated under ultrasound guidance to confirm the diagnosis and to promote healing. Perihepatic fluid collections and abscesses are also common after LDLT. Intra-hepatic collections may represent seromas, haematomas or infarction. Ultrasound is a sensitive means of detecting these collections and can be employed to guide drainage in suitable patients.Transplant-related malignancies include recurrent neoplasia and post-transplant lymphoproliferative disease (PTLD). Ultrasound can be used to screen for recurrent disease and to detect PTLD in the transplanted liver.

Neuronal Intranuclear Inclusion Disease Presenting as Chronic Intestinal Pseudo‐Obstruction in the Neonatal Period in the Absence of Neurologic Symptoms

Central adiposity, a component of insulin resistance syndrome, is a risk factor for nonalcoholic fatty liver disease (NAFLD) in adults. To determine whether a similar relationship occurs in children, hepatic fat content and adipose tissue distribution were assessed in obese children at risk for NAFLD.We reviewed the charts of obese children undergoing evaluation for NAFLD because of hepatomegaly or elevated serum alanine aminotransferase (ALT) without obvious etiology. Hepatic fat fraction and adipose tissue distribution were obtained by rapid magnetic resonance imaging (MRI) techniques. Hepatic fat content was determined by a modification of the Dixon method that involves fast gradient echo. Body fat distribution was assessed by using heavily T1-weighted fast gradient echo technique on a single slice at the level of the umbilicus, and regions of interest were demarcated based upon pixel intensity threshold value including visceral adipose tissue (VAT) and subcutaneous adipose tissue content (SAT).Ten children underwent hepatic MRI only. Twenty-nine children underwent hepatic and adipose tissue distribution MRI. There was a correlation between hepatic fat fraction and VAT (r = 0.37, P < 0.05) but not body mass index or SAT. Elevated serum ALT was associated with a higher hepatic fat fraction (P < 0.001) and VAT (P = 0.06).Visceral adiposity is a risk factor for pediatric NAFLD.

Relationship of Hepatic Steatosis to Adipose Tissue Distribution in Pediatric Nonalcoholic Fatty Liver Disease

ABSTRACTObjective:Central adiposity, a component of insulin resistance syndrome, is a risk factor for nonalcoholic fatty liver disease (NAFLD) in adults. To determine whether a similar relationship occurs in children, hepatic fat content and adipose tissue distribution were assessed in obese children at risk for NAFLD.Methods:We reviewed the charts of obese children undergoing evaluation for NAFLD because of hepatomegaly or elevated serum alanine aminotransferase (ALT) without obvious etiology. Hepatic fat fraction and adipose tissue distribution were obtained by rapid magnetic resonance imaging (MRI) techniques. Hepatic fat content was determined by a modification of the Dixon method that involves fast gradient echo. Body fat distribution was assessed by using heavily T1‐weighted fast gradient echo technique on a single slice at the level of the umbilicus, and regions of interest were demarcated based upon pixel intensity threshold value including visceral adipose tissue (VAT) and subcutaneous adipose tissue content (SAT).Results:Ten children underwent hepatic MRI only. Twenty‐nine children underwent hepatic and adipose tissue distribution MRI. There was a correlation between hepatic fat fraction and VAT (r = 0.37, P &lt; 0.05) but not body mass index or SAT. Elevated serum ALT was associated with a higher hepatic fat fraction (P &lt; 0.001) and VAT (P = 0.06).Conclusion:Visceral adiposity is a risk factor for pediatric NAFLD.

Eosinophilic Hepatic Necrosis

To compare the findings of magnetic resonance (MR) imaging with those of computed tomography (CT) of focal liver lesions related to peripheral eosinophilia. For 12 patients with peripheral eosinophilia (>7%) examined with hepatic MR imaging and CT, 52 focal hepatic lesions larger than 0.5 cm, including 31 lesions simultaneously found on the 2 imaging modalities, were subjected to a comparative analysis of their imaging features. The total number of lesions distinguished from background liver was 39 (75%) on MR imaging and 44 (85%) on CT scans. On arterial phase images of 10 patients with comparable data, homogeneously hyperintense lesions were demonstrated more frequently (P = 0.006) on MR imaging (16 [50%] of 32 lesions) than on CT scans (4 [13%] of 32 lesions). Only 7 (22%) of the 32 hypoattenuating lesions on portal phase CT were depicted as hypointense lesions on portal phase MR images in 12 patients. On delayed phase images in 8 patients, the number of hyperintense lesions on MR images (9 [56%] of 16) was greater (P = 0.077) than that seen on the CT scans (4 [25%] of 16). For many focal hepatic lesions related to peripheral eosinophilia, dynamic MR imaging more easily demonstrates lesional enhancement on arterial and delayed phases than CT scans. Because of the higher degree of lesional enhancement of MR imaging compared with CT, the lesion-to-liver contrast may not be sufficient to distinguish the lesion from the background liver, resulting in decreased sensitivity of portal phase dynamic MR imaging.

Study on computer‐aided diagnosis of hepatic MR imaging and mammography

It is well known that the liver is an organ easily attacked by diseases. The purpose of this study is to develop a computer‐aided diagnosis (CAD) scheme for helping radiologists to differentiate hepatic diseases more efficiently. Our software named LIVERANN integrated the magnetic resonance (MR) imaging findings with different pulse sequences to classify the five categories of hepatic diseases by using the artificial neural network (ANN) method. The intensity and homogeneity within the region of interest (ROI) delineated by a radiologist were automatically calculated to obtain numerical data by the program for input signals to the ANN. Outputs were the five pathological categories of hepatic diseases (hepatic cyst, hepatocellular carcinoma, dysplasia in cirrhosis, cavernous hemangioma, and metastasis). The experiment demonstrated a testing accuracy of 93% from 80 patients. In order to differentiate the cirrhosis from normal liver, the volume ratio of left to whole (LTW) was proposed to quantify the degree of cirrhosis by three‐dimensional (3D) volume analysis. The liver region was firstly extracted from computed tomography (CT) or MR slices based on edge detection algorithms, and then separated into left lobe and right lobe by the hepatic umbilical fissure. The volume ratio of these two parts showed that the LTW ratio in the liver was significantly improved in the differentiation performance, with in cirrhosis versus the normal liver . In addition, the application of the ANN method for detecting clustered microcalcifications in masses on mammograms was described here as well. A new structural ANN, so‐called a shift‐invariant artificial neural network (SIANN), was integrated with our triple‐ring filter (TRF) method in our CAD system. As the result, the sensitivity of detecting clusters was improved from 90% by our previous TRF method to 95% by using both SIANN and TRF.

Magnetic resonance imaging of hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common primary hepatic malignancy, usually develops in patients with cirrhosis, growing sequentially from low-grade dysplastic nodules to frank malignant HCC. Its recognition is critical because curative treatment and prognosis require early diagnosis. Survival in patients with HCC relates directly to the number, size, and extent of lesions at diagnosis. Imaging of HCC is complicated because the tumor has a varied imaging appearance and frequently coexists with other cirrhotic nodules. Magnetic resonance imaging (MRI), the best available diagnostic technique, offers good contrast resolution and diagnostic sensitivity ranging from 33% to 77%. The main difficulty is not in diagnosing large tumors, but rather small tumors (<2 cm), because of considerable overlap on imaging between benign (regenerative), borderline (dysplastic), and malignant nodules. Increasing degrees of histological malignancy are associated with increasing arterialization and loss of portal blood supply; therefore, recognition of HCC requires dynamic imaging with gadolinium-enhanced T1-weighted sequence. Typically, HCC is a focal lesion with high signal intensity on T2-weighted images, variable signal intensity on T1-weighted images, intense arterial phase enhancement after gadolinium injection, and isointensity or hypointensity at the portal venous phase. The sensitivity of MRI for detecting small lesions is low, and improvement is still needed. Newer contrast agents, higher field strength (3 Tesla) imaging, and perfusion and diffusion MRI techniques possibly will provide greater sensitivity and specificity for detecting small HCCs in the future.

Non-resective ablation therapy for hepatocellular carcinoma: effectiveness measured by intention-to-treat and dropout from liver transplant waiting list.

Orthotopic liver transplantation (OLT) for patients with small hepatocellular carcinoma (HCC) is widely accepted, and the usefulness of local ablation techniques as a bridge for liver transplantation is still under investigation. From December 1997 to February 2003, patients with cirrhosis and T0-T1-T2-T3 stage HCC received multi-modality ablative therapy (MMT) for the treatment of their HCC and were evaluated for OLT; listed, and transplanted when an allograft became available. MMT included radiofrequency ablation (RFA), and/or Trans-Arterial Chemo-Embolization (TACE), and alcohol (EtOH) ablation, followed by Trans-Arterial Chemo-Infusion (TACI), with repeated treatments based on follow up hepatic magnetic resonance imaging (MRI) during the waiting period for OLT. A total of 135 HCC patients were seen at our center within this time frame. The intention-to-treat group included 33 (24.4%) patients with T0, T1, T2, T3 HCC and cirrhosis. There were 31 men and two women. The mean age was 53.6 +/- 7.2 yr. All patients received MMT with a mean of 2.90 +/- 1.5 procedures per patient. Tumor-node-metastasis (TNM) stages at time of listing were: T0 in one patient, T1 in nine patients, T2 in 17 patients, and T3 in six patients. Twenty-eight (85%) patients have received OLT. Five (12.19%) patients were listed and removed (dropout) from the transplant waiting list after waiting 5, 5, 5, 8, and 14 months respectively. The waiting time of the HCC listed group was 9.1 +/- 14.8 months with a mean follow up of 32 months. OLT patient survival and cancer-free survival are 92.9% and 95.24%, respectively; the overall survival of intention-to-treat group was 79% at 32 months follow up. Predictors of dropout included an alpha-fetoprotein (AFP, >400 ng/mL) and T3 HCC stage. Aggressive ablation therapy with a short transplant waiting time optimizes the use of OLT for curative intent in selective cirrhotic HCC patients.

Microvessel density of malignant and benign hepatic lesions and MRI evaluation.

To study the difference of microvessel density (MVD) between malignant and benign hepatic lesions and study the relationship between MVD and dynamic enhanced magnetic resonance imaging (MRI) for evaluation of microvessels within malignant and benign hepatic lesions. A total of 265 specimens of hepatocellular carcinoma (HCC), 122 cirrhosis tissues and 22 hepatic benign lesions were enrolled for MVD by immunohistochemistry on tissue microarray, of which 49 underwent MRI examination before surgery, then contrast-to-noise ratios (CNR) and enhancement index (EI) in all the phases were calculated. Pearson correlation was performed for correlation analysis between CNR, EI and MVD. MVD of HCC was 22.7+/-15.8 (mean+/-SD), which was obviously higher than that of cirrhosis tissue (8.3+/-7.6, P<0.01), but was not statistically different from that of benign lesions (31.3+/-22.7, P>0.05). Among HCC, MVD of grades I-II was 29.9+/-18.6, which was much higher than those of grade III (22.2+/-18.2, P<0.01) and grade IV (22.9+/-19.0, P<0.01). MVD of HCC (P=0.018) and of benign lesions (P=0.014) were both correlative with CNR in arterial phase. Neoangiogenesis is an important feature for malignant tumor, and MVD may act as a biological marker in differentiating malignant from benign hepatic lesions. Dynamic enhanced MRI, especially image in arterial phase, may act as an MVD evaluation criterion for malignant and benign hepatic lesions.

Segmental high intensity on T1-weighted hepatic MR images

We investigated the diagnostic importance of segmental high-intensity (SHI) areas not corresponding to mass lesions on T1-weighted magnetic resonance (MR) images. We conducted a retrospective investigation of hepatic MR images obtained from 634 patients during a 4-year period at our institution. Images were compared with findings reported in the patients' medical records. There were 16 patients (2.5%) with SHI areas not corresponding to a mass lesion. We compared MR images with plain computed tomographic (CT) scans (n = 16), angiograms (n = 12), and histologic findings (n = 10). The segments with intrahepatic bile duct dilatation showed hyperintensity on T1-weighted images. In six of 16 patients, the biliary duct was more dilated in the area of hyperintensity than in areas without hyperintensity. The SHI areas appeared as areas of low attenuation (n = 13), high attenuation (n = 1), or isoattenuation (n = 2) on plain CT scans. Histologically, these areas showed ductular proliferation and deposition of bile pigment within the hepatocytes. Segmental areas of increased signal intensity on T1-weighted images were probably due to intrahepatic cholestasis.

Double Contrast MR Imaging of Hepatocellular Carcinoma Evaluating Lesion Detection and Conspicuity

Hepatocellular carcinoma (HCC) is the most common primary malignant neoplasm of the liver. It develops with underlying liver cirrhosis or chronic hepatitis in most patients. Detection of HCC is critical in the follow-up of patients with chronically damaged livers. Although dynamic spiral computed tomography (CT) is a sensitive choice for detecting HCC (1), magnetic resonance (MR) imaging is increasingly applied for the detection of all hepatic lesions, especially HCC lesions in patients with chronic liver disease, and the use of contrast agents has the potential to increase the sensitivity and spesificity of hepatic MR imaging.

Efficacy and safety of mangafodipir trisodium (MnDPDP) injection for hepatic MRI in adults: Results of the U.S. Multicenter phase III clinical trials. Efficacy of early imaging

The efficacy of contrast-enhanced magnetic resonance imaging (MRI) for detecting and characterizing, or excluding, hepatic masses was assessed in 404 patients, following the intravenous administration of mangafodipir trisodium (MnDPDP) injection, a hepatic MRI contrast agent. An initial contrast-enhanced computed tomography (CT) examination was followed by unenhanced MRI, injection of MnDPDP (5 μmol/kg IV), and enhanced MRI at 15 minutes post injection. Agreement of the radiologic diagnoses with the patients' final diagnoses was higher for enhanced MRI and for the combined unenhanced and enhanced MRI evaluations than for unenhanced MRI alone or enhanced CT using the clinical diagnosis as the gold standard. Mangafodipir-enhanced MRI uniquely provided additional diagnostic information in 48% of the patients, and patient management was consequently altered in 6% of the patients. MnDPDP-enhanced MRI was comparable or superior to unenhanced MRI and enhanced CT for the detection, classification, and diagnosis of focal liver lesions in patients with known or suspected focal liver disease. J. Magn. Reson. Imaging 2000;12:689–701. © 2000 Wiley-Liss, Inc.

Nondiffuse fatty change of the liver: discerning pseudotumor on MR images enhanced with ferumoxides-initial observations.

To clarify the findings of nondiffuse fatty change of the liver on ferumoxides-enhanced magnetic resonance (MR) images. Of 202 patients who underwent ferumoxides-enhanced MR imaging, eight who had nondiffuse fatty change of the liver at computed tomography (CT) were examined as study subjects. MR imaging findings before and 1 hour after ferumoxides administration were compared with CT findings. Focal fatty areas of the liver showing low attenuation on CT images were depicted as areas of relatively high intensity on the ferumoxides-enhanced T1-weighted images in all patients. On enhanced T2-weighted images, focal fatty change showed relatively high intensity in three and isointensity in one of the four patients. Focal spared areas appearing as areas of relatively high attenuation on CT images were depicted as areas of relatively low intensity on the ferumoxides-enhanced T1- and T2-weighted images in all patients. Although prior reports of hepatic MR imaging with ferumoxides indicated that there is accumulation of ferumoxides within focal fatty areas that are no longer seen after the administration of contrast medium, this study revealed that focal fatty change and focal spared areas of fatty liver may be pseudotumors because of the relatively high intensity of fatty areas of the liver. Radiologists can distinguish these conditions from hepatic tumors by using the opposed-phase gradient-echo sequence or the fat-saturation technique.

Hepatic MR Imaging with a Dynamic Contrast-enhanced Isotropic Volumetric Interpolated Breath-hold Examination: Feasibility, Reproducibility, and Technical Quality

To evaluate the feasibility, reproducibility, and technical quality of a dynamic contrast material-enhanced isotropic three-dimensional (3D) volumetric interpolated breath-hold hepatic magnetic resonance (MR) imaging examination. Fifty patients underwent 3D spoiled gradient-echo imaging (4.2/1.8 [repetition time msec/echo time msec]; flip angle, 12 degrees; interpolation in three directions; intermittent fat saturation; pixel size </= 2.5 mm in all dimensions) before and dynamically after administration of gadopentetate dimeglumine, with the first enhanced acquisition timed for hepatic arterial dominance by using a test bolus of contrast material. Qualitative and quantitative measures of image quality were determined. Patterns of arterial and venous anatomy were assessed. Ten patients (20%) underwent repeat imaging within 6 months, and reproducibility was evaluated. Hepatic contrast-to-noise ratios for nonenhanced and arterial, portal venous, and equilibrium phase studies averaged 13.0 +/- 12.6 (SD), 17.4 +/- 11.8, 30.4 +/- 16.2, and 28.6 +/- 21.1, respectively. During arterial phase, the liver enhanced a mean of 29% of the maximal enhancement as measured during portal venous phase. Hepatic vascular anatomic variants were comparable in distribution to those cited in published articles. Repeat studies were not significantly different in image quality when compared with original studies. High-quality arterial phase 3D volumetric interpolated breath-hold images can be obtained reliably and reproducibly when timed by using a test dose of contrast material.