Neurodevelopment. Parasympathetic neurons originate from nerve-associated peripheral glial progenitors

The peripheral autonomic nervous system reaches far throughout the body and includes neurons of diverse functions, such as sympathetic and parasympathetic. We show that the parasympathetic system in mice--including trunk ganglia and the cranial ciliary, pterygopalatine, lingual, submandibular, and otic ganglia--arise from glial cells in nerves, not neural crest cells. The parasympathetic fate is induced in nerve-associated Schwann cell precursors at distal peripheral sites. We used multicolor Cre-reporter lineage tracing to show that most of these neurons arise from bi-potent progenitors that generate both glia and neurons. This nerve origin places cellular elements for generating parasympathetic neurons in diverse tissues and organs, which may enable wiring of the developing parasympathetic nervous system.

Portosplenomesenteric venous thrombosis in patients with acute pancreatitis is associated with pancreatic necrosis and usually has a benign course

BACKGROUND & AIMS

Although there are some data on prevalence of portosplenomesenteric venous thrombosis (PSMVT) in patients with acute pancreatitis (AP), the progression of PSMVT in patients who have and have not received anticoagulants has not been studied systematically. We evaluated the prevalence and natural history of PSMVT in a well-defined cohort of individuals with AP.

METHODS

In a retrospective study, we analyzed data from the University of Pittsburgh Medical Center on 162 patients with a sentinel attack of AP from 2003-2010. Data were collected on patient demographics, clinical presentation, etiology, clinical course, and outcomes. One hundred twenty-two patients underwent contrast-enhanced computed tomography; the scans were reviewed to identify thromboses and/or narrowing of splanchnic veins (splenic, superior mesenteric, and portal).

RESULTS

PSMVT was detected in 22 patients overall (14%; 18% among patients who underwent contrast-enhanced computed tomography). Median time to detection of PSMVT was 17 days (interquartile range, 11-40 days). PSMVT formed most frequently in the splenic vein (19 of 22, 86%), followed by portal (8 of 22, 36%) and superior mesenteric (6/22, 27%) veins. Development of PSMVT was associated with presence (21 of 22, 95%), location, and extent of pancreatic necrosis. Fifty-three percent of patients (21 of 40) with necrosis developed PSMVT. Anticoagulants were administered infrequently (6 of 22, 27%) and always for indications unrelated to PSMVT. Most patients with PSMVT developed collateral veins (19 of 22, 86%), and 27% (6 of 22) were found to have varices during endoscopic evaluation, but clot resolution was infrequent (2 of 22, 9%). No patient developed complications directly related to PSMVT.

CONCLUSIONS

PSMVT develops in about half of patients with necrotizing AP and is rare in the absence of necrosis. Despite infrequent administration of anticoagulants, complications directly related to PSMVT are rare.

Quantitative sodium MR imaging of native versus transplanted kidneys using a dual-tuned proton/sodium (1H/ 23Na) coil: initial experience

OBJECTIVES

To compare sodium ((23)Na) characteristics between native and transplanted kidneys using dual-tuned proton ((1)H)/sodium MRI.

METHODS

Six healthy volunteers and six renal transplant patients (3 normal function, 3 acute allograft rejection) were included. Proton/sodium MRI was obtained at 3 T using a dual-tuned coil. Signal to noise ratio (SNR), sodium concentration ([(23)Na]) and cortico-medullary sodium gradient (CMSG) were measured. Reproducibility of [(23)Na] measurement was also tested. SNR, [(23)Na] and CMSG of the native and transplanted kidneys were compared.

RESULTS

Proton and sodium images of kidneys were successfully acquired. SNR and [(23)Na] measurements of the native kidneys were reproducible at two different sessions. [(23)Na] and CMSG of the transplanted kidneys was significantly lower than those of the native kidneys: 153.5 ± 11.9 vs. 192.9 ± 9.6 mM (P = 0.002) and 8.9 ± 1.5 vs. 10.5 ± 0.9 mM/mm (P = 0.041), respectively. [(23)Na] and CMSG of the transplanted kidneys with normal function vs. acute rejection were not statistically different.

CONCLUSIONS

Sodium quantification of kidneys was reliably performed using proton/sodium MRI. [(23)Na] and CMSG of the transplanted kidneys were lower than those of the native kidneys, but without a statistically significant difference between patients with or without renal allograft rejection.

KEY POINTS

Dual-tuned proton/sodium RF coil enables co-registered proton and sodium MRI. Structural and sodium biochemical property can be acquired by dual-tuned proton/sodium MRI. Sodium and sodium gradient of kidneys can be measured by dual-tuned MRI. Sodium concentration was lower in transplanted kidneys than in native kidneys. Sodium gradient of transplanted kidneys was lower than for native kidneys.

Hepatic steatosis in diabetic patients does not predict adverse liver-related or cardiovascular outcomes

BACKGROUND & AIMS

Steatosis is a defining feature of nonalcoholic fatty liver disease (NAFLD). However, evidence that severity of steatosis can predict adverse outcomes in NAFLD or nonalcoholic steatohepatitis (NASH) is lacking. The aim of this study was to determine whether steatosis assessed by computed tomography (CT) imaging predicts adverse outcomes in diabetic patients at risk for NAFLD/NASH.

METHODS

We studied deaths, liver-related and cardiovascular adverse outcomes in a 5-year retrospective observational cohort of 2343 type 2 diabetic patients in a large care network who had noncontrast CT imaging for clinical indications. We measured steatosis by subtraction of spleen from liver attenuation, a method that showed low sensitivity (0.417) and high specificity (0.882) compared with histopathological scoring. We evaluated outcomes prediction using multivariate Cox proportional hazards modelling of steatosis both as a categorical (≥ 30%) and continuous variable.

RESULTS

Steatosis ≥ 30% was present in 233 (9.9%) of the cohort at baseline. Over 5 years, there were 372 total deaths, 18 liver-related and 99 cardiovascular deaths, 48 liver transplants, 51 occurrences of hepatic encephalopathy, 41 hepatocellular carcinomas, 653 myocardial infarctions, 66 strokes, 180 occurrences of angina, 735 occurrences of arrhythmia and 772 occurrences of congestive heart failure. Steatosis had no predictive value for any adverse outcome. Patients with steatosis averaged 8 years younger than those without it. Age had a strong covariate influence on occurrence of total deaths, cardiovascular deaths, myocardial infarctions, arrhythmias and congestive heart failure.

CONCLUSION

Although steatosis on imaging is often the abnormality that triggers diagnosis and assessment of NAFLD/NASH, it lacks predictive value for adverse clinical outcomes.

Fibrosis reduces severity of acute-on-chronic pancreatitis in humans

BACKGROUND & AIMS

Acute pancreatitis (AP) and chronic pancreatitis (CP) share etiologies, but AP can be more severe and is associated with a higher rate of mortality. We investigated features of CP that protect against severe disease. The amount of intrapancreatic fat (IPF) is increased in obese patients and fibrosis is increased in patients with CP, so we studied whether fibrosis or fat regulate severity of AP attacks in patients with CP.

METHODS

We reviewed records from the University of Pittsburgh Medical Center/Presbyterian Hospital Autopsy Database (1998-2008) for patients with a diagnosis of AP (n = 23), CP (n = 35), or both (AP-on-CP; n = 15). Pancreatic histology samples from these patients and 50 randomly selected controls (no pancreatic disease) were analyzed, and IPF data were correlated with computed tomography data. An adipocyte and acinar cell Transwell coculture system, with or without collagen type I, was used to study the effects of fibrosis on acinar-adipocyte interactions. We studied the effects of nonesterified fatty acids (NEFAs) and adipokines on acinar cells in culture.

RESULTS

Levels of IPF were significantly higher in nonobese patients with CP than in nonobese controls. In patients with CP or AP-on-CP, areas of IPF were surrounded by significantly more fibrosis than in controls or patients with AP. Fat necrosis-associated peri-fat acinar necrosis (PFAN, indicated by NEFA spillage) contributed to most of the necrosis observed in samples from patients with AP; however, findings of peri-fat acinar necrosis and total necrosis were significantly lower in samples from patients with CP or AP-on-CP. Fibrosis appeared to wall off the fat necrosis and limit peri-fat acinar necrosis, reducing acinar necrosis. In vitro, collagen I limited the lipolytic flux between acinar cells and adipocytes and prevented increases in adipokines in the acinar compartment. This was associated with reduced acinar cell necrosis. However, NEFAs, but not adipokines, caused acinar cell necrosis.

CONCLUSIONS

Based on analysis of pancreatic samples from patients with CP, AP, or AP-on-CP and in vitro studies, fibrosis reduces the severity of acute exacerbations of CP by reducing lipolytic flux between adipocytes and acinar cells.

Short-term mortality in acute pulmonary embolism: clot burden and signs of right heart dysfunction at CT pulmonary angiography

PURPOSE

To assess the correlation between volumetric measurements of clot, semiquantitative clot burden indexes, and signs of right heart dysfunction at computed tomographic (CT) pulmonary angiography in patients with acute pulmonary embolism (PE) and to determine whether clot burden and signs of right heart dysfunction are associated with short-term mortality.

MATERIALS AND METHODS

This retrospective study was institutional review board approved and HIPAA compliant. CT pulmonary angiographic studies (January 2007 through December 2007) with findings positive for PE were retrieved. Two readers evaluated signs of right heart dysfunction at CT pulmonary angiography, measured clot volume using a dedicated software program, and assessed clot burden using semiquantitative scores (Qanadli and Mastora). Spearman rank coefficient was used to investigate correlation between clot burden measures and signs of right heart dysfunction. Uni- and multivariate analyses were used to test association between CT pulmonary angiographic findings and short-term mortality.

RESULTS

A total of 635 CT pulmonary angiographic studies from 635 patients (304 men, 331 women; mean age, 59 years) were included; 39 (6%) patients died within 30 days. Clot volume was strongly correlated with Qanadli score (ρ=0.841, P<.01) and Mastora score (ρ=0.863, P<.01) and moderately correlated (ρ=0.378, P<.01) with the ratio of right ventricle diameter to left ventricle diameter (RV/LV ratio). Among the pulmonary angiographic signs, only increase in RV/LV ratio (cut-off value, 1.0) was independently associated with short-term mortality in multivariate analysis.

CONCLUSION

Clot volume strongly correlated with semiquantitative CT scores of clot burden, and greater clot volume was associated with higher incidence of right heart dilatation. Increase in RV/LV ratio was associated with short-term mortality; however, measures of clot burden were not.

Met acts through Abl to regulate p53 transcriptional outcomes and cell survival in the developing liver

BACKGROUND & AIMS

Genetic studies indicate that distinct signaling modulators are each necessary but not individually sufficient for embryonic hepatocyte survival in vivo. Nevertheless, how signaling players are interconnected into functional circuits and how they coordinate the balance of cell survival and death in developing livers are still major unresolved issues. In the present study, we examined the modulation of the p53 pathway by HGF/Met in embryonic livers.

METHODS

We combined pharmacological and genetic approaches to biochemically and functionally evaluate p53 pathway modulation in primary embryonic hepatocytes and in developing livers. RT-PCR arrays were applied to investigate the selectivity of p53 transcriptional response triggered by Met.

RESULTS

Met recruits p53 to regulate the liver developmental program, by qualitatively modulating its transcriptional properties: turning on the Mdm2 survival gene, while keeping death and cell-cycle arrest genes Pmaip1 and p21 silent. We investigated the mechanism leading to p53 regulation by Met and found that Abl and p38MAPK are required for p53 phosphorylation on S(389), Mdm2 upregulation, and hepatocyte survival. Alteration of this signaling mechanism switches p53 properties, leading to p53-dependent cell death in embryonic livers. RT-PCR array studies affirmed the ability of the Met-Abl-p53 axis to modulate the expression of distinct genes that can be regulated by p53.

CONCLUSIONS

A signaling circuit involving Abl and p38MAPK is required downstream of Met for the survival of embryonic hepatocytes, via qualitative regulation of the p53 transcriptional response, by switching its proapoptotic into survival properties.

Lipotoxicity causes multisystem organ failure and exacerbates acute pancreatitis in obesity

Obesity increases the risk of adverse outcomes during acute critical illnesses such as burns, severe trauma, and acute pancreatitis. Although individuals with more body fat and higher serum cytokines and lipase are more likely to experience problems, the roles that these characteristics play are not clear. We used severe acute pancreatitis as a representative disease to investigate the effects of obesity on local organ function and systemic processes. In obese humans, we found that an increase in the volume of intrapancreatic adipocytes was associated with more extensive pancreatic necrosis during acute pancreatitis and that acute pancreatitis was associated with multisystem organ failure in obese individuals. In vitro studies of pancreatic acinar cells showed that unsaturated fatty acids were proinflammatory, releasing intracellular calcium, inhibiting mitochondrial complexes I and V, and causing necrosis. Saturated fatty acids had no such effects. Inhibition of lipolysis in obese (ob/ob) mice with induced pancreatitis prevented a rise in serum unsaturated fatty acids and prevented renal injury, lung injury, systemic inflammation, hypocalcemia, reduced pancreatic necrosis, and mortality. Thus, therapeutic approaches that target unsaturated fatty acid-mediated lipotoxicity may reduce adverse outcomes in obese patients with critical illnesses such as severe acute pancreatitis.

Sox2 and Mitf cross-regulatory interactions consolidate progenitor and melanocyte lineages in the cranial neural crest

The cellular origin and molecular mechanisms regulating pigmentation of head and neck are largely unknown. Melanocyte specification is controlled by the transcriptional activity of Mitf, but no general logic has emerged to explain how Mitf and progenitor transcriptional activities consolidate melanocyte and progenitor cell fates. We show that cranial melanocytes arise from at least two different cellular sources: initially from nerve-associated Schwann cell precursors (SCPs) and later from a cellular source that is independent of nerves. Unlike the midbrain-hindbrain cluster from which melanoblasts arise independently of nerves, a large center of melanocytes in and around cranial nerves IX-X is derived from SCPs, as shown by genetic cell-lineage tracing and analysis of ErbB3-null mutant mice. Conditional gain- and loss-of-function experiments show genetically that cell fates in the neural crest involve both the SRY transcription factor Sox2 and Mitf, which consolidate an SCP progenitor or melanocyte fate by cross-regulatory interactions. A gradual downregulation of Sox2 in progenitors during development permits the differentiation of both neural crest- and SCP-derived progenitors into melanocytes, and an initial small pool of nerve-associated melanoblasts expands in number and disperses under the control of endothelin receptor B (Ednrb) and Wnt5a signaling.

Multichannel transceiver dual-tuned RF coil for proton/sodium MR imaging of knee cartilage at 3 T

Sodium magnetic resonance (MR) imaging is a promising technique for detecting changes of proteoglycan (PG) content in cartilage associated with knee osteoarthritis. Despite its potential clinical benefit, sodium MR imaging in vivo is challenging because of intrinsically low sodium concentration and low MR signal sensitivity. Some of the challenges in sodium MR imaging may be eliminated by the use of a high-sensitivity radiofrequency (RF) coil, specifically, a dual-tuned (DT) proton/sodium RF coil which facilitates the co-registration of sodium and proton MR images and the evaluation of both physiochemical and structural properties of knee cartilage. Nevertheless, implementation of a DT proton/sodium RF coil is technically difficult because of the coupling effect between the coil elements (particularly at high field) and the required compact design with improved coil sensitivity. In this study, we applied a multitransceiver RF coil design to develop a DT proton/sodium coil for knee cartilage imaging at 3 T. With the new design, the size of the coil was minimized, and a high signal-to-noise ratio (SNR) was achieved. DT coil exhibited high levels of reflection S11 (∼-21 dB) and transmission coefficient S12 (∼-19 dB) for both the proton and sodium coils. High SNR (range 27-38) and contrast-to-noise ratio (CNR) (range 15-21) were achieved in sodium MR imaging of knee cartilage in vivo at 3-mm(3) isotropic resolution. This DT coil performance was comparable to that measured using a sodium-only birdcage coil (SNR of 28 and CNR of 20). Clinical evaluation of the DT coil on four normal subjects demonstrated a consistent acquisition of high-resolution proton images and measurement of relative sodium concentrations of knee cartilages without repositioning of the subjects during the same MR scanning session.

The revised Atlanta classification for acute pancreatitis: a CT imaging guide for radiologists

Accurate diagnosis and description of the various findings in acute pancreatitis is important for treatment. The original Atlanta classification for acute pancreatitis sought to create a uniform system for classifying the severity of acute pancreatitis as well as common language to describe the various events that can occur in acute pancreatitis. The goal was to allow accurate communication between physicians using standardized language so correct treatment options could be used. Since that time, advances in the understanding of acute pancreatitis as well as improvements in both interventions and imaging have led to criticisms of the system and its abandonment by physicians. A 2007 revision of the Atlanta classifications sought to address many of these issues. This article will explain the changes to the Atlanta classification system and provide pictorial examples of the findings in acute pancreatitis as described by the Atlanta classification system.

Efficacy of Carbopol 974P (Siccafluid) in the treatment of severe to moderate keratoconjunctivitis sicca (KCS) in patients with primary Sjögren’s syndrome (SS) not responding to standard treatment with artificial tears

OBJECTIVE

To determine efficacy and safety of Carbopol 974P in the treatment of severe to moderate keratoconjunctivitis sicca (KCS) in patients with primary Sjögren's syndrome (SS) not responding to standard treatment with artificial tears.

METHODS

60 patients (57 F, 3 M, mean age 52.5+/-12.0, mean disease duration 12.2+/-7.1 yrs) affected with primary SS diagnosed according to the European Community Study Group criteria were studied. Foregoing medications for SS and artificial tears for KCS have not been changed within 3 and 2 months respectively prior to the study onset. In all cases Carbopol 974P was added because symptoms of KCS were not adequately controlled with traditional lubricants. Schirmer I test, B.U.T. (break up time), rose Bengal-stain, clinical ophthalmological examination (i.e. fluorescein staining, keratis, corneal infiltrates and ulcers) and a questionnaire for dry eye symptoms (range 0-30) were performed at entry (T0) and after 2 (T1) and 12 (T2) weeks. Assessment of global efficacy was obtained by VAS 0-100 at T2 either by patients and by the ophthalmologist.

RESULTS

Lachrymal tests significantly improved after 2 and, even more, after 12 weeks. Clinical ophthalmologic picture also ameliorated: a remarkable reduction of fluorescein positive lesions was demonstrated from 71.6% of the cases at T0 to 38.3% at T2. Total score of symptoms (T0: 16.1+/-7.3) dropped to 11.9+/-6.6 (T1) (p=0.000) and then to 6.7+/-5.3 (T2) (p=0.000). Global efficacy expressed by patients and physician was 74.8+/-15.9 and 76.6+/-13.0, respectively. No adverse events (blurred vision, allergy) were reported throughout the study.

CONCLUSIONS

Our study seems to demonstrate that addition of Carbopol 974P to the traditional therapeutic armamentarium for moderate to severe KCS is useful and well accepted in patients with primary SS in which management of ocular symptoms is unsatisfactory.

Abl interconnects oncogenic Met and p53 core pathways in cancer cells

The simplicity of BCR-ABL 'oncogene addiction' characterizing leukemia contrasts with the complexity of solid tumors where multiple 'core pathways', including receptor tyrosine kinases (RTKs) and p53, are often altered. This discrepancy illustrates the limited success of RTK antagonists in solid tumor treatment compared with the impact of Imatinib in BCR-ABL-dependent leukemia. Here, we identified c-Abl as a signaling node interconnecting Met-RTK and p53 core pathways, and showed that its inhibition impairs Met-dependent tumorigenesis. Met ensures cell survival through a new path in which c-Abl and p38-MAPK are employed to elicit p53 phosphorylation on Ser(392) and Mdm2 upregulation. We found a clinical correlation between activated Met, phospho-p53, and Mdm2 levels in human tumors, supporting the role of this path in tumorigenesis. Our findings introduce the concept that RTK-driven tumors may be therapeutically treated by hitting signaling nodes interconnecting core pathways. Moreover, they underline the importance of evaluating the relevance of c-Abl antagonists for combined therapies, based on the tumor signaling signature.

The wide spectrum of hyperechoic lesions of the breast

Although breast lesions are commonly detected because of their hypoechogenicity, some lesions may present with hyperechogenicity due to their histological components. Hyperechogenicity has been shown to be highly predictive of benignity; however, hyperechoic lesions can occasionally be malignant. This article reviews hyperechoic lesions of the breast, describes the underlying histological causes associated with hyperechogenicity, and the sonographic features useful for the differential diagnosis between benign and malignant hyperechoic lesions.

Imaging findings of liver resection using a bipolar radiofrequency electrosurgical device--initial observations

OBJECTIVE

To assess contrast-enhanced US (CEUS), computed tomography (CT) and magnetic resonance (MR) imaging findings and serial changes of the treated area at follow-up in patients who underwent liver resection using a bipolar radiofrequency electrosurgical device.

METHODS

Imaging findings of 27 patients with resected hepatocellular carcinomas (HCCs) (n=24) and metastases (n=3) (mean size: 2.6cm), were retrospectively evaluated. Two readers assessed: the (a) presence, (b) thickness, (c) shape and (d) echogenicity (CEUS)/attenuation (CT)/signal intensity (MR imaging) at coagulated site and the (e) presence of residual tumor of the bipolar radiofrequency electrosurgical device resection margin.

RESULTS

Follow-up was performed with either CT (n=20) or MR imaging (n=7) and repeated in 16 patients with CT (n=7), MR imaging (n=4), or both techniques (n=5). Four patients also had a single CEUS examination. At first imaging follow-up a peripheral halo was depicted at resection site (100%). A fluid collection within the surgical area was found in 67% of patients. During the following imaging examinations a progressive involution of both findings was observed, respectively, in 81% and 62% of patients. Viable tissue was detected in three patients (11%).

CONCLUSIONS

After liver resection with bipolar radiofrequency electrosurgical device successfully ablated tumor is demonstrated at imaging by an unenhancing partial linear peripheral halo, in most cases, surrounding a fluid collection reducing in size during follow-up.

Pneumatosis intestinalis versus pseudo-pneumatosis: review of CT findings and differentiation

Pneumatosis intestinalis is defined as the presence of gas within the wall of the gastrointestinal tract. Originally described on plain abdominal radiographs, it is an imaging sign rather than a specific diagnosis and it is associated with both benign and life-threatening clinical conditions. The most common life-threatening cause of pneumatosis intestinalis is bowel ischaemia. Computed tomography (CT) is usually requested to detect underlying disease. The presence of pneumatosis intestinalis often leads physicians to make a diagnosis of serious disease. However, an erroneous diagnosis of pneumatosis intestinalis may be made (i.e. pseudo-pneumatosis) when intraluminal beads of gas are trapped within or between faeces and adjacent mucosal folds. The purpose of this pictorial essay is to review and describe the CT imaging findings of pneumatosis and pseudo-pneumatosis intestinalis and to discuss key discriminatory imaging features.

Hepatocellular carcinoma in cirrhotic patients at multidetector CT: hepatic venous phase versus delayed phase for the detection of tumour washout

OBJECTIVES

Our aim was to compare retrospectively hepatic venous and delayed phase images for the detection of tumour washout during multiphasic multidetector row CT (MDCT) of the liver in patients with hepatocellular carcinoma (HCC).

METHODS

30 cirrhotic patients underwent multiphasic MDCT in the 90 days before liver transplantation. MDCT was performed before contrast medium administration and during hepatic arterial hepatic venous and delayed phases, images were obtained at 12, 55 and 120 s after trigger threshold. Two radiologists qualitatively evaluated images for lesion attenuation. Tumour washout was evaluated subjectively and objectively. Tumour-to-liver contrast (TLC) was measured for all pathologically proven HCCs.

RESULTS

48 HCCs were detected at MDCT. 46 of the 48 tumours (96%) appeared as either hyper- or isoattenuating during the hepatic arterial phase subjective washout was present in 15 HCCs (33%) during the hepatic venous phase and in 35 (76%) during the delayed phase (p<0.001, McNemar's test). Objective washout was present in 30 of the 46 HCCs (65%) during the hepatic venous phase and in 42 of the HCCs (91%) during the delayed phase (p=0.001). The delayed phase yielded significantly higher mean TLC absolute values compared with the hepatic venous phase (-16.1±10.8 HU vs -10.5±10.2 HU; p<0.001).

CONCLUSIONS

The delayed phase is superior to the hepatic venous phase for detection of tumour washout of pathologically proven HCC in cirrhotic patients.

Regional presentation of hepatic diseases: CT and MR imaging findings of differential diagnosis

Neoplastic and nonneoplastic diseases may involve the liver with a regional distribution, which is defined as a non-focal process without any specific anatomic predilection. In this pictorial essay we review hepatic diseases commonly presenting with a regional distribution in the liver and describe the CT and MR imaging findings helpful for differential diagnosis. Knowledge of the characteristic imaging manifestations of neoplastic and non-neoplastic diseases affecting the liver regionally will facilitate an accurate diagnosis and result in the appropriate clinical management of these liver diseases.