The Egyptian Journal of Radiology and Nuclear Medicine (2013) 44, 453–461

Egyptian Society of Radiology and Nuclear Medicine

The Egyptian Journal of Radiology andNuclearMedicine

www.elsevier.com/locate/ejrnmwww.sciencedirect.com

ORIGINAL ARTICLE

Can diffusion weighted MRI differentiate between

benign and malignant hepatic focal lesions?

Manal E. Badawy a, Manal Hamesa a,*, Ashraf Elaggan a,

Abd Elmonem Nooman a, Mamdouh Gabr b

a Department of Radio Diagnosis, Faculty of Medicine, Tanta University, Tanta, Egyptb Internal Medicine Departments, Faculty of Medicine, Tanta University, Tanta, Egypt

Received 28 April 2013; accepted 4 June 2013Available online 29 June 2013

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KEYWORDS

Diffusion;

MRI;

Hepatic focal lesions

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Abstract The aim of this study is to evaluate the role of diffusion-weighted magnetic resonance

imaging in differentiation between benign and malignant hepatic focal lesions.

Patients and methods: Fifty-five hepatic focal lesions in 40 patients. All those patients were sub-

jected to full clinical evaluation and radiological assessment using conventional MRI study of

the liver and diffusion-weighted MRI (Different b values: 100, 500 and 750 s/mm2). All lesions were

evaluated regarding size, signal intensity, enhancement pattern, qualitative assessments by the dif-

ferent b values and quantitative assessment by measurement of the ADC values.

Results: ADCs of focal hepatic lesions were significantly different between benign (2.869 ·10�3 mm2/s ± 0.652) and malignant (0.995 · 10�3 mm2/s ± 0. 274) hepatic focal lesions. The mean

ADCs were 0.76 · 10�3 mm2/s ± 0.53 for metastases, 1.3 · 10�3 mm2/s ± 0.55 for HCCs, 1.95 · 10�3 mm2/s ± 0.24 for benign hepatocellular lesions, 2.92 · 10�3 mm2/s ± 0.102 for hemangiomas,

and 3.64 · 10�3 mm2/s ± 0.14 for cysts.

Conclusion: Diffusion-weighted imaging (DWI) offers the possibility to obtain criteria for charac-

terization of focal liver lesions with subsequent differentiation between benign and malignant hepa-

tic focal lesions without the need for contrast agent administration-by quantifying diffusion effects

via apparent diffusion coefficient (ADC) measurements.� 2013 Production and hosting by Elsevier B.V. on behalf of Egyptian Society of Radiology and Nuclear

Medicine. Open access under CC BY-NC-ND license.

331423.com (M. Hamesa).

tian Society of Radiology and

g by Elsevier

ing by Elsevier B.V. on behalf of E

://dx.doi.org/10.1016/j.ejrnm.2013

1. Introduction

Diffusion is the thermally induced motion of water moleculesin biologic tissues, called Brownian motion. The microscopic

motion includes molecular diffusion of water and microcircu-lation of blood in the capillary network (microperfusion). Withthe addition of diffusion gradient pulses, magnetic resonance

(MR) imaging by means of apparent diffusion coefficient

gyptian Society of Radiology and Nuclear Medicine.

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454 M.E. Badawy et al.

(ADC) measurement is currently the best imaging method forin vivo quantification of the combined effects of capillary per-fusion and diffusion (1,2).

The primary application of diffusion-weighted MR imaginghas been in brain imaging, mainly for the evaluation of acuteischemic stroke, intracranial tumors, and demyelinating dis-

ease (3,4). With the advent of the echo-planar MR imagingtechnique, diffusion weighted MR imaging of the abdomenhas become possible with fast imaging times, which minimizes

the effect of gross physiologic motion from respiration andcardiac movement (9,12).

DWI (diffusion-weighted imaging) is a simple and sensitivemethod for screening focal hepatic lesion and is useful for dif-

ferential diagnosis. With advances in software, hardware andcoil systems, diffusion-weighted (DW) MR imaging can nowbe applied to liver imaging with improved image quality, prop-

er lesion detection and characterization. DW MR imaging en-ables qualitative and quantitative assessment of tissuediffusivity (apparent diffusion coefficient) without the use of

gadolinium chelates, which makes it a highly attractive tech-nique, particularly in patients with renal dysfunction at riskfor nephrogenic systemic fibrosis (5).

With regard to focal liver lesions, DW imaging is able todifferentiate lesions with high water content (cysts and angio-mas) from solid lesions. With regard to the latter, althoughthere are differences between benign lesions [focal nodular

hyperplasia (FNH), adenoma] and malignant lesions [metasta-sis, hepatocellular carcinoma (HCC) in their apparent diffu-sion coefficient (ADC) (6).

Diffusion weighted technique should be used as an addi-tional sequence to supplement conventional MRI protocolstudies for proper characterization of focal liver lesions (7).

The purpose of this study was to evaluate the ability of dif-fusion-weighted magnetic resonance imaging in differentiationbetween benign and malignant hepatic focal lesions.

2. Patients and methods

2.1. Patients

This study was conducted on (40) patients over a period of12 months starting from May 2011 to May 2012. Those pa-

tients were referred to Diagnostic Radiology Department atTanta University Hospital from the different medical and sur-gical departments as well as oncology unit of Tanta University

Hospital.Informed consent was obtained from all patients after full

explanation of the benefits and risks of the procedure. All pa-

tients were subjected to full clinical evaluation and specific lab-oratory investigations. All patients performed abdominal USand MRI study for the liver.

2.2. Liver MRI imaging protocol

All MR images were obtained on the available 1.5-T supercon-ductingMRI scanner (SignaHD · 14.0,GEHealthcare) installed

at radiology department at Tanta university hospital as follows:

1. Unenhanced axial T1-weighted acquisitions Parameters are

repetition time (TR) 150–200/ms, echo time (TE) minimum,

optional fat suppression, matrix, 256_192, 3/4 field of view,

8_2 mm, respiratory gating.2. T1 (Axial 2D breath hold spoiled GRE sequence applied in

phase and out of phase) (repetition time ms/echo time ms,

126/4.6 [in-phase], 2.3 [out-of-phase]; flip angle, 80�; matrix,179_256; section thickness, 8 mm; intersection gap, 2.5 mm;one signal acquired; field of view, 320 mm).

3. Axial & Coronal T2-weighted fast spin-echo sequence with

spectral fat saturation (1800/85; fast spin-echo factor, 16;matrix, 512_512; section thickness, 8 mm; intersectiongap, 2.5 mm; two signals acquired; field of view, 320 mm).

Respiratory trigger, superior/inferior saturation bands,32 kHz, fat suppression.

4. Heavily T2-weighted pulse sequences obtained with a mini-

mum TE of 160 ms.5. Diffusion weighted sequences (Respiratory-triggered proto-

col using b value = 0, 100, 500 and 750). Before contrastmaterial injection, diffusion-weighted MR sequences were

performed with the single shot echo-planar imaging tech-nique (EPI). These sequences combined diffusion gradientpulses before and after the 180� pulse. Spectral fat satura-

tion was used systematically to exclude chemical shift arti-facts. Qualitative assessments by the different b values aswell as quantitative assessment by measurement of the

ADC values were done.6. Dynamic contrast material–enhanced (Gd-DTPA) imaging

(Axial 3D GRE T1). Axial dynamic 3D fat-suppressed

GRE sequence, LAVA [liver acquisition with volumeacceleration] section thickness, 4–8 mm, interpolated toabout 60 overlapping reconstructed sections of 2–4 mmeach; bandwidth, 62 kHz): Performed during all phases

after bolus injection of 0.2 mL/kg body weight of Gd-DTPA flushed with 20 ml of sterile 0.9% saline solutionfrom the antecubital vein. At 20 s (arterial phase), 40 s

(portal phase) 60 s (Venous phase), and 120 s (equilib-rium phase) after the injection of Gd. And again at10 min and may be variable up to 1 h after injection

(delayed phase).

The diagnosis of the cases was established by means oftypical MRI findings (specially the pattern of enhancement),

specific laboratory investigation and favorable clinical data.The histopathological confirmation was done for fifteen atyp-ical lesions by the mean of ultrasound & CT guided biopsy.

(See Figs. 1–4 and Tables 1–3) (See Chart 1).

2.3. Statistical analysis

Data were analyzed using Statistical Program for Social Sci-ence (SPSS) version 17.0. Quantitative data were expressedas mean ± stander deviation (SD).

The following tests were done:

n Independent-samples T test of significance was used whencomparing between two means.

n A one-way analysis of variance (ANOVA) when comparingbetween more than two means.

Probability (P-value) less than 0.05 was considered signifi-cant and less than 0.01 was considered as highly significant.

Fig. 1 Female patient aged 50 years old presented with an accidentally discovered hypoechoic hepatic focal lesion upon fatty liver during

US check up. MRI study revealed a Lobulated left hepatic lobe subcapsular focal lesion showing hyperintense SI on T2 and heavy T2

weighted images (A and B). The lesion appeared hyperintense on diffusion study (C) as well as at the ADC map (D) with mean ADC

value = 2.9 · 10�3 mm2/s. The lesion showed incomplete ring of peripheral nodular enhancement at the arterial phase (E) after contrast

injection with gradual filling at the portal phase (F) and complete filling with contrast at delayed images (G). The lesion showed the typical

MRI findings of the hemangioma.

Can diffusion weighted MRI differentiate between benign and malignant hepatic focal lesions? 455

Fig. 2 Female patient aged 65 years old presented with accidentally discovered right hepatic lobe mass upon cirrhotic liver during US

follow up and elevated a – fetoprotein up to 600 ng/ml. MRI study revealed a right hepatic lobe mass with maximal diameter = 5 cm, the

mass exhibits hypointense SI on T1- wi (A) and hyperintense SI on T2wi (B) and diffusion study(C) and hypointense on ADC map (D)

with mean ADC value = 1.34 · 10�3 mm2/s. The mass showed immediate heterogeneous enhancement at the arterial phase (E) with rapid

washout at the subsequent porto-venous (F) and delayed phases (G). The mass showed the typical MRI findings of HCC together with

histopathological confirmation after surgical excision (Right lobectomy).

456 M.E. Badawy et al.

Fig. 3 Female patient with cancer colon aged 40 years old presented with jaundice and elevated liver enzymes. MRI study findings: The

liver showed two well defined focal lesions, one at the 4a segment and the other at the 8th segment. The lesions exhibits hypointense SI on

T1wi (A) and hyperintense SI on T2wi (B), diffusion study (C) and hypointense on ADC map (D) with mean ADC

value = 0.695 · 10�3 mm2/s. The mass showed marginal enhancement after Gd-DTPA administration (E). The diagnosis was established

as hypovascular metastasis based on the clinical history and the MRI findings.

Can diffusion weighted MRI differentiate between benign and malignant hepatic focal lesions? 457

3. Results

This study included fifty-five hepatic focal lesions in 40 pa-tients, they included 19 lesions of hepatic metastasis from dif-ferent primary malignancies, 14 lesions of HCC, 7 lesions of

hemangioma, 4 lesions of CCA, 4 lesions of FNH, 3 simple he-patic cyst, 2 hydatid cyst, one hepatic adenoma and one case ofhepatic lymphoma.

On diffusion studies All cystic lesions showed facilitated dif-

fusion, where they showed reduction of signal intensity onincreasing the b-values, and those which did not show reduc-tion of signal showed high signal on ADC map, which also re-

flects facilitated diffusion. On the other hand all malignantsolid lesions showed restricted diffusion evidenced by increasedsignal on increasing the b-values and low signal on ADC maps.

4. Discussion

During the last two decades, technical developments have dra-

matically improved the quality of liver MRI. These include in-

creases in field strength, more powerful gradients, and more

sensitive receiver coils, all of which contribute to substantiallyimproved spatial resolution in the images with subsequentaccurate, noninvasive detection and characterization of hepa-

tic lesions (8,9).The characterization of focal hepatic lesions continues to be

a challenge. Magnetic resonance (MR) imaging plays animportant role in the evaluation of a wide range of benign

and malignant focal hepatic lesions (10).Recently, diffusion-weighted MR sequences have been

proposed for the characterization of focal hepatic lesions

by using single-shot echo-planar imaging (EPI) techniquewith diffusion gradients in three directions and with differentb values (11).

The aim of this study was to evaluate the role of diffusion-weighted magnetic resonance imaging in differentiation be-tween benign and malignant hepatic focal lesions. This study

included fifty-five hepatic focal lesions in 40 patients, they in-cluded 19 lesions of hepatic metastasis from different primarymalignancies, 14 lesions of HCC, 7 lesions of hemangioma, 4lesions of CCA, 4 lesions of FNH, 3 simple hepatic cyst, 2

Fig. 4 Male patient aged 65 years old presented with accidentally discovered hepatic focal lesion during US check up. MRI Findings:

The liver showed a well defined focal lesion at the 4a segment with central area of necrosis, the lesion exhibits hypointense SI on T1WI (A),

Hyperintense SI on T2WI (B) and on diffusion study (C), hypointense on ADC map (C) with mean ADC value = 0.925 · 10�3 mm2/s.

The lesion appeared hypointense on arterial phase (E) with delayed contrast enhancement after 30 min from injection(G). Retraction of

the adjacent liver capsule is noted (arrow). The lesion was diagnosed as peripheral cholangiocarcinoma according to the MRI findings that

confirmed by histopathological study after CT guided biopsy.

458 M.E. Badawy et al.

Table 1 Mean apparent diffusion coefficient (ADCs) values of the hepatic focal lesion in this study using different b values.

Lesion 1st sequence 2nd sequence 3rd sequence SD P Sig

Simple cyst 3.63 3.745 3.701 0.121 0.493 NS

Hydatid cyst 3.505 3.335 3.315 0.064 0.262 NS

Hemangioma 3.017 2.897 2.827 0.102 0.223 NS

Adenoma 2.25 2.09 2.05 – – –

FNH 1.85 1.785 1.725 0.021 0.3 NS

HCC 1.368 1.27 1.25 0.05 0.074 NS

CCA 0.925 0.822 0.804 0.11 0.246 NS

Lymphoma 1.37 1.20 1.18 – – –

Metastasis 0.786 0.72 0.695 0.048 0.185 NS

Normal liver tissue 2.89 2.73 2.68 0.58 0.212 NS

Benign lesions 2.942 2.828 2.809 0.651 0.786 NS

Malignant lesions 1.059 0.961 0.921 0.267 0.491 NS

b value = 100, 500 and 750 s/mm2at the 1st, 2nd and 3rd sequences respectively.

NS, non significant. SD = Standard Deviation. P = p value.

Table 2 The difference between the mean ADC values of benign and malignant lesions in this study using different b values.

Benign lesions SD Malignant lesions SD P Sig.

First sequence 2.942 0.611 1.059 0.281 <0.001 HS

Second sequence 2.828 0.641 0.961 0.257 <0.001 HS

Third sequence 2.809 0.631 0.921 0.237 <0.001 HS

b value = 100, 500 and 750 s/mm2 at the 1st, 2nd and 3rd sequences respectively.

HS, highly significant: SD = Standard Deviation.

� Mean ADC value = (Number · 10�3 mm2/s) ± SD (Standard deviation).

� The lowest ADCs were found in metastases, CCA and HCCs and the highest values were found in hemangiomas and hepatic cysts.

� The difference between the mean ADC values of benign and malignant lesions was statistically significant (P< 0.001). No statistically sig-

nificant differences in ADC values among the different benign lesions or among the different malignant lesions at different sequences.

� P values indicate statically insignificant differences between the difference sequences.

Table 3 MR signal intensity characteristics of the hepatic focal lesion in this study after dynamic contrast (Gd-DTPA) material–

enhanced imaging (Axial 3D GRE T1).

Lesion Sequence

Arterial phase Portal venous phase Equilibrium phase Delayed phase

Simple cyst fl fl fl flHydatid cyst fl fl fl flHemangioma › › › ›Adenoma ›* Iso Iso flFNH ›* (fl) ›* ›* fl (›)HCC ›* fl fl flCCA fl fl fl Variable

Lymphoma fl fl ›* ›*Metastasis › fl fl fl

� Arrows indicate increased (‘‘up’’ arrow) or decreased (‘‘down’’ arrow) enhancement relative to the surrounding normal liver.Arrows in parentheses indicate increased or decreased enhancement in an area of central scarring. Iso = isoenhancing.

� The enhancement pattern of hemangioma at the 7 lesions in this study is an incomplete ring of peripheral nodular enhance-ment at the arterial phase with gradual filling at the port-venous and equilibrium phases and complete filling at the delayedphase.

* Heterogeneous enhancement.

Can diffusion weighted MRI differentiate between benign and malignant hepatic focal lesions? 459

hydatid cyst, one hepatic adenoma and one case of hepaticlymphoma.

DWI (Diffusion-weighted imaging) is a simple and sensitivemethod for screening focal hepatic lesions and is useful for dif-

00.5

11.5

22.5

33.5

4

S.cyst

H.cyst

Haemangioma

Adenoma

FNHHCC

CCALymphoma

Metastasis

Normal Liver

Column 1 Seq 1 Seq 2 Seq 3

AD

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X

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Chart 1 Mean apparent diffusion coefficient (ADCs) values of

the different hepatic focal lesion in this study using different b

values.

460 M.E. Badawy et al.

ferential diagnosis. DW MR imaging enables qualitative andquantitative assessment of tissue diffusivity. Quantitative anal-ysis may be performed with the generation of apparent diffu-

sion coefficient (ADC) maps from diffusion images obtainedat different b values (5,12).

Aliya et al. reported that the actual detection of liver tumor

is reported to be greater at low b values (50–150 s/mm2) (12).Parikh et al. reported a significant improvement in the detec-tion of focal liver lesions with low b-value diffusion-weightedimaging (88% accuracy) compared with T2-weighted imaging

(70%). High b values are considered to be more importantfor the characterization of focal liver lesions; however, the highsignal intensity of a lesion at high b values is most effectively

interpreted in conjunction with the lesion characteristics seenwith other conventional MR sequences (13).

The use of high b value overcomes the effect of capillary

perfusion and water diffusion in extracellular extravascularspace, as high b value will result in the reduction of signal frommoving protons in the bile ducts, cysts, vessels, and fluid in the

bowel. This will result in an increased contrast between the le-sion and liver. Furthermore, the differences in the relative con-trast ratio between malignant and benign lesions wereincreased with a high b value (14,15).

The absolute ADC values of the different types of lesionswere not similar, which is probably due to differences in tech-niques applied (b value, breath measurement methods, and

mathematical technique applied). This finding was also statedby Petra and Eric eta al where they stated that in spite there arean increasing number of studies dealing with quantitative mea-

surements of ADC in liver lesions, there are many discrepan-cies in the reported ADC values where there is no cut-offvalue for ADC values in normal parenchyma, benign andmalignant lesions and this is often associated with many tech-

nical parameters such as the use of respiratory-triggered versusbreath- hold diffusion-weighted protocol and significantly bvalue as high b value results in low ADC value and vice versa

(16), these agreeing with Bachir Taouli et al. who stated thatADCs tend to be higher when using low b values (17).

The SNR (Signal to noise ratio) of the normal liver was sig-

nificantly better on respiratory-triggered DWI than on breath-hold DWI. The mean CNR (Contrast to noise ratio) of metas-tases, hepatocellular carcinomas, and abscesses was signifi-

cantly better in the respiratory-triggered DWI than in thebreathhold DWI sequences (18).

This owed to the protocol of DWI in our study, which was

carried by using respiratory-triggered protocol with b value(100 s/mm2) for proper detection of the hepatic focal lesionsand b value (500 and 750 s/mm2) to overcome the effect of cap-

illary perfusion and water diffusion in extracellular extravascu-lar space with subsequent reduction of signal from movingprotons.

Yet the findings in the present work were similar to previ-ous studies in many aspects, the difference between the meanADC values of benign and malignant lesions was statisticallysignificant (P < 0.001) and no statistically significant differ-

ences in ADC values among the different benign lesions oramong the different malignant lesions which supports similarprevious findings where Onura et al. stated that the mean

ADC values of benign lesions were higher than malignant le-sions and these differences were statistically significant for all3 diffusion gradients with P values of 0.0023, 0.0001, and

<0.0001 (19). These values are agreeing with Miller et al.who stated that the ADC values of benign hepatic lesions weresignificantly higher than those of malignant hepatic tumors,

with a P value <0.05 (20). Demir et al. also stated that the dif-ference between the mean ADC values of benign and malig-nant lesions was statistically significant (P < 0.01) and nostatistically significant differences in ADC values among the

different benign lesions or among the different malignant le-sions (21). Bachir Taouli et-al also stated that the lowest ADCswere found in metastases, CCA and HCCs and the highest val-

ues were found in hemangiomas and hepatic cysts (17).

5. Conclusion

Diffusion-weighted imaging (DWI) offers the possibility to ob-tain criteria for characterization of focal liver lesions with sub-sequent differentiation between benign and malignant hepatic

focal lesions without the need for contrast agent administra-tion-by quantifying diffusion effects via apparent diffusioncoefficient (ADC) measurements.

References

(1) Le Bihan D, Breton E, Lallemand D, Aubin ML, Vignaud J,

Laval-Jeantet M. Separation of diffusion and perfusion in intra-

voxel incoherent motion MR imaging. Radiology 1988;168:497.

(2) Le Bihan D, Turner R, Douek P, Patronas N. Diffusion MR

imaging: clinical applications. AJR Am J Roentgenol

1992;159:591.

(3) Bammer R, Stollberger R, Augustin M. Diffusion-weighted

imaging with navigated interleaved echo-planar imaging and a

conventional gradient system. Radiology 1999;211:799.

(4) Schaefer PW, Grant PE, Gonzalez RG. Diffusion-weighted MR

imaging of the brain. Radiology 2000;217:331.

(5) Low RN, Gurney J. Diffusion-weighted MRI (DWI) in the

oncology patient: value of breathhold D compared to unenhanced

and gadolinium-enhanced MRI. J Magn Reson Imaging

2007;25:848.

(6) Taouli B, Koh DM. Diffusion-weighted MR imaging of the liver.

Radiology 2010;254(1):47.

(7) Vergara ML, Fernandez M, Pereira R. Diffusion-weighted MRI

characterization of solid liver lesions. Revista Chilena De

Radiologıa 2010;16(1):510.

Can diffusion weighted MRI differentiate between benign and malignant hepatic focal lesions? 461

(8) Philip J.A, Robinson, Janice Ward. MR of the Liver, A Practical

Guide Published by Taylor & Francis Group 270 Madison

Avenue New York, NY 2006; 10016.

(9) Alvin CSilva, James M, Evans Ann E, McCullough. MR imaging

of hypervascular liver masses: a review of current techniques.

RadioGraphics March–April 2009;29:385.

(10) Thoeny HC, De Keyzer F. Extracranial applications of diffusion-

weighted magnetic resonance imaging. Eur Radiol

2007;17(6):1385.

(11) Taouli B, Vilgrain V, Dumont E. Evaluation of liver diffusion

isotropy and characterization of focal hepatic lesions with two

single-shot echo-planar MR imaging sequences: prospective study

in 66 patients. Radiology 2003;226:71.

(12) Qayyum Aliya. Diffusion-weighted imaging in the abdomen and

pelvis: concept and applications. RadioGraphics 2009;29:1797.

(13) Parikh T, Drew SJ, Lee VS. Focal liver lesion detection and

characterization with diffusion weighted MR imaging: compar-

ison with standard breath-hold T2-weighted imaging. Radiology

2008;246(3):812.

(14) Hosny IA, Diffusion MRI. Of focal liver lesions. Pak J Radiol

2010;20:01.

(15) Koike N, Cho A, Nasu K. Role of diffusion weighted magnetic

resonance imaging in the differential diagnosis of focal hepatic

lesions. World J Gastroenterol 2009;15(46):5805–12.

(16) Petra GK, Eric J. Diffusion-weighted imaging in the liver. World

J Gastroenterol 2010;16:1567.

(17) Bachir Taouli, Valerie Vilgrain, Erik Dumont, Jean-Luc, Daire.

Evaluation of liver diffusion isotropy and characterization of

focal hepatic lesions with two single-shot echo-planar MR

imaging sequences: prospective study in 66 patients. Radiology

2003;226:71.

(18) Harsh Kandpal, Raju Sharma1 KS, Madhusudhan, Kulwant

Singh, Kapoor. Respiratory-triggered versus breath-hold diffu-

sion-weighted mri of liver lesions* comparison of image quality

and apparent diffusion coefficient values. AJR 2009;192:915.

(19) Onura MR, Cicekcia M, Kayali A. The role of ADC measure-

ment in differential diagnosis of focal hepatic lesions. Eur J

Radiol 2012;81(3):171.

(20) Miller FH, Hammond N, Siddiqi AJ. Utility of diffusion-

weighted mri in distinguishing benign and malignant hepatic

lesions. J Magn Reson Imaging 2010;32:138.

(21) Demir O, Obuz F, Sagol O, Dicle O. Contribution of diffusion-

weighted MRI to the differential diagnosis of hepatic masses.

Diagn Interv Radiol 2007;13:81.