Diffusion-weighted MRI in the characterization of cystic pancreatic lesions: usefulness of ADC values

doi:10.1016/j.mri.2010.06.031

Magnetic Resonance Imaging

Volume 28, Issue 10, December 2010, Pages 1447-1455

https://doi.org/10.1016/j.mri.2010.06.031 Get rights and content

Abstract

Purpose

To evaluate the usefulness of diffusion-weighted magnetic resonance imaging (DW-MRI) in the differentiation of cystic pancreatic lesions.

Materials and Methods

Institutional review board approval was obtained, and written informed consent was taken from all enrolled subjects. Fifty-four patients with cystic pancreatic lesions of at least 1 cm in diameter (range:10–96 mm) at ultrasonography and/or computed tomography and 10 normal subjects underwent MRI at 1.5 T. These subjects included thirty-four patients with intraductal papillary mucinous tumors (IPMTs), 10 with pseudocysts, 5 with serous cystoadenoma and 5 with mucinous cystoadenoma. The MR protocol included axial T1w and T2w sequences and coronal MR cholangiopancreatography images. DW-MRI was performed using a breath-hold single-shot echo-planar sequence with a b gradient factor value of 500 s/mm² in the three orthogonal axes. Apparent diffusion coefficient (ADC) was calculated for cerebrospinal fluid, normal pancreatic parenchyma, and for each focal pancreatic lesion. Imaging results were correlated with endoscopic retrograde cholangiopancreatography, endoscopic ultrasound-guided fine needle aspiration, surgery and/or imaging follow-up.

Results

Mean ADC value was 4.1×10⁻³ mm²/s for cerebrospinal fluid, 1.73×10⁻³ mm²/s for normal pancreatic parenchyma, 4.09×10⁻³ mm²/s for IPMT, 3.89×10⁻³ mm²/s for mucinous cystoadenoma, 3.65×10⁻³ mm²/s for serous cystoadenoma and 2.83×10⁻³ mm²/s for pseudocyst. Mean ADC values of each of the different types of pancreatic lesions were statistically different (P<.05).

Conclusion

DW-MRI may be helpful in the differential diagnosis of cystic pancreatic lesions.

Introduction

Magnetic resonance imaging (MRI) has the capability of allowing non-invasive evaluation of pancreatic parenchyma, pancreatic ducts, adjacent soft tissues, and vascular network in a single session [1].

Nevertheless, MRI, as the other imaging techniques, has a number of limitations in the diagnosis of pancreatic abnormalities, particularly in the differentiation of various types of cystic lesions. Often, patients with cystic pancreatic lesions undergo serial follow-up imaging, endoscopic ultrasound (EUS) or endoscopic retrograde cholangiopancreatography (ERCP), and sometimes, pancreatectomy before lesions are fully characterized. A noninvasive method to identify these different types of lesions would be a useful addition to the diagnostic armamentarium.

Diffusion-weighted magnetic resonance imaging (DW-MRI) is a magnetic resonance technique based on intravoxel incoherent motion that reflects molecular diffusion (the Brownian motion of the spins) in biologic tissues [2], [3]. Several authors have reported that quantification of diffusion-weighted (DW) images as apparent diffusion coefficient (ADC), which integrates the effects of both capillary perfusion and water diffusion in the extracellular extravascular space [2], can be useful in differentiating normal and abnormal tissues and can help characterize a number of abnormalities [4], [5], [6], [7], [8], [9], [10], [11].

There is limited data in the literature on DW-MRI of the pancreas and particularly on the use of this technique in the diagnosis of cystic pancreatic lesions [3], [12], [13], [14], [15], [16], [17], [18]. Two prior studies showed discordant findings: Yamashita et al. [3] showed lower ADC in intraductal papillary mucinous tumors (IPMTs) compared to serous cystadenomas, whereas Irie et al [12] showed a total overlap of ADC between different categories of cystic lesions.

The purpose of our study was to evaluate the usefulness of DW-MRI in the differentiation of cystic pancreatic lesions.

Section snippets

Patients

Our institutional review board approved this study and written informed consent was taken after explanation of the complete examination procedure from all enrolled subjects. Between March 2005 and December 2007, 54 patients (21 men and 33 women; age range: 22–82 years; mean age, 57.3±15.0 years) with cystic pancreatic lesions of at least 1 cm in diameter at ultrasonography and/or computed tomography (CT) were prospectively enrolled in our study group.

The pancreatic lesions ranged from 10 to 96

Results

On DW-MRI, a slight degree of image distortion due to susceptibility artifacts and a chemical shift artifact in the abdominal wall were observed in all patients; however, these artifacts did not preclude the evaluation of the focal lesions and calculation of the ADCs in all patients.

Mean ADC values of cerebrospinal fluid (CSF) and normal pancreatic parenchyma were 4.1×10⁻³±0 mm²/s and 1.73×10⁻³±0.03 mm²/s, respectively. On scatter diagram of Fig. 1, ADC values of each lesion are reported.

In all

Discussion

Increased detection of cystic lesions of the pancreas on cross-sectional imaging studies [19] has led to a rise in the number of pancreatic surgical resections; however, because many cystic lesions are known to be benign, in many cases resection may be unnecessary [20]. Therefore, it is important to accurately characterize various cystic lesions of the pancreas.

Three major papers [3], [12], [18] have addressed the usefulness of DW-MRI in the diagnosis of cystic pancreatic lesions.

Two older

Acknowledgments

The authors acknowledge Lorenzo Faggioni, MD and Ferruccio Aquilini, statistician for their support with the statistical analysis in this study.

References (23)

MatosC. et al.
MR imaging of the pancreas: a pictorial tour
Rev Radiographics
(2002)
Le BihanD. et al.
Separation of diffusion and perfusion in intravoxel incoherent motion MR imaging
Radiology
(1988)
YamashitaY. et al.
Mucin-producing tumor of the pancreas: diagnostic value of diffusion-weighted echo-planar MR imaging
Radiology
(1998)
NamimotoT. et al.
Focal liver masses: characterization with diffusion-weighted echo-planar MR imaging
Radiology
(1997)
IchikawaT. et al.
Diffusion weighted MR imaging with a single-shot echoplanar sequence: detection and characterization of focal hepatic lesions
AJR Am J Roentgenol
(1998)
YamashitaY. et al.
Ultrafast MR imaging of the abdomen: echo planar imaging and diffusion-weighted imaging
J Magn Reson Imaging
(1998)
YamadaI. et al.
Diffusion coefficients in abdominal organs and hepatic lesions: evaluation with intravoxel incoherent motion echo-planar MR imaging
Radiology
(1999)
IchikawaT. et al.
Diffusion weighted MR imaging with single-shot echo-planar imaging in the upper abdomen: preliminary clinical experience in 61 patients
Abdom Imaging
(1999)
ChowL.C. et al.
Single breath-hold diffusion-weighted imaging of the abdomen
J Magn Reson Imaging
(2003)
TaouliB. et al.
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)

ThoenyH.C. et al.

Diffusion-weighted MR imaging of kidneys in healthy volunteers and patients with parenchymal diseases: initial experience

Radiology

(2005)

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Original ContributionDiffusion-weighted MRI in the characterization of cystic pancreatic lesions: usefulness of ADC values

Abstract

Purpose

Materials and Methods

Results

Conclusion

Introduction

Section snippets

Patients

Results

Discussion

Acknowledgments

MR imaging of the pancreas: a pictorial tour

Rev Radiographics

Separation of diffusion and perfusion in intravoxel incoherent motion MR imaging

Radiology

Mucin-producing tumor of the pancreas: diagnostic value of diffusion-weighted echo-planar MR imaging

Radiology

Focal liver masses: characterization with diffusion-weighted echo-planar MR imaging

Radiology

Diffusion weighted MR imaging with a single-shot echoplanar sequence: detection and characterization of focal hepatic lesions

AJR Am J Roentgenol

Ultrafast MR imaging of the abdomen: echo planar imaging and diffusion-weighted imaging

J Magn Reson Imaging

Diffusion coefficients in abdominal organs and hepatic lesions: evaluation with intravoxel incoherent motion echo-planar MR imaging

Radiology

Diffusion weighted MR imaging with single-shot echo-planar imaging in the upper abdomen: preliminary clinical experience in 61 patients

Abdom Imaging

Single breath-hold diffusion-weighted imaging of the abdomen

J Magn Reson Imaging

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

Diffusion-weighted MR imaging of kidneys in healthy volunteers and patients with parenchymal diseases: initial experience

Radiology

Original Contribution
Diffusion-weighted MRI in the characterization of cystic pancreatic lesions: usefulness of ADC values