Abstract
Objectives
To evaluate the usefulness of diffusion-weighted (DW) magnetic resonance images for distinguishing non-neoplastic cysts from solid masses of indeterminate internal characteristics on computed tomography (CT) in the mediastinum.
Methods
We enrolled 25 patients with pathologically proved mediastinal masses who underwent both thoracic CT and magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI). MRI was performed in patients with mediastinal masses of indeterminate internal characteristics on CT. Two thoracic radiologists evaluated the morphological features and quantitatively measured the net enhancement of the masses at CT. They also reviewed MR images including unenhanced T1- and T2-weighted images, gadolinium-enhanced images and DW images.
Results
The enrolled patients had 15 solid masses and ten non-neoplastic cysts. Although the morphological features and the extent of enhancement on CT did not differ significantly between solid and cystic masses in the mediastinum (P > 0.05), non-neoplastic cysts were distinguishable from solid masses by showing signal suppression on high-b-value DW images or high apparent diffusion coefficient (ADC) values of more than 2.5 × 10-3 mm2/s (P < 0.001). ADC values of non-neoplastic cysts (3.67 ± 0.87 × 10-3 mm2/s) were significantly higher than that of solid masses (1.46 ± 0.50 × 10-3 mm2/s) (P < 0.001).
Conclusions
DWI can help differentiate solid and cystic masses in the mediastinum, even when CT findings are questionable.
Key Points
• Non-invasive diagnosis of non-neoplastic cysts can save surgical biopsy or excision.
• Conventional CT or MRI findings cannot always provide a confident diagnosis.
• Mediastinal masses can be well-characterised with DWI.
• Non-neoplastic mediastinal cysts show significantly higher ADC values than cystic tumours.
• DWI is useful to determine treatment strategy.
Similar content being viewed by others
Abbreviations
- ADC:
-
Apparent diffusion coefficient
- CSF:
-
Cerebrospinal fluid
- DWI:
-
Diffusion-weighted MR imaging
- HU:
-
Hounsfield units
- ROI:
-
Region of interest
References
Zambudio AR, Lanzas JT, Calvo MJ, Fernandez PJ, Paricio PP (2002) Non-neoplastic mediastinal cysts. Eur J Cardiothorac Surg 22:712–716
Duwe BV, Sterman DH, Musani AI (2005) Tumors of the mediastinum. Chest 128:2893–2909
Kim JH, Goo JM, Lee HJ et al (2003) Cystic tumors in the anterior mediastinum. Radiologic-pathological correlation. J Comput Assist Tomogr 27:714–723
Jeung MY, Gasser B, Gangi A et al (2002) Imaging of cystic masses of the mediastinum. Radiographics 22:S79–S93
Tomiyama N, Honda O, Tsubamoto M et al (2009) Anterior mediastinal tumors: diagnostic accuracy of CT and MRI. Eur J Radiol 69:280–288
Padhani AR, Liu G, Koh DM et al (2009) Diffusion-weighted magnetic resonance imaging as a cancer biomarker: consensus and recommendations. Neoplasia 11:102–125
Lang P, Wendland MF, Saeed M et al (1998) Osteogenic sarcoma: noninvasive in vivo assessment of tumor necrosis with diffusion-weighted MR imaging. Radiology 206:227–235
Sugahara T, Korogi Y, Kochi M et al (1999) Usefulness of diffusion-weighted MRI with echo-planar technique in the evaluation of cellularity in gliomas. J Magn Reson Imaging 9:53–60
Gauvain KM, McKinstry RC, Mukherjee P et al (2001) Evaluating pediatric brain tumor cellularity with diffusion-tensor imaging. AJR Am J Roentgenol 177:449–454
Yi CA, Jeon TY, Lee KS et al (2007) 3-T MRI: usefulness for evaluating primary lung cancer and small nodules in lobes not containing primary tumors. AJR Am J Roentgenol 189:386–392
Matoba M, Tonami H, Kondou T et al (2007) Lung carcinoma: diffusion-weighted MR imaging—preliminary evaluation with apparent diffusion coefficient. Radiology 243:570–577
Henzler T, Schmid-Bindert G, Schoenberg SO, Fink C (2010) Diffusion and perfusion MRI of the lung and mediastinum. Eur J Radiol 76:329–336
Yernault JC, Kuhn G, Dumortier P, Rocmans P, Ketelbant P, De Vuyst P (1986) “Solid” mediastinal bronchogenic cyst: mineralogic analysis. AJR Am J Roentgenol 146:73–74
Glazer HS, Siegel MJ, Sagel SS (1989) Low-attenuation mediastinal masses on CT. AJR Am J Roentgenol 152:1173–1177
McAdams HP, Kirejczyk WM, Rosado-de-Christenson ML, Matsumoto S (2000) Bronchogenic cyst: imaging features with clinical and histopathologic correlation. Radiology 217:441–446
Glazer HS, Molina PL, Siegel MJ, Sagel SS (1991) High-attenuation mediastinal masses on unenhanced CT. AJR Am J Roentgenol 156:45–50
Fischbach R, Benz-Bohm G, Berthold F, Eidt S, Schmidt R (1994) Infradiaphragmatic bronchogenic cyst with high CT numbers in a boy with primitive neuroectodermal tumor. Pediatr Radiol 24:504–505
Kumar AJ, Kuhajda FP, Martinez CR, Fishman EK, Jezic DV, Siegelman SS (1983) Computed tomography of extracranial nerve sheath tumors with pathological correlation. J Comput Assist Tomogr 7:857–865
Cohen LM, Schwartz AM, Rockoff SD (1986) Benign schwannomas: pathologic basis for CT inhomogeneities. AJR Am J Roentgenol 147:141–143
Sakai F, Sone S, Kiyono K et al (1992) Intrathoracic neurogenic tumors: MR-pathologic correlation. AJR Am J Roentgenol 159:279–283
Suh JS, Abenoza P, Galloway HR, Everson LI, Griffiths HJ (1992) Peripheral (extracranial) nerve tumors: correlation of MR imaging and histologic findings. Radiology 183:341–346
Gümüştaş S, Inan N, Sarisoy HT et al (2011) Malignant versus benign mediastinal lesions: quantitative assessment with diffusion weighted MR imaging. Eur Radiol 21:2255–2260
Tondo F, Saponaro A, Stecco A et al (2011) Role of diffusion-weighted imaging in the differential diagnosis of benign and malignant lesions of the chest-mediastinum. Radiol Med 116:720–733
Taouli B, Koh DM (2010) Diffusion-weighted MR imaging of the liver. Radiology 254:47–66
Razek AA, Elmorsy A, Elshafey M, Elhadedy T, Hamza O (2009) Assessment of mediastinal tumors with diffusion-weighted single-shot echo-planar MRI. J Magn Reson Imaging 30:535–540
Inan N, Arslan A, Akansel G et al (2007) Diffusion-weighted imaging in the differential diagnosis of simple and hydatid cysts of the liver. AJR Am J Roentgenol 189:1031–1036
Tsuruda JS, Chew WM, Moseley ME, Norman D (1990) Diffusion-weighted MR imaging of the brain: value of differentiating between extraaxial cysts and epidermoid tumors. AJR Am J Roentgenol 155:1059–1065, discussion 1066-1058
Acknowledgments
C.A. Yi was a guarantor of entire study. C.A. Yi and K.E. Shin developed the design and the organisation of this study, participated in all stages of the study, made the initial interpretation of the study findings, and prepared the first draft of the manuscript. C.A. Yi was responsible for the MRI scanning and had overall responsibility for all MRI features of the study. T.S. Kim and H.Y. Lee researched on references and contributed to manuscript writing. Y.S. Choi, H.K. Kim and J. Kim were responsible for patient enrolment and the management of the clinical data.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Shin, K.E., Yi, C.A., Kim, T.S. et al. Diffusion-weighted MRI for distinguishing non-neoplastic cysts from solid masses in the mediastinum: problem-solving in mediastinal masses of indeterminate internal characteristics on CT. Eur Radiol 24, 677–684 (2014). https://doi.org/10.1007/s00330-013-3054-0
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00330-013-3054-0