Impact of Protein Content on Proton Diffusibility in Intracranial Cysts

Abstract

Purpose: The physical background of diffusion phenomena in intracranial cysts is unclear in some cases. To evaluate a potential dependency of proton diffusion on the concentration of proteins in cystic lesions we investigated the correlation of diffusion weighted imaging (DWI) and magnetization transfer ratio imaging (MTR) in intracranial cystic pathologies in vivo and in vitro with protein solutions.

Materials and Methods: 21 patients (14 male/7 female) with intracranial cystic lesions underwent preoperative MRI (1.5 T) including MTR and DWI sequences. For comparison a series of samples with declining concentration of albumin was investigated in vitro with a 7 T animal scanner.

Results: In the patients examination mean ADC values were 1.93 × 10⁻³mm²/sec and mean MTR values were 0.2. Mean ADC value of the albumin solutions was 0.22 × 10⁻³ mm²/sec and mean MTR was 0.12. ADC and MTR values showed a strong negative correlation in the patients (Spearman’s rank correlation r_s = –0.80, p < 0.01) and a very strong negative correlation in the in vitro examinations (r_s = –1.0, p < 0.01).

Conclusion: The strong negative correlation of ADC and MTR values suggest a strong influence of proteins on proton diffusion in intracranial cysts. The phenomena can be explained by macromelecules that bind nearby protons in their vicinity.

Zusammenfassung

Ziel: Die physikalische Grundlage von Diffusionsphänomenen intrakranieller Raumforderungen ist in vielen Fällen unbekannt. Um einen möglichen Einfluss des Proteingehalts in intrakraniellen Zysten auf die Protonendiffusion zu untersuchen, wurde die Korrelation von Diffusionsdaten (DWI) und Magnetisation Transfer Ratio Imaging (MTR) in intrakraniellen Zysten und in vitro untersucht.

Material und Methoden: 21 Patienten (m/w: 14/7) mit intrakraniellen zystischen Läsionen wurden präoperativ mit ADC- und MTR-Bildgebung kernspintomografisch (1,5 T) untersucht. Vergleichend wurde eine Verdünnungsreihe mit Albuminlösungen, in vitro, in einem 7 T MRT-Gerät untersucht.

Ergebnisse: Der durchschnittliche ADC-Wert in den zystischen Läsionen betrug 1,93 × 10⁻³ mm²/s und der durchschnittliche MTR-Wert 0,20. Der durchschnittliche ADC-Wert in den Albuminlösungen betrug 0,22 × 10⁻³ mm²/s und der durchschnittliche MTR-Wert 0,12. Es zeigte sich eine deutliche negative Korrelation der ADC- und MTR-Werte in den verschiedenen zystischen Läsionen (Spearman Rang Korrelation r_s = –0,80, p < 0,01) und eine sehr starke, negative Korrelation in der Verdünnungsreihe der Proteinlösungen (r_s = –1,0, p < 0,01).

Schlussfolgerung: Die deutliche negative Korrelation der ADC- und MTR-Werte belegt einen starken Einfluss des Proteingehalts auf die Protonendiffusibilität in zystischen intrakraniellen Läsionen. Das Phänomen kann durch die Bindung des Wassers an Makromoleküle erklärt werden.

Key words

CNS - MR-imaging - Abscess - Diffusion imaging

• References

• 1 Chatterjee S, Deepak KS, Banuprakash S et al. T1 Hyperintense Cystic Lesion – an Epidermoid or an Abscess?. Clin Neuroradiol 2010; 20: 66-69
• 2 Bergui M, Zhong J, Bradac GB et al. Diffusion-weighted images of intracranial cyst-like lesions. Neuroradiology 2001; 43: 824-829
• 3 Bukte Y, Paksoy Y, Genc E et al. Role of diffusion-weighted MR in differential diagnosis of intracranial cystic lesions. Clin Radiol 2005; 60: 375-383
• 4 Gupta RK, Prakash M, Mishra AM et al. Role of diffusion weighted imaging in differentiation of intracranial tuberculoma and tuberculous abscess from cysticercus granulomas – a report of more than 100 lesions. Eur J Radiol 2005; 55: 384-392
• 5 Hu XY, Hu CH, Fang XM et al. Intraparenchymal epidermoid cysts in the brain: diagnostic value of MR diffusion-weighted imaging. Clin Radiol 2008; 63: 813-818
• 6 Lai PH, Ho JT, Chen WL et al. Brain abscess and necrotic brain tumor: discrimination with proton MR spectroscopy and diffusion-weighted imaging. Am J Neuroradiol 2002; 23: 1369-1377
• 7 Luthra G, Parihar A, Nath K et al. Comparative evaluation of fungal, tubercular, and pyogenic brain abscesses with conventional and diffusion MR imaging and proton MR spectroscopy. Am J Neuroradiol 2007; 28: 1332-1338
• 8 Park SH, Chang KH, Song IC et al. Diffusion-weighted MRI in cystic or necrotic intracranial lesions. Neuroradiology 2000; 42: 716-721
• 9 Reddy JS, Mishra AM, Behari S et al. The role of diffusion-weighted imaging in the differential diagnosis of intracranial cystic mass lesions: a report of 147 lesions. Surg Neurol 2006; 66: 246-250 ; discussion 50-51
• 10 Gupta RK, Rao AM, Mishra AM et al. Diffusion-weighted EPI with magnetization transfer contrast. Magn Reson Imaging 2005; 23: 35-39
• 11 Santhosh K, Thomas B, Radhakrishnan VV et al. Diffusion tensor and tensor metrics imaging in intracranial epidermoid cysts. J Magn Reson Imaging 2009; 29: 967-970
• 12 Ringelstein A, Turowski B, Gizewski ER et al. Evaluation des ADC-Mappings als Prädiktor für ein Ansprechen von Glioblastomrezidiven auf eine Therapie mit Avastin. Fortschr Röntgenstr 2010; 182: 868-872
• 13 Grossman RI, Gomori JM, Ramer KN et al. Magnetization transfer: theory and clinical applications in neuroradiology. Radiographics 1994; 14: 279-290
• 14 Mishra AM, Gupta RK, Saksena S et al. Biological correlates of diffusivity in brain abscess. Magnetic Resonance in Medicine 2005; 54: 878-885
• 15 Goebell E, Fiehler J, Siemonsen S et al. Macromolecule content influences proton diffusibility in gliomas. Eur Radiol 2011; 21: 2626-2632
• 16 Engelbrecht V, Scherer A, Rassek M et al. Diffusion-weighted MR imaging in the brain in children: findings in the normal brain and in the brain with white matter diseases. Radiology 2002; 222: 410-418
• 17 Sener RN. Diffusion magnetic resonance imaging patterns in metabolic and toxic brain disorders. Acta Radiol 2004; 45: 561-570
• 18 Louis DN, Ohgaki H, Wiestler OD et al. The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol 2007; 114: 97-109
• 19 Kuhnke M, Langner S, Khaw AV et al. Diffusionsgewichtete MRT – wie viele Diffusionsfaktoren sind notwendig?. Fortschr Röntgenstr 2012; 184: 303-310
• 20 McAuliffe MJ, Lalonde FM, McGarry D et al. (eds) Medical Image Processing, Analysis and Visualization in clinical research. Computer-Based Medical System. CBMS 2001 Proceedings 14th IEEE Symposium; 2001
• 21 Mishra AM, Gupta RK, Jaggi RS et al. Role of diffusion-weighted imaging and in vivo proton magnetic resonance spectroscopy in the differential diagnosis of ring-enhancing intracranial cystic mass lesions. J Comput Assist Tomogr 2004; 28: 540-547
• 22 Sener RN. Colloid cyst: diffusion MR imaging findings. J Neuroimaging 2007; 17: 181-183
• 23 Mishra AM, Reddy SJ, Husain M et al. Comparison of the magnetization transfer ratio and fluid-attenuated inversion recovery imaging signal intensity in differentiation of various cystic intracranial mass lesions and its correlation with biological parameters. J Magn Reson Imaging 2006; 24: 52-56
• 24 Tofts PS, Lloyd D, Clark CA et al. Test liquids for quantitative MRI measurements of self-diffusion coefficient in vivo. Magn Reson Med 2000; 43: 368-374
• 25 Tanner JE. Intracellular diffusion of water. Arch Biochem Biophys 1983; 224: 416-428
• 26 Otaduy MC, Callegaro D, Bacheschi LA et al. Correlation of magnetization transfer and diffusion magnetic resonance imaging in multiple sclerosis. Mult Scler 2006; 12: 754-759
• 27 Aprile I, Iaiza F, Lavaroni A et al. Analysis of cystic intracranial lesions performed with fluid-attenuated inversion recovery MR imaging. Am J Neuroradiol 1999; 20: 1259-1267
• 28 Kim YJ, Chang KH, Song IC et al. Brain abscess and necrotic or cystic brain tumor: discrimination with signal intensity on diffusion-weighted MR imaging. Am J Roentgenol 1998; 171: 1487-1490
• 29 Nath K, Agarwal M, Ramola M et al. Role of diffusion tensor imaging metrics and in vivo proton magnetic resonance spectroscopy in the differential diagnosis of cystic intracranial mass lesions. Magn Reson Imaging 2009; 27: 198-206
• 30 Chang SC, Lai PH, Chen WL et al. Diffusion-weighted MRI features of brain abscess and cystic or necrotic brain tumors: comparison with conventional MRI. Clin Imaging 2002; 26: 227-236
• 31 Holtas S, Geijer B, Stromblad LG et al. A ring-enhancing metastasis with central high signal on diffusion-weighted imaging and low apparent diffusion coefficients. Neuroradiology 2000; 42: 824-827
• 32 Sasaki M, Yamada K, Watanabe Y et al. Variability in absolute apparent diffusion coefficient values across different platforms may be substantial: a multivendor, multi-institutional comparison study. Radiology 2008; 249: 624-630