Diffusion-Tensor-Imaging MR-Neurography for the detection of polyneuropathy in T1D

A new article published in Diabetes (April 2017) by Danish Diabetes Academy PhD Michael Væggemose evaluates if MR-Neurography of the sciatic and tibial nerves can be used for detection and staging of diabetic peripheral neuropathy (DPN) in patients with type 1 diabetes. 

EARLY DIAGNOSIS OF DPN IS IMPORTANT

DPN is a common complication that often remains undiagnosed until advanced stages. DPN causes irreversible damage to the peripheral nerves. Thus, to prevent progression of DPN, early diagnosis is important emphasizing the need for more sensitive diagnostic techniques.

OBJECTIVE

The objective of this research is to evaluate if diffusion-tensor-imaging MR-Neurography (DTI-MRN) can detect lesions of peripheral nerves in patients with type 1 diabetes.

DETERMINATION OF THE PRESENCE AND SEVERITY OF DPN 

49 type 1 diabetic patients (11 with severe polyneuropathy (sDPN), 13 with mild/moderate polyneuropathy (mDPN) and 25 without polyneuropathy (nDPN)) and 30 healthy controls (HC) were included in the study. Clinical examinations, nerve-conduction-studies and vibratory-perception-thresholds, determined the presence and severity of DPN. DTI-MRN covered proximal (sciatic nerve) and distal regions of the lower extremity (tibial nerve). FA and ADC were calculated and compared to T2 relaxometry and proton-spin-density obtained from a multi-echo TSE sequence.

RESULTS AND CONCLUSION

DTI-MRN could accurately discriminate between DPN, nDPN and HC. The proximal and distal FA was lowest in sDPN with higher values in patients with mPDN and nDPN as well as in HC. Likewise, proximal ADC was highest in sDPN and decreasing according to the reduction in neuropathy severity. The severity of neuropathy was correlated to DTI-MRN demonstrating a strong association of proximal and distal nerve lesions. T2 relaxometry and proton-spin-density did not enable detection of nerve lesions.

DTI-MRN enables detection of DPN by decreasing nerve FA and increasing ADC closely related to the severity of DPN. These alterations are likely to reflect proximal and distal nerve fiber pathology.

AUTHORS AND AFFILIATION

Vaeggemose M^1,2, Pham M^3, Ringgaard S⁴, Tankisi H⁵, Ejskjaer N⁶, Heiland S⁷, Poulsen PL⁸, Andersen H^1,9

¹Department of Neurology, Aarhus University Hospital, Denmark
²Danish DiabetesAcademy, Odense, Denmark
³Department of Neuroradiology, Würzburg University Hospital, Germany
⁴MR Research Centre, Aarhus University Hospital, Denmark
⁵Department of Clinical Neurophysiology, Aarhus University Hospital, Denmark
⁶Departments of Clinical Medicine and Endocrinology, Aalborg University Hospital, Aalborg
⁷Department of Neuroradiology, Heidelberg University Hospital, Germany
⁸Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Denmark
⁹International Diabetic Neuropathy Consortium (IDNC), Aarhus University, Denmark 

Source: Diabetes