After extended review of the literatures, publications regarding cord by MR in vivo in humans are scarce, principally on account of the technical difficulties.
The difficulties for MR perfusion in the cervical/cervicomedullary region include the intrinsic susceptibility artifacts as well as motion swallowing artifacts, CSF pulsation, and partial volume impacts .
In our study, a significant high perfusion values (rCBV) of the intramedullary tumors than in non-neoplastic lesions was found. The rCBV mean for neoplasms was 2 when compared to the normal cervical cord above or below the lesion, this value is fundamentally higher than the non-neoplastic category where their mean value of rCBV was 1 (p = 0.003).
This is similar to an earlier research of brain lesions that revealed increased rCBV ratio in cerebral gliomas than in demyelinating lesions  and matching with the observation listed by Xiang et al.  using a perfusion imaging to differentiate intramedullary cervical neoplasm from tumor-like masses .
In a publication by Liu et al. , for glioblastoma diagnosed by autopsy from upper cervical spinal cord, they observed an increase in rCBV which suggested a high-grade glioma.
Absence of frank angiogenesis and hypoperfusion sequel to diminished metabolism in the non-neoplastic lesions, explained the difference in tissue perfusion in malignant lesions and inflammatory processes .
We noticed that three of our cases with myelitis were slightly hyperperfused; this was similar to an observation noted in a study done by R Hourani et al.  who evaluated the value of perfusion MR in characterizing neoplasms from other brain issues. He reported a mean rCBV value in two cases with demyelinating lesions to be 1.3 + 0.49. This could be explained by the transient hyperemia occurring in the acute phase of myelitis. A cutoff value equal to or higher than 1.38 of rCBV compared to the normal cord had 78% sensitivity and 83% specificity to distinguish neoplastic from the non-neoplastic process.
Calculation of the rCBV ratio is the hardest point, which is an important imaging index in brain perfusion studies. In the brain, the rCBV ratio is calculated by dividing CBV values of a lesion by the CBV value of normal-appearing brain at the other side.
This prerequisite, however, may be non-applicable in diffuse infiltrating lesions that can affect most of the cord/medulla with subsequent erroneous ratio measurements .
There are controversies in the acquisition plane selection. Traditionally, axial orientation is frequently used for brain perfusion acquisitions, and ROI is placed in the parenchyma of the unaffected cerebral hemisphere for rCBV and ratio calculations.
However, cervical intramedullary masses may affect multiple segments and also involve the medulla/cord on both sides. Thus, the axial scanning will not assess the entire lesion, with the reference ROI being placed in an adjacent, perilesion part that will not exclude an underestimation of pathologic changes .
We selected the sagittal acquisition in our cases to bypass this problem. We assessed the rCBV relative to the pons in four cases with tumors, where the lesions were involving the whole cervical cord. In our study, the average range of normal cervical cord/pons ratio calculated in 30 cases was about 0.3. After measuring the rCBV in these four cases, the resulting ratio was ranging from 0.7 to 2.5, suggesting hyperperfusion of these lesions. The rCBV to the pons was calculated in three cases with tumor-like demyelinating lesions. The ratios were 0.35, 0.5, and 0.583 in a case with NMO, a case with transverse myelitis, and a third case of post irradiation changes respectively.
This was matching with the recommendations of Liu et al. ; they suggested that the sagittal acquisition may be a helpful approach for perfusion acquisition in cervical cord assessment as it can evaluate the entire lesion and the likelihood of utilizing the cerebellum for the placement of the reference ROI .