Perfusion Measurements
The mean and maximum values of rCBV,
rPH and rPSR,
calculated for different types of examined sellar/parasellar tumors are demonstrated in table 1.
Pituitary macroadenomas revealed high values of the rCBV parameter.
The maximum rCBV values for adenomas ranged between 2.42 and 7.55 (mean max.
rCBV= 5.18).
Sellar meningiomas,
similarly to adenomas,
showed high values of rCBV (ranging 2.99 and 12.18,
mean max.
rCBV= 8.22).
Both pituitary adenomas and sellar meningiomas revealed signal-intensity curves with little or no return to the baseline levels characterized by high values of PH and low values of PSR (table 1).
Comparing adenomas and meningiomas we found a statistically significant difference in mean and maximum rCBV values (p= 0.026 and p= 0.019,
respectively),
but not in rPH and rPSR values.
When a cut off value for maximum rCBV was fixed at > 7.14,
the sensitivity and specificity of PWI in distinguishing adenomas from meningiomas was 63% and 91%,
respectively.
When a cut off value for mean rCBV was fixed at >5.74,
the sensitivity and specificity reached 38% and 100%,
respectively.
Apart from adenomas and meningiomas,
the other sellar/parasellar tumors demonstrating high perfusion values (maximum rCBV>2) were: metastases,
glioma,
hemangioblastoma and squamous-papillary type of craniopharyngioma.
These tumors did not differ significantly in rCBV values,
but they showed different signal-intensity curves with variable rPH and rPSR values.
Hemangioblastoma and glioma revealed high rPH values,
craniopharyngiomas showed intermediate rPH,
and metastases - low rPH value.
On the other hand,
glioma and metastases demonstrated intermediate rPSR values,
while hemangioblastoma presented a very low rPSR value (rPSR<0.00) with characteristic descending signal-intensity curve.
rPSR values of squamous-papillary type craniopharyngiomas were higher,
compared to hemangioblastoma,
but lower than rPSR values of glioma and metastasis.
The low perfusion (maximum rCBV<2) sellar/parasellar tumors included adamantinomatous type of craniopharyngiomas as well as lymphomas.
These tumors showed low values of rCBV (maximum rCBV= 1.12 and rCBV= 1.08,
respectively),
as well as low rPH value.
They presented a very high rPSR value (rPSR>1.00) with a characteristic ascending signal-intensity curve.
Diffusion Measurements
The mean and minimum values of ADC and rADC,
calculated for different types of examined sellar/parasellar tumors are demonstrated in table 2.
There were no significant differences in ADC values between adenomas and meningiomas (p>0.05),
while other tumors revealed significantly different values of ADC,
compared to pituitary adenomas.
Hemangioblastoma and craniopharyngiomas (both types) showed high ADC values,
while metastases and lymphomas presented very low ADC values (table 2).
Glioma revealed intermediate ADC values compared to other sellar/parasellar lesions.