Congress:
RANZCR-AOCR 2012
Keywords:
Oncology, Abdomen, Lymph nodes, MR-Diffusion/Perfusion, Imaging sequences, Cancer
Results
43 cases were executed whole-body MRI and PET/CT:
40 of 43 patients had confirmed metastasis.
1 case: showed additional small vertebral body metastasis that were not seen on PET/CT.
2 case: whole-body MRI showed one additional node in liver (metastasis) that was not seen on PEP/CT.
3 case Whole-body MRI showed one intra-abdominal lymph node (benign lymph node) that was not seen on PEP/CT.
1 case PET/CT showed one pelvic peritoneal focal had increased metabolic activity,
that was not seen on MRI.
All the cases left showed the same results between whole-body MRI and PET/CT.
Whole body Diffusion Weighted – MRI (WBDW-MRI) has sensitivities for detecting lesions higher than PET/ CT. Because most of lesions have contained water molecules very sensitive to diffusion sequences,
especially in bone tissues (spine) are low-signal intensity on MRI,
so the lesions of matastatic bone are showed more clearly.
For example to detect metastasis of spine better than PET/CT (Figs.
1,2).
WBDW-MRI can distinguish between metastasis of bone and early degenerative spine,
while PET/CT can increase metabolic activities with both two cases.
One patient with cancer of the nasopharynx,
PET/CT showe bilateral neck lymph node (metastasis) and metastasis of the hepatic lobe VI,
but not seen one node metastasis of the hepatic lobe VIII,
7mm seen on WBDW-MRI (Fig.
3).
Base on ADC of diffusion pulse sequences,
We can measure (ROI) lesions with MRI machine software to distinguish between benign and malignant lesions.
The malignant lesions have mean ADC number lower than benign lesions (Fig.
5).
In Fig.
4,
PET/CT showed light absorption of radioactive the abdominal peritonium,
WBDW-MRI was not seen on MRI.
This patient has had colon cancer and chemotherapy,
we checked it six months later but we did not see the change of size,
property damage,
so keep following up.
However,
the specificity of PET/CT is higher than WBDW-MRI,
because it detects benign lesions early as inflamed lymph node,
hepatic hemangioma,
cysts… (Figs.
6,
7),
in these cases we must inject contrast media to be distinguished more exactly.
The number of our study about patients is little,
research time is limited,
however,
to evaluate the effectiveness of detecting metastatis of WBDW-MRI compared with PET/CT is the first and reduce costs in the diagnosis and the treatment.