Purpose
To evaluate accuracy of DWI compared to Gd-enhanced and T2W MR sequences,
for the detection of hepatic metastases from neuroendocrine tumours,
verified by arterial CT scan.
Methods and Materials
Five patients (3 female,
2 male; mean age: 58.48 ± 22.7 years; range 25.7-81.7 years),
with a total number of 257 liver metastases from neuroendocrine tumours (mean: 64.25 ± 53.66 lesions; range: 18-138 lesions),
were selected for percutaneous treatment with hepatic transcatheter arterial embolization (Fig.
1).
Before therapeutic embolization,
all patients underwent MRI with 1.5 T magnet and surface coil,
with a standardized MR protocol,
including (Fig.
2): 5 mm triggered diffusion-weighted imaging (DWI-EPI),
with four different b values (0; 250; 500; 1000 s/mm²); 2...
Results
Arterial CT scans (a-CT) and MR images (DWI-EPI; THRIVE; T2W-SS-SPAIR) were evaluated by two radiologists,
who independently assessed the number and dimension of liver neuroendocrine metastases,
with an almost perfect interobserver agreement.
Lesions were counted and divided into three dimensional groups: A (0-9.9 mm lesions); B (10-19.9 mm lesions); C (≥ 20 mm lesions).
Of the 150 A group lesions assessed on a-CT,
DWI,
THRIVE and T2W-SS-SPAIR detected,
respectively: 87,
72 and 37 lesions.
Of the 57 B group lesions assessed on a-CT,
DWI,
THRIVE...
Conclusion
Diffusion-weighted imaging was more accurate than other MRI sequences for the detection of liver neuroendocrine metastases.
In comparison to a-CT scan,
DWI showed a high accuracy for the detection of lesions greater than 10 mm in size (group B and C),
while it showed less accuracy for the detection of 0-9.9 mm lesions (group A).
In our preliminary experience,
diffusion-weighted MR imaging showed also some technical artifacts,
apart from dimensions: lesions located at the hepatic dome or in left lobe (segments II and III) can...
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