On MRI, we evaluated the findings of low-grade chondrosarcoma, such as entrapped fat within the tumor, lobular architecture, and ring-and-arc enhancement, and those of high-grade chondrosarcoma, such as central high signal on T1-weighted images, soft-tissue mass formation, and central non-enhancement portion [ 19].
Some reports in the literature indicated that orbital cavernous haemangiomas showed an initial central point or portion enhancement after administration of gadopentetate dimeglumine [ 7, 12– 12].
Less commonly, flash filling of an entire small haemangioma or enhancement of small portions of the lesion, on arterial phase images, may be seen.
Enhancement of solid portions is typically seen after injection of contrast material, as well as infiltration into the perimandibular soft-tissues.
Our results demonstrate that, in presence of a well-defined, ovoid, intraconal mass with markedly homogeneous hyperintensity signal on T2-weighted imaging, one small point or portion of enhancement initially noted after administration of contrast medium and "progressive" enhancement on later enhancement images, favours the diagnosis of cavernous haemangioma instead of schwannoma.
Although the celiac and superior mesenteric arteries were occluded at the proximal portion, contrast enhancement of the bowel wall was good in contrast-enhanced computed tomography (CECT).
Enhancement of the solid portion of the tumour is variable, ranging from non-enhancement (50% of cases) to ringlike enhancement to homogeneous enhancement.
More recently, the hypothesis of a demyelinating mechanism affecting the oculomotor nerves has been put forward, following the demonstration by imaging of swelling and enhancement of the intracisternal portion of the third nerve.
Dense enhancement of the solid portion of the tumor was found in 46.2% of gastric cancer metastases but only 10.3% of colon cancers.
Delayed contrast enhancement of the central portion of the lesion can be observed, as a result of a desmoplastic reaction secondary to the stimulation of hepatic stellate cells.
On early imaging after the injection, one small point or portion of enhancement is initially noted because of its low-flow arterial supply, and the slow progressive accumulation of contrast medium continues within the dilated vascular spaces filling in centrally during the late venous phase.
