Michael E. Arch MD, Presenter: Nothing to Disclose

Daniel F. Broderick MD, Abstract Co-Author: Nothing to Disclose

Amy Louise Kotsenas MD, Abstract Co-Author: Nothing to Disclose

Douglas Scott Fenton MD, Abstract Co-Author: Nothing to Disclose

The purpose is to evaluate the utility of additional 3 mm axial imaging with triple-dose gadolinium for the detection of intracranial metastases.

A database of brain MRIs was scanned to obtain a list of patients who had undergone a triple-dose gadolinium (0.3 mmol/kg) MRI of the brain. A total of 41 patients were included. Five patients had the single-dose comparison performed on a different day, but within one week of the triple-dose exam. Seven patients had both the single and triple dose studies performed at 5 mm. The series were evaluated independently by three neuroradiologists with all the identifying information removed. The size, location, image number and confidence of malignancy (yes, equivocal, or no) was recorded for each lesion.

All results are listed separately for each examiner. The total numbers of lesions interpreted as malignant for the single-dose exams are 99, 87, and 88. The corresponding total numbers for the triple-dose exams are 164, 134, and 131. Equivocal lesions totaled 30, 23 and 36 on the single-dose exams and 47, 34 and 36 on the triple-dose exams. Forty-four percent of the patients (19/41, 18/41, 17/41) had additional lesions interpreted as malignant on the triple-dose exams (P<0.001). No patient had more lesions interpreted as malignant on the single-dose exam than on the corresponding triple-dose exam. Thirty-eight percent of the studies with a solitary yes lesion on the single-dose exam [(6/15-two equivocal lesions became yes, while four were new lesions), (5/13-all new lesions), (6/17-all new lesions)], had additional yes lesions on the triple-dose exam. Twenty-six percent of the patients with no lesions interpreted as malignant on the single-dose exam [(1/6-new lesion), (3/11-one new lesion, one equivocal lesion to yes, one with two equivocal lesions to yes), (2/6-one new lesion, one equivocal lesion to yes)], had a yes lesion on the triple-dose exam.

Clearly, more metastases are detected with 3 mm axial triple-dose images than 5 mm axial single-dose images. There is a subset of patients that benefit from additional imaging, particularly patients being considered for surgical resection or stereotactic radiosurgery.

Arch, M, Broderick, D, Kotsenas, A, Fenton, D, 3mm Axial Imaging with Triple-Dose Gadolinium for the Detection of Intracranial Metastases.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4404169.html