Related Experiment Videos
Pulmonary arteriovenous malformations: diagnosis by gradient-refocused MR imaging
B J Dinsmore1, W B Gefter, H Hatabu
1Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104.
Abstract:
Six known or suspected pulmonary arteriovenous malformations (AVMs) in four patients were evaluated with magnetic resonance (MR) imaging at 1.5 T. All lesions were imaged using a gradient-refocused echo pulse sequence with a 25/13 ms [repetition (TR)/echo (TE) times] and a 30 degrees flip angle, as well as with a cardiac-gated spin echo short TR/TE pulse sequence technique. Five of the lesions were vascular in nature based on their signal intensity characteristics, and one nonvascular lesion was a carcinoid tumor. On the spin echo images, the AVMs showed a central signal intensity void with a peripheral rim of intermediate signal intensity that was detectable for lesions greater than or equal to 1.5 cm in size. Smaller lesions were more difficult to distinguish from the surrounding air-filled lung, which normally generates no appreciable signal on MR images. The AVMs demonstrated uniform high signal intensity on the gradient echo pulse sequence and were more conspicuous, irrespective of size. With a single breath-hold scan, the vascular nature of the lesion could be rapidly confirmed with an acquisition time of 13 s. In three patients, the cine MR gradient echo images showed a pulsatile quality to the signal intensity in the lesion over the cardiac cycle similar to that within adjacent pulmonary vessels. The results of this study show a potential role for gradient echo MR imaging as a rapid, noninvasive method to evaluate the vascular nature of an atypical pulmonary nodule.
Insights
Gradient echo magnetic resonance (MR) imaging effectively identifies pulmonary arteriovenous malformations (AVMs). This rapid, noninvasive technique aids in diagnosing atypical pulmonary nodules by visualizing their vascular nature.
Area of Science:
- Radiology
- Cardiovascular Imaging
- Pulmonary Medicine
Background:
- Pulmonary arteriovenous malformations (AVMs) are abnormal vascular connections in the lungs.
- Accurate diagnosis of pulmonary AVMs is crucial for patient management.
- Conventional imaging may have limitations in characterizing these lesions.
Purpose of the Study:
- To evaluate the utility of magnetic resonance (MR) imaging, specifically gradient echo sequences, in characterizing pulmonary AVMs.
- To compare the effectiveness of gradient echo and spin echo MR sequences for AVM detection.
Main Methods:
- Six known or suspected pulmonary AVMs in four patients were imaged using 1.5 T MR.
- Gradient-refocused echo and cardiac-gated spin echo pulse sequences were employed.
- Signal intensity characteristics and lesion conspicuity were analyzed.
Main Results:
- AVMs showed uniform high signal intensity on gradient echo sequences, making them conspicuous regardless of size.
- Spin echo sequences revealed a signal void with a peripheral rim for lesions >= 1.5 cm.
- Gradient echo cine imaging demonstrated pulsatile signal intensity within AVMs, similar to pulmonary vessels.
Conclusions:
- Gradient echo MR imaging is a rapid and noninvasive method for evaluating the vascular nature of pulmonary nodules.
- This technique shows potential for differentiating vascular lesions like AVMs from other pulmonary abnormalities.
- MR imaging, particularly gradient echo sequences, can aid in the diagnosis of atypical pulmonary nodules.