Это не обязательно проверка развертки

--------------------------------------------------
Note added at 1 hr (2008-09-13 11:19:09 GMT)
--------------------------------------------------

Точный перевод sweep зависит от контекста. Это может быть и зондирование как таковое (в этом случае можно было бы перевести как "проверка зондированием по внешнему источнику"), и амплитуда сигнала ("проверка амплитуды сигнала по внешнему источнику"), и развертка.

http://www.ariser.info/training/imgproc.php
Image based registration can be divided into extrinsic, i.e., based on foreign objects introduced into the imaged space, and intrinsic methods, i.e., based on the image information as generated by the patient.

Extrinsic methods rely on artificial objects attached to the patient, objects which are designed to be well visible and accurately detectable in all of the pertinent modalities. As such, the registration of the acquired images is comparatively easy, fast, can usually be automated, and, since the registration parameters can often be computed explicitly, has no need for complex optimization algorithms. The main drawbacks of extrinsic registration are the prospective character, i.e., provisions must be made in the pre-acquisition phase, and the often invasive character of the marker objects.