Rosenfield K, Losordo D W, Ramaswamy K, Pastore J O, Langevin R E, Razvi S, Kosowsky B D, Isner J M
Department of Medicine (Cardiology), St. Elizabeth's Hospital, Tufts University School of Medicine, Boston, MA 02135.
Circulation. 1991 Nov;84(5):1938-56. doi: 10.1161/01.cir.84.5.1938.
Intravascular ultrasound provides high-resolution images of vascular lumen, plaque, and subjacent structures in the vessel wall; current instrumentation, however, limits the operator to viewing a single, tomographic, two-dimensional image at any one time. Comparative analysis of serial two-dimensional images requires repeated review of the video playback recorded during the two-dimensional examination, followed by a "mind's eye" type of imagined reconstruction.
Computer-based, automated three-dimensional reconstruction was used to generate a tangible format with which to assess and compare a "stacked" series of two-dimensional images. Three-dimensional representations were prepared from sequential images obtained during intravascular ultrasound examination in 52 patients, 50 of whom were studied before and/or after percutaneous revascularization. Conventional two-dimensional ultrasound images were acquired by means of a systematic, timed pullback of the ultrasound catheter through the respective vascular segments. Images were then assembled in automated fashion to create a three-dimensional depiction of the vessel lumen and wall. Computer-enhanced three-dimensional reconstructions were generated in both sagittal and cylindrical formats. The sagittal format resulted in a longitudinal profile similar to that obtained during angiographic examination; in contrast to angiography, however, the sagittal reconstruction offered 360 degrees of limitless orthogonal views of the plaque and arterial wall as well as the vascular lumen. The cylindrical format yielded a composite view of a given vascular segment, and a hemisected version of the cylindrical reconstruction enabled en face inspection of the reconstructed luminal surface. Sagittal reconstructions facilitated analysis of dissections and plaque fractures resulting from percutaneous revascularization, and the hemisected cylindrical reconstructions enhanced analysis of endovascular prostheses.
This preliminary experience demonstrates that computer-based three-dimensional reconstruction may further augment the use of intravascular ultrasound in assessing vascular pathology and guiding interventional therapy.
血管内超声可提供血管腔、斑块及血管壁下层结构的高分辨率图像;然而,目前的仪器设备限制了操作者在任何时刻只能查看单一的断层二维图像。对系列二维图像进行对比分析需要反复查看二维检查过程中录制的视频回放,随后进行“心眼”式的想象重建。
采用基于计算机的自动三维重建技术生成一种有形的形式,用于评估和比较一系列“堆叠”的二维图像。从52例患者血管内超声检查获得的序列图像中制备三维图像,其中50例患者在经皮血管重建术前和/或术后接受了研究。通过超声导管在相应血管段进行系统的定时回撤来获取传统二维超声图像。然后以自动方式将图像组装起来,以创建血管腔和血管壁的三维描绘。计算机增强的三维重建以矢状面和圆柱面两种形式生成。矢状面形式产生的纵向轮廓类似于血管造影检查时获得的轮廓;然而,与血管造影不同的是,矢状面重建提供了斑块及动脉壁以及血管腔360度的无限正交视图。圆柱面形式给出了给定血管段的复合视图,圆柱面重建的半剖视图能够对重建管腔表面进行正面检查。矢状面重建有助于分析经皮血管重建术引起的夹层和斑块破裂,半剖圆柱面重建增强了对血管内假体的分析。
这一初步经验表明,基于计算机的三维重建可能会进一步扩大血管内超声在评估血管病变和指导介入治疗方面的应用。