320-row CT scanning: reduction in tube current parallels reduction in radiation exposure?

The Value of Multidetector Row Computed Tomography Angiography for Preoperative Planning of Freestyle Pedicled Perforator Flaps

BACKGROUND

Because the course and territory of perforators are different in each region, careful preoperative planning to identify the proper perforators can be critical to ensure a successful dissection of a freestyle pedicled perforator flap. In this study, our first experience for preoperative perforator mapping of a freestyle pedicled perforator flap using multidetector row computed tomography (MD-CT) angiography is presented.

METHODS

Twelve patients were planned to undergo various soft-tissue reconstructions with freestyle pedicled perforator flaps. They were evaluated with preoperative MD-CT angiography. The OsiriX for mac software was used to process the data obtained from MD-CT angiography. The available images from MD-CT angiography were analyzed to determine where the proper perforators were located for preoperative planning of a freestyle pedicled perforator flap. Through the MD-CT angiography, the optimal perforators were mapped and a reliable flap design could be made so that the flap was elevated more safely and perfectly to cover an adjacent soft-tissue defect.

RESULTS

In all 12 patients, each flap was elevated successfully based on the perforators mapped preoperatively with MD-CT angiography. A total of 27 perforators (1-3 perforators per flap) were identified by MD-CT angiography in 12 patients and later confirmed during the flap dissection (sensitivity, 100%).

CONCLUSIONS

The MD-CT angiography can be a new but very effective imaging modality for preoperative planning of a freestyle pedicled perforator flap surgery. It allows surgeons to accurately select the most appropriate perforators with the shortest intramuscular or suprafascial course preoperatively leading to safer and easier flap dissection.

Three-dimensional reconstruction of coronary arteries and plaque morphology using CT angiography--comparison and registration with IVUS

Background

The aim of this study is to present a new methodology for three-dimensional (3D) reconstruction of coronary arteries and plaque morphology using Computed Tomography Angiography (CTA).

Methods

The methodology is summarized in six stages: 1) pre-processing of the initial raw images, 2) rough estimation of the lumen and outer vessel wall borders and approximation of the vessel’s centerline, 3) manual adaptation of plaque parameters, 4) accurate extraction of the luminal centerline, 5) detection of the lumen - outer vessel wall borders and calcium plaque region, and 6) finally 3D surface construction.

Results

The methodology was compared to the estimations of a recently presented Intravascular Ultrasound (IVUS) plaque characterization method. The correlation coefficients for calcium volume, surface area, length and angle vessel were 0.79, 0.86, 0.95 and 0.88, respectively. Additionally, when comparing the inner and outer vessel wall volumes of the reconstructed arteries produced by IVUS and CTA the observed correlation was 0.87 and 0.83, respectively.

Conclusions

The results indicated that the proposed methodology is fast and accurate and thus it is likely in the future to have applications in research and clinical arena.