CT, MR, and CR products highlight latest group of FDA clearances

Radiotherapy and image management dominate

Computer-assisted detection for CT lung scans, a head coil for a 3T scanner, and a CR modification were marquee FDA clearances in July. There were several other notable products, among them an image management tool that aligns MR images with 3D models constructed from an atlas of the brain and a 16-slice CT upgrade, making this latest month of clearances a standout for the quality of products passing review, if not the quantity.

The flow of clearances in past months has settled into a steady low 20s. July's total of 22 was comparable to the number cleared in the same period in each of the two preceding years--21 in July 2001 and 24 in July 2000. Image management and radiotherapy together accounted for more than half of the most recent clearances, seven and six respectively.

The seven image management products covered a wide range, from a Hitachi multimodality workstation capable of fusion imaging to a monochrome liquid crystal display monitor developed by Japan-based Eizo Nanao. The workstation, called Sceptre, was unveiled in early June at the annual meeting of the Society of Nuclear Medicine (SCAN 6/26/02). Among these image management products was a standout called AutoAlign, a software package that compares localized images taken during a brain MR exam to images in a preexisting

atlas of the human brain. The software, developed by CorTech of Charlestown, MA, calculates a set of coordinates that can be used to align subsequent MR images to the atlas. The output is an optimized 3D registration matrix that permits brain alignment regardless of the actual physical position of the subject's head. This allows the alignment of images obtained during separate scanning sessions. Another notable image management product, developed by Barco, tracks the consistency of individual soft-copy displays as a quality control measure. This product, called MediCal Administrator, is designed as a hospital-wide image quality management system.

As has been typical, radiotherapy products were minor advances, such as a carrier for radionuclide seeds. An exception was Advantage Sim 6.0, treatment planning software developed by GE Medical Systems. The product relates geometric parameters of a proposed treatment field to volumetric models created from CT data.

Three of the four ultrasound devices clearing the FDA involved system upgrades or transducers. The fourth, a niche product developed by Inceptio Medical Technologies of Farmington, UT, is a vascular imaging device optimized to guide physicians in needle placement and vessel catheterization. The device, called PunctSure, has a Doppler component that allows the operator to determine the direction of blood flow.

CT had two notable introductions--a 16-slice upgrade from Toshiba (SCAN 8/14/02) and a 3D reconstruction package from Siemens that employs computer-assisted detection. The LungCare CT image analysis software evaluates CT volume data sets to identify lung nodules. It reconstructs the data, applies pattern-matching algorithms to identify and characterize nodules, then reports findings to the physician. The tool allows for volumetric analysis of pulmonary nodules, including measurement of size over time. This supports the assessment of changes in growth. LungCare CT is also designed to help classify suspicious regions of tissue in regard to size, dimension, shape, and position. The product is comparable to GE's Advanced Lung Analysis product, which cleared in October 2001.

MR, nuclear medicine, and x-ray each had one clearance, and each was notable in its own right. USA Instruments of Aurora, OH, obtained clearance for a quadrature transmit receive head coil for use on Siemens' 3T Magnetom Trio. The coil captures images of the brain and cervical spine, as well as soft tissues and vasculature of the head, neck, and upper chest. Houston-based PET manufacturer Positron won the right to market three versions of its whole-body PET scanner--Posicam HZ, Posicam HZL, and mPower. The scanners allow iterative reconstruction and postinjection transmission acquisition. DICOM 3 Part 10 compliance provides secondary image capture in both color and gray scale for remote viewing on a PACS.

The lone x-ray clearance was for a modification of Kodak's DirectView CR 800/CR 900 systems that allow the capture of images stretching 130 cm x 43 cm. Individual computed radiographs are limited to the size of a CR cassette, the largest being 35 cm x 43 cm. The Kodak Long-Length Imaging System includes a vertical cassette holder that can hold up to four CRs. Image stitching software assembles the images, correcting them for magnification, as well as translational and rotational differences, and eliminating redundant pixels in overlapping regions.