We present a new algorithm, called marching cubes, that creates triangle models of constant density surfaces from 3D medical data. Using a divide-and-conquer approach to generate inter-slice connectivity, we create a case table that defines triangle topology. The algorithm processes the 3D medical data in scan-line order and calculates triangle vertices using linear interpolation. We find the gradient of the original data, normalize it, and use it as a basis for shading the models. The detail in images produced from the generated surface models is the result of maintaining the inter-slice connectivity, surface data, and gradient information present in the original 3D data. Results from computed tomography (CT), magnetic resonance (MR), and single-photon emission computed tomography (SPECT) illustrate the quality and functionality of marching cubes. We also discuss improvements that decrease processing time and add solid modeling capabilities.

/pdf/marching-cubes-a-high-resolution-3d-surface-construction-3ealswkmtb.pdf

Marching cubes: A high resolution 3D surface construction algorithm

Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

https://users.fmrib.ox.ac.uk/~jesper/papers/readgroup_071009/Ashburner07.pdf

A fast diffeomorphic image registration algorithm

http://midag.cs.unc.edu/pubs/papers/Neuroimage06_Yushkevich.pdf

User-guided 3D active contour segmentation of anatomical structures: Significantly improved efficiency and reliability

A novel approach to correcting for intensity nonuniformity in magnetic resonance (MR) data is described that achieves high performance without requiring a model of the tissue classes present. The method has the advantage that it can be applied at an early stage in an automated data analysis, before a tissue model is available. Described as nonparametric nonuniform intensity normalization (N3), the method is independent of pulse sequence and insensitive to pathological data that might otherwise violate model assumptions. To eliminate the dependence of the field estimate on anatomy, an iterative approach is employed to estimate both the multiplicative bias field and the distribution of the true tissue intensities. The performance of this method is evaluated using both real and simulated MR data.

/pdf/a-nonparametric-method-for-automatic-correction-of-intensity-4smqm7oz20.pdf

A nonparametric method for automatic correction of intensity nonuniformity in MRI data

Gastrointestinal (GI) tract examination with computed tomography (CT) is currently performed by slice-based visual inspection despite the volumetric nature of the problem. The entire abdomen may now be continuously scanned within a single breath-hold with spiral CT. The GI tract can be computationally extracted from spiral CT images, the lumen explicitly unraveled onto a plane, and colonoscopy virtually simulated via fly-through display. A semi-automatic approach was developed for fly-through and unraveling in vivo. Automation of this approach was investigated in numerical simulation. The techniques are promising for colon cancer screening.

GI Tract Unraveling in Volumetric CT

Computed tomography is not the most frequent radiologic imaging procedure, but is arguably the most important in terms of clinical impact. CT is used extensively for emergencies, cardiovascular, pulmonary, gastrointestinal, endocrine, neurological, orthopedic and other applications -often as the first and only imaging procedure needed for diagnosis. The chances are very high that a patient will have a CT scan in the emergency department, as an outpatient or as an inpatient for a multitude of indications - pain, trauma, suspected infection or malignancy, and frequently to investigate symptoms such as pain, or to answer a question raised by another abnormal test, such as an EKG abnormality or ultrasound finding. Despite the universality of CT in hospitals and clinics as well as free-standing imaging centers, the technology continues to evolve with greater coverage, faster acquisition and multienergy sources or detectors. The most demanding imaging applications are cardiovascular, where complex motion and small morphologic features coexist, so imaging methods that are very satisfactory elsewhere in the body may not be successful. Clinical CT scanning consists of administering toxic materials, e.g., contrast media, often monitoring the EKG and illuminating the body with high brightness x-rays. Larger area detectors and higher acquisition rates are welcome improvements, but don't solve all of the problems encountered with scan variability due to respiratory, random body, and cardiac motion, especially in a spectrum of patients from infant to massively obese adult sizes (< 1 kg to 250 kg or more). The challenges and pitfalls in CT will be delineated and evaluated relative to current and future technology.

CT clinical perspective: Challenges and the impact of future technology developments

Surface and volumetric three-dimensional imaging methods have found application in fields as diverse as diagnostic medical imaging and paleontological research The acquisition, modeling, classificati

Three-Dimensional Surface Reconstruction Software System for IBM Personal Computers

The Biological Implications Of Varying Element Design In Finite-element Scaling Analyses Of Growth

The objective of this panel is to reflect on the advances that volume rendering has brought to the medical community and, even more important, to discuss its current short-comings and future needs. This direct feedback from the medical community will hopefully inspire the IEEE Visualization audience and help to focus on new research areas that will further advance the state of the art in medical visualization. The panel assembles end-users from well-known medical facilities and research institutions who have a background in visualization but primarily are experts using this technology for practical diagnostic applications.

Michael W. Vannier

Papers

GI Tract Unraveling in Volumetric CT

CT clinical perspective: Challenges and the impact of future technology developments

Three-Dimensional Surface Reconstruction Software System for IBM Personal Computers

The Biological Implications Of Varying Element Design In Finite-element Scaling Analyses Of Growth

End users' perspectives on volume rendering in medical imaging: A job well done or not over yet?