A projector/backprojector with slice-to-slice blurring for efficient three-dimensional scatter modeling


     Related Videos

     Related Hubpages

    Field: Engineering  DOWNLOAD  BOOKMARK REPORT
    •  Doc. Url:    Embed Code: 

    • IEEE  status
      (0) (0 Votes)
      		Views: (2005)   Date: (Publication Date: Aug. 1999)   Pages: ()

    • Author:  Zeng  G.L. Chuanyong Bai Gullberg  G.T. Dept. of Radiol.  Utah Univ.  Salt Lake City  UT  USA;  

    • Abstract:  Abstract Scatter correction is an important factor in single photon emission computed tomography (SPECT). Many scatter correction techniques, such as multiple-window subtraction and intrinsic modeling with iterative algorithms, have been under study for many years. Previously, the authors developed an efficient slice-to-slice blurring technique to model attenuation and system geometric response in a projector/backprojec tor pair, which was used in an ML-EM algorithm to reconstruct SPECT data. This paper proposes a projector/backprojec tor that models the three-dimensional (3-D) first-order scatter in SPECT, also using an efficient slice-to-slice blurring technique. The scatter response is estimated from a known nonuniform attenuation distribution map. It is assumed that the probability of detection of a first-order scattered photon from a photon that is emitted in a given source voxel and scattered in a given scatter voxel is proportional to the attenuation coefficient value at that voxel. Monte Carlo simulations of point sources and an MCAT torso phantom were used to verify the accuracy of the proposed projector/backprojec tor model. An experimental Jaszczak torso/cardiac phantom SPECT study was also performed. For a 64/spl times/64/spl times/64 image volume, it took 8.7 s to perform each iteration per slice on a Sun ULTRA Enterprise 3000 (167 MHz, 1 Gbyte RAM) computer, when modeling 3-D scatter, attenuation, and system geometric response functions. The main advantage of the proposed method is its easy implementation and the possibility of performing reconstruction in clinically acceptable time.

         Related Documents

           Related Groups

             Related Science News

             More on Sciencestage

             Answers

             News
        • A 5-state ban for 'Piggyback Bandit'
          The stocky man showed up in a basketball uniform for a game at Century High School in North Dakota. Players and coaches assumed he was a fan who had come with another team, so nobody objected when he began to pitch in around the bench.
        • Featherweight songbird is a long-distance champ
          A tiny songbird weighing just two tablespoons of sugar migrates from the Arctic to Africa and back, a distance of up to 29,000 kilometres (18,000 miles), scientists reported on Wednesday.
        • Featherweight flyer is a long-distance champ
          A tiny songbird weighing just two tablespoons of sugar migrates from the Arctic to Africa and back, a distance of up to 29,000 kilometres (18,000 miles), scientists reported on Wednesday.
        • Walmart wins with a back-to-basics approach
          (Reuters) - Wal-Mart Stores Inc's turnaround appears to be gaining traction as simple strategies like undercutting competitors by a penny on a gallon of milk are helping to restore its image as the go-to retailer for budget-conscious Americans. When the world's largest retailer reports fiscal fourth-quarter results on February 21, analysts on average expect to see the company's best U.S. sales ...
        • A new NBA star, Jeremy Lin becomes a bankable name
          NEW YORK (Reuters) - Less than two weeks ago anyone looking to buy a ticket to watch the New York Knicks play the Dallas Mavericks this weekend could expect to pay around $270. Today, the same ticket would cost about twice that. Call it Linflation. Jeremy Lin's surprising basketball heroics have made the 23-year-old point guard a sports sensation and media darling nearly overnight, and there are ...
        • A year on, Libyans enjoy freedoms but anxieties abound
          TRIPOLI (Reuters) - Libyan jewelry shopkeeper Hassan El-Kekli used to be careful what he said on the phone to his family and friends. Any criticism of Muammar Gaddafi's regime was off-limits for fear security officials listening in could show up at his home and arrest him. "Before we couldn't say anything, we were frightened," the 35-year-old said. "Now I can talk about anything." A year after ...
        • From New York to Asia, Lin is a hoops sensation
          Bigger than Shaq? Larger than LeBron? The Knicks as NBA champions?
        • Glencore's Xstrata bid: Betting on a sweeter deal
          LONDON (Reuters) - Shareholders in global miner Xstrata want suitor Glencore to boost its all-share offer, and over a week after the tie-up was announced, investors appear to be pricing in a modest sweetener. Glencore made its long-awaited bid last week, unveiling a potentially record deal both sides believe will create a mining and trading powerhouse, and offering 2.8 of its shares for every 1 ...
        • Unemployment applications drop to a 4-year low
          The number of people seeking unemployment benefits fell to the lowest point in almost four years last week, the latest signal that the job market is steadily improving.
        • Charlotte journalist's book is a new movie
          An avid reporter never wants to let go of a piece of news until it receives its due. But that can work the other way, too: A piece of news may bite hard on a reporter and never seem to let him go.

             Related on Wikipedia




























         

        Powered free by PHPmotion