Biomedical subjects

D R Reinecke

Publications and source records attributed to D R Reinecke.

6 recordsLinked to original sources

PubMed2000

Breast cancer in vivo: contrast enhancement with thermoacoustic CT at 434 MHz-feasibility study.

The authors performed thermoacoustic computed tomography (CT) with 434-MHz radio waves in five patients with documented breast cancer. Three of the patients underwent imaging before chemotherapy was initiated and two at the conclusion of their primary chemotherapy. In the former three patients, thermoacoustic CT demonstrated contrast enhancement in the region of the tumor. In the latter two patients, no contrast enhancement was seen, and pathologic examination after surgical resection of the area of original tumor confirmed complete remission of disease.

Acoustics↗

PubMed1999

Thermoacoustic computed tomography--technical considerations.

We have constructed a thermoacoustic computed tomography scanner for imaging soft tissue in the human body. Thermoacoustic signals are induced in soft tissue by irradiation with 434 MHz rf energy. The thermoacoustic signals are detected by an array of transducers mounted on a hemispherical bowl. A three-dimensional, filtered backprojection algorithm is used to reconstruct rf absorption patterns within soft tissue. We have demonstrated soft tissue differentiation sufficient to delineate the normal internal structures of an excised lamb kidney using safe levels of rf radiation.

Acoustics↗

PubMed1999

Thermoacoustic CT with radio waves: a medical imaging paradigm.

The authors evaluated images obtained with a prototypic thermoacoustic computed tomographic (CT) scanner constructed for use at 434 MHz, a promising radio frequency for detecting breast cancer. In one excised porcine kidney, acoustic energy emanating from the kidney was detected with transducers. The resultant electric signals were used to create a three-dimensional data set. Two-dimensional images reconstructed in multiple planes were compared with state-of-the-art T1- and T2-weighted magnetic resonance images. The renal outline, parenchyma, and collecting system were clearly delineated on the thermoacoustic CT images.

Acoustics↗

PubMed1997

Teaching deception skills in a game-play context to three adolescents with autism.

Baron-Cohen (1992) found that students with autism are impaired in their ability to deceive. A multiple-baseline across-subjects design was conceptualized to test the hypothesis that such students could be taught to deceive. Two conditions were presented in baseline and treatment phases. In Condition 1, the student guessed in which hand a small object was hidden when the experimenter presented two closed fists. In Condition 2, the student hid the object and presented two closed fists to the experimenter for a guess. Reinforcement was delivered contingently upon independent guessing during Condition 1 in both baseline and treatment phases. Under Condition 2, reinforcement was delivered noncontingently during the baseline phase and contingently upon successive approximations to the target behavior of deception during the treatment phase. All students displayed the acquisition of at least three of the responses included in the deception response during the baseline phase, and two students showed an erratic acquisition of the total skill during the baseline phase. Results indicate that students with autism can learn to deceive, even without formal intensive training.

Adolescent↗

PubMedDate not supplied

Reconstruction of blood vessels from x-ray subtraction projections: limited angle geometry.

Several algorithms have been investigated for reconstructing blood vessels from a limited number of x-ray subtraction projections, distributed over a limited range of angles. Both computer simulations and an in vivo animal study were carried out. The best reconstruction performance was achieved using an algorithm that folded in two pieces of a priori knowledge of the vascular density distributions: (1) the object is dilute, consisting mainly of a void; and (2) the density distribution in the reconstructions is most likely to be non-negative. Both the signal-to-noise ratio (SNR) and the signal to out-of-focus blur were quantitated. Compared to tomosynthetic reconstruction (backprojection), the amount of residual blur from out-of-focus planes was significantly reduced with only a small penalty in diminished SNR. The combined effect resulted in significant qualitative image improvement for real arterial distributions as demonstrated in a canine arterial imaging example.

Algorithms↗

PubMedDate not supplied

Light equalization radiography.

An electro-optical, photographic dodging technique, called light equalization radiography (LER), has been developed. The use of LER extends the dynamic range of radiographic film by enhancing the film contrast in the "toe" region of a radiographic film. Contrast recorded above some predetermined optical density is unaffected. The use of LER permits high-contrast films to be used in radiographic exams where low-contrast, "latitude" film types have been used traditionally, e.g., in chest radiography.

Humans↗