Faculty Bibliography

An integrated approach to existing methods of extracting biodistribution data, pharmacokinetics and radiation absorbed dose estimates from serial scintigraphic images is described. This approach employs a single computer-generated user interface to reformat planar scans into a standard file type, align conjugate (anterior and posterior) images, draw regions of interest (ROIs) over selected organs and lesions and generate count data for anterior and posterior views and calculated geometric means. Using standard correction methods, the fraction injected activity is obtained for all ROIs and total body. This methodology has been applied to the analysis of indium-III-labelled breast-cancer-directed antibodies and technetium-90m-labelled CEA-specific antibody fragments in non-small-cell lung cancer. It is anticipated that this approach will be useful for evaluating the dosimetry of other radiolabelled monoclonal antibodies, as well as other radiopharmaceuticals

We have developed a graphical interface which allows users of varying levels of computer experience and proficiency to manipulate medical image-processing data with 'point-and-click' ease. The power which had formerly been associated with protocols and shell scripts has been combined with the flexibility and 'user-friendliness' of buttons and dialog boxes

A retrospective evaluation was performed of the location and attenuation characteristics of abdominal and pelvic lymphadenopathy, identified at dynamic sequential bolus computed tomography (CT) in 69 patients with acquired immunodeficiency syndrome (AIDS). Lymph node appearance at CT was characterized as hyperattenuating, isoattenuating, or hypoattenuating relative to the iliopsoas muscle. The significance of finding hyperattenuating adenopathy in the patient population was evaluated. Thirty-three patients had hyperattenuating adenopathy, including 26 with the epidemic form of Kaposi sarcoma (KS). Of 38 patients with epidemic KS, 26 had hyperattenuating, 11 had isoattenuating, and one had hypoattenuating lymphadenopathy. The positive predictive value of hyperattenuating adenopathy for epidemic KS was 79%. These findings were statistically significant at the 95% confidence interval (P < .005). Hyperattenuating lymphadenopathy, identified on dynamic sequential bolus CT scans in AIDS patients, was seen with disseminated KS in approximately 80% of cases

The task of the Dutch social insurance physician is to evaluate claims for disability compensation and to support clients in the process of vocational rehabilitation. Because rehabilitation outcome is associated with length of time out of work, individual rehabilitation plans should be designed at an early stage. Of vital importance in the design of such plans are the client's remaining working capacities. Earlier assessment of functional capacity could be stimulated by more reciprocal consultation and closer collaboration between social insurance and treating physicians. When complete rehabilitation is not yet possible, working shorter hours, if necessary in a different job, could be an initial solution. As a result the client keeps in touch with the working environment and also a clearer picture is provided of what he or she is still capable of doing. Besides, the influx into the disability law system, which automatically follows if the non-working period exceeds 1 year, with its serious financial, social and emotional effects for the client, may be reduced

In-111-labeled monoclonal antibodies (MAbs) directed against colorectal carcinoma are close to routine clinical use. In-111 offers advantages as a label for radioimmunodetection. The MAbs used most for detecting colorectal cancer are specific for CEA or TAG-7 The sensitivity of In-111-MAbs in clinical studies has ranged from 60 to >90% with highest sensitivity in the pelvis and lowest in the live). The sensitivity for liver lesions is rising as chelate chemistry improves. Radioimmunodetection of colorectal cancer is most useful in the patient with a possible recurrence based on an equivocal CT finding (e.g. scar vs. tumor) or an elevated serum CEA (i.e.. occult disease), or in the patient with a single known recurrence/metastasis and in whom resection is contemplated

A method of image analysis was developed for correlation of hemangiomas detected at computed tomography (CT) and/or magnetic resonance (MR) imaging with increased blood pool activity evident at single photon emission CT (SPECT) performed after labeling of red blood cells with technetium-99m. Image analysis was performed in 20 patients with 35 known hepatic hemangiomas. After section thickness and pixel sizes of the different studies were matched, intrinsic landmarks were chosen to identify anatomically corresponding locations. Regions of interest (ROIs) drawn on the CT and/or MR images were translated, rotated, and reprojected to match the areas of interest on the corresponding SPECT images by means of a two-dimensional polynomial-based warping algorithm. Analysis of ROIs on 30 SPECT-MR and 20 SPECT-CT pairs of registered images provided absolute confirmation that 34 suspected hemangiomas identified on SPECT images correlated exactly with lesions seen on CT and/or MR images. Accuracy of fusion was within an average of 1.5 pixels +/- 0.8 (+/- 1 standard deviation). The technique enabled diagnostic confirmation of hemangiomas as small as 1.0 cm and proved useful for evaluating lesions located adjacent to intrahepatic vessels

Eighty-four computed tomographic (CT) scans from patients referred for bowel obstruction between January 2, 1988, and December 31, 1989, were retrospectively evaluated. A pair of radiologists without knowledge of patient histories determined the presence or absence of bowel obstruction. Sixty-four patients ultimately proved to have intestinal obstruction, and 20 did not. Diagnosis was established by means of surgery (n = 39), barium studies (n = 17), and clinical course (n = 28). Causes of obstruction included adhesions (n = 37), metastases (n = 6), primary tumor (n = 7), Crohn disease (n = 4), hernia (n = 3), hematoma (n = 2), colonic diverticulitis (n = 2), and other (n = 3). In addition, 83 CT examinations in patients with no history or indication of intestinal obstruction were simultaneously reviewed. The overall sensitivity was 94%, specificity was 96%, and accuracy was 95%. The cause of obstruction was correctly predicted in 47 of 64 cases (73%). Intestinal obstruction was not diagnosed in any of the 83 control patients. CT is most useful in patients with a history of abdominal malignancy and in patients who have not been operated on and who have signs of infection, bowel infarction, or a palpable abdominal mass

The fidelity of visualizing craniofacial features using two modern three-dimensional (3D) imaging algorithms - one employing surface and the other volume rendering - are compared. Each rendering technique was evaluated for its ability to display closed cranial sutures, loss of thin bone through partial volume averaging, and the presence of artifacts. Linear measurements of the orbits, foramina, and mounting holes were taken on the 3D renderings and compared with direct measurements. Both techniques visualized the closed cranial sutures, orbits, mandibles, and teeth. The errors in linear measurement averaged less than 1.5 mm (root mean square) and were not statistically different between the two techniques. Errors are attributable to uncertainty in locating edges due to partial transparency (volume rendering) and sub- optimal lighting. Both rendering techniques suffer from step pattern and thin bone artifacts. We conclude that an algorithm for surface construction can provide detailed and accurate representation of the craniofacial anatomy