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Biomedical subjects

L Hanelin

Publications and source records attributed to L Hanelin.

6 recordsLinked to original sources
PubMed1986

Radiotherapy treatment planning using lymphoscintigraphy.

A method for the three dimensional location of lymph nodes with respect to the skin surface is described. The technique is based on the reconstruction of surface shape using isocentric radiographs taken with metal chains draped on the patient. Registration of the radiographic study to the lymphoscintigraphic study is accomplished automatically by matching the location of four radiopaque and radioisotope markers. This method allows nodes to be located in a beam's eye view with any set up of an isocentric radiotherapy machine. An accurate determination of the depth of lymph nodes is obtained, which is of value in electron beam therapy.

Breast Neoplasms↗
PubMed1985

Effect of obesity on esophageal transit.

Esophageal transit time as measured by radionuclide scintigraphy using a swallowed technetium sulfur colloid bolus was measured in obese patients with gastroesophageal reflux, lean patients with reflux, and lean volunteers without reflux. The esophageal transit time was significantly prolonged in the obese group compared with both lean groups (p less than 0.001). Esophageal manometric measurement also confirmed that obese patients have an elevated gastroesophageal pressure gradient, presumably caused by increased intraabdominal pressure resulting from the mechanical burden of excess fat. The esophageal transit time is significantly related to the gastroesophageal pressure gradient. This finding, coupled with those in previous manometric investigations showing that esophageal muscle has a decreased maximum velocity with increasing afterload, explains in part why obese patients have delayed esophageal transit time. Therapy for reflux in obese patients should be aimed at improving esophageal transit.

Adult↗
PubMed1978

Colon polyps, sebaceous cysts, gastric polyps, and malignant brain tumor in a family.

A unique family with a distinct syndrome of adenomatous colonic polyps and sebaceous cysts without osseous or soft tissue abnormalities is presented. One member had benign gastric polyps limited to the upper half of the stomach and another had a medulloblastoma of the cerebellum. A histologic feature in the colon of the propositus was the presence of atypical epithelium in flat mucosa as well as in the colonic polyps.

Adolescent↗
PubMed1977

Yersinia colitis.

A 2-year-old child with a febrile, non-bloody diarrheal illness of acute onset with repeatedly negative stool and blood cultures for pathogenic bacteria is presented. Sigmoidoscopic and roentgenographic studies revealed an inflammatory colitis. Unfortunately, diagnostic perserverance and a high index of suspicion resulted in a positive stool culture for Yersinia enterocolitica. Serologic study and clinical course provided data consistent with the diagnosis of an infectious colitis due to Yersinia enterocolitica. This case demonstrates the necessity to consider Yersinia enterocolitica in the radiographic differential diagnosis of Crohn's disease of the colon or ulcerative colitis, as well as intractable diarrhea of childhood.

Biopsy↗
PubMedDate not supplied

Combined corrections for attenuation, depth-dependent blur, and motion in cardiac SPECT: a multicenter trial.

BACKGROUND: The diagnostic accuracy of cardiac single photon emission computed tomography (SPECT) is limited by image-degrading factors, such as heart or subject motion, depth-dependent blurring caused by the collimator, and photon scatter and attenuation. We developed correction approaches for motion, depth-dependent blur, and attenuation and performed a multicenter validation. METHODS AND RESULTS: Motion was corrected both transversely and axially with a cross-correlation technique. Depth-dependent blurring was corrected by first back-projecting each projection and then applying a depth-dependent Wiener filter row by row. Attenuation was corrected with an iterative, nonuniform Chang algorithm, based on a transmission scan-generated attenuation map. We validated these approaches in 112 subjects, including 36 women (20 healthy volunteers, 8 angiographically normal patients, and 8 patients with coronary artery disease [CAD] found by means of angiography) and 76 men (23 healthy volunteers, 10 angiographically normal patients, and 43 patients with CAD found by means of angiography). Either technetium 99m or thallium 201 was used for emission; either gadolinium 153 or Tc-99m was used for transmission. Images were reconstructed and blindly interpreted with a 5-point scale for receiver operating characteristic analysis in 2 ways: motion correction plus a Butterworth filter, and combined motion and blur and attenuation corrections. The interpretation by means of consensus was for the overall presence of CAD and vascular territory. The receiver operating characteristic curves for overall presence and each of the 3 main coronary arteries were all shifted upward and to the left and had larger areas under the curve, for combined corrections compared with motion correction and Butterworth. Sensitivity/specificity for motion correction and Butterworth were 84/69, 64/71, 32/94, and 71/81 overall for the left anterior descending, the right coronary artery, and circumflex territories, respectively, compared with 88/92, 77/93, 50/97, and 74/95, respectively, for the combined corrections. CONCLUSIONS: The proposed combined corrections for motion, depth-dependent blur, and attenuation significantly improve diagnostic accuracy, when compared with motion correction alone.

Coronary Disease↗