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D G Bragg

Publications and source records attributed to D G Bragg.

At least 37 records · Page 2Linked to original sources
PubMed1987

Effects of improved contrast on lung-nodule detection. A clinical ROC study.

We evaluated the effects of unsharp masking and highly efficient scatter rejection on film-screen chest radiographs of cancer patients. Unsharp masking significantly improved the detectability of lung nodules and visibility of anatomic structures in poorly penetrated areas of the chest. Highly efficient scatter rejection by an improved antiscatter grid provided only modest additional benefits. The study supports the conclusion that nodule detection in poorly penetrated areas on conventional chest radiographs is limited primarily by display contrast, whereas in the well-penetrated lung fields it is limited primarily by confusing background structures, rather than inadequate contrast. A method for analyzing clinical nodule detection data by transforming the FROC data to ROC coordinates also is demonstrated.

Humans↗
PubMed1987

Non-Hodgkin's lymphoma of the head and neck: CT evaluation of nodal and extranodal sites.

Forty-five patients with non-Hodgkin's lymphoma (NHL) of the extracranial head and neck who had undergone CT as part of their evaluation were reviewed to assess the impact of CT on clinical management. The sites of tumor deposition were subdivided by location: I, nodal; II, extranodal, lymphatic (Waldeyer's ring); and III, extranodal, extralymphatic (orbit, sinonasal, deep facial spaces, mandible, salivary gland, skin, and larynx). The CT appearance of NHL in each of the three locations was analyzed for characteristic CT signatures. Nodal NHL was suspected when CT showed multiple, large, homogeneous lymph nodes, often in unusual nodal chains of the head and neck. Extranodal, lymphatic NHL of Waldeyer's ring was indistinguishable from squamous cell carcinoma of this area unless synchronous tumor deposit in an extranodal, extralymphatic location was also present. When NHL was in nodes and/or Waldeyer's ring, CT-derived information was of limited clinical value since treatment was unfocused (chemotherapy and/or large-field radiotherapy). The CT appearances of extranodal, extralymphatic NHL was generally not distinguishable from other malignancies of these areas. However, CT-derived information regarding deep-tissue tumor size and extent was critical to planning the radiotherapy ports.

Adult↗
PubMed1986

New concepts in the non-Hodgkin lymphomas: radiologic implications.

Non-Hodgkin lymphomas are a heterogeneous group of neoplasms believed to be derived in the majority of cases from a common ancestor, the lymphocyte. The clinical and radiologic implications of the newer concepts in the classification, staging, and treatment of these neoplasms form the basis for this review. The disease course, staging requirements, and treatment strategies are determined by histologic classification, prognostic grade of the tumor, disease presentation in a nodal or extranodal site, and clinical stage. The unique and common radiologic features of these neoplasms are reviewed in each of the major anatomic regions of the body.

Abdominal Neoplasms↗
PubMed1984

Thoracic neoplasms: imaging requirements for diagnosis and staging.

This article reviews the pathophysiology of thoracic neoplasms and discusses current imaging recommendations for diagnosis and staging of these tumors. Particular emphasis is given to primary lung cancers, which comprise a variety of tumors of differing histologic type and behavior. The development of cost-effective diagnostic/staging sequences with continually changing imaging technology continues to be a challenging goal. Our recommendations are based on the TNM system and data from the current literature employing the experience from our institution.

Adenocarcinoma↗
PubMed1981

Tumor imaging in diagnostic radiology.

Medical imaging benefitted from major technological advances during the decade of the 1970s. These newly evolving procedures have been accused of significantly adding to health care expenditures and confusing clinicians in the selection of the appropriate examination. The purpose of this presentation is to place these new technologies in their current perspectives, emphasizing the advantages and limitations of each. To illustrate the appropriate imaging technique, decision trees will be developed for each major anatomic site. In many instance, the complementary rather than competitive nature of these imaging studies will become apparent. Average national charges for these procedures will be shown to illustrate the impact of cost on these decisions. Each imaging decision must still be individualized to the patient and disease, as well as the institution's equipment and professional expertise.

Abdominal Neoplasms↗
PubMed1978

Gossypiboma--the problem of the retained surgical sponge.

Commonly used surgical sponges and appliances all have standardized, readily recognized opaque markers visible on radiographs. When these markers are identified on postoperative radiographs, they should be assumed to represent retained surgical sponges or appliances. With the rare exception of thoracotomy dressings, these marked materials are seldom, if ever, used as external bandaging materials. AP and lateral radiographs should provide an immediate answer as to the location of any retained surgical device. The early recognition of these retained surgical sponges should eliminate most complications related to their presence.

Adolescent↗