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Biomedical subjects

J R Haaga

Publications and source records attributed to J R Haaga.

At least 91 records · Page 5Linked to original sources
PubMed1982

Periaortic fluid aspiration for recognition of infected graft: preliminary report.

Diagnostic aspiration of a periaortic fluid collection was performed four times on three patients suspected of aortic graft infection. One aspiration was positive for Staphylococcus epidermidis and the others were sterile. The results of aspiration were critical in determining if radical surgical treatment should be performed. CT guidance is well suited for this type of aspiration because it results in accurate needle placement without inadvertent puncture of bowel or the graft.

Abscess↗
PubMed1982

Multiple microaerophilic streptococcal lung abscesses after orthodontic treatment.

An immunocompetent 12-year-old boy developed multiple microaerophilic streptococcal lung abscesses after application of orthodontic bands ("braces"). The dental work was done in the supine position. The data suggest that the patient aspirated the organisms and, possibly, flecks of dental cement, during orthodontic treatment. "Rubber dams" should be used to help prevent aspiration in children who receive dental work in the supine position. When a rubber dam cannot be used, as with orthodontic treatment, physicians should advise patients who are at risk for developing pulmonary infection (eg, patients with neuromuscular diseases which compromise cough and/or gag, cystic fibrosis, sickle cell anemia, primary immunodeficiency, etc) to have this dental work, including orthodontic treatment, performed in the erect position.

Child↗
PubMed1981

The effect of mAs variation upon computed tomography image quality as evaluated by in vivo and in vitro studies.

The effect of different mAs settings on computed tomobraphy (CT) image quality was evaluated by a clinical study and phantom studies. In the clinical portion of this study, a number of CT images, obtained at various mAs settings, were reviewed by experienced CT interpreters. From these same images, graphs were charted of the root-mean-standard deviation (RMSD) vs. body size; there appeared to be a linear relationship between noise, as measured by RMSD, and body size. A performance phantom was used to evaluate the effect of the different mAs settings on resolution. There was some loss in low contrast resolution at 6 and 20 mAs; however, the resolution was identical at 40 and 100 mAs.

Humans↗
PubMed1980

CT appearance of renal infarct.

A case is presented in which a histologically proven focal infarct of the kidney appeared as a low density mass lesion on computed tomography (CT). In patients with appropriate history, infarction should be included in the differential diagnosis of an area of low CT attenuation within the kidney.

Abscess↗
PubMed1980

Detection of low-contrast lesions in computed body tomography: an experimental study of simulated lesions.

Observer accuracy in the identification of low-contrast objects in computed tomography (CT) was studied. Thresholds were established for detection of lesions of various sizes and attenuation differences in CT images produced at different radiation doses. Noise reduction was important in identifying certain types of lesions. Detection was not accurate when the standard deviation of the mean of an organ exceeded the difference in the means of the lesion and the surround region.

Humans↗
PubMed1980

CT-guided percutaneous aspiration and drainage of abscesses.

CT-guided procedures were attempted in 103 patients suspected of having abscesses. CT-guided procedures were performed for diagnostic specimens in 70 patients; they were successful in 30 of 34 sterile collections and 33 of 36 abscesses. In another 33 patients, diagnostic aspiration was performed and percutaneous drainage was attempted; aspirations were successful in 33 of 33 and drainage in 28 of 33 cases. Of the five not drained, four were undrainable because of anatomic extent or high viscosity of the purulent material. The fifth was a necrotic, squamous cell tumor erroneously thought to be an abscess. No complications were encountered. CT-guided procedures are an effective method for obtaining diagnostic specimens in selected patients.

Abscess↗
PubMed1979

Computed tomographic guided liver biopsy using the Menghini needle.

CT guided biopsies of the liver using the Menghini needle were performed in 42 patients. The recovery of diagnostic tissue was successful in 86% of focal lesions. Advantages over the blind liver technique include better recovery of diagnostic specimens, while advantages over the ultrasonic guided techniques include greater amount of tissue obtained and better occuracy in guidance. This technique is indicated in those patients with a small number of focal defects in the liver in whom a diagnostic histologic specimen is desired.

Biopsy, Needle↗
PubMed1979

New techniques for CT-guided biopsies.

Two new recently instituted techniques have eliminated the shortcomings associated with computed tomography-guided biopsy procedures. By using the bolus biopsy technique, it has been possible to assess the vascular anatomy and vascularity of abnormalities so that cutting-type needles can be used on a routine basis. In a series of 47 cases, this method was used to select cases for cutting biopsies. In 29 cases in which the cutting biopsy was performed, tissue was successfully recovered in 25 cases. Advantages of large specimens obtained by such large needles are discussed. Secondly, the fourth generation scanning devices permit scanning at low radiation doses that provide slightly noisier but suitable images to perform the biopsy procedures. This eliminates the possibility of objectionably high radiation dose if more than one scan is required.

Biopsy↗
PubMed1979

Clinical comparison of computed tomography and lymphangiography for detection of retroperitoneal lymphadenopathy.

The advantages of CT scan over lymphangiography are numerous and significant. The accuracy of CT scan was virtually identical to lymphogram for the detection of para-aortic lymph node involvement; however, CT provides a better means of assessing the true extent of disease. In such cases it is possible to determine whether the neoplastic process involves retroperitoneal structures such as the kidneys, ureters, pancreatic region, hilum of the liver, or the major vessels. Moreover, this excellent definition permits accurate follow-up assessment of therapy. Finally, CT is a noninvasive examination and does not require significant technical expertise, and the examination is easily reproducible following any time period from the initial examination. Finally, although we have not specifically discussed biopsy procedures, the CT scan is an excellent means for guiding biopsy procedures even for retroperitoneal abnormalities, perhaps precluding the necessity for laparotomy in order to provide histologic diagnosis of disease (Fig. 11). The disadvantages of CT are several. Of course, the acquisition of CT equipment is expensive and the cost effectiveness has not yet been proven. The most significant disadvantage is its inability to resolve or detect neoplastic disease within normal-sized lymph nodes. This was not a significant problem in our series, because our series contained only a few cases of suspected metastatic disease as opposed to lymph node neoplasms. The advantages of lymphography have been discussed by other authors. Because of the better spatial resolution of lymphograms, it is possible by proper interpretation to distinguish between neoplastic disease and lipogranulomatous changes. In a few cases in our series, this did not prove to be true; however, this may have been due to deficiencies in our interpretations (two cases of lymphoma were called positive for neoplasm, but proved to be lipogranulomatous changes by biopsy). Secondly, surveillance films may be easily and cheaply obtained to detect recurrences of disease. In addition, lymphography also provides the opportunity for biopsy of lymphoma masses, but to date this has only been accomplished by skinny-needle biopsy aspirations and not by large core biopsy techniques. After reviewing the literature and evaluating our data, we believe that several recommendations are appropriate with respect to the roles of computed tomography and lymphography. We agree with the previously stated concept that CT should be used for screening for lymphoma; however, we disagree that lymphograms have a greater advantage over CT in the biopsy-proven cases of lymphoma. Rather we believe that CT is better suited than lymphography for those cases with biopsy proven lymphoma. CT is better able to accurately localize the lymph node masses for surgeons if the surgical approach is desired and better able to define the extent of the disease throughout the abdomen. As a result of this it is capable of providing a better follow-up for therapy...

Biopsy, Needle↗