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Biomedical subjects

K D Hopper

Publications and source records attributed to K D Hopper.

At least 19 recordsLinked to original sources
PubMed1992

Current usage of nonionic contrast.

All physicians who had billed Pennsylvania Blue Shield for at least three intravenous contrast studies during 1989 were surveyed on their use of nonionic versus ionic contrast. This surveyed group represents a diversity of hospital sizes, practice types, and group sizes. Of the 383 physician groups surveyed, responses were obtained from 285. The majority of the responding groups were radiologists (94.0%). Nonionic contrast is utilized in 41.3% of all intravenous studies. Radiologists use nonionic contrast in a much greater proportion than nonradiologists (P < 0.0001), with 17.6% of radiologists utilizing nonionic contrast in all of their patients. Conversely, 75% of nonradiologists utilize ionic contrast in all of their patients. For all physician groups surveyed, 40.3% utilize nonionic for at least 50%, while 27.6% use nonionics for more than 75% of their patients. The routine use of steroid premedication prior to the injection of ionic contrast is not a common practice. The increased utilization of nonionic contrast found in this survey may reflect the cross-section of physicians and practice types surveyed or may represent changing practice patterns among physicians utilizing contrast material.

Contrast Media↗
PubMed1992

Patients' attitudes toward informed consent for intravenous contrast media.

OBJECTIVES: To assess patient attitudes concerning informed consent and the risks of ionic and nonionic contrast material, 1,197 completed questionnaires were obtained from individuals either awaiting contrast injection or waiting for other services. METHODS: Six different questionnaire formats were administered, including two detailing the specific risks of ionic and nonionic contrast, respectively. Different questionnaire formats were used to assess whether the severity or the probability of adverse consequences had more influence on a patient's desire for information. Two questionnaires evaluated the effect of comparing medical risks to equivalent risks from everyday nonmedical activities. RESULTS AND CONCLUSIONS: Regardless of questionnaire format and the severity of potential risk, the large majority of individuals want some information before contrast injection, and approximately half view such information as essential. Individuals reacted more to the probability of a potential reaction than its severity, and to items ordered toward the end of a particular questionnaire than at the beginning.

Adult↗
PubMed1992

CT and MR imaging of the pediatric orbit.

Orbital abnormalities encountered in the pediatric population differ substantially from those found in adult patients. Retinoblastoma, the most serious intraocular tumor, is often difficult to diagnose, but use of computed tomography (CT) (which reveals the characteristic focal calcification) and magnetic resonance (MR) imaging allows this tumor to be differentiated from pseudogliomas, such as Coats disease, and retrolental fibroplasia. CT and MR imaging help in the differentiation of orbital cellulitis from preseptal, lacrimal, and eyelid infectious processes and of orbital pseudotumor from Graves disease. In cases of orbital trauma, CT is excellent for detecting orbital fractures and metallic foreign bodies; MR imaging is better for depicting ocular and optic nerve injuries. Both modalities allow the differentiation of rhabdomyosarcoma from dermoid, cavernous hemangioma, and lymphangioma and provide helpful information for the diagnosis of many other tumors. Since CT and MR imaging have widely expanded the capabilities of orbital imaging, it is more important than ever before for radiologists to understand pediatric orbital disease.

Eye Abnormalities↗
PubMed1992

Use of informed consent for ionic and nonionic contrast media.

The use of informed consent before intravenous administration of contrast material remains a controversial issue. It involves explaining the risks of intravenous contrast material and obtaining the patient's permission for its use. All physician groups who had billed Pennsylvania Blue Shield for at least three intravenous contrast material-enhanced procedures performed in 1989 were surveyed. Informed consent was obtained from at least some patients by about two-thirds of physician groups before using intravenous contrast material, regardless of whether it was ionic or nonionic. Nonradiologists were more likely to obtain informed consent before the use of ionic contrast material than radiologists. Regardless of specialty, practices associated with larger hospitals (greater than 250 beds), larger physician groups (greater than 10), or a university used informed consent less often than smaller physician groups or those associated with a smaller hospital or a private practice. Though results may be affected by regional variation or increased usage since previous surveys, the use of informed consent before the intravenous injection of contrast material is a common practice; it is obtained in the majority of patients.

Attitude of Health Personnel↗
PubMed1992

Brain abnormalities in male children and adolescents with hemophilia: detection with MR imaging. The Hemophilia Growth and Development Study Group.

Cranial magnetic resonance (MR) imaging was performed in 124 male patients (aged 7-19 years), from 14 institutions, in whom a diagnosis of moderate to severe hemophilia was made. Blood tests in all subjects were negative for human immunodeficiency virus. Findings in MR studies were abnormal in 25 (20.2%) subjects. Six lesions in five subjects were classified as congenital. The most commonly identified congenital lesion was a posterior fossa collection of cerebrospinal fluid (five cases). Twenty-two subjects had acquired lesions that were probably related to the hemophilia or its treatment. The most commonly acquired lesions were single- or multifocal areas of high signal intensity within the white matter on T2-weighted images noted in 14 (11.3%) subjects. Two subjects had large focal areas of brain atrophy, and six had some degree of diffuse cerebral cortical atrophy. Three subjects (2.4%) had hemorrhagic lesions. To the authors' knowledge, the unexpected finding of small, focal, nonhemorrhagic white matter lesions has not previously been reported.

Adolescent↗
PubMed1992

Fine-needle aspiration biopsy for cytopathologic analysis: utility of syringe handles, automated guns, and the nonsuction method.

The performances of seven techniques and devices used with 22-gauge needles to obtain biopsy specimens for cytologic analysis were compared by means of single-blinded evaluation with an objective, previously published grading scheme. A total of 420 specimens were obtained from 10 fresh human cadavers (42 specimens per cadaver), including 30 hepatic, 20 renal, and 10 pancreatic specimens per technique or device. No statistical differences existed in the liver, kidney, or pancreas or in the combined data in the performance of the aspirator gun, syringe holders, vacuum needle, and end-cut gun versus the manual aspiration biopsy technique performed with a 22-gauge Chiba needle. However, nonaspiration, fine-needle capillary biopsy (FNCB) performed statistically significantly worse than any other technique or device in the kidney and pancreas and in comparison with the overall combined data. In the liver, no statistically significant difference existed in the overall performance of FNCB versus conventional aspiration biopsy, but the amount of cellular material obtained with FNCB was statistically significantly less.

Biopsy, Needle↗
PubMed1991

The slit infrahepatic IVC: pathologic entity or normal variant?

A common finding on abdominal ultrasound and CT examinations is variation in the size of the inferior vena cava (IVC). On occasion the infrahepatic IVC even assumes a slit-like appearance. Though commonly related to respiratory change and to the degrees of intra-abdominal pressure, some have claimed the slit-IVC may be an indicator of hypovolemia. To study this phenomenon, we evaluated prospectively the IVC in 26 normal volunteers. These individuals were studied supine by dynamic image ultrasound at end-inspiration, end-expiration, and during the Valsalva maneuver. The size of the IVC was maximal with the patient supine and at end-inspiration (A-P 1.8 cm). The subhepatic IVC decreased in size at end-expiration (A-P 1.2 cm) and frequently collapsed with the Valsalva maneuver (A-P 0.7 cm). Dramatic changes in the size of the IVC with changes in ventilation are normal variants. The use of the slit-IVC to diagnose hypovolemia should be done with caution.

Adult↗
PubMed1991

The prevalence of asymptomatic gallstones in the general population.

The gallbladder and biliary system were scanned by real-time ultrasound in 2274 patients undergoing diagnostic ultrasound for other than gallbladder disease. Patients (212) with previous gallbladder symptoms or with nonvisualization of their gallbladder were excluded from the study. Obesity is the most important risk factor for the development of asymptomatic gallstones in women (P less than .01), although it is not a significant factor in men. Increasing age is an important risk factor for both sexes, and the only significant risk factor in men (P less than .01). While few men have asymptomatic gallstones before the age of 40, 5% of women aged 20-29 and 9% aged 30-39 do. In the 40 and over age group, men (14%) and women (11%) had insignificantly different prevalences. In women, the number of previous pregnancies is a significant risk factor (chi-square = 5.4, P = .02). For instance, there is a 3%, 8%, and 17% overall frequency of gallstones in women with 0, 3, and 6 or more previous pregnancies, respectively. A stepwise logistic regression analysis, after adjusting for age, body mass index, and for women, number of pregnancies, found no significant increased risk related to race (P = .40), high blood pressure (P = .43), heart disease (P = .47), or diabetes (P = .46). After age adjustment, there is no significant gender effect (P = .25). Asymptomatic gallstones are a relatively common occurrence in men over 40 and women over 30. While age is the only significant risk factor in men, obesity, parity, and to a lesser extent age were significant risk factors in women.

Adult↗
PubMed1991

Mediastinal bulk in Hodgkin disease. Method of measurement versus prognosis.

The presence of a large mediastinal mass (bulk disease) in patients with newly diagnosed Hodgkin disease is believed by many to predict a poorer prognosis and to warrant more aggressive treatment. These masses are formed by an aggregate of mediastinal lymph nodes. The determination of bulk disease is confusing, with at least 27 definitions having been proposed. This study seeks to determine the best definition, and determine the role of thoracic computed tomography (CT) versus chest radiographs in the evaluation of mediastinal bulk disease. One hundred seven consecutive newly diagnosed adult patients with Hodgkin disease were evaluated using 13 commonly used definitions of mediastinal bulk. Of the 76 patients with mediastinal disease, 73 had bulk disease as defined by at least one definition. Of the 16 patients who had recurrence of mediastinal disease, only the presence of bulk disease according to one definition (hilar adenopathy, greater than or equal to 2 cm) was statistically significant in its prediction (P = .05). No definition based on the size of the mediastinal nodal mass reliably predicted those patients with recurrence. No differences in our data were found for differing stages or disease cell types, the presence of extension, or with differing treatment regimens. This study highlights the confusion and controversy surrounding the use of bulk disease of the mediastinum as an adverse prognostic indicator. The numerous methods of measuring mediastinal bulk in patients with newly diagnosed Hodgkin disease are confusing, overlap, and are not statistically reliable in predicting recurrence. Efforts to create a standard or ideal definition were unsuccessful. Thoracic CT was useful in those patients whose bulk disease distorted only one side of the mediastinal silhouette on chest radiographs.

Adult↗
PubMed1991

Nonpalpable breast lesions: stereotactic automated large-core biopsies.

One hundred two patients with mammographically suspicious, nonpalpable lesions underwent stereotactic breast biopsy with a biopsy gun and an automated 14-gauge cutting needle. After biopsy, a localization wire was placed and surgical biopsy performed. There was agreement of the histologic results from the gun biopsy and the surgical biopsy specimens in 98 cases (96%), including 22 of 23 carcinomas (96%) (kappa = 0.936). The gun biopsy yielded findings that led to the correct diagnosis in two cases involving lesions that were missed at surgical biopsy; two lesions found at surgery were missed at gun biopsy. The results of this study suggest that the use of 14-gauge needles improves agreement between surgical and needle core biopsy findings and that stereotactic biopsy with an automated needle and gun can be an acceptable alternative to surgical biopsy in women with mammographically suspicious breast lesions.

Adenofibroma↗
PubMed1991

Diagnostic radiology peer review: a method inclusive of all interpreters of radiographic examinations regardless of specialty.

A proposed method of assessing the quality of diagnostic radiographic examinations includes peer review designed to evaluate physicians, including nonradiologists, involved in the performance and interpretation of such examinations. A pilot project evaluated this system with randomly selected Pennsylvania Blue Shield data files of 10 providers billing for chest radiography interpretations during the second quarter of 1989. Of the 98 chest radiographs reviewed blindly, all inadequately marked radiographs and incomplete written reports were produced by nonradiologists. Technical quality of images obtained by radiologists did not significantly differ from that of images obtained by nonradiologists (P = .189). All five interpretive errors that could have seriously affected the patient's health care were produced by nonradiologists (P = .019). Four of these serious errors were made by providers billing for fewer than 25 radiographs. While administrative and time cost limitations are obvious, this method of peer review encompasses all physicians billing for a particular radiographic service, irrespective of specialty.

Blue Cross Blue Shield Insurance Plans↗
PubMed1991

The pattern of intrathoracic Hodgkin's disease assessed by computed tomography.

Computed tomography (CT) was used to define the sites of intrathoracic abnormality in Hodgkin's disease, determine a pattern of progression of disease in the thorax, and establish the place of this pattern of spread in the differential diagnosis of thoracic abnormalities. One hundred eight patients with newly diagnosed Hodgkin's disease were studied by chest CT. Seventy-seven patients had intrathoracic abnormalities. The pattern seen was one of contiguous spread from the anterior mediastinal/paratracheal area to the other mediastinal lymph node groups (aortopulmonary, subcarinal, posterior mediastinal, and internal mammary), to the hila, and then into the lung by extension or as discrete nodules. Involvement of the pleura, pericardium, or chest wall occurred only after the anterior mediastinal/paratracheal mass had enlarged to greater than 30% of the thoracic diameter. The probability that this pattern of contiguous lymph node spread occurred by chance alone was very small. Hodgkin's disease spreads from the anterior mediastinal/paratracheal area in a contiguous manner. Exceptions are unusual enough that when they occur, diagnoses other than Hodgkin's disease are more likely.

Adult↗
PubMed1991

Imaging of gallbladder variants.

A wide range of normal gallbladder variations are seen on gallbladder imaging. This essay illustrates the major variations that may be encountered, including anomalies in location, number, and form.

Diagnosis, Differential↗
PubMed1991

The efficacy of transrectal ultrasound and prostate cancer.

An increased interest in the diagnosis and treatment of prostate cancer, particularly in the last few years, is reflected in the literature. Numerous articles have been published since 1980 on the subject of imaging of the prostate gland. This article is a review of transrectal ultrasound and its efficacy in the diagnosis and treatment of prostate cancer. Included is a review of the normal prostate anatomy, typical and atypical sonographic features, clinical and radiographic staging of prostate cancer, efficacy of the digital rectal examination, role of ultrasound in prostate cancer screening, surgical treatment, and radiotherapy of prostate cancer.

Adenocarcinoma↗
PubMed1990

Neurologic manifestations in 18q- syndrome.

We report a mother and son with a deletion at 18q22.3. Both have the typical manifestations of the 18q- syndrome. In addition, both have an action tremor which became apparent in childhood. The mother subsequently developed chorea and dysmetria in late adolescence. Magnetic resonance imaging of their brains showed poor myelination of the central white matter tracts with relatively normal myelination of the corpus callosum. We propose that these neurologic findings are most likely due to a failure of expression of the myelin basic protein gene.

Abnormalities, Multiple↗
PubMed1990

Prostate cancer: comparison of pre-operative 0.35 T MRI with whole-mount histopathology.

Magnetic resonance imaging of the prostate was performed in eight patients prior to radical prostatectomy. The results of the imaging studies were then directly compared to histopathologic findings from whole-mount histologic sections. Magnetic resonance imaging identified 82% of cancers greater than 5 mm in minimal diameter. Cancers were identified as areas of decreased signal intensity compared to the high signal intensity peripheral zone on long TR/TE sequences. Cancers were best detected when they involved the middle level of the gland and the posterior half of the prostate. Of the individual tumors identified by imaging, the amount of tumor involvement was underestimated by 37% and overestimated by 22% by MRI. We conclude that magnetic resonance imaging can identify prostate cancer, but has limitations as a screening modality and in accurately assessing the amount of involvement of the prostate gland by cancer.

Carcinoma↗