Routine imaging studies for the posttreatment surveillance of breast and colorectal carcinoma.

Current recommendations on follow-up procedures for patients who have been treated for cancer include imaging studies and other laboratory tests at relatively frequent intervals. At least two questions should be asked to evaluate the benefits of this practice for patients: Do frequent routine surveillance tests detect recurrences "earlier" in asymptomatic patients? and Does earlier treatment of these recurrences reduce morbidity or prolong survival? The practical import of surveillance with imaging and laboratory tests for recurrence in patients with cancer of the breast and colon is discussed. Reported autopsy data, findings at elective reoperation, and clinical data have been examined to ascertain the justification for routine periodic tests in the treated but asymptomatic patient. It is concluded that earlier detection of a local recurrence or of metastatic disease through periodic tests in the asymptomatic patient with breast or colon cancer rarely alters the treatment or the outcome. A notable exception is regular screening mammography following treatment for adenocarcinoma of the breast.

Current use of imaging in the evaluation of primary mediastinal masses.

A wide variety of lesions occur in the mediastinum in patients of every age. Twenty five to 50 percent of these primary mediastinal masses may be malignant, making early diagnosis and therapy crucial. Since most arise from normal structures in the region, localization of lesions to compartments of the mediastinum may assist in diagnosis. This article reviews imaging techniques for lesions originating in the mediastinum.

Imaging techniques in the evaluation of pulmonary parenchymal neoplasms.

Conventional PA and lateral chest radiographs continue to be the initial examination of choice to evaluate patients who are suspected of having a pulmonary parenchymal neoplasm. A lung lesion can be characterized as probably benign or malignant based on its radiographic appearance (size, shape, margins, presence of calcification, cavitation or air bronchograms, growth rate). A spiculated or lobulated lesion greater than 3 cm in size that is noncalcified is highly suspicious for malignancy. A lung lesion less than 3 cm in size with smooth borders that appears noncalcified on conventional radiographs should be examined by CT, including densitometry to detect calcification or fat, which indicates benignity. In patients with known lung cancer, CT can help to stage the tumor by indicating hilar or mediastinal involvement, or distant metastases. Currently, MR imaging has a limited role, but can be used as a "problem solving" modality for selected cases in evaluating pulmonary parenchymal neoplasms.

Acute effects of a perfluorochemical oxygen carrier on normal tissues of the mouse.

A single iv dose of 15 ml/kg fluosol DA (20%), a perfluorochemical oxygen carrier, caused hepatomegaly and splenomegaly which persisted for at least 3 weeks after drug injection. The peak increase in weight was at 3 days in the spleen (1.7x) and at 14 days in the liver (1.5x). Lung and kidney weights were not altered 1-21 days after administration of fluosol DA. The slopes of the single-dose radiation survival curves for intestinal epithelial cells and spermatogenic stem cells in mice breathing air or oxygen were not significantly altered by the administration of fluosol DA 10 min before irradiation, and the doses to achieve an isoeffect were altered by 1.03 or less. When mice were challenged with iv injected FSa tumor cells 24 h after treatment with fluosol DA, no increase in the number of artificial pulmonary metastases was observed.

Experimental evaluation of absorbable copolymer staples for hysterectomy.

Absorbable copolymer staples of three different variants were tested for retention of tensile strength after implantation into the peritoneal cavity of rats. One type maintained tensile strength for two weeks, but then lost it rapidly over the next week. The same three staple compounds were further compared after use for vaginal vault closure during ovariohysterectomy in adult sheep. In all ewes the absorbable staples were effective in providing a stable vaginal cuff closure. The postoperative tissue reaction was minimal. The goal of developing an absorbable staple that would degrade rapidly without compromising wound stability was achieved.

An integrated approach to the evaluation of metastatic bone disease.

The radionuclide bone scan is the most effective whole body screening test for bone metastases. Conventional radiography, although relatively insensitive to the presence of bone metastases, is the best modality for characterizing them once they are detected in radionuclide scans. When the radionuclide bone scan and appropriate correlative radiographs are analyzed and reported together, false-positive scan findings are reduced, and scan specificity is increased. Valuable information on response to treatment may be obtained by correlating the changes seen in radiographs and radionuclide bone scans. CT or MR imaging may be useful for evaluating suspicious radionuclide bone scan findings that cannot be explained radiographically, and may influence the decision regarding the need for biopsy. CT can also be used to monitor needle-biopsy procedures. The use of CT or MR imaging is helpful in determining the local extent of metastatic disease when planning palliative surgery or radiotherapy. Although a positive diagnosis by needle biopsy is considered definitive, a negative result must be suspect and may eventually necessitate open surgical biopsy. An algorithmic approach to the workup of a possible skeletal metastasis is illustrated in Figure 12.

Diagnostic imaging techniques in lung carcinoma.

For the early detection of lung cancer at a stage when it is localized and hence resectable, persons in a high-risk group should be screened periodically with sputum cytologic studies and chest radiographs. For determination of the intrathoracic extent of a lesion, posteroanterior and lateral chest radiographs should be followed by computerized tomography to evaluate the hila, mediastinum, pleura, and chest wall. Computerized tomographic examination of the chest should be extended to include the upper abdomen. The adrenal glands can be evaluated by such examination, but adequate examination of the liver requires both precontrast and postcontrast computerized tomography scans. The radiologic workup for assessing distant metastases to the liver, brain, or bone should be performed only when clinical and biochemical findings suggest such metastases. For detection of recurrent carcinoma following treatment, computerized tomograms of the chest are more sensitive than routine radiographs. Magnetic resonance imaging may prove useful in the future for initial staging and for differentiating posttreatment fibrosis from recurrent bronchogenic carcinoma.

Diagnostic imaging techniques in mediastinal malignancies.

Mediastinal masses occur in both men and women of every age, and close to half of affected patients are asymptomatic. Screening of asymptomatic persons is not economically feasible. Symptomatic patients should be evaluated initially with posteroanterior and lateral chest radiographs. Additional imaging techniques may be required in patients suspected of having a mediastinal mass, when there is a questionable abnormality seen on chest radiographs or when local or systemic symptoms suggest a mediastinal mass. These techniques include oblique views, over-penetrated radiographs, and fluoroscopy of the chest. Computerized tomography of the chest is the imaging modality of choice for further assessment of a mediastinal mass. It can also be an important adjunct in radiotherapy portal planning. The use of other imaging modalities depends on the location of the tumor, the equipment available, and the expertise of local radiologists. In following up treated patients for disease recurrence, periodic chest radiographs are usually sufficient. Computerized tomography scans, because of their expense, should only be obtained as a baseline after completion of therapy or in patients with a suspected relapse.

Birth weights and stillbirths in historical perspective.

Data on birth weights and the percentage of stillborn babies during the late nineteenth and early twentieth century, taken from hospitals records in Edinburgh, Vienna, Dublin, Boston, Montreal and Philadelphia reflect the social class and living standard of their patients as well as socio-economic developments in these cities. To the extent that these hospital records also contained information on the mother's age, parity, occupation, ethnic and religious background, marital status and gender of the child, some inferences can be made on influences on intrauterine growth and birth outcome.

Metastasis of unknown origin.

Metastasis of unknown origin (MUO) constitutes between 5% and 10% of all noncutaneous cancers. An MUO is defined as a metastatic tumor for which the site of origin is not suggested by thorough history, physical examination, chest x-ray studies, routine blood and urine studies, and histologic evaluation. Two major groups of MUO can be defined: MUO to lymph nodes only (N1-3), and MUO to visceral sites. The prognosis may be quite good for patients with MUO limited to lymph nodes in the mid to high cervical, axillary, and groin areas. However, MUO in other lymph node areas is far more serious, with the possible exception of that in patients with a new syndrome, i.e., "advanced poorly differentiated carcinoma of unknown primary origin." There is some suggestion that these patients may respond to cisplatin-based combination chemotherapy. Patients with MUO to visceral sites have a poor prognosis. However, metastases from some primary tumors are sensitive to chemotherapy and a limited search for these tumors should be undertaken. These tumors include leukemia-lymphoma, germ cell tumors, small cell carcinoma of the lung, adenocarcinomas of the breast, ovary, endometrium, thyroid, or prostate, and possibly adrenal carcinoma. We start by reviewing the biochemical events of metastasis that may be targets for therapy. The importance of a correct tissue diagnosis is then considered, including the role of standard histochemistry, electron microscopy, enzyme histochemistry, and immunohistochemistry. The relatively limited value of radiologic tests in localizing the primary site of origin of the tumor is emphasized, as well as the limited role of currently available biomarkers. We conclude by discussing the treatment of each of the subtypes of MUO.

Improving the quality of care through routine teleradiology consultation.

RATIONALE AND OBJECTIVES: The hypotheses of this study were as follows: (a) University subspecialty radiologists can provide consultations effectively to general radiologists as part of routine clinical operations; (b) these consultations will improve the quality of the final radiologic report; and (c) the consultations will improve the care process and may save money, as well. MATERIALS AND METHODS: For 2,012 consecutive computed tomographic or magnetic resonance (MR) imaging studies, the initial interpretations provided by radiology generalists were subsequently reviewed by specialists, with a final consensus report available. "Truth" was established by final consensus reports. To control for potential bias, 150 adult MR imaging and 250 pediatric radiologic studies were interpreted initially by specialists and then by generalists. Again, truth was established by final consensus reports. RESULTS: There was disagreement between generalist and specialist radiologist interpretations in 427 (21.2%) of the cases reviewed. These disagreements were stratified further by independent specialists, who graded them as important, very important, or unimportant. Differences were considered important or very important in 99% of the cases reviewed. CONCLUSION: Consultations by subspecialty radiologists improved the quality of the radiology reports studied and, at least in some cases, improved the process of care by eliminating unnecessary procedures or suggesting more specific follow-up examinations. The consultation services can be provided cost-effectively from the payer's perspective and may save additional costs when unnecessary procedures can be eliminated.

Clinical radionuclide perfusion lymphangiography.

In an initial pilot study technetium-99m-labelled human serum albumin was perfused directly into bipedal lymphatic cannulae prior to a standard lymphangiogram, in order to assess rapidly normal and abnormal lymph flow patterns in the lower extremity, pelvic and para-aortic lymph chains. A continuing study of these patients has lent further support to the hypothesis that the radionuclide perfusion study, when negative, may prove more accurate in some patients than the standard lymphangiogram in predicting the clinical course and/or the results of histopathological lymph node examination. The radionuclide technique also seems to meet, in this preliminary evaluation, the requirements for a pre-lymphangiogram screening study, particularly for use in high-risk patients.

Mediastinal masses: magnetic resonance imaging in comparison with computed tomography.

Seventy-eight patients with mediastinal abnormalities were imaged with magnetic resonance imaging (MRI) to evaluate mediastinal masses and associated lung, pleural, or chest wall disease. Magnetic resonance images were compared with computed tomography (CT) scans, which were available in 45 patients. While MRI and CT were equally effective in demonstrating mediastinal lesions, CT was superior for displaying calcification within a mass in eight patients and for demonstrating associated lung abnormality in four patients. Computed tomography should remain the imaging procedure of choice after chest radiography to evaluate mediastinal masses, although MRI may be indicated in selected patients.

Scintigraphic identification of skeletal muscle damage in horses 24 hours after strenuous exercise.

The uptake of the bone-seeking radiopharmaceutical 99mTc-MDP by damaged skeletal muscle in horses is evaluated. Twenty-four hours following strenuous exercise, 109 racehorses with a history of inadequate athletic performance and subtle lameness were imaged using scintigraphic techniques. Ten horses (9.2 per cent) demonstrated abnormal uptake of the radioisotope within skeletal muscles. A muscle biopsy from one of these horses confirmed that the muscles with increased scintigraphic activity had histologic evidence of rhabdomyolysis. This technique allows localisation and relative quantification of muscle damage and is a valuable aid in the evaluation of the athletic horse.

Electrical stimulation on skin wound healing in the horse: preliminary studies.

The effect of low-level direct-current stimulation on skin wound healing in the horse was assessed. Self-sustaining electrical circuits with electrodes were implanted subcutaneously in or near the wound. Stimulation by direct current (10 or 20 microA) was used to determine the effect on equine skin healing. The efficacy of electrotherapy was evaluated by sequentially comparing the clinical appearance of the wound and measuring the size of the granulating wound bed. The histologic appearance of the healing stimulated wounds was compared with that in nonstimulated control wounds created on 9 horses. Seemingly, electrical stimulation had no discernible effect on experimentally created skin wounds. Clinical observation and histologic examination of the wounds indicated that severe tissue reaction from the implanted electrodes and concurrent local infection produced local detrimental effects to wound healing.

Single intravenous and multiple intramuscular dose pharmacokinetics and tissue residue profile of gentamicin in sheep.

Single and multiple dose gentamicin regimens were compared in sheep to determine the relevant pharmacokinetic differences. Seven mature sheep were given 10 mg/kg of gentamicin by IV bolus. Serum concentrations were monitored for 19 days. Four weeks after the initial bolus, gentamicin was administered IM (3 mg/kg every 8 hours) for 7 days. Ewes were euthanatized and necropsied at 1, 8, and 15 days after termination of the IM regimen and the tissues were assayed for gentamicin. Serum concentrations were analyzed using a triexponential equation. The IV kinetic studies revealed an alpha half-life (t1/2) of 0.31 +/- 0.14 hours, beta t1/2 of 2.4 +/- 0.5 hours, and gamma t1/2 of 30.4 +/- 18.9 hours. Multiple IM dose kinetic studies revealed a beta t1/2 of 2.8 +/- 0.6 hours and gamma t1/2 of 82.1 +/- 17.8 hours. After multiple dosing, gamma t1/2 was significantly longer than after the single IV bolus (P less than 0.05). Twenty-four hour urine collection accounted for 75% to 80% of the total IV dose. Renal cortical gentamicin concentration reached 224 micrograms/g of tissue and then decreased, with a 90-hour t1/2. Renal medullary gentamicin concentration reached 18 micrograms/g with a 42-day t1/2. After multiple dosing, liver gentamicin concentration reached 11 micrograms/g and skeletal muscle concentrations were less than or equal to 0.6 micrograms/g. Route or duration of administration significantly affected the gamma-phase serum concentrations, which may influence gentamicin nephrotoxicosis. The present study also illustrated the complexities in predicting aminoglycoside withdrawal times for food-producing animals before slaughter.

Branchial cleft cyst in a bull.

Branchial cleft cyst was diagnosed in a 6-month-old Angus bull with a large swelling in the distal ventral neck region. A definitive diagnosis could not be attained from results of the clinical examination, radiography, and ultrasonography. Diagnosis was made from histologic examination of the surgically removed mass. Branchial cleft cysts are remnants of the branchial apparatus and are considered rare in domestic animals. The differential diagnosis should include the thymic form of bovine viral leukosis, thymoma, abscess, goiter, and thyroid gland tumors as well as other rare cysts that can develop in the same location.

Treatment of lacerated flexor tendons in a dairy cow, using specialized farriery.

A heel extension shoe was used as an adjunct to primary tendon repair in a dairy cow. A shoe was placed on the foot for 6 weeks after the foot had been immobilized for 6 weeks in a cast. The shoe was continuous across the toes to provide even support for both claws and was nailed and clinched in the same way a shoe is applied to a horse's hoof. Special adaptations included drilling nail holes closer to the rim of the shoe to accommodate the narrower bovine hoof wall. The cow was permitted controlled exercise for gradual remodeling and strengthening of the tendon repair. When the shoe was removed 12 weeks after surgery, the metatarsophalangeal and distal interphalangeal joints were in normal posture. We consider application of a therapeutic shoe to be an important adjunct to surgical repair of major tendon injuries in adult cattle.

Diskospondylitis in five horses.

Diskospondylitis was diagnosed in 5 horses admitted to the Purdue University Large Animal Clinic during a 3-year period. Each horse had evidence of cervical pain. Clinical signs and radiography were useful for identifying the diskospondylitis. Cerebrospinal fluid was normal.

Granulosa-theca cell tumor associated with an ovulation fossa and normal ovarian stroma in a mare.

A granulosa-theca cell tumor was found in an ovary that had an ovulation fossa and normal ovarian tissue. The ovary was removed from a mare with a history of ovarian enlargement and behavioral changes. The affected ovary had a multicystic appearance on ultrasonographic examination performed before surgery, and an ovulation fossa was not palpable on examination per rectum. However, during surgery, the affected ovary was found to be within normal size limits, with an enlargement on 1 pole, and to contain an ovulation fossa. Atrophy of the infundibulum of the affected ovary helped to confirm the diagnosis of granulosa-theca cell tumor, and the ovary was removed. The mare's testosterone concentrations were normal. Granulosa-theca cell tumors are usually associated with a spherical ovary, attributable to ablation of the ovulation fossa, with no normal ovarian tissue present.