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Biomedical subjects

R L Smathers

Publications and source records attributed to R L Smathers.

At least 19 recordsLinked to original sources
PubMed1990

Internal mammary lymphadenopathy: imaging of a vital lymphatic pathway in breast cancer.

The prognostic significance of metastases to the internal mammary lymph nodes in patients with breast carcinoma has long been recognized. While ipsilateral dissection of axillary nodes remains a popular staging strategy for breast cancer, surgical sampling of the upper anterior intercostal spaces, a tedious procedure, has been largely abandoned. Diagnostic imaging of the parasternal lymphatic pathway is a useful and noninvasive alternative to surgical staging. This report reviews the pertinent regional anatomy and illustrates the criteria for diagnosing internal mammary lymphadenopathy by means of lateral chest radiography, computed tomography, high-resolution sonography, magnetic resonance imaging, and radionuclide lymphoscintigraphy.

Breast↗
PubMed1987

Testes and scrotum: MR imaging at 1.5 T.

Magnetic resonance (MR) images of the scrotum were obtained at 1.5 T in 20 subjects, 13 patients with intrascrotal pathologic conditions and seven healthy subjects. Characteristic MR imaging signals obtained on T1- and T2-weighted images allowed differentiation of testis from epididymis and spermatic cord. Masses were differentiated from normal testicular parenchyma in all cases. Atrophic or ischemic testes had lower signal intensity than normal testes on T2-weighted images. Hematoma displayed a characteristic high intensity on both T1- and T2-weighted images. Intratesticular and extratesticular pathologic conditions were readily differentiated. These results suggest that MR imaging is useful in the diagnosis of scrotal and testicular abnormalities.

Genital Diseases, Male↗
PubMed1986

Mammographic microcalcifications: detection with xerography, screen-film, and digitized film display.

Pulverized bone specks and aluminum oxide specks were measured by hand into sizes ranging from 0.2 mm to 1.0 mm and then arranged in clusters. These clusters were superimposed on a human breast tissue phantom, and xeromammograms and screen-film mammograms of the clusters were made. The screen-film mammograms were digitized using a high-resolution laser scanner and then displayed on cathode ray tube (CRT) monitors. Six radiologists independently counted the microcalcifications on the xeromammograms, the screen-film mammograms, and the digitized-film mammograms. The xeromammograms were examined with a magnifying glass; the screen-film images were examined with a magnifying glass and by hot light; and the digitized-film images were examined by electronic magnification and image processing. The bone speck size that corresponded to a mean 50% detectability level for each technique was as follows: xeromammography, 0.550 mm; digitized film, 0.573 mm; and screen-film, 0.661 mm. We postulate that electronic magnification and image processing with edge enhancement can improve the capability of screen-film mammography to enhance the detection of microcalcifications.

Breast Diseases↗
PubMed1986

[3-dimensional craniofacial computerized tomography].

Computed tomography allows today to reconstruct three-dimensional (3D) images from axial scans. The authors report their experience in cranio-facial pathology achieved in two Departments of Radiology (University of Trieste, Italy and University of Stanford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The applications in maxillo-facial traumas, cranio-facial malformations and head tumours are discussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demonstration of the lesion and have potential applications in cranio-facial surgery and radiotherapy.

Facial Bones↗
PubMed1985

Intravenous cholangiography in the CT era.

With the availability of computed tomography (CT), ultrasonography (US), percutaneous transhepatic cholangiography (PTC), and endoscopic retrograde cholangiopancreatography (ERCP), the use of intravenous cholangiography (IVC) has waned. A retrospective study of 69 intravenous cholangiograms performed from 1979 through 1982 assessed the utility of intravenous cholangiography, as well as its effect on patient management, at an institution where CT was highly developed. In no case after normal findings on CT and/or ultrasound examination did IVC make a positive pathologic diagnosis. After abnormal results on CT and/or US examinations, in no case did IVC add to the diagnosis. Finally, after technically suboptimal results of CT and/or US examinations, IVC made only 1 positive pathologic diagnosis. Overall, IVC correctly demonstrated only 5 of 9 cases of common duct stones or strictures. Of the 26 cases with anatomical correlation there were a total of 7 false-positive and -negative IVC examinations. In this series, IVC was rarely useful in the diagnosis of biliary tract disease. Given the high inaccuracy rate of IVC in this study, its use for the exclusion of biliary tract disease is discouraged.

Biliary Tract Diseases↗
PubMed1985

Intratesticular adrenal rests diagnosed by ultrasound.

Adrenal rest tumors of the testes may occur in conditions associated with increased circulating adrenocorticotropic hormone (ACTH), including congenital adrenal hyperplasia (CAH) and Addison disease. Sonographically, these tumors appear as multiple round, hypoechoic nodules near the testicular hilus and are usually bilateral. They may undergo extensive fibrosis and become hyperechoic with acoustic shadowing. In the absence of excess ACTH or characteristic ultrasound findings, biopsy is recommended to exclude malignancy. Because malignant degeneration is very rare, close clinical and sonographic follow-up without biopsy is generally sufficient. Serial sonograms are useful to document stability or regression of tumor size during glucocorticoid replacement therapy.

Adrenal Rest Tumor↗
PubMed1985

Digital processing of film radiographs.

Initial clinical experience with a system for the digitization, processing, and display of film radiographs is described. Film is digitized using a high-intensity laser scanner; the recorded image data may then be subjected to a wide variety of processing options, with display of processed images on television monitors. The possibilities of clinical applications to processing and display of chest radiographs and film mammograms are described. A comparison of conventional analog subtraction and digitized film subtraction angiography indicated equivalent diagnostic capability, with the advantage of flexible, interactive image processing with the digital technique. A specially designed, energy-selective cassette permits dual-energy imaging from two films effectively exposed to different x-ray energy spectra. Dual-energy imaging may be capable of the characterization of body materials, including lung nodules, and useful for eliminating obscuring radiographic shadows overlying regions of interest.

Angiography↗
PubMed1985

[Digital radiology. Clinical experience].

The authors report the experience achieved at the Stanford University (USA) with a digital radiography system which allows the digitization of the film and of the images collected with photostimulable phosphors. The phosphor is essentially an intensifying screen where a latent image is stored after exposure to X-rays and is extracted by a laser scanning. The images collected with the digitized film and with the phosphor (chest, breast, bone) have been analyzed. The digitized film offers potential diagnostic advantages over the conventional film, because of the contrast manipulation and many other processing options. The possibility to recover the information of overexposed films appears very attractive. The photostimulable phosphors allow to get good quality images, with a consistent reduction of dose and costs. These plates offer the possibility, in the next future, to replace the conventional screen-film systems.

Female↗
PubMed1984

The diagnostic significance of posttraumatic sphenoid sinus effusions: correlation with head computed tomography.

In review of 1544 patients with both head computed tomography (CT) examinations and skull radiographs, 150 patients were found to have a history of acute head trauma. Twenty-nine of these patients had sphenoid sinus effusions. Ninety-three percent (27/29) of those cases had abnormal CT examinations, as compared with 48% (58/121) of cases without sphenoid effusions. Of the patients with sphenoid effusions, 31% (9/29) had intracerebral hematomas, 24% (7/29) had extracerebral hematomas, 13% (4/29) had pneumocephalus, and 13% (4/29) had cerebral edema. We conclude that the presence of posttraumatic sphenoid sinus effusion on the skull radiograph is a sensitive sign for intracranial damage and serves as an emergent indication for head CT.

Brain Edema↗
PubMed1984

Computed tomography of fatal hepatic rupture due to peliosis hepatis.

Hepatic rupture with subcapsular hematoma and hemoperitoneum is shown by CT in a patient with peliosis hepatis. Peliosis hepatis is pathologically characterized by blood-filled cystic spaces in the liver associated with the administration of anabolic androgenic steroids or oral contraceptive agents, particularly those with large components of estrogen. We report a fatal case in a patient receiving diethylstilbestrol for 3 years. In patients receiving these medications, peliosis hepatis should be considered in the differential diagnosis of low attenuation areas in the liver by CT. These patients are subject to increased risk of spontaneous hepatic rupture.

Aged↗
PubMed1984

CT of benign soft-tissue masses of the extremities.

The computed tomographic (CT) scans and medical records of 35 patients with proven benign soft-tissue masses of the extremities were reviewed to assess the contribution of CT in the evaluation of such masses. CT demonstrated the mass in all 35 cases and was able to provide a specific diagnosis in 28 (80%); 25 prospectively, three retrospectively. Correct diagnoses made using CT included hematomas (five), synovial cysts (seven), myositis ossificans (six), fatty tumors (four), aneurysms (three), pseudoaneurysms (two), schwannoma (one), and abscess (one). The CT appearance of a hematoma depends on its age. Synovial cysts are near-water-density masses, often associated with a small joint effusion. Myositis ossificans can be differentiated from parosteal osteosarcoma by virtue of its characteristic zonal ossification. Lipomas are recognized on noncontrast scans by the characteristic low attenuation of fat, while aneurysms and pseudoaneurysms are best diagnosed on postcontrast scans. In seven cases (20%) a specific diagnosis could not be made on the basis of the CT scan. However, in these cases CT delineated the extent of the mass and demonstrated its relation to surrounding structures; this anatomic information was helpful in planning surgical excision or percutaneous biopsy. The authors conclude that CT is a valuable noninvasive imaging method for the evaluation of soft-tissue masses of the extremities.

Adolescent↗
PubMed1984

Differentiation of complicated cholecystitis from gallbladder carcinoma by computed tomography.

Differentiation between complicated cholecystitis and advanced gallbladder carcinoma can be difficult when clinical findings are confusing. Computed tomographic (CT) scans were reviewed from 22 patients with a surgical diagnosis of complicated cholecystitis (11 cases) or advanced gallbladder carcinoma (11 cases). The presence of a curvilinear low-attenuation "halo" around the gallbladder wall was specific for complicated cholecystitis. Findings indicative of gallbladder carcinoma included a focal soft-tissue mass, biliary obstruction at the level of the porta hepatis, and direct hepatic invasion or metastases. Other findings, such as diffuse wall thickening, streaky soft-tissue densities in the pericholecystic fat, and thickening of the hepatoduodenal ligament, could be seen in both entities and, therefore, were less useful in differentiating these two disease processes. Knowledge of these differential CT findings may result in a more accurate preoperative diagnosis.

Aged↗
PubMed1982

Hepatobiliary scan with delayed gallbladder visualization in a case of acute appendicitis.

A 40-year-old woman presented with acute epigastric pain with vomiting. Within 24 hours, the pain spread to the right periumbilical region. Tc-99m disofenin hepatobiliary scan failed to demonstrate the gallbladder on a 60-minute view. The presumative diagnosis of acute cholecystitis was thought to be confirmed on this basis by the patient's physicians. However, a 75-minute view demonstrated filling of the gallbladder. In hepatobiliary scanning for acute abdominal pain, delayed views (2 to 24 hours) are recommended when the gallbladder is not visualized on the 60-minute view. If the gallbladder is visualized, cystic duct obstruction can be excluded and diagnoses such as pancreatitis, acalculous cholecystitis, and acute appendicitis should be investigated.

Acute Disease↗