Showing papers in "Radiology in 1982"
TL;DR: A representation and interpretation of the area under a receiver operating characteristic (ROC) curve obtained by the "rating" method, or by mathematical predictions based on patient characteristics, is presented and it is shown that in such a setting the area represents the probability that a randomly chosen diseased subject is (correctly) rated or ranked with greater suspicion than a random chosen non-diseased subject.
Abstract: A representation and interpretation of the area under a receiver operating characteristic (ROC) curve obtained by the "rating" method, or by mathematical predictions based on patient characteristics, is presented. It is shown that in such a setting the area represents the probability that a randomly chosen diseased subject is (correctly) rated or ranked with greater suspicion than a randomly chosen non-diseased subject. Moreover, this probability of a correct ranking is the same quantity that is estimated by the already well-studied nonparametric Wilcoxon statistic. These two relationships are exploited to (a) provide rapid closed-form expressions for the approximate magnitude of the sampling variability, i.e., standard error that one uses to accompany the area under a smoothed ROC curve, (b) guide in determining the size of the sample required to provide a sufficiently reliable estimate of this area, and (c) determine how large sample sizes should be to ensure that one can statistically detect difference...
19,398Â citations
TL;DR: Patients with intraventricular hemorrhage diagnosed by computed tomography were reviewed retrospectively to determine the etiology and prognosis, relationship to delayed hydrocephalus, and effect on neurological outcome.
Abstract: Sixty-eight patients with intraventricular hemorrhage (IVH) diagnosed by computed tomography (CT) were reviewed retrospectively to determine the etiology and prognosis, relationship to delayed hydrocephalus, and effect on neurological outcome. The most common causes were a ruptured aneurysm, trauma, and hypertensive hemorrhage. Ruptured aneurysms of the anterior communicating artery can often be predicted from the nonenhanced CT scan. The total mortality rate was 50%; however, 21% of patients returned to normal or had only mild disability. Patients in whom no cause was identified had a better prognosis. Delayed hydrocephalus was related to the effects of subarachnoid hemorrhage rather than obstruction of the ventricular system by blood. IVH per se is seldom a major factor in the neurological outcome.
395Â citations
TL;DR: Five patients who had undergone radiation therapy for cerebral tumors and whose conditions were deteriorating were examined by means of positron emission tomography (PET) with [18F] fluorodeoxyglucose and the two cases of radiation necrosis were distinguished from the three recurrent tumors.
Abstract: Five patients who had undergone radiation therapy for cerebral tumors and whose conditions were deteriorating were examined by means of positron emission tomography (PET) with [18F] fluorodeoxyglucose. All five cases had similar clinical and computed tomographic findings. Using the PET technique the two cases of radiation necrosis were distinguished from the three recurrent tumors. In the two cases of radiation necrosis the rate of glucose utilization in the lesion was markedly reduced compared with the normal brain parenchyma. In the recurrent gliomas, however, the glucose metabolic rate was elevated. All five diagnoses were confirmed by biopsy or autopsy.
270Â citations
TL;DR: The authors present a method of collecting several tomographic images sequentially during the time required for a single image, which shows the theoretical advantages of nuclear magnetic resonance imaging at higher field strengths.
Abstract: The theoretical advantages of nuclear magnetic resonance imaging at higher field strengths are discussed. Examples of images created at 3.5 KGauss (0.35 T) are demonstrated. The authors present a method of collecting several tomographic images sequentially during the time required for a single image.
231Â citations
TL;DR: The physical principles which underlie the phenomenon of nuclear magnetic resonance (NMR) are presented and the major scanning methods are reviewed, and the principles of technique are discussed.
Abstract: The physical principles which underlie the phenomenon of nuclear magnetic resonance (NMR) are presented in this primer. The major scanning methods are reviewed, and the principles of technique are discussed. A glossary of NMR terms is included.
227Â citations
TL;DR: A combination of computed tomography, ultrasonography, and fluoroscopy was utilized to guide percutaneous catheter drainage of 58 abscesses and fluid collections in 51 patients, and guidelines for drainage are presented.
Abstract: A combination of computed tomography, ultrasonography, and fluoroscopy was utilized to guide percutaneous catheter drainage of 58 abscesses and fluid collections in 51 patients. Cavities were evacuated in 53 cases, with surgery avoided in 44 of these. There were two failures and six recurrences. The mean duration of catheter drainage was seven days. Five complications occurred, including a small bowel fistula and a lacerated mesenteric vessel. Based on this experience, guidelines for drainage are presented, as well as principles for the critical step of access route planning. Double-lumen sump drainage catheters and the irrigation procedure have simplified and improved drainage. Causes and solutions for unsatisfactory results are defined.
219Â citations
TL;DR: The sensitivity of ultrasound in detecting portal hypertension, based on the measurement of caliber variation, was 79.7%, and the specificity was 100%, while the sensitivity of the method, assessed on the basis of portal dilatation, was only 41.8%.
Abstract: This study assesses the usefulness of ultrasound in the diagnosis of portal hypertension due to hepatic cirrhosis. Seventy-nine patients with portal hypertension and 45 control subjects underwent ultrasonography. Two factors were measured: (a) the caliber of the portal vein and (b) the caliber variation of the splenic and superior mesenteric veins during respiration. A lack of normal caliber variation (an increase during inspiration and a decrease during expiration) in these vessels is put forward as an ultrasonographic sign of portal hypertension, and the pathophysiological and clinical significance of this finding are discussed. The sensitivity of ultrasound in detecting portal hypertension, based on the measurement of caliber variation, was 79.7%, and the specificity was 100%. In contrast, the sensitivity of the method, assessed on the basis of portal dilatation, was only 41.8%.
202Â citations
TL;DR: The effect of perfluoroctylbromide (PFOB) on liver and tumor echogenicity was evaluated in rabbits and the reviewers correctly identified all rabbits that received PFOB by visualization of an echogenic rim around the hepatic tumors.
Abstract: The effect of perfluoroctylbromide (PFOB) on liver and tumor echogenicity was evaluated in rabbits. The echogenicity of the kidney, which is not affected by PFOB, was used as the basis for comparison in the liver studies. For the liver echogenicity study, sonography was performed on four rabbits, two with PFOB and two without PFOB, and four rabbits prior to and following the intravenous administration of 5 ml/kg PFOB. All livers were equal to or less echogenic than kidney in the control animals. All livers became more echogenic than kidney two days after administration of PFOB. The effect of PFOB on tumor echogenicity was evaluated in 18 rabbits with VX2 tumor implanted in the liver. Ultrasound studies of all rabbits were performed by the same physician before and two days after half the rabbits had received PFOB (5 ml/kg intravenously). The reviewers correctly identified all rabbits that received PFOB by visualization of an echogenic rim around the hepatic tumors.
192Â citations
TL;DR: The relationship between data acquisition parameters and contrast in nuclear magnetic resonance (NMR) images was studied and it was shown that NMR imaging of flow in major vessels is possible.
Abstract: The relationship between data acquisition parameters and contrast in nuclear magnetic resonance (NMR) images was studied. NMR imaging by the pulse echo technique selectively enhanced intracranial abnormalities; imaging by the inversion recovery technique heightened the difference between cerebral gray and white matter. Using a blood flow model, the authors also showed that NMR imaging of flow in major vessels is possible.
188Â citations
TL;DR: Hepatic artery collaterals in 40 patients who had had hepatic artery occlusion following peripheral or central embolization, surgical ligation, intra-arterial chemotherapy, or intimal injury from catheterization were studied.
Abstract: Hepatic artery collaterals in 40 patients who had had hepatic artery occlusion following peripheral or central embolization, surgical ligation, intra-arterial chemotherapy, or intimal injury from catheterization were studied. The collaterals were classified as intrahepatic or extrahepatic collaterals. Intrahepatic arterial collaterals develop in the portal triads and subcapsular area between the lobes of the liver. Extrahepatic arterial collaterals develop in the ligaments that suspend the liver in the peritoneal cavity and through the structures that are closely attached to the liver. A simplified angiographic classification of hepatic arterial collaterals is presented.
178Â citations
TL;DR: In the cases studied, there was close correlation between the size of the metastatic lesion at palpation and mammography, a feature also characteristic of the well-circumscribed carcinomas.
Abstract: Metastatic foci to the breast from a wide variety of primary malignancies appear on mammograms as circumscribed spheroid shadows with only slightly irregular margins, and without evidence of microcalcifications, spiculations, or other signs of desmoplastic response that characterize many primary scirrhous carcinomas. In the cases studied, there was close correlation between the size of the metastatic lesion at palpation and mammography, a feature also characteristic of the well-circumscribed carcinomas. This is not the case with most scirrhous breast carcinomas, whose associated desmoplastic reaction results in an apparent larger size by palpation than observed on mammography.
TL;DR: The parallel pitch line measurement helps to identify patients with Haglund syndrome and patients predisposed to develop this condition, and also to differentiate local causes of posterior heel pain from systemic causes.
Abstract: Haglund syndrome is a common cause of posterior heel pain, characterized clinically by a painful soft-tissue swelling at the level of the achilles tendon insertion. On the lateral heel radiograph the syndrome is characterized by a prominent calcaneal bursal projection, retrocalcaneal bursitis, thickening of the Achilles tendon, and a convexity of the superficial soft tissues at the level of the Achilles tendon insertion, a "pump-bump." An objective method for evaluating prominence of the bursal projection is measurement using the parallel pitch lines. This measurement helps to identify patients with Haglund syndrome and patients predisposed to develop this condition, and also to differentiate local causes of posterior heel pain from systemic causes. The parallel pitch line measurement was determined in 10 symptomatic feet and 78 control feet and the results were analyzed statistically.
TL;DR: In 47 patients with confirmed obstruction, CT and US were comparable accurate in differentiating obstruction from nonobstruction, and both methods detected useful additional information, such as cholelithiasis or retroperitoneal adenopathy.
Abstract: A total of 103 consecutive patients with suspected biliary obstruction were studied using both computed tomography (CT) and ultrasound (US) to evaluate the relative accuracy of the methods. In 47 patients with confirmed obstruction, CT and US were comparable accurate in differentiating obstruction from nonobstruction. The precise level of obstruction was identified by CT in 88% and by US in 60%; the cause of obstruction was accurately predicted by CT in 70% and by US in 38%. Both methods detected useful additional information, such as cholelithiasis or retroperitoneal adenopathy. The authors use US as a screening examination; if there is doubt about the level and cause of sonographically demonstrated obstruction, CT has proved to be an accurate means of further evaluation.
TL;DR: The thickness of the thymus showed a definite decrease in size with increasing age; although the width showed a similar general tendency, a wide variation was noted within each age group.
Abstract: Recognition of variations in size, shape, and density of the normal thymus on computed tomographic (CT) scans is of paramount importance, lest it be misinterpreted as an abnormal mediastinal mass. Studying patients subsequently proved free of active chest disease, we analyzed 154 CT scans of the mediastinum, performed on a fourth-generation scanner, to determine the incidence of visualization and appearance of the normal thymus. The thymus was seen in 100% of patients under age 30, 73% of patients between 30 and 49 years, and in 17% of patients over 49 years of age. The thickness of the thymus showed a definite decrease in size with increasing age; although the width showed a similar general tendency, a wide variation was noted within each age group. In younger patients, the density of the thymus was similar to that of muscle; the attenuation values progressively decreased in older patients, finally approaching that of fat.
TL;DR: A retrospective study of 109 patients who underwent renal biopsy was designed to correlate the sonographic appearance of the kidney with the histologic changes and clinical and laboratory findings in various renal parenchymal diseases.
Abstract: A retrospective study of 109 patients who underwent renal biopsy was designed to correlate the sonographic appearance of the kidney with the histologic changes and clinical and laboratory findings in various renal parenchymal diseases. The clinical, pathologic, and sonographic data were analyzed blindly and independently by a team from each corresponding discipline. There was no correlation between the specific sonographic appearance and the type of renal disease. There was a significant correlation between renal length and the prevalence of global sclerosis, focal tubular atrophy, and the number of hyaline casts per glomerulus. A significant positive correlation was also found between cortical echogenicity and the severity of global sclerosis, focal tubular atrophy, the number of hyaline casts per glomerulus, and focal leukocytic infiltration. While there was overall significant correlation between the degree of cortical echogenicity and blood urea nitrogen and creatinine concentrations in each group, a ...
TL;DR: The clinical and radiographic findings of 194 patients with rheumatoid arthritis and atlantoaxial (C1-C2) subluxation and/or atlantonaxial impaction were reviewed and Settling of the skull and C1 onto C2 (AAI) were considered to be present.
Abstract: The clinical and radiographic findings of 194 patients with rheumatoid arthritis and atlantoaxial (C1-C2) subluxation and/or atlantoaxial impaction (AAI) were reviewed. The condition of most patients with C1-C2 alignment abnormalities remained unchanged or became worse with time (i.e., the misalignment became fixed, subluxation increased, or AAI developed). The chance of developing upper cervical cord compression was not related to worsening per se, but to the degree of deformity. Upper spinal cord compression developed more often in men; when C1-C2 subluxation was greater than 9 mm; and in the presence of atlantoaxial impaction. The presence of lateral C1-C2 subluxation probably also contributes to the development of upper spinal cord compression. Settling of the skull and C1 onto C2 (AAI) were considered to be present when the anterior arch of C1 was abnormally low in relation to C2.
TL;DR: A comparative study of arteriography and pancreatic venous sampling (PVS) was performed in 55 patients with Zollinger-Ellison syndrome and patients with insulinomas in an attempt to localize a suspected endocrine tumor.
Abstract: A comparative study of arteriography and pancreatic venous sampling (PVS) was performed in 55 patients. Twenty-seven patients with Zollinger-Ellison syndrome, 24 with insulinomas, and 4 control subjects underwent arteriography and PVS (for pancreatic hormonal radioimmunoassays) in an attempt to localize a suspected endocrine tumor. Accurate tumor localization was achieved by arteriography in 13% of the cases of gastrinoma and 29% of the cases of insulinoma. Although arteriographic signs could be described retrospectively in 62% of insulinomas, erroneous localization was relatively frequent. In contrast, localization by PVS was successful in 36 out of the 38 patients who underwent surgery; false-negative results were obtained in two patients, but in no case did PVS result in false localization. In 27% of insulinomas and 43% of gastrinomas, gross examination during surgery was negative but microscopic tumors were identified.
TL;DR: Fifteen patients with malignant tumors involving the liver were treated with hepatic intraarterial injection of yttrium 90 microsphres, and four patients are alive and functionally active with follow-up periods of 6, 6, 9, and 12 months.
Abstract: Fifteen patients with malignant tumors involving the liver were treated with hepatic intraarterial injection of yttrium 90 microsphres. With the exception of one patient, no acute or long-term side effects were noted. Four patients are alive and functionally active with follow-up periods of 6, 6, 9, and 12 months. Vascularity of the metastases, absence of extrahepatic disease, and performance status prior to treatment were determining factors for a successful result.
TL;DR: Although a synovial cyst may clinically simulate a herniated disk or a intraspinal tumor at myelography, it can be identified reliably by CT, and thereby exploratory laminectomy may be prevented.
Abstract: Synovial cysts rarely have been recognized in the spinal canal. In one subsequently proved case, and in three other unproved cases that we are reporting, computed tomography (CT) showed the synovial cyst as an encapsulated cystic structure that was adjacent to a degenerated L4-5 facet joint. Although a synovial cyst may clinically simulate a herniated disk or a intraspinal tumor at myelography, it can be identified reliably by CT, and thereby exploratory laminectomy may be prevented.
TL;DR: It was found that focal areas of low density within the contrast enhanced pituitary gland can be caused by various normal and pathologic conditions such as pitsuitary microadenomas, pars intermedia cysts, foci of metastasis, infarcts, epidermoid cysts and abscesses.
Abstract: The incidence of low-density regions in the contrast-enhanced pituitary gland and the possible causes of these regions were investigated by a retrospective review of computed tomographic (CT) scans of the head in 50 patients and autopsy specimens of the pituitary in 100 other patients. It was found that focal areas of low density within the contrast enhanced pituitary gland can be caused by various normal and pathologic conditions such as pituitary microadenomas, pars intermedia cysts, foci of metastasis, infarcts, epidermoid cysts, and abscesses. Although most focal low-density regions probably represent pituitary microadenomas, careful clinical correlation is needed to establish a diagnosis.
TL;DR: In order to determine the clinical usefulness of nuclear magnetic resonance (NMR) imaging, the investigators examined a variety of normal volunteers, patients with neoplastic lesions, and experimental animals and found NMR applications in the vascular system, spine, brain, lung, and mediastinum offer certain advantages over other modalities.
Abstract: In order to determine the clinical usefulness of nuclear magnetic resonance (NMR) imaging, the investigators examined a variety of normal volunteers, patients with neoplastic lesions, and experimental animals. Preliminary results were obtained with the use of potential contrast agents. It was found that imaging applications of NMR in the vascular system, spine, brain, lung, and mediastinum offer certain advantages over other modalities. The absence of biological hazard as well as the ability to obtain unenhanced, noninvasive, gated images of the vascular system, as demonstrated in this study, make NMR particularly attractive. In addition to single-section capability, NMR makes it possible to obtain volume images of the spine and other organs which can be displayed in any desired plane or section thickness.
TL;DR: 6 cases in which mucosal tears and transmural perforations of the upper gastrointestinal tract were either unrecognizable or inadequately shown during initial evaluation with methylglucamine diatrizoate are presented.
Abstract: Iodinated water-soluble compounds have been widely recommended as the most suitable contrast media for diagnosis of gastrointestinal perforations. However, the authors present 6 cases in which mucosal tears and transmural perforations of the upper gastrointestinal tract were either unrecognizable or inadequately shown during initial evaluation with methylglucamine diatrizoate. Re-examination with barium sulfate demonstrated the precise location and extent of the perforations. Reasons for the higher diagnostic yield of barium studies are explained on the basis of experimental and clinical observations.
TL;DR: Retrospectively analysis using slightly modified criteria resulted in a correct prediction of resectability in 28 of 30 (93%) patients, and nonresectability for cure in 34 of 34 (100%) patients.
Abstract: Preoperative determination of the extent of bronchogenic carcinoma at presentation was assessed by CT using a 4th generation scanner with a 3-second scan time in 98 patients whose disease was later surgically staged. Prospective CT interpretations correctly staged 33 of 35 (94%) resectable lesions, and disease in 41 of 45 (91%) patients who had lesions that were not resectable for cure. No definite opinion was rendered on the scans of the remaining 18 patients. Retrospectively analysis using slightly modified criteria resulted in a correct prediction of resectability in 28 of 30 (93%) patients (scans showed a normal mediastinum with no lymph node larger than 1 cm in diameter), and nonresectability for cure in 34 of 34 (100%) patients (scans showed either direct extension of the primary neoplasm into the mediastinum or mediastinal lymph-node enlargement greater than 2 cm in diameter). However, scans of 34 of 98 (35%) patients showed inconclusive findings (mediastinal lymph-nodes with 1-cm to 2-cm diameters, neoplasms abutting but not definitely invading the mediastinum, pleural or pericardial thickening, or additional noncalcified nodules).
TL;DR: It was found that major life-threatening reactions involving the respiratory system are usually accompanied by minor or less serious reactions, while those involving the cardiovascular system are accompanied by the more serious reactions.
Abstract: The second phase of the survey of adverse reactions to contrast media was based on 4,120 case reports and involved the collaboration of radiologists in 45 institutions. It was directed primarily to a study of the distribution patterns of adverse reactions and the likelihood of recurrence of the same reaction on repetition of the examination. It was found that major life-threatening reactions involving the respiratory system are usually accompanied by minor or less serious reactions, while those involving the cardiovascular system are accompanied by the more serious reactions. Major life-threatening reactions do not usually recur on reexamination, while minor reactions tend to be repeated more often.
TL;DR: Angiographic evidence is sufficiently compelling to justify description of this pathway and its significance, and Histologic confirmation of this route has been sought for many years.
Abstract: Arterioportal shunting is observed angiographically in a wide variety of pathologic conditions. The route of flow has classically been considered to be via the hepatic sinusoids (transsinusoidal). This route occurs in cases of cirrhosis or the Budd-Chiari syndrome, and results in retrograde hepatofugal flow in portal branches. More recently, a transvasal route has been recognized angiographically, in which portal flow often remains hepatopetal. The transvasal route occurs in cases of hepatocellular carcinoma, metastases, shock, hepatic arterial obstruction, and many other conditions. Histologic confirmation of this route has been sought for many years, with other partial success. Nevertheless, angiographic evidence, as presented here, is sufficiently compelling to justify description of this pathway and its significance. Arterioportal flow may also occur via a post-traumatic fistula (disruption of adjacent portions of hepatic artery and portal vein), and via benign tumor vessels in hemangioma or hemangioendothelioma.
TL;DR: When a subsample of 29 scans were analyzed using linear and volumetric measurements, the linear measurements showed less pronounced differences between the demented subjects and the controls, explaining the conflicting results of different investigators concerning variations in ventricular and sulcal size in dementia and normal aging.
Abstract: Forty-seven subjects 65 to 80 years of age, of whom 20 were demented and 27 were normal, were studied by computed tomography. Volumetric indices of ventricular (V%) and sulcal size (S%) were determined by pixel counts without knowledge of clinical status. V% was 5.30 (+/- 1.92) for the controls and 10.46 (+/- 4.78) for the demented subjects. S% was 6.14 (+/- 2.51) for the controls and 10.61 (+/- 3.32) for the demented subjects. In each case, differences between the two groups were significant (P less than 0.0001). When a subsample of 29 scans were analyzed using linear and volumetric measurements, the linear measurements showed less pronounced differences between the demented subjects and the controls. These findings explain the conflicting results of different investigators concerning variations in ventricular and sulcal size in dementia and normal aging.
TL;DR: No technique was accurate enough for routine staging; their value may lie in directing biopsy or in treatment planning in patients with inoperable disease.
Abstract: Forty-two patients with T2 bronchogenic carcinoma were evaluated with plain radiography, conventional 55 degrees oblique hilar and anteroposterior mediastinal tomography, and computed tomography (CT) to compare their accuracy in assessing mediastinal and hilar nodal metastases. Definitive staging was achieved by thoracotomy and histopathological evaluation of resected specimens. All modalities demonstrated about the same accuracy; however, in the 25 patients with hilar and/or mediastinal lymphadenopathy, CT of the mediastinum was more sensitive but not more specific than the other two and conventional tomography was no more accurate than CT for hilar evaluation. Overall, no technique was accurate enough for routine staging; their value may lie in directing biopsy or in treatment planning in patients with inoperable disease.
TL;DR: The average interpleural distance (AID), which is obtained from three linear measurements, closely predicts true pneumothorax size as determined by radiographic thoracic gas volume measurement (mean variation -2.4 +/- 7.23 SD).
Abstract: A simple measurement, the average interpleural distance (AID), which is obtained from three linear measurements, closely predicts true pneumothorax size as determined by radiographic thoracic gas volume measurement (mean variation -2.4 +/- 7.23 SD). The distribution of pneumothorax volume between the affected lung and the ipsilateral thoracic cage is variable and unpredictable. It was found that the average volume of pneumothorax that is accommodated by thoracic cage expansion (8%) is much less than previously reported. This appears to be the result of variable degrees of splinting and chest wall pain associated with pneumothorax.
TL;DR: Results indicate that although balloon dilatation appears feasible as palliation for aortic coarctation, further studies of its safety are necessary before instituting clinical trials.
Abstract: Seven children 1-6 years of age underwent aortic resection and re-anastomosis for coarctation of the thoracic aorta. The excised segments were 1-2 cm long and were dilated in vitro with a Gruntzig balloon catheter less than two hours after resection. A pressure of 4-8 atmospheres was used, and the inflated diameter of the balloon was twice the luminal diameter of the undilated coarctation. The diameter of each specimen was increased by an average of 85%, largely because of an increase in the external diameter of the coarctation. However, extremely high pressures were required for successful dilatation, producing transmedial tears in the "normal" aorta distal to the coarctation in three specimens. These results indicate that although balloon dilatation appears feasible as palliation for aortic coarctation, further studies of its safety are necessary before instituting clinical trials.