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To compare stepping-table digital subtraction gadolinium-enhanced magnetic resonance (MR) angiography of the distal aorta and lower extremity arteries with conventional catheter digital subtraction x-ray angiography in patients with arterio-occlusive disease.Twenty patients underwent both conventional catheter angiography and fast three-dimensional gadolinium-enhanced MR angiography of the aorta and outflow vessels at 1.5 T; the images were acquired in three consecutive imaging locations during a single infusion of a gadolinium chelate.Compared with catheter angiography, according to the findings of two blinded independent reviewers, MR angiography had sensitivities of 81% and 89% and specificities of 91% and 95%, respectively, for demonstration of insignificant (or = 50%) stenosis versus significant (51%-100%) stenosis. For demonstration of occlusion, the sensitivity and specificity were 94% and 97%, respectively, by consensus. There was good interobserver correlation between the two readers overall (kappa = 0.65 for reporting the degree of narrowing in all lesions; 0.86, for reporting of insignificant versus significant stenoses; and 0.928, for reporting of occluded versus patient segments).Stepping-table digital subtraction contrast material-enhanced MR angiography has high accuracy compared with catheter angiography in patients with arterio-occlusive disease of the aorta and outflow vessels. These preliminary study results suggest that this technique may ultimately provide a safe, noninvasive, and cost-effective alternative to catheter angiography.

To describe the computed tomographic (CT) appearance of perflubron-filled lungs during partial liquid ventilation to treat acute respiratory distress syndrome, scans of the thorax were obtained in nine patients between June 1994 and December 1995. The distribution of perflubron was gravity dependent in four patients, with a mean interval of 6.25 days between scanning and perflubron administration; was patchy in four patients (mean interval, 16 days); and was homogeneous in one patient (interval, 3 days). Extraparenchymal perflubron was seen in intrathoracic lymph nodes (n = 4), supraclavicular nodes (n = 2), axillary nodes (n = 1), and both the retroperitoneum and the mediastinum (n = 2). In one patient, perflubron was seen in a pneumatocele and the pleural space. The distribution of perflubron in the lungs is typically gravity dependent.

To prospectively assess quantitatively the inherent contrast of electromagnetic (EM) properties that can be imaged by using available technology in women with abnormal findings at conventional breast imaging who underwent subsequent biopsy.The protocol was HIPAA compliant and approved by the institutional review board. All participants provided informed consent. Fifty-three women with normal (Breast Imaging Reporting and Data System [BI-RADS] category 1) and ninety-seven women with abnormal (BI-RADS category 4 or 5) screening mammograms were imaged with three EM imaging methods: electrical impedance spectroscopy (EIS), microwave imaging spectroscopy (MIS), and near-infrared spectral tomography (NIR). A region-of-interest (ROI) analysis was used to assess the EM image properties for comparison of findings with conventional image findings and correlation with specific pathologic parameters for women with abnormal findings. Statistical analyses were conducted.One hundred fifty participants (age range, 35-81 years) were included. EM image property contrast ratios of 150%-200% were found in breast abnormality ROIs relative to the ipsilateral breast background. Analysis of variance demonstrated significant differences in ROI image summaries of mammographically normal versus abnormal breasts for EIS, across diagnostic groups for NIR, and for MIS (analysis restricted to lesions larger than 1 cm(3)). Receiver operating curve (ROC) analysis of the EM properties for cancers among subjects with BI-RADS category 4 or 5, compared with the EM properties for the subjects with normal breasts (BI-RADS category 1), yielded areas under the ROC curve ranging from 0.67 to 0.81. Pathologic correlations with mean vessel density, mean vessel area, and epithelium-to-stroma ratio suggest a biological origin of the EM image properties associated with disease.Results from EM breast examinations provide statistical evidence of a mean increase in image contrast of 150%-200% between abnormal (benign and malignant) and normal breast tissue.

To determine retrospectively whether the anterior spinal artery (ASA) is visualized in the cervical region with contrast material-enhanced high-spatial-resolution three-dimensional magnetic resonance (MR) angiography of the extracranial carotid and vertebral arteries.The institutional research ethics committee approved this study and provided a waiver for informed consent. Data sets were evaluated in 50 consecutive patients referred for contrast-enhanced three-dimensional MR angiography of the carotid arteries (32 male and 18 female patients; age range, 15-80 years; mean age, 59 years). The ASA was defined as a linear area of high signal intensity that is seen anterior to the spinal cord in an arterial phase of enhancement and connects directly to a known arterial structure. If the linear area of high signal intensity was seen in the arterial phase but did not connect to a known arterial structure, it was considered a probable ASA. Venous enhancement was graded on a five-point scale (0-4) with grade 0 (no venous enhancement) or grade 1 (trace venous enhancement) considered to be in the arterial phase.The ASA was identified with certainty in 37 of 50 patients. A vessel visualized anterior to the spinal cord, which probably represented the ASA, was seen in another 11 of 50 patients. In 29 of 50 patients the vessel was visualized only on the full-volume maximum intensity projection (MIP) image. In the remainder of cases the artery was identified on operator-defined subvolume MIP images. Continuity between the vessel and the vertebrobasilar arterial structures was identified in 35 of 50 patients. The vessel was seen as a continuous structure throughout its length in 34 patients and appeared discontinuous in 14. Radiculomedullary feeders were identified in 24 of 50 patients.The normal cervical ASA was visualized in 48 of 50 of subjects with contrast-enhanced high-spatial-resolution three-dimensional MR angiography.

Representative data are provided for three electromagnetic breast imaging techniques—near-infrared spectroscopy, electrical impedance spectroscopy, and microwave imaging spectroscopy—to serve as potential benchmarks for future investigation. The breasts of 23 women without clinical or mammographic findings of disease were imaged in the coronal plane with nonionizing radiation of varying frequencies. Average electromagnetic property values were reconstructed at each frequency on the basis of computational models of light diffusion, current flow, and microwave propagation. Electromagnetic properties were correlated with subject characteristics and between techniques. Each technique yielded information on breast tissue features (eg, conductivity, permittivity, light scattering, and absorption) that had not previously all been measured in the same individuals. © RSNA, 2004

Digital subtraction angiography (DSA) of the heart was performed in 54 patients for the evaluation of congenital heart disorders. DSA produced high-quality diagnostic images and accurate physiologic shunt data that compared favorably with catheter angiography and nuclear medicine studies. Retrospective analysis of this series of patients indicated that DSA studies contributed sufficient information to shorten significantly or modify cardiac catheterization in 85% (79/93) of the defects that were identified. Interatrial septal defects were particularly well diagnosed, with identification occurring in 10 of 10 cases, whereas intraventricular septal defects were identified in only 6 of 9 patients. Evaluation of postsurgical patients was accurate in 19 of 20 cases.

Thirty-five human neoplasms from various sites and of various histologic types and stages were examined with phosphorus-31 magnetic resonance spectroscopy in situ. The tumors included 13 squamous cell carcinomas of the head and neck (lymph nodes), eight Hodgkin lymphomas, six non-Hodgkin lymphomas, four carcinomas of the breast, one melanoma, one sarcoma, one neuroblastoma, and one mucoepidermoid sarcoma of the salivary glands. Thirty-four of the neoplasms had normal to slightly alkaline pH before irradiation. During fractionated radiation therapy, the pH stayed in a range of from near neutral to alkaline and rose to 7.6-8.0 at several time points of radiation therapy for some tumors. These results suggest that most tumor cells in human neoplasms are well oxygenated and that only a negligible fraction are chronic hypoxic cells. The fluctuating alkaline pH during radiation therapy occurred regardless of the responsiveness of the treated tumors.

The effect of nuclear magnetic resonance (NMR) imaging on six representative cardiac pacemakers was studied. The results indicate that the threshold for initiating the asynchronous mode of a pacemaker is 17 gauss. Radiofrequency levels are present in an NMR unit and may confuse or possibly inhibit demand pacemakers, although sensing circuitry is normally provided with electromagnetic interference discrimination. Time-varying magnetic fields can generate pulse amplitudes and frequencies to mimic cardiac activity. A serious limitation in the possibility of imaging a patient with a pacemaker would be the alteration of normal pulsing parameters due to time-varying magnetic fields.

The purpose of this investigation was to extend previous steady state flow studies with magnetic resonance (MR) to pulsatile flow measurements obtained with gated cardiac techniques in man with a pulsatile artificial heart device. Bovine blood and a solution of MnCl2 were studied. Correlation was made with complex and time-varying MR signals observed in the descending aorta on cardiac gated images obtained through the midthorax. MR signals from flowing fluids represent velocity distribution as shown in a velocity profile, and laminar flow is distinguished from nonlaminar. At very slow flow rates, signal intensity is lower than background. As the rate is increased, paradoxical enhancement occurs followed by loss of signal, which is complete at 7 liters per minute with fluid and 15 liters per minute with blood. These areas correspond to maximum fluid velocities of 41 and 88 cm/sec, respectively.

Central and peripheral intravenous injections of contrast material for digital subtraction angiography were compared in 30 patients. With 40 ml of contrast material, visualization of the carotid bifurcations was as good with the peripheral as with the central injection. A more consistently high-quality examination of the small intracranial vessels was obtained with the central injection.

Magnetic resonance (MR) gated cardiac imaging was performed in ten subjects using a prototype 0.15-T resistive magnet imaging system. Volume and planar imaging techniques utilizing saturation recovery, proton Tl-weighted relaxation time pulse sequences produced images of the heart and great vessels with exquisite anatomic detail that showed excellent correlation with cadaver sections of the heart. The left ventricular myocardial segments also showed excellent correlation with the thallium-201 cardiac single photon emission computed tomography images. Volume acquisition allowed postprocessing selection of tomographic sections in various orientations to optimize visualization of a particular structure of interest. The excellent spatial and contrast resolution afforded by MR volume imaging, which does not involve the use of ionizing radiation and iodinated contrast material, should assure it a significant role in the diagnostic assessment of the cardiovascular system.

Thirty-four patients with 37 pheochromocytomas were studied by catheter angiography and results of these studies were reviewed. The radiographic approach to the patient with suspected pheochromocytoma is discussed. Following clinical and laboratory work-up and general radiographic procedures (urography with adrenal laminagraphy), arteriography with careful monitoring is indicated. Selective catheterization is recommended before aortography. Adrenal venography is necessary if all arterial studies are negative. This protocol permits safe and accurate evaluation of patients suspected of having pheochromocytoma.

Digital subtraction angiography (DSA) was used to study the cardiovascular system in more than 400 patients and was specifically compared with conventional angiography of the aorta and renal arteries in 30 patients. For the renal arteries, the overall accuracy of DSA was 71% (50/70). Excluding 11 cases of inadequate visualization of the renal arteries on DSA, the sensitivity of the new technique was 93% (55/59) and the specificity 91.5% (54/59). Aortic disease, including intravascular clots and occlusions, was faithfully delineated by DSA.

“Medial fibroplasia” is a term used by McCormack et al. to designate the most common of the various nonatherosclerotic lesions which has a characteristic string-of-beads appearance on arteriograms (1–3). The term replaces “fibromuscular hyperplasia,” originally used to describe a specific, nonatherosclerotic lesion of the renal artery (4, 8) but which came to be applied to various lesions that have dissimilar arteriographic and histologic patterns. McCormack et al. classified the nonatherosclerotic lesions according to the primary site of involvement in the arterial wall and have shown a correlation between the histologic and the arteriographic appearance of the lesions. These have been termed medial fibroplasia, subadventitial fibroplasia, intimal fibroplasia, and fibromuscular hyperplasia (1). In this classification, the term fibromuscular hyperplasia is reserved for one of the nonatherosclerotic lesions in which there is hypertrophy of the muscle in the media as originally described, and our experience...

THE PLACE of renal arteriography in theT diagnosis and management of patients with suspected renal masses has been the subject of controversy since dos Santos introduced translumbar aortography in 1929 (1). Errors were made, however, in differentiating renal cysts from neoplasms (2–4). The kidney might be overlapped by extrarenal arteries, and the contrast medium diluted to such an extent as to limit vascular details. Many physicians believed that all patients with urographic evidence suggesting neoplasm should undergo surgical exploration and that renal angiography was unnecessary. The advent of the selective technic of renal angiography prompted a reappraisal of the role of arteriography in the diagnosis of renal lesions. As experience with this new method increased, however, it became evident that the angiographic appearances of renal adenomas, hamartomas, and inflammatory processes might be confused with those of cysts and malignant tumors, and that renal-cell carcinoma might be mistakenly diagnosed a...

Information about the natural history of renal arterial disease is important for the approach to a precise selection of hypertensive patients for medical or surgical therapy. Surgery carries a high risk of myocardial infarction and stroke in patients with renal atherosclerosis and associated coronary and cerebrovascular disease. Moreover, technical problems arise when the arterial disease affects branches of the renal artery, is bilateral, or affects the renal artery supplying a solitary kidney. Although antihypertensive drug therapy has proved effective in controlling blood pressure in patients with renal vascular hypertension (1), concern may arise that renal function deteriorate because of progression of the arterial disease. This report presents the information obtained in 91 patients studied by serial renal arteriography for periods ranging from six months to ten years. Clinical Material, Method, and Criteria of Study The 91 patients (32 males and 59 females) in the study were admitted to the Clevela...

Correlation was positive between angiographic and subsequent pathologic findings in 40 of 53 patients with chronic unexplained gastrointestinal bleeding. It is believed that, in a patient with a history of chronic recurrent bleeding, an anatomic lesion is generally present and can be demonstrated by arteriography even if active bleeding is not in progress at the time of examination. Only 2 of the 53 patients in this study were actively bleeding at the time of examination. The arteriographie details of an intussusception and an ulcerated Meckel's diverticulum are also described.

The diagnosis of pheochromocytoma is suspected in patients with paroxysmal or sustained hypertension associated with symptoms of headache, excessive perspiration, and palpitation (1). Many patients have nonspecific symptoms, however, and additional diagnostic evidence is sought from chemical, pharmacologic, or radiologic studies. Standard roentgen examinations, e.g., urography or laminagraphy, have not been sufficiently accurate for the diagnosis and localization of pheochromocytoma (2–4). The specialized radiographic technics such as retroperitoneal gas insufflation and arteriography may provide direct visualization of the tumor, but they carry a risk and have been associated with fatalities. Air embolism may be a complication of retroperitoneal gas insufflation. Death after aortography undertaken in patients with pheochromocytoma was reported by Saltz and his associates (6), and by Koonce, Pollock, and Glassy (7). In the two cases, the blood pressure was elevated after aortography, and vasomotor collaps...

Management of the patient after renal homotransplantation is often complicated and frequently requires answers to problems not previously encountered. Oliguria is the most common diagnostic question in the early postoperative period. In cadaver renal transplants oliguria may be the result of acute renal failure secondary to ischemia (1), vascular thrombosis, ureteral perforation and slough, or the rejection phenomenon. The ideal management of each of these entities requires early and accurate diagnosis. In an effort to distinguish between these complications, angiography was performed on 20 patients who received renal homotransplantations from living or from cadaver donors at the Cleveland Clinic Hospital, Cleveland, Ohio, since August 1963. Angiograms were obtained primarily to evaluate persistent anuria or oliguria in cadaver transplants, or oliguria after initial diuresis in live donor transplants. Materials and Methods Angiograms were obtained of 20 renal homografts, 15 of which were kidneys from cada...

Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram.

One thousand consecutive computed tomograms were reviewed to determine the accuracy of the procedure in the detection of juxtasellar lesions. The detection rate was compared to those of plain skull films, radionuclide studies, angiography, and pneumoencephalography. Computed tomography was slightly superior to angiography and was surpassed only by pneumoencephalography, both of which are invasive procedures which carry a definite risk. The data indicate that computed tomography is the screening method of choice in the detection of juxtasellar masses.

In a group of 188 patients, 192 computed tomographic (CT) scans of the pancreas were done, and the diagnostic accuracy of CT determined relative to other modalities. CT was the most effective method of detecting neoplastic and inflammatory diseases. The full extent of the disease process, including involvement of the retroperitoneum and metastasis to the liver, was visualized with one examination. Calcification and cystic collections associated with pancreatitis were also clearly seen.

Most magnetic resonance imaging has used body orthogonal axes with the Z axis placed along the length of the body and the X and Y axes at right angles to the body. This orientation is not optimum for the heart; visualization of sections along the short and long cardiac axes would best define cardiac structural detail and functional status. The new orientation was accomplished by selection of electronic angulation of the magnetic fields for each subject rather than by attempting to approximate the cardiac axes by altering the position of the patient. This technique improved visualization of comparative wall segments, valvular structures, and the true four-chamber view of the heart, and also gave the best visualization of the pericardium. In addition, more accurate estimates of chamber size and myocardial mass can be made from the short-axis orientation, since the sections are orthogonal to the myocardium.

Major socioeconomic changes in the practice of medicine in the past 2 decades have had a great impact on diagnostic radiology and have encouraged other physicians and entrepreneurs to enter many areas of this specialty. Major alterations in the practice of diagnostic radiology will be required if the specialty is to survive. Diagnostic radiologists must move from a position of dependency to self-sufficiency by encouraging patients to access their services and talents directly.

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.

The utility of computed tomography (CT) in the study of the anatomy, physiology, and pathology of the human body has been the subject of considerable interest since the introduction of CT scanning. The advent of a new prototype scanning device has made it possible to examine a variety of abnormalities in the abdomen and thorax in a manner not previously possible. This development permits a remarkable insight into the study of human disease in vivo.

We evaluated an experimental digital subtraction unit in terms of field uniformity, linearity of signal response to x-radiation, response of the log amplifier, and imaging capability as measured with the Rose phantom. For comparison, conventional film subtraction phantom measurements were made. Our results indicate that this unit exhibits greater sensitivity to contrast media than conventional film subtraction units.

A preliminary report of a simple and accurate method for measurement of blood flow in the intact circulation is presented. Density measurements are obtained from each frame of the projected cineangiograms, using photoresistive cells placed across the diameter of the projected vessel. Calculation of flow is based upon data derived from the integrated density-washout rate of the contrast material and the cross section of the vessel, corrected for magnification on the projection of the cine film.

Psoriatic arthritis, as commonly understood, is an arthritis affecting patients with long-standing psoriasis. The joint manifestations predominantly involve the hands and usually are associated with psoriatic changes in the nails. The term psoriatic arthritis has been the source of much controversy since the condition was described by Bourdillon (2) in 1888. The discussion centers about whether psoriatic arthritis is an entity in itself or merely represents the association of psoriasis with rheumatoid arthritis. It is the purpose of this paper to propose a two-group classification of the concurrence of psoriasis and arthritis on the basis of the roentgen findings in 15 patients. The background for much of the controversy concerning psoriatic arthritis possibly stems from the study by Dawson and Tyson (5) who, in 1,000 cases of rheumatoid arthritis, found the incidence of psoriasis to be 2.6 per cent, as compared with only 0.3 per cent in 1,000 cases of osteoarthritis. The significance of these figures app...