Detection of bone-marrow metastases using quantitative computed tomography

A method is described for using quantitative computed tomography (CT) to detect subtle skeletal metastases not readily identified or precisely located by conventional methods. Four patients with intramedullary metastases are presented along with data from 13 control subjects. The results indicate that CT may demonstrate intramedullary changes that occur in skeletal metastases and that cannot be detected by other techniques. A difference in medullary CT number greater than 20 HU between limbs is abnormal. This asymmetry, however, is not specific for metastatic disease, and clinical judgment must be exercised in interpreting this finding.

Radiologist's guide to the use of the laboratory in diagnosing rheumatic diseases

Laboratory tests that are commonly used in the evaluation of rheumatic diseases are described. The techniques for performing these tests; their use in screening, diagnosis, and follow-up; and the pitfalls in interpreting their results are discussed to provide the radiologist with an understanding of the current technology relating to rheumatic disorders.

Quantitative and qualitative comparison of two microfocus-tube imaging systems

Two microfocus-tube magnification systems were compared: one used an RSI tube (stationary anode, Pierce-gun cathode) and the other used a GE tube (rotating anode, biased cathode). Imaging parameters for body parts of three thicknesses, the hand (low), knee (medium), and hip (high), were considered at a magnification of 2. The focal-spot MTF was measured on and off the central ray of the beam, as well as beam quality and the intensity of scatter in the image plane. Patient exposures were also determined. While both systems gave high-quality images at acceptable exposure levels, the RSI unit was judged superior for body parts up to 15 cm thick. For thicker parts, scatter degraded contrast with the RSI unit, making the GE unit superior.

Pseudohypoparathyroidism presenting as renal osteodystrophy

Pseudohypoparathyroidism (pseudo HPT) is the prototype of a group of diseases with end organ unresponsiveness to parathyroid hormone (PTH). Patients with the classic form of this disease have both renal and osseous resistance to PTH. We describe a rare variant of pseudo HPT with classic renal unresponsiveness to PTH but normal skeletal responsiveness to this hormone. The latter patients develop metabolic bone disease in response to depressed calcium and elevated PTH levels. Skeletal abnormalities are histologically and radiologically indistinguishable from renal osteodystrophy and these patients frequently present in childhood with symptoms relating to slipped capital femoral epiphyses. The latter radiologic findings, in the face of normal renal function or the classic somatic features of the syndrome, are highly suggestive of pseudo HPT with normal skeletal responsiveness to PTH.

Spinal mineral loss in oophorectomized women. Determination by quantitative computed tomography

Computed tomography (CT) provides precise anatomic localization coupled with quantitative x-ray attenuation information that can be used to determine bone mineral content. A precise and sensitive method for vertebral mineral measurement by CT is described and illustrated with results from an ongoing study of mineral loss in oophorectomized women. Spinal mineral loss measured by quantitative CT is compared with peripheral loss determined by photon absorptiometry and radiogrammetry. Vertebral cancellous bone loss was significant for the group as a whole at 12 months, while mean peripheral measurements showed no change. In two subjects in whom mineral change was significant at both sites, spinal loss was approximately five times greater than peripheral loss.

Computed tomography of the musculoskeletal system

To demonstrate the potential impact of computed tomography on orthopaedics, a brief review was done of four generations of scanners and of one new development (assay of bone mineral in the spine) that is presently being researched. To assess the utility of the method in treating orthopaedic problems, the cases of 140 patients, including patients with congenital anomalies, tumors, infections, and traumatic lesions, were analyzed. In the majority of the patients the technique provided useful information, often unobtainable with any other technique.

Precise measurement of vertebral mineral content using computed tomography

A precise method of measuring vertebral mineral content by computed tomography has been developed. Calibration phantoms scanned with patients are used to provide corrections for machine drifts. Advanced software manipulation of the display images is used to reposition precisely to the midportion of each vertebral body. A long-term precision of 2.8% for mineral content has been obtained in excised vertebrae in a phantom simulating the human torso.

Loosening of the total knee arthroplasty: detection by radionuclide bone scanning

Pain after total knee arthroplasty is a common clinical problem in orthopedics, and prosthetic loosening, often requiring surgical revision, is usually the etiology. Since standard clinical and radiographic diagnostic measures have not proven totally satisfactory, a study of the utility of bone scintigraphy to assess stability of the knee prosthesis was done. Thirty-five patients with 39 prostheses were studied. Seventeen patients with 21 total knee arthroplasties served as controls and were asymptomatic, were stable at surgery, or improved with conservative management. Eighteen knees in 18 symptomatic patients composed the experimental group. Of these, 11 knees were loose at surgery and seven have had surgery recommended. Scintigrams of the knees were obtained using 99mTc-MDP, and ranked 0-3 corresponding to increasingly abnormal localization by three observers. Highly significant differences were observed between the abnormal and control groups (p less than 0.001). Reciprocal changes in sensitivity and specificity with increasingly stringent criteria were shown. While it is apparent that the bone scan cannot be used as the sole diagnostic method for evaluation of prosthetic stability, it does seem to be useful adjunct along with clinical criteria and radiographic studies.

Unilateral primary osteoarthritis of the hand in monoplegia

Unilateral osteoarthritis of the functional hand was observed in a 67-year-old monoplegic woman. The contralateral hand with flaccid paralysis was spared. In this and similar cases in the literature, there is apparently some need for neural innervation to an extremity for osteoarthritis to develop.

Comparison of vertebral and peripheral mineral losses in disuse osteoporosis in monkeys

Vertebral mineral loss (measured by computed tomography) was compared to peripheral mineral loss (measured by photon absorptiometry) in immobilized monkeys. Significantly greater loss was found in axial cancallous bone than in peripheral cortical bone. The accuracy of vertebral CT measurements in one animal was determined using direct chemical analysis of excised vertebrae. Results indicate that mineral changes may be detected earlier in the vertebrae by CT than in peripheral bone using photon absorptiometric techniques.

99mTc-methylene diphosphonate bone imaging in the evaluation of total hip prostheses

A retrospective study was performed to determine the accuracy of 99mTc-methylene diphosphonate bone imaging in the evaluation of total hip arthrosplasty for lossening and/or infection. Using focally increased activity at the tip of the femoral component or in the region of the acetabular component as a criterion, the examination was 77% specific and 100% sensitive for loosening and/or infection. A possible explanation for the increased uptake at the tip of the femoral component and the role of this examination in the management of a painful total hip prosthesis are discussed.

Computed tomography evaluation of fatty tumors of the somatic soft tissues: clinical utility and radiologic-pathologic correlation

The role of computed tomography (CT) in the evaluation of fatty tumors of the somatic soft tissues was investigated. Six surgically proven cases of fatty tumors were studied preoperatively by CT and standard radiographic means--conventional radiographs, xeroradiography, and angiography. Our case material included a simple lipoma, two infiltrative lipomas, an angiolipoma, and two liposarcomas. The radiologic-pathologic correlation was evaluated with respect to the various imaging modalities. The unique tissue characteristics of fatty tumors makes them particularly adaptable to CT scanning. In addition to its ability to define accurately tissue densities, the facility of CT in depicting depth, size, and extent of the lesion in the axial plane was found to be most useful in the preoperative evaluation of our case material.

In vivo assessment of bone metabolism using the cortical striation index

Metacarpal cortical striations were evaluated in 350 patients using fine-detail radiography with optical magnification. Compared to the control population, mean striation-indices were elevated in growing children, primary and secondary hyperparathyroidism, osteomalacia and reflex sympathetic dystrophy syndrome. This technique may provide a useful quantitative assessment of bone metabolism, allowing differentiation of normal from hypermetabolic states. Serial assessment of cortical striation may be useful in monitoring response to therapy.

Controlled single-blind clinical evaluation of low-dose mammographic screen--film systems

The ability of five low-dose mammographic screen--film systems to portray normal and abnormal breast structures was evaluated in parallel with a study of physical image properties. Single-blind evaluations of the visibility of normal breast architecture, mass lesions, and calcifications were made on the mammograms of 100 patients radiographed with each of the systems. There was increased noise and slightly poorer resolution for the faster recording systems, but there was no difference in final diagnostic impressions among the five systems. These results suggest that the faster systems will result in substantial dose reduction without sacrificing diagnostic accuracy.

Calcified bodies in popliteal cysts: a characteristic radiographic appearance

Calcified bodies in popliteal cysts have a characteristic radiographic appearance which can be confirmed by arthrography. Calcified bodies may arise in the true joint due to trauma, arthropathy resulting in joint destruction, or synovial osteochondromatosis. These calcified loose bodies may pass into a popliteal cyst through posterior joint-bursal communications or can arise in a popliteal cyst by chondrometaplasia. Correct radiographic interpretation will exclude soft tissue tumors and vascular lesions as differential considerations. Management of these patients will be determined by the clinical circumstances since neither popliteal cysts nor synovial osteochondromatosis are necessarily symptomatic.

Avascular necrosis of bone after renal transplantation

Avascular necrosis (AN) of bone developed in 11 of 100 children who received renal transplants from 1964 to 1977. Bones involved were femoral heads, 14; femoral condyles, 12; tall, two; and carpal naviculars, two. Seven children with symptomatic AN of the femoral heads were treated with limited weight bearing; three subsequently required arthroplasty, and degenerative joint disease developed in one. The AN at other joints healed clinically but not roentgenographically. Although the prevalence of AN decreased after 1967 coincident with a decrease in prednisone dose, children with AN received the same cumulative prednisone dose as children in a control group. Serum phosphorus levels were different in the AN and control groups, but other indexes of hyperparathyroidism were similar. The relative contributions of prednisone therapy and hyperparathyroidism to the development of AN could not be delineated.

Unifocal bone findings by scintigraphy. Clinical significance in patients with known primary cancer

Preliminary findings suggest that in patients with known primary cancer, a large percentage of unifocal lesions seen on radionuclide bone scans are not metastatic. In a survey of radionuclide bone studies done on 861 consecutive patients, 30 patients with known primary cancer had solitary lesions. Adequate follow-up information was available on 21 of these 30 patients. In only four did the lesions prove to be caused by metastatic malignancy.

Applications and limitations of quantitative sacroiliac joint scintigraphy

Evaluation of sacroiliac joint pathology by quantitative analysis of radionuclide bone scanning has been advocated as a useful technique. We have examined this technique in 61 patients and controls. The procedure was useful in detecting early sacroiliitis but was of limited value in patients with advanced sacroiliac joint findings radiographically. False positive values were found in patients with metabolic bone disease or structural abnormalities in the low back. Normative data must be determined for each laboratory.

Computed tomography. Its use in space-occupying lesions of the musculoskeletal system

The value of computed tomography in the diagnosis and management of lesions of the musculoskeletal system is being determined. Illustrative cases including a lipoma of the thigh, osteochondroma of the hip, simple cyst of the ilium, recurrent liposarcoma of the lumbar spine, desmoid tumor in the gluteal region, and postoperative interspace infection of the lumbar spine are presented to indicate the potential value of this procedure in the diagnosis and planning of treatment of musculoskeletal lesions.

Computed tomography of musculoskeletal disorders

The utility of computed tomography (CT) in evaluation of musculoskeletal disorders was assessed in 55 selected patients. CT provided unique information leading to a correct diagnosis in 45% of cases. In 78% the extent of a lesion was more clearly defined than on conventional imaging procedures, and in the same percentage the CT findings were used to plan optimal therapy. CT was most useful in demonstrating absence of a suspected mass lesion and in defining the full extent of a lesion involving the soft tissues.

Heavy-ion radiography: density resolution and specimen radiography

Heavy-ion radiography is performed by the passage of a beam of nuclei accelerated to energies of several hundred MeV/nucleon through an object. The technique of recording transmitted nuclei in a downstream stack of plastic sheets affords excellent resolution of density by recording the nuclei only at their stopping points. Imaging of a phantom--which stimulated tumors of low density contrast in a body part--by conventional radiography, computed tomographic scanning and the heavy-ion technique indicated superior density resolution for heavy-ion imaging at radiation dose. Superior imaging of tumors in pathologic specimens was demonstrated for heavy-ion imaging compared to conventional radiography. Values of stopping power for various tumors and normal tissues were determined by a computer-aided technique. Heavy-ion radiography shows promise for superior imaging of low contrast tumors at relatively low radiation low levels.

HLA-B27 associated arthropathies

The association between histo-compatibility antigens and disease is reviewed, in particular that between HLA-B27 and spondylitic disorders, i.e., ankylosing spondylitis, Reiter's arthritis, psoriatic arthritis, and ankylosing hyperostosis. We determined whether the presence of HLA-B27 predicted specific radiographic findings and, conversely, whether specific radiographic changes predicted antigenic status. The prevalences of the HLA-B27 antigen in our patients were: ankylosing spondylitis, 100%; Reiter's arthritis, 93%; psoriatic arthritis, 55%; and ankylosing hyperostosis, 12%. The only specific radiographic finding associated with B27 positivity was severe spondylitis in psoriasis.

Ratio of late to early radionuclide uptake: a method for distinguishing osteoporosis from osteomalacia in animal models

The ration of late to early uptake of several radionuclides was examined as a method for distinguishing states of abnormal bone metabolism. Nutritional osteoporosis (secondary hyperparathyroidism) and osteomalacia were produced in young rats and compared to a control group. The ratio of early (3-6 hrs.) to late (4-6 days) uptake of barium-131, nitrate, indium-111 EDTMP, and lead-203 were studied, as was that of strontium-85 chloride, a calcium analogue. Ratios of late to early uptake were found to distinguish osteomalacia from osteoporosis in the models when strontium-85 or barium-131 were used. Barium-131 may be a clinically useful alternative to strontium-85 in the evaluation of metabolic bone disease due to its shorter half-life and lower radiation dose.

Subchondral pseudocysts in rheumatoid arthritis

Subchondral cyst formation (geode) is a not uncommon manifestation of rheumatoid arthritis which may at times impede correct radiologic interpretation. Four patients with rheumatoid arthritis who demonstrated striking subarticular cystic erosive disease are described. These cases emphasize the nature and appearance of this interesting finding.

Quantitative bone mineral analysis using dual energy computed tomography

This preliminary evaluation indicates that CT scanning permits measurement of cancellous, cortical or integral bone. With the single energy technique, precision is high and with mode, CT scanning may prove an important tool for assessing the axial skeleton is osteoporotic conditions.

Magnification film mammography: image quality and clinical studies

Direct radiographic magnification (1.5 X) of the breast with a microfocus x-ray tube was compared with conventional contact mammography. Measurements of modulation transfer functions, Wiener spectra, scattered radiation, and dosimetry permitted quantitative comparisons of resolution, noise, contrast, and patient exposure. Images of surgical specimens of the breast, and the breasts of 125 patients, were qualitatively compared. Magnification images were superior (increased resolution, reduced noise) to conventional mammography images, at the expense of increased radiation dose. Clinical study revealed that the superior magnification image is useful in distinguishing malignant from benign breast disease, in selected cases.

Intra-articular calcification in scleroderma

Two patients with scleroderma demonstrated intra-articular calcification, which is rarely observed in this disease. The authors suggest that intra-articular calcification and erosion of adjacent cartilage and bone are related.

Mixed connective tissue disease: the spectrum of radiographic manifestations

Mixed connective tissue disease (MCTD) is a serologically distinct entity defined by a ribonuclease-sensitive extractable nuclear antigen. This unusual overlap syndrome has clinical features of scleroderma, systemic lupus erythematosus, polymyositis, and rheumatoid arthritis. In order to define the radiographic changes in MCTD, radiographs of the hands of 17 patients were studied, utilizing a fine-detail technique. Diffuse and periarticular osteopenia were found in 8 and 10 patients, respectively; soft-tissue swelling in 11; erosive changes in 9; joint-space narrowing in 7; tuft resorption and soft-tissue atrophy in 6; and subluxations in 2. In individual cases radiographs may appear normal or exhibit features of scleroderma, systemic lupus erythematosus or rheumatoid arthritis, thereby mirroring the clinical diversity of this entity.

Direct radiographic magnification for skeletal radiology. An assessment of image quality and clinical application

Recent advances in technology have made radiographic magnification of the skeleton clinically feasible. A new electron gun micro-focal tube combined with new high-resolution recording systems were used to perform magnification radiography which was then compared with conventional contact radiography. Quantitative evaluation included measurements of speed, contrast, resolution, and noise. Qualitative evaluation included an analysis of 215 clinical cases in which both techniques were used. The superior image quality of direct radiographic magnification is confirmed and the clinical areas in which it proved most helpful are defined.

Skeletal demineralization and growth retardation in inflammatory bowel disease

Skeletal growth and mineralization in 54 adolescent and adult patients with inflammatory bowel disease have been analyzed comprehensively. Quantitative and qualitative radiologic techniques consisted of conventional roentgenography, photon absorptiometry, and radiographic morphometry. The data are correlated with the type, duration, and severity of disease, and with several modes of therapy. The results indicate the osteopenia and retardation of growth are common in patients with inflammatory bowel disease, particularly in adolescents, in whom the effects of corticosteroids on the skeleton are most deleterious.

Patellar giant cell tumor

Primary patellar neoplasms are distinctly unusual. A rare case of patellar giant cell tumor which caused clinical, radiographic, and histologic confusion is described. The lesion progressed rapidly, underscoring the potential aggressive behavior of the tumor. Amputation is the preferred treatment. A review of the literature is also presented.

Comparison of non-screen techniques (medical vs. industrial film) for fine-detail skeletal radiography

High resolution radiographic techniques for imaging the peripheral skeleton (hand and foot) have gained wide clinical acceptance. The two procedures receiving widest attention are non-screen techniques: one uses medical film (Kodak RP); and the other uses industrial film (Kodak Type M) combined with optical magnification. The imaging properties and clinical applications of these two techniques were examined. The modulation transfer functions (MTF's) of the recording systems, Wiener spectrum analyses of noise, and film sensitometry were obtained. Clinical comparisons were made from 200 consecutive patients radiographed with both techniques and the relative merits in metabolic, arthritic and traumatic afflictions were assessed. The results demonstrate the superiority of the industrial film compared to medical film technique in all parameters of image quality. However, the inconveniences of special processing and viewing necessitated by this technique, as well as the increased radiation exposure, limit its clinical application to small, selection groups of patients as determined from the clinical comparative study.

Roentgenographic aspects of calcium pyrophosphate dihydrate crystal deposition disease (pseudogout)

A comprehensive review of the roentgenographic features of calcium pyrophosphate crystal deposition disease (pseudogout) is presented. The roentgenographic techniques are reviewed. Those recommended as optimal are as follows: for small peripheral joints, industrial Type M film with contact exposure; for large central joints, direct radiographic magnification (3-4 X) with a microfocus tube. The classic appearances of articular chondrocalcinosis in fibrocartilage, hyaline cartilage, and capsular structures are discussed. Distinctive features of pyrophosphate arthropathy, including the distribution of involvement and the degree of destruction, are emphasized. Finally, the relationship among articular chondrocalcinosis, arthropathy, microscopic crystals, and symptoms is discussed.

The reflex sympathetic dystrophy syndrome. II. Roentgenographic and scintigraphic evidence of bilaterality and of periarticular accentuation

Patchy osteoporosis is the primary roentgenologic manifestation of the reflex sympathetic dystrophy syndrome (RSDS). As recent clinical and histologic data suggested articular changes in RSDS, fine-detail roentgenograms were obtained in eight consecutive patients. Juxta-articular and soft-tissue swelling, osteoporosis and erosions of the subchondral bone were found. 99mTcO4 and 99mTc-EHDP scintigraphy showed localization of nuclide predominantly in the juxta-articular tissues. Serial roentgenographic, scintigraphic and quantitative bone densitometric measurements showed changes that reflected the clinical course of the disease.

Radionuclide imaging of the bones and joints of the hand. A definition of normal and a comparison of sensitivity using 99mTc-pertechnetate and 99mTc-diphosphonate

Normal radionuclide patterns of the hand obtained with 99mTcO4 and 99mTc-Sn-EHDP are described and their validity supported by clinical, radiographic, and laboratory examinations performed to exclude articular disease in the control group. Comparison of the 99mTcO4 and 99mTc-Sn-EHDP images in patients with various articular diseases demonstrated higher sensitivity of 99mTc-Sn-EHDP in detection of involved joints; this was also true when the radionuclide images were compared with fine-detail radiographs in patients with rheumatoid arthritis.

Comparison of image quality obtained with optical and radiographic magnification techniques in fine-detail skeletal radiography: effect of object thickness

High-resolution radiography may be done using either optical or radiographic magnification. In the former technique, industrial Type M film was used without screens and the image was viewed with 4-10X optical magnification. In the latter technique, RP film was used with Detail screens and 4X geometric magnification together with a microfocus x-ray tube having a nominal focal spot size of 50 mum. The imaging properties of both techniques were evaluated by means of H & D curves, modulation transfer functions, and Wiener spectra. It was found that for thin objects such as the hand, optical magnification provides better bone images than radiographic magnification; whereas for thicker parts such as the knee, radiographic magnification is superior.

Radionuclide joint imaging

Modern radionuclide techniques of joint imaging involve the use of either 99mTc-pertechnetate or 99mTc-phosphate compounds in conjunction with the Anger camera. In general, images obtained with both types of radiocompound are nonspecific--although increased uptake of 99mTc-pertechnetate usually denotes the presence of synovitis. The most popular uses of the technique are in documenting the extent and severity of inflammatory joint disease, assessing the effect of therapy, and establishing the diagnoses of Legg-Perthes disease and septic arthritis. The method is also useful in judging the extent of involvement in osteoarthritis of the knee prior to surgical intervention. Radionuclide joint imaging is more sensitive than clinical or radiographic techniques in detecting early joint involvement but usually it must be supplemented by other techniques to establish a specific diagnosis.

The reflex sympathetic dystrophy syndrome. A comprehensive analysis using fine-detail radiography, photon absorptiometry, and bone and joint scintigraphy

Nine patients with reflex sympathetic dystrophy were examined. Clinical manifestations suggesting arthropathy were supported by radiographic demonstration of juxta-articular and subchondral bone erosions and by radionuclide demonstration of increased activity localized in the joint regions. Aggressive demineralization was demonstrated by fine-detail radiography and consisted of endosteal and intracortical excavation and subperiosteal and trabecular bone resorption. A one-third reduction in bone mineral was confirmed by quantitative analyses. Newer modalities of study have aided in the documentation of arthropathy in reflex sympathetic dystrophy and have helped in defining the patterns of aggressive bone resorption.

Osteosclerosis in primary hyperparathyroidism

Osteosclerosis in adults with primary hyperparathyoidism is rare; the usual skeletal manifestation, when presented, is diffuse osteropenia. We describe a patient with generalized osteosclerosis in association with primary hyperparathyroidism. The findings are documented by conventional and fine-detail radiography, absorptiometric bone mineral analysis, quantitative microradiography and histologic examination of bone. The unique features are contrasted with the manifestations recorded in a recently studied group of 87 hyperparathyroid patients. The data presented here support a causal relationship in this patient between parathyroid hormone excess and the development of densely sclerotic bones.

Optical versus radiographic magnification for fine-detail skeletal radiography

Fine-detail radiographic techniques for peripheral skeletal imaging have gained wide clinical acceptance. In this study, the imaging properties and clinical applications of the optical magnification technique, which employs fine-grain industrial film and a large focal spot, are compared quantitatively and qualitatively with those of three slow screen-film techniques, namely, contact exposure with a large focal spot, 2 times radiographic magnification with a 0.3 mm focal spot, and 4 times radiographic magnification with a 50 mu focal spot. The modulation transfer functions (MTF's) of the recording systems and focal spots are obtained and film sensitometry performed. Clinical comparisons are made for patients with metabolic, arthritic, and neoplastic skeletal disorders. The results illustrate the superiority of the optical magnification technique over contact or 2 times magnification techniques using slow screen-film systems. If a microfocus tube is used, however, direct radiographic magnification may provide images comparable in resolution, noise and contrast to those made with the optical magnification technique, and at lower radiation exposure to the patient.