Magnetic resonance (MR) has been shown to provide superior soft tissue contrast as well as superior anatomical definition when compared with other diagnostic modalities in the evaluation and staging of many bone and soft tissue tumors. MR signal patterns with various parameter weighting can provide information that aids in the tissue characterization of the lesion. Technical factors as well as the clinical role of MR in the evaluation of musculoskeletal tumors are discussed.
Implementation of a Picture Archiving and Communication System (PACS) is a system integration task and requires the knowledge of multidisciplinary fields. This paper reviews current PACS development with emphasis on radiological images. The following topics are covered: methods of image acquisition, image compression, storage, display, communication, and image database structure. Methods of implementation of PACS in a clinical environment as well as current operational PACS in hospitals are reviewed. A survey of private industry participating in PACS research and development are also given.
Close scrutiny of the size, shape, density and margins of the pedicles may permit the clinical radiologist to suggest a wide variety of systemic diseases.
Computed tomography (CT) is currently the imaging modality of choice for assessing the morphology of the adrenal glands in adult patients. Much useful information can be gained using CT in disease processes which primarily involve one or both of the adrenal glands, such as adenomas, as well as in entities which secondarily affect the adrenals, such as pituitary or metastatic disease. The size and configuration of the glands can be readily determined, and masses may be detected. We discuss CT of normal and abnormal adrenal glands with sonographic (US) and pathological correlation, when available. Entities which may mimic adrenal abnormalities are emphasized. Relative advantages of US over CT in the pediatric patient are discussed.
Recurrent occlusive disease was found by noninvasive methods and confirmed arteriographically in 7 patients who had undergone endarterectomy for stenosis of one [5] or both iliac arteries [1] or the subclavian artery [1]. Three patients with iliac artery stenosis had percutaneous transluminal angioplasty (PTA) 1 to 5 years after endarterectomy. One patient with stenosis of the external iliac artery had PTA 4 years after endarterectomy, and dilatation was repeated 7 months later because of recurrence. One patient had 2 endarterectomies and 2 PTAs within 8 years for stenosis of the right common iliac artery. One patient had recanalization of the left common iliac artery 6 years after endarterectomy with low-dose streptokinase followed by PTA. Another patient underwent endarterectomy of the left subclavian artery 3 months after PTA and required further dilatation at 5 and 10 months because of recurrence. The authors conclude that endarterectomy does not preclude PTA (or vice versa) in patients with recurrent arterial occlusive disease.
When high-density barium coats the intrinsically smooth squamous mucosa of the pharynx, many nodules are seen at the base of the tongue and valleculae and many longitudinally oriented lines are seen in the lateral and posterior pharyngeal walls. This normal radiographic appearance reflects the lymphoid tissue and longitudinal muscle layer which intimately underlie the squamous mucosa. This paper discusses the gross and microscopic anatomy pertinent to interpretation of double-contrast films of the pharynx. The techniques for achieving a high-quality double-contrast examination of the pharynx are presented.
This review discusses the disease of the rotator cuff and evaluates our current tools for imaging it. The rotator cuff consists of the cojoined tendons of the short rotator muscles of the shoulder. Derangements of the cuff, which can result from degeneration, trauma, or overuse, are frequent causes of shoulder pain. Until the present decade, imaging of the cuff depended on injection of contrast into either the underlying joint (arthrogram) or overlying bursa (bursogram). Computed tomography (CT) has added additional dimensions to arthrography but has not played a major role in the diagnosis of cuff pathology. Ultrasonography (US) has been shown to be of diagnostic value in imaging cuff tears and has shown promise in defining pathology in the intact cuff. Magnetic resonance imaging (MRI) has the potential for imaging the cuff; its roles here are not yet defined.
Since its first clinical application in 1980, the use of extracorporeal shock wave lithotripsy (ESWL) has dramatically changed the treatment of urinary tract stone disease. More than 80% of patients with urolithiasis will undergo ESWL as a first line therapy. Detection of stones, appropriateness of ESWL treatment, successful stone therapy, termination of the ESWL procedure, and evaluation of treatment complications are all dependent on radiologic input. The application of adjuvant interventional radiologic percutaneous techniques will extend the use of ESWL to an additional 15% of patients and reduce the need for surgical intervention. Additionally, percutaneous techniques can be used to improve success rates in problematic cases and to treat complications related to the ESWL procedure. This article discusses the pre- and postprocedural radiologic evaluation of patients undergoing ESWL. Adjuvant interventional radiologic techniques useful in the management of these patients are also discussed.
The pouch of Douglas (cul-de-sac) represents the caudal extension of the peritoneal cavity. It is the rectovaginal pouch in the female and the rectovesical pouch in the male. The cul-de-sac is in a dependent position when either upright or supine; it is, therefore, a frequent location for seeded lesions. Abnormalities in the cul-de-sac include metastases, abscesses, and endometriosis. These lesions may be detected by multiple modalities, including barium enema, computed tomography, and ultrasound. Examples of numerous cul-de-sac lesions are presented as they appear with different imaging modalities.
The early embryo (blastocyst) is implanted about 6 to 7 days after fertilization and becomes completely imbedded within the decidua at 9.5 days. As the exocoelomic cavity (or early gestational sac) enlarges, it becomes visible by ultrasonography. The gestational sac, however, remains within markedly thickened ipsilateral decidua. The uterine cavity remains relatively undistorted (i.e., straight) and can be delineated by ultrasonography. The gestational sac, therefore, can be seen adjacent to a straight uterine cavity within a thickened decidua. This is called an intradecidual sign. Before the appearance of a visible gestational sac, an echogenic area within the thickened decidua may be seen. This is the earliest sign of intrauterine gestation, and it can be seen as early as 25-days menstrual age. The earliest evidence of an embryo is seen about 2 weeks later, when two small bubbles (amniotic and yolk sacs) attach to the wall of the gestational sac. The embryonic disc is located between the two bubbles. This is called the double-bleb sign. The intradecidual and double-bleb signs represent the most important signs of early intrauterine pregnancy.
Computed tomography (CT) has provided a imaging modality by which the central pulmonary arteries can be studied noninvasively. CT provides cross-sectional images which accurately depict the pulmonary arteries and adjacent structures. Magnetic resonance (MR) imaging with its ability to image vessels without contrast media provides a potential truly noninvasive means of examining the pulmonary arteries. These modalities are well suited to evaluate pathology involving the central pulmonary arteries. Normal CT and MR anatomy is illustrated and discussed. The clinical presentation and appearance of pathological processes involving the pulmonary arteries are described.
Fractures of the tibial plateau consist of two important components. One is depression of the plateau surface and the other a detached and peripherally displaced component referred to as the split fragment. The classification of these fractures is based on the morphologic appearance as well as the location of the above components. The surgical treatment of these fractures is dependent upon several factors, including the type of fracture, the degree of the fracture depression, and fracture fragment separation as well as the patient's age and physical condition. The degree of the plateau depression is a particularly important criteria for surgical-treatment planning. However, the anatomic configuration of the proximal tibia is such that the fractures of these regions are not adequately visualized on conventional radiographs. In the past, conventional tomography was routinely employed for evaluation of tibial plateau fractures. Recently, computed tomography (CT) has shown to be a more accurate and easier method for evaluation of these fractures. CT can be performed without removal of the knee brace or cast and usually requires less than 12 axial images. Furthermore, the degree of fracture separation and depression can be measured by computerized technique. CT scanning is a reliable method for evaluation and an accurate classification of tibial plateau fractures.
The percutaneous approach has become an accepted procedure for the removal of kidney stones in the urinary tract. Developed initially from our method of transvenous punch biopsy and transvenous cholangiography, the "inside-out" retrograde nephrostomy technique involves either cystoscopic or fluoroscopic placement of a 9 or 10 French catheter into a selected minor calix, through which a fine 21-gauge needle passes and exists the skin. The tract is then dilated over the needle. Used in over 200 cases without any complications directly attributable to the nephrostomy, the retrograde approach is safer, more reliable, and less time consuming than the previous standard antegrade approach, particularly in the nondilated pelvicalyceal system. Also presented are several new modifications to the original procedure and further technical considerations for operators.
The proximal femur is a dynamic region whose internal architecture reflects the biomechanical demands of weight-bearing. It is composed of two major trabecular systems arranged along the lines of compressive and tensile stresses. Adaptive alterations in these trabeculae occur in a variety of disorders, including osteoporosis, osteoarthritis, and ischemic necrosis. Plain film radiography and computed tomography (CT) have been utilized to study these changes and provide insight into the pathophysiology of these disorders. Analysis of the order of resorption of trabeculae in osteoporosis, the proliferation of trabeculae in osteoarthritis, and the reparative changes in ischemic necrosis often allows accurate assessment of the severity of involvement and can give valuable information to aid treatment planning.
The use of imaging procedures for breast cancer staging and follow-up should be based on the natural history of the disease as well as the accuracy, cost, and availability of the studies themselves. Early detection of metastases may provide palliation but probably does not affect survival. For staging, chest X-ray and mammogram are both recommended on all patients; radionuclide bone scan is advised in the presence of either an elevated alkaline phosphatase, axillary metastases, or a primary tumor measuring more than 2 cm; abdominal CT should be performed if liver chemistries are abnormal; CT brain scan is the procedure of choice for neurological symptoms. Chest CT should be reserved for selected patients with an abnormal chest X-ray. Follow-up recommendations include annual chest X-rays and mammogram, bone scans every 5 years when a staging scan was indicated, and CT of the liver and/or brain in the presence of appropriate symptoms or laboratory values.
Computed tomography (CT) has proven to be an important diagnostic imaging technique for the evaluation of a variety of spinal disorders. The method is useful for identifying and characterizing acute fractures in traumatized patients and can accurately quantify spinal canal encroachment. Intervertebral disc disease and facet joint osteoarthritis are readily demonstrated by CT in both the cervical and lumbar regions. The technique can reliably distinguish between infection and neoplastic disease in the spine and is helpful for the guidance of percutaneous biopsy. A variety of congenital and developmental vertebral abnormalities, including dysraphic states, spondylolysis, and spinal stenosis, are optimally assessed using CT. Quantitative CT affords selective analysis of trabecular bone in the spine and has proven useful for the detection and follow-up of osteoporosis as well as other forms of metabolic bone disease. Most recently, the application of multiplanar reformation and three-dimensional image reconstruction has enhanced presentation of diagnostic information contained on cross-sectional images.
The author presents his experience with computed tomography (CT) in the diagnosis of sternal anomalies. The normal anatomy of the sternum and the peristernal soft tissues are described. The embryology, pertinent to the understanding of congenital sternal anomalies, is reviewed. The technique used to image the sternum is briefly explained. Variants of the sternum, traumatic changes, iatrogenic alterations, inflammation, and neoplastic lesions are illustrated. It is concluded that CT offers definite advantages in the evaluation of presumed sternal pathology and should be the examination of choice in the appropriate clinical setting.
When chronic renal failure was a routinely fatal condition little attention needed to be paid to the recognition and management of the associated bone disease. The improved medical and surgical management have prolonged the lives of children with chronic renal disease, but in so doing it has also changed the nature of their biochemical environment. These two factors contribute to an increase in the spectrum of abnormalities we see in the bones of children with renal failure, some of which are still unexplained. It has become even more important for the radiologist to recognize subtle as well as overt alterations in the bony architecture because these will influence the clinical management. This is especially true in children because of the severe growth impairment as well as the bony deformities that result from long-standing renal disease.
Recent technical advances have greatly increased the effectiveness of barium enema examinations for detection of common diseases of the colon. As documented in the literature, the double-contrast enema may equal or exceed colonoscopy in detection of colonic neoplasms and, with proper technique, the single-contrast enema may also closely approach these results. This presentation reviews recent technical improvements in the areas of radiographic-fluoroscopic equipment, fluoroscopic images, film-screen combinations, barium suspensions, examination techniques, filming sequences, and quality controls. These are employed to optimize both the double- and single-contrast barium enemas to where their sensitivities are competitive with endoscopy.
Evaluation of gallbladder diseases by computed tomography (CT) is limited compared with ultrasonographic evaluation. However, CT can bring about excellent information in advanced carcinoma of the gallbladder, severe and complicated cholecystitis, porcelain gallbladder, and indication for dissolution of gallbladder stones. Unique findings are also available in emphysematous cholecystitis, xanthogranulomatous cholecystitis, stones with gas (Mercedez-Benz sign), limy bile, and enhancement in acute cholecystitis. Combined use of CT and ultrasound apparently increase the accuracy of diagnosis in carcinoma and cholecystitis. This article is composed of sections on carcinoma, cholecystitis, stone, bile in the gallbladder, calcification, gas and fat, and miscellaneous topics including polypoid lesions, adenomyomatosis, hydrops, and wall thickening.
