Therapeutic biliary endoscopy is a more recent subspecialty than interventional biliary radiology, and much has been learned from the pioneering work of interventional radiologists. The areas of interest to biliary radiologists and biliary endoscopists are largely identical. The common bile duct can be approached either by the antegrade percutaneous transhepatic approach or by the retrograde endoscopic transpapillary route. In most cases, endoscopy is the treatment of choice because of its lower risk. A new era in therapeutic endoscopy began with the invention of endoscopic papillotomy in 1973 by Classen and Demling in Germany  and Kawai et al. in Japan . This technique made access to the hepatobiliary and pancreatic ductal systems possible, and endoscopic papillotomy has replaced choledochotomy for the treatment of bile duct stones in many centers. Endoscopic or radiologic treatment can entirely replace surgical management. The radiologic approach is advantageous via the endoscopic route when a patient has residual stones in a T tube or intrahepatic stones that lie proximal to a stricture. For patients who have had abdominal surgery and in whom access to the papilla is sometimes impossible because of a long afferent jejunal loop, radiologic therapy is suitable. They also can be treated by the rendezvous approach, whereby the radiologist feeds a guidewire through the papilla into the duodenum and the endoscopist then accesses the bile duct in a retrograde fashion. Calculous disease and ductal stenoses are the main indications for endoscopic therapy; these and other conditions of the biliary tract will be discussed here.
Cardiovascular disease is the leading cause of death in the United States. According to numbers compiled by the American Heart Association, nearly one of every two Americans dies of cardiovascular disease. For example, in 1987, 976,706 (46%) of the estimated 2,127,000 deaths recorded in the United States were attributable to diseases of the heart and blood vessels . Most of these deaths can be attributed to atherosclerosis and its ensuing complications. The pathogenesis of atherosclerosis is not completely understood. Nevertheless, the purpose of this review is to provide an overview of how an atherosclerotic lesion might develop on the basis of our current understanding. This overview will focus on one hypothesis of atherosclerosis development, the modified response-to-injury hypothesis. Several additional hypotheses will be described briefly. These descriptions can serve as a framework on which researchers can build a more complete understanding of the processes involved in this complicated, multifactorial disease.
Hypercoagulability is a state in which an alteration of the blood shifts the hemostatic balance toward excessive platelet/fibrin deposition leading to arterial and/or venous thrombosis . Although the concept of hypercoagulability has been recognized clinically for more than a century, in recent years a number of specific disorders have been define, diagnostic tests developed, and treatment regimens improved. The currently recognized disorders are generally classified as primary or secondary states, although some of the primary conditions may develop as a result of other disorders (Table 1). The primary disorders generally result from abnormalities of proteins in the coagulation or fibrinolytic systems. Although the number of secondary conditions is much greater, generally these syndromes are not as precisely defined on a molecular basis. Secondary hypercoagulability syndromes are subclassified into abnormalities of platelets, coagulation and fibrinolysis, and blood vessels and rheology (Table 1). While the prevalence and clinical significance of hypercoagulability are becoming increasingly apparent to physicians in general, this pathologic state is an especially practical concern to vascular interventionalists, as hypercoagulability is an important cause of early thrombosis after otherwise uncomplicated arterial interventional procedures. The purpose of this review is to describe the clinical presentation, diagnosis, and treatment of the hypercoagulability syndromes most likely to be encountered by the interventional radiologist.
Most radiologists are familiar with the clinical and radiologic features of the familial adenomatous polyposis syndromes . The hamartomatous polyposis syndromes occur less frequently, however, and their radiologic and clinical manifestations are not as well known. This group of syndromes includes Peutz-Jeghers, multiple hamartoma, juvenile polyposis, Cronkhite-Canada, and Bannayan-Riley-Ruvalcaba. The predominant gastrointestinal lesion in these diseases is some form of hamartomatous polyp. The term hamartoma implies a nonneoplastic tumor or tumorlike condition composed of tissue elements normally present in the particular area . In many of these syndromes, it is now recognized that hamartomatous polyps of the gastrointestinal tract coexist with adenomas and that adenomas may develop within hamartomatous polyps. Either situation may contribute to the frequent association of alimentary tract adenocarcinoma that occurs in most of these syndromes. Various types of benign mucocutaneous lesions are common and often lead to the correct diagnosis. Of greater importance is the frequent occurrence of other extraintestinal manifestations, including several forms of malignant disease. Because of this frequent association with both gastrointestinal and nongastrointestinal malignant tumors, early and accurate diagnosis of these syndromes is essential. Meticulously performed double contrast studies are the preferred radiologic procedures for the diagnosis of gastrointestinal polyps in all of these diseases.
The aneurysmal bone cyst is the result of a specific pathophysiologic change, which is probably the result of trauma or a tumor-induced anomalous vascular process. In approximately one third of cases, the preexisting lesion can be clearly identified. The most common of these is the giant cell tumor, which accounts for 19-39% of cases in which the preceding lesion is found. Other common precursor lesions include osteoblastoma, angioma, and chondroblastoma. Less common lesions include fibrous dysplasia, fibroxanthoma (nonossifying fibroma), chondromyxoid fibroma, solitary bone cyst, fibrous histiocytoma, eosinophilic granuloma, and even osteosarcoma. Interestingly, some of the controversy surrounding this lesion may be the result of a change in how the lesion was defined by Lichtenstein in 1953, when intramedullary lesions were added to the previously described juxtacortical (superficial) lesions. Members of the AFIP have suggested that many of the intramedullary lesions in which no previous lesion can be identified may represent giant cell tumors of bone. Their similarity to proved giant cell tumors in skeletally immature patients can be striking and seems more than coincidental. Appropriate treatment of an aneurysmal bone cyst requires the realization that it results from a specific pathophysiologic process, and identification of the preexisting lesion, if possible, is essential. Clearly an osteosarcoma with superimposed secondary aneurysmal bone cyst change must be treated as an osteosarcoma, and giant cell tumor with secondary features of aneurysmal bone cyst would be expected to be more likely to recur locally. The vast majority (approximately 80%) of patients presenting with aneurysmal bone cystlike findings are less than 20 years old. More than half of all such lesions occur in long bones, with approximately 12-30% of cases occurring in the spine. The pelvis accounts for about half of all flat bone lesions. Most patients present with pain and/or swelling, with symptoms usually present for less than 6 months. The imaging appearance of aneurysmal bone cyst reflects the underlying pathophysiologic change. Radiographs show an eccentric, lytic lesion with an expanded, remodeled "blown-out" or "ballooned" bony contour of the host bone, frequently with a delicate trabeculated appearance. Radiographs may rarely show flocculent densities within the lesion, which may mimic chondroid matrix. CT scanning will define the lesion and is especially valuable for those lesions located in areas in which the bony anatomy is complex, and which are not adequately evaluated by plain films. Fluid-fluid levels are common and may be seen on CT scans and MR images.(ABSTRACT TRUNCATED AT 250 WORDS)
Percutaneous catheter drainage of intrathoracic collections has developed as a natural extension of similar interventional radiologic procedures in the abdomen. The advent of CT and sonography, which allow detection and characterization of pleural and parenchymal collections, combined with advances in drainage catheter design and interventional techniques, have made imaging-guided management of intrathoracic collections a safe and effective alternative to traditional surgical therapy. This article begins with a review of the etiology, pathophysiology, diagnosis, and treatment of parapneumonic pleural effusion, which remains the most common indication for image-guided percutaneous drainage. Subsequent sections consider issues related to percutaneous drainage of malignant pleural effusion, lung abscess, and pneumothorax.
This study evaluates small-bore catheter thoracostomy combined with doxycycline sclerotherapy for palliative treatment of presumed malignant pleural effusions.
Forty-seven consecutive patients referred from the medical oncology department to the thoracic radiology section with known primary malignant tumors and symptomatic pleural effusions over a 2-year period were treated with small-bore pleural catheter drainage followed by doxycycline sclerotherapy. Of the 47 patients, 20 (43%) died less than 30 days after sclerotherapy, one (2%) died without radiographic follow-up, and five (11%) were lost to follow-up. Twenty-one patients formed the study group. Response to treatment was defined based on findings on follow-up chest radiographs obtained 30 days after sclerotherapy as complete (no reaccumulation of pleural effusion), partial (accumulation above postpleurodesis level but below that at presentation), or as a failure (reaccumulation to the amount seen at presentation).
Seventeen (81%) evaluable patients showed complete response to sclerotherapy, three (14%) showed a partial response, and one (5%) showed no response. All complete and partial responders were clinically improved with resolution of their shortness of breath. Therefore, 95% of evaluable patients had clinically and radiographically successful treatment. Six patients underwent sclerotherapy when their tube output was greater than 100 ml/24 hr. Five of the six had completely successful pleurodesis, and one failed to respond. Two (10%) of the 21 patients had greater than 150 ml drainage in the 24 hr after initial doxycycline administration and were therefore given a second dose of intrapleural doxycycline. Both of these patients subsequently had less than 150 ml drainage in an additional 24-hr observation period and went on to complete response. Complications included three patients (14%) with mild discomfort at the chest tube site during drainage, one patient (5%) with pain during instillation of doxycycline, and one patient (5%) with transient fever (38.3 degrees C body temperature) one day after sclerotherapy.
Small-bore catheter thoracostomy followed by doxycycline sclerotherapy successfully resolves symptomatic pleural effusion in patients with known primary malignant tumors.
Several recent clinical studies have described an association between HIV seropositivity and lung cancer. The purpose of this study was to describe the spectrum of imaging findings in HIV-positive patients who had proved carcinoma of the lung. In particular, we attempted to define the role of CT in diagnosing HIV-associated lung cancer.
The study population consisted of 23 HIV-positive patients from two institutions who had lung cancer diagnosed between 1989 and 1993. All patients had both chest radiographs and CT scans. The group included 19 men and four women with a mean age of 42 years. The diagnosis of lung cancer was confirmed by bronchoscopy in eight patients, by pleural fluid aspiration or pleural biopsy in seven, by percutaneous needle biopsy of a lung lesion in three, by biopsy of an extrathoracic site in four, and by thoracotomy in one. Two thoracic radiologists retrospectively evaluated the chest radiographs and CT scans to identify parenchymal masses, lymphadenopathy, pleural disease, chest wall or mediastinal invasion, and metastatic lesions.
Fifteen (65%) of the 23 patients had a central or peripheral mass or nodule. Eight (35%) had extensive pleural disease, either as an isolated finding or in combination with other abnormalities. CT scans showed the malignant lesion underlying the extensive pleural disease in all but one case. All patients with extensive pleural disease had adenocarcinoma. No patient in the study was considered a candidate for resection on the basis of clinical and radiologic evaluation.
Lung cancer in HIV-positive patients manifested most often on chest radiographs as a central or peripheral mass or nodule. Extensive pleural disease in the absence of an apparent primary lesion was the second most common major manifestation. Lung cancer therefore merits serious consideration in the differential diagnosis of extensive pleural disease in HIV-positive patients. CT was most useful in evaluating malignant lesions associated with extensive pleural disease.
Postthoracotomy atrophy of chest wall muscles results from nerve injury during surgery. After encountering patients with different patterns of chest wall muscular atrophy postthoracotomy, we performed this study to determine the relationship between type of thoracotomy and atrophic muscles as seen on CT scans.
CT scans of 58 patients who had previously undergone unilateral thoracotomy were reviewed. Forty patients had a posterolateral thoracotomy, and 18 had an anterolateral thoracotomy. In two cases, the incision extended posteriorly. Atrophy seen on CT scans was defined as a marked decrease in size or thickness of a muscle compared with the muscle on the other side.
Atrophy of the latissimus dorsi muscle and of the inferior portion of the serratus anterior muscle was detected on CT scans in 40 patients. No atrophy was found in 16 patients. The remaining two displayed atrophy only in the serratus anterior muscle. Atrophy of the latissimus dorsi muscle and of the inferior portion of the serratus anterior muscle developed in all patients who had a posterolateral thoracotomy. Atrophy developed in only two of the 18 patients who had an anterolateral thoracotomy, and in these two, the incision had been extended posteriorly.
A direct correlation was found between type of thoracotomy and site of atrophy of the chest wall muscles seen on CT scans. This finding may account for different CT appearances of the thoracic wall in patients who have had thoracic surgery.
We wanted to determine minimal tube current (mAs) required for consistently good image quality on conventional 10-mm collimation chest CT and effect of tube current reduction on detection of mediastinal and lung abnormalities. Tube current reduction is desirable to reduce patient radiation dose.
Prospectively, 30 consecutive patients (mean weight, 68 kg; range, 34-93 kg) older than 45 undergoing conventional chest CT with standard technique (120 kVp, 400 mAs) had four additional sections imaged at reduced tube current (200, 140, 80, 20 mAs) at two levels (tracheal carina and left atrium). CT scans were evaluated in random order by two independent observers who were blinded to technical factors used. Subjective image quality was graded on a five-point scale from non-diagnostic to excellent. Visualization of mediastinal adenopathy (n = 18), pleural plaques (n = 17), effusions (n = 28), lung parenchymal nodules (n = 37), and emphysema (n = 15) were assessed. The 400 mAs scan was considered the reference standard.
When compared with the reference technique (400 mAs), the first and second (200 mAs and 140 mAs) reduction levels showed no significant difference (p > .05) in subjective image quality. A significant difference (p < .001) was seen at the third and fourth (80 mAs and 20 mAs) reduction levels. However, no significant difference (p > .05) was seen in detection of mediastinal or lung parenchymal abnormalities with different tube currents.
A twofold reduction in tube current (400-140 mAs) and resultant radiation dose did not cause a significant change in subjective image quality or in detection of mediastinal or lung abnormalities with conventional chest CT. One hundred forty milliampere-seconds is the minimal tube current required to provide good image quality in patients of average weight.
Advances in organ procurement and surgical techniques have made orthotopic liver transplantation (OLT) an accepted treatment for many adult patients with end-stage hepatic disease. At present, OLT is being performed in patients with a variety of diseases, and 5-year survival is estimated at 65-78% . Over 80% of hepatic transplants are performed in patients with cirrhosis or primary cholestatic liver disease, and only 5% of transplants are performed for malignant hepatic neoplasms (Table 1) . Because the supply of donor organs is limited, preoperative clinical and radiologic evaluation of the transplant candidate is critical for appropriate patient selection. The main objective of preoperative imaging is to provide the surgeon with the pertinent information needed to plan and perform OLT and to exclude patients for whom surgery either is not feasible or will be of no benefit.
The purpose of this study was to compare two time delays between injection of contrast material and helical CT scanning to determine relative conspicuity of hepatic metastases.
Twenty-five patients with hepatic metastases were examined with helical CT. The first imaging phase was initiated at 50 sec and the second 75 sec after the start of contrast material injection (3 ml/sec, 150 ml). Differences in lesion and liver attenuation were measured quantitatively. Four radiologists used a 5-point scale to assess lesion conspicuity subjectively.
Mean differences in enhancement between liver and lesion were 41 H during the first phase and 59 H for the second phase (p = .0001). Radiologists' conspicuity score averaged 2.4 for lesions in the first phase versus 3.3 for lesions in the second phase (p = .0001). In 56 (88%) of 64 lesions, objective measurements showed greater enhancement of lesions during the later phase. Radiologists found 60 (94%) of 64 lesions to be more conspicuous on these later images.
Our results show that conspicuity of hepatic metastases on helical CT scans is better with a 75-sec scan delay between contrast administration and scanning than with a 50-sec scan delay. The longer delay time should be used when scanning is used to detect metastases.
Differentiating between cavernous hemangiomas of the liver and hepatic metastases on the basis of single-pass, contrast-enhanced CT is a significant and frequently encountered diagnostic challenge. Recognition of characteristic enhancement features of cavernous hemangiomas can aid in effectively distinguishing between these lesions. The purpose of this study was to determine sensitivity and specificity of dense, globular enhancement for differentiating cavernos hemangiomas and metastases during single-pass, contrast-enhanced CT.
CT appearance of 133 lesions in 91 patients with cavernous hemangiomas (44 patients) or metastases (47 patients) was retrospectively evaluated in a blinded review. CT examinations were performed with nonhelical technique following injection of 150 ml of contrast material. All patients with metastases had pathologic proof (n = 47). Patients with cavernous hemangiomas were clinically stable for at least 2 years after CT (n = 43) or had tissue proof (n = 1). All lesions were evaluated based on the following criteria: (1) Type of enhancement: globular, linear, diffuse and homogeneous, or diffuse and heterogeneous. (Globular enhancement was considered to be present when enhancing nodules less than 1 cm in diameter were seen within lesions.) (2) Continuity of enhancing tissue: continuous or noncontinuous. (Uninterrupted collections of contrast material within at least 50% of a lesion were considered continuous. Multiple, separate collections of contrast material were considered noncontinuous.) (3) Degree of enhancement: hypo-, iso-, or hyperdense relative to the aorta. (4) Distribution of enhancement: peripheral, central, or mixed.
Seventy-six percent of cavernous hemangiomas had globular enhancement, compared to 10% of metastases (p < .001). Seventy-two percent of cavernous hemangiomas had enhancement isodense with the aorta, and 96% of metastases were hypodense (p < .001). Sixty-seven percent of cavernous hemangiomas had peripheral enhancement, compared to 38% of metastases (p < .001). The combined finding of globular, isodense enhancement was seen in 67% of cavernous hemangiomas and none of the metastases. Only 10% of cavernous hemangiomas had nonglobular, hypodense enhancement, compared with 90% of metastases. Combining all criteria, reviewers correctly classified 122 (92%) of the lesions. Presence of globular enhancement, isodense with the aorta, was 67% sensitive and 100% specific in differentiating cavernous hemangiomas from hepatic metastases.
In most cases, differentiation of cavernous hemangiomas from hepatic metastases can confidently be made with single-pass, contrast-enhanced CT. Globular enhancement, isodense with the aorta, is 67% sensitive and 100% specific in differentiating cavernous hemangiomas and hepatic metastases.
The pancreas is located deep within the retroperitoneum in the anterior pararenal space. The distal portion of the pancreatic tail extends along the course of the splenic artery and vein (Fig. 1) and enters the splenic hilum contained within the splenorenal ligament. Because of these anatomic relationships, the spleen and splenic vessels may be involved by pancreatitis. Although rare (frequency, 1-5%), splenic involvement by pancreatitis includes intrasplenic pseudocyst, abscess, hemorrhage, infarction, splenic rupture, and vascular injury. Because these complications can be life-threatening, the extent and course of the disease are closely monitored with CT to determine whether and when aggressive intervention is necessary to avoid catastrophic clinical outcomes. The purpose of this essay is to illustrate the spectrum of CT findings in cases of pancreatitis with splenic involvement.
CT and conventional MR imaging are helpful in characterizing adrenal tumors, but a specific diagnosis is not achieved for a substantial number of lesions. Chemical-shift imaging relies on the different resonance frequencies of protons in water and triglyceride molecules and therefore may permit a more specific diagnosis of adrenal adenomas, which are known to contain abundant lipid. The purpose of this study was to evaluate the usefulness of chemical-shift MR imaging in the differentiation of adrenal adenomas from other adrenal masses.
Forty-one adrenal masses (17 nonhyperfunctioning adenomas, two aldosteronomas, six pheochromocytomas, one ganglioneuroma, five adrenal carcinomas, one lymphoma, seven metastases, one case of extramedullary hematopoiesis, and one leiomyosarcoma) suspected clinically or identified by sonography or CT in 38 patients were prospectively evaluated with MR imaging. Pathologic proof of diagnosis was obtained for 28 lesions, and stability on imaging follow-up (mean, 19 months) was accepted as proof of diagnosis of benign adenoma for 13 lesions. In-phase T1-weighted spin-echo sequences (500/20 [TR/TE]) and opposed-phase gradient-echo sequences (142/6.3, flip angle = 90 degrees) of the adrenal regions were applied. Quantitative analysis of signal intensity loss in the adrenal lesions relative to reference tissues (liver, muscle, and spleen) on in-phase and opposed-phase sequences was done to differentiate adenomas from nonadenomas. Region-of-interest signal intensity measurements were obtained in a standard fashion by selection of the largest possible representative sample.
Using liver as the reference standard, we found that mean signal intensity ratios were 0.47 (range, 0.23-0.97) for adrenal adenomas and 0.88 (range, 0.65-1.32) for nonadenomas; signal intensity ratios for two adenomas overlapped those of the nonadenomas. Using muscle as the reference standard, we found that mean signal intensity ratios were 0.44 (range, 0.22-0.66) for adrenal adenomas and 0.85 (range, 0.59-1.39) for nonadenomas; signal intensity ratios for two adenomas overlapped those of the nonadenomas. Using spleen as the reference standard, we found that mean signal intensity ratios were 0.45 (range, 0.27-0.73) for adrenal adenomas and 0.97 (range, 0.8-1.18) for nonadenomas, with no overlap. The mean signal intensity ratios were significantly different between adenomas and nonadenomas for all three reference tissues (p < .001).
Our results show that chemical-shift MR imaging is an important new technique that enables the differentiation of adrenal adenomas from other adrenal masses, reducing the need for biopsy and prolonged imaging follow-up in patients with adrenal tumors.
The purpose of this study was to determine the gray-scale and color Doppler sonographic appearance of testicular lymphoma and leukemia to aid in its differentiation from primary testicular neoplasms and inflammatory processes.
We retrospectively reviewed the testicular sonograms of eight male patients 5-74 years old (mean age, 43 years) with pathologically proved testicular leukemia or lymphoma. All patients presented with testicular enlargement. Gray-scale sonograms were obtained to determine the presence or absence of a mass, focal nodule, or diffuse infiltration, as well as the degree of parenchymal echogenicity. Color Doppler sonography was applied in each case to determine the degree of vascularity compared with normal ipsilateral or contralateral testicular parenchyma. In patients with focal, measurable lesions, the size was correlated with its color Doppler sonographic appearance.
Gray-scale sonograms showed either homogeneously hypoechoic testes in patients with diffuse round-cell infiltration or multifocal hypoechoic lesions of various sizes. Five patients had a total of 11 focal lesions that ranged in size from 8 mm to 26 mm in maximum diameter (mean diameter, 16 mm). Color Doppler sonography revealed increased intralesional flow in all areas of lymphomatous or leukemic involvement irrespective of lesion size.
Our results show that testicular lymphoma and leukemia are hypervascular on color Doppler sonograms regardless of the size of the tumor. Although color Doppler sonography may provide useful information, differentiating round-cell infiltration from inflammatory processes of the testes remains difficult.
Retrograde flow in the internal spermatic vein, which is characteristic of varicocele, can occur despite competent valves because of the presence of bypassing anastomoses. The resulting condition has been called aberrantly fed varicocele. The purpose of this study was to determine the frequency of aberrantly fed varicocele, to analyze its various venographic appearances, and to review the results of attempted embolotherapy.
We performed left-sided (n = 213) and/or right-sided (n = 121) spermatic venography in 213 patients who were examined for infertility (n = 179), for physical complaints of their varicocele (n = 17), or for varicocele impeding testicular growth (n = 17). The resulting 334 venograms were subdivided as negative or positive for varicocele, and positive venograms were further classified as showing normally or aberrantly fed varicoceles. The aberrantly fed varicoceles were classified according to the sites of the bypassed competent valves and the levels at which the bypassing anastomoses joined the internal spermatic veins. The technical success rate of 192 attempted embolizations of normally and aberrantly fed varicoceles was determined.
Of the left-sided spermatic venograms, 42 (20%) were negative and 171 (80%) were positive for varicoceles, which in turn consisted of 125 normally and 30 (19%) aberrantly fed varicoceles (16 could not be classified). On the right side, 78 (64%) venograms were negative and 43 (36%) were positive for varicoceles, consisting of 34 normally and seven (17%) aberrantly fed varicoceles (two were not classified). Venographic classification showed that about half of the cases were in patients with competent orificial valves, which were bypassed by anastomoses joining the internal spermatic veins in their cranial lumbar subsegments. Competent valves lower down were seen only on the left side, and anastomoses joining the internal spermatic veins in their cranial pelvic subsegments occurred relatively more frequently on the right side. Coil embolization was attempted in 118 left-sided and 32 right-sided normally fed varicoceles and in 30 left-sided and seven right-sided aberrantly fed varicoceles. The technical success rate was 97% for left- and right-sided normally fed varicoceles and 73% for left-sided and 57% for right-sided aberrantly fed varicoceles.
Aberrantly fed varicoceles are found in 17-19% of patients examined with spermatic venography. Coil embolization of aberrantly fed varicoceles is usually successful, but not as reliably as with normally fed varicoceles.
Spinal tuberculosis, the most common form of skeletal involvement, is increasing in prevalence because of the resurgence of tuberculosis during the past decade in patients with AIDS, the spread of tuberculosis among the homeless, and the expanding immigrant population. Spinal infection is usually the result of hematogenous seeding of the vertebral body, and the diagnosis often remains elusive because of the indolent nature of tuberculous infection. As a result, the radiographic findings and the signs and symptoms are typically far advanced when the diagnosis is finally established. Radiographic manifestations of tuberculous spondylitis include intraosseous and paraspinal abscess formation, subligamentous spread of infection, vertebral body destruction and collapse, and extension into the spinal epidural space. Significant instability and deformity of the spine can result, mandating prompt diagnosis and treatment to prevent permanent neurologic damage. The purpose of this essay is to illustrate the broad spectrum of imaging findings on plain radiographs, bone scans, CT scans, myelograms, and MR images of patients with spinal tuberculosis. The value of MR imaging in determining the extent of disease is demonstrated.
Imaging the lumbar spine after surgery for disk herniation is all too often an unrewarding challenge. A constellation of findings is inevitable, and determining their significance is often impossible. The challenge is greatest during the first few months following surgery, when the rules of scar enhancement, deformity, and mass effect do not apply to differentiation of the abnormal from the normal. A clear understanding of normal postoperative healing is necessary to avoid overreaction to misleading findings. This report reviews imaging of the lumbar spine in the early postoperative period (i.e., the first 6 months after surgery), focusing on the normal healing process that so often mimics complicating or recurrent disease.
Arterial dissection occurs when an intimal tear allows blood to enter the arterial wall, potentially compromising the lumen and reducing blood flow. Carotid and vertebral artery dissections typically occur after major trauma, although they also can arise spontaneously or after trivial injury. Arterial dissection has been associated with a variety of factors, including hypertension, fibromuscular dysplasia, Marfan syndrome, cystic medial necrosis, oral contraceptives, drug abuse (sympathomimetics), and infection [1-8]. It is important to recognize arterial dissection early so that prompt treatment can be initiated to prevent ischemic complications . In this essay, we illustrate the use of MR angiography in the diagnosis of carotid and vertebral artery dissection.
Lichtenstein  in 1938 coined the term fibrous dysplasia to describe a disorder characterized by the progressive replacement of normal bone elements by fibrous tissue. Histopathologically, these lesions consist of an abnormal proliferation of fibrous elements intermixed with haphazardly arranged trabeculae of woven bone. The disease can involve any bone in the body. In the head and neck, the skull and facial bones are involved in 10-25% of cases of monostotic fibrous dysplasia and in 50% of the polyostotic variety. Involvement of the temporal bone, however, is relatively rare, and only 53 cases have been reported. The three major radiographic classifications of fibrous dysplasia are pagetoid, sclerotic, and cystic. Any of these types may involve the temporal bone and related structures, including the external canal, middle ear, jugular foramen, or, rarely, the otic capsule. In this essay, we illustrate the radiographic features of the disease based on our experience with seven cases, seen at our institution since 1977, of fibrous dysplasia involving the temporal bone.
Lesions of the skull vault are fairly common; however, they are often difficult to diagnose. By using specific imaging criteria, one may readily diagnose a calvarial hemangioma. These lesions account for 10% of benign primary neoplasms of the skull . This essay illustrates the spectrum of imaging findings seen on plain radiography, CT, MR imaging, and angiography for patients with calvarial hemangiomas.
Obstructive lung disease is a major complication of bone marrow transplantation related to graft-versus-host disease. The purpose of this study was to determine the usefulness of high-resolution CT to evaluate obstructive lung disease occurring in children after bone marrow transplantation.
Ten high-resolution CT scans of the lungs were obtained in seven children who developed chronic obstructive lung disease after bone marrow transplantation. All seven patients had chronic graft-versus-host disease. Spirometry, the gold standard test, confirmed airflow obstruction in each case, five prior to high-resolution CT. Two patients were too young to have spirometry until 10 and 15 months respectively after successful high-resolution CT. Selected images from these studies were randomized with similar images from five control subjects and reviewed blindly. All images from scans in patients with obstructive lung disease were analyzed retrospectively for parenchymal hypoattenuation, bronchial dilatation, bronchial wall thickening, and abnormal parenchymal opacity. Expiratory air-trapping was assessed on cine high-resolution CT done in four cases.
Three blinded observers each correctly identified all five controls among 15 high-resolution CT examinations. No scan from a patient with obstructive lung disease was considered normal. Areas of parenchymal hypoattenuation affected 35 of 35 lobes of the lung. Expiratory air-trapping was shown by cine high-resolution CT. Subsegmental or segmental bronchial dilatation was seen in 23 of 25 lobes in five patients. Bronchial wall thickening was not a prominent feature. Increasing abnormality was demonstrated in three patients on follow-up high-resolution CT. The high-resolution CT abnormalities were similar to those reported in patients with bronchiolitis obliterans.
High-resolution CT of the lungs can show extensive abnormality in children who develop chronic obstructive lung disease after bone marrow transplantation. High-resolution CT is a useful noninvasive technique in the evaluation of this disease.
The purpose of this study was to identify CT characteristics of rhabdoid tumor of the kidney, a rare, aggressive, malignant neoplasm of unknown origin that occurs mainly in infants and young children.
CT scans of eight children (newborn to 13 years old; mode, 4 months old; six boys and two girls) with histopathologic diagnosis of rhabdoid tumor of the kidney were evaluated retrospectively by two of the authors, who were not blinded to the diagnosis. All eight CT scans were performed with intravenous and oral contrast, and noncontrast intravenous CT scans were available in four cases. The following CT characteristics were evaluated: location of tumor within the kidney; presence of calcification, subcapsular hematoma, multiple tumor lobules, enlarged vessels, vascular invasion, or central tumor necrosis or hemorrhage; visibility of tumor margin; distant metastasis; and primary tumor size.
All eight primary tumors (five on the left, one of which had contralateral renal nodules) were central in location and involved the hilum. Calcification outlining the tumor lobule was present in two of the four tumors on noncontrast CT scans. Subcapsular hematoma was seen in five children. Tumor necrosis and hemorrhage were seen in seven children. Tumors were well defined from the renal cortex in four children. Lobules of tumor were seen in seven children.
CT findings of calcification, subcapsular hematoma, and lobular appearance in a large, centrally located, and heterogeneous renal mass in a child suggest a rhabdoid tumor of the kidney.
The purpose of our study was to identify the radiographic signs that aid in the diagnosis of obstruction of the ureteropelvic junction of the lower pole (or moiety) of the kidney in children with complete duplication of the ureter and to describe the imaging appearance of this unusual cause of lower-pole hydronephrosis.
We reviewed the medical records and imaging studies of 16 children (11 boys and five girls) with complete ureteral duplication and ureteropelvic junction obstruction of the lower pole of the kidney over a 5-year period. standard criteria for determining urinary tract obstruction were used.
Sonograms showed a lower-pole abnormality (hydronephrosis or cystic mass) in all 15 children who underwent sonography. Voiding cystourethrography, performed for all children, showed vesicoureteral reflux into the lower pole in addition to ureteropelvic junction obstruction in eight children (seven boys and one girl). For the other eight, the diagnosis of lower-pole ureteropelvic junction obstruction was made by excretory urography, at times complemented with diuretic renography or retrograde ureterography.
Ureteropelvic junction obstruction of the lower pole of the kidney in children with complete duplication of the ureter should be a diagnostic consideration when there is dilatation of the lower moiety. Imaging changes parallel those of ureteropelvic junction obstruction in a nonduplicated system. This anomaly, unlike others seen in duplication, appears to be more common in boys than in girls.
Intrauterine growth retardation (IUGR) may arise from a variety of causes, including placental insufficiency, maternal diseases, and fetal anomalies. Sonography plays a number of important roles in the diagnosis and management of growth retardation. Diagnosis of IUGR is based on fetal measurements, assessment of amniotic fluid volume, and other sonographic findings. Once IUGR has been diagnosed, sonography can help establish its cause. If a lethal cause is excluded, the fetus is monitored for the remainder of the pregnancy using sonography, including serial fetal measurements, biophysical profiles, and Doppler waveform indexes. Used appropriately, sonography can improve the outcome of fetuses with IUGR.
The goal of our study was to analyze the fetal renal pelvic diameters measured sonographically at several gestational intervals in live-born neonates subsequently found to have either obstructive uropathy or normal kidneys. This information will improve the efficacy of sonography in the diagnosis of obstructive uropathy.
From an ongoing prospective study assessing the significance of fetal renal pelvic diameters of 4 mm or more at obstetric sonography, the findings in 29 obstructed kidneys in 24 babies were compared with the findings in 380 kidneys from 233 infants who had no obstruction. Twenty-three infants had unilateral obstruction of the ureteropelvic junction, two had unilateral renal obstruction at the ureterovesical junction, one had posterior urethral valves and in addition had both kidneys obstructed because of obstruction at the ureterovesical junction, one kidney was obstructed because of megaloureter, and one kidney was obstructed because of obstruction in a duplex collecting system. Obstruction was identified on nephrostograms, excretory urograms, or radionuclide renograms. The sonographic findings were compared at three gestational age ranges: 16-23 weeks' gestation, 24-30 weeks' gestation, and 31-40 weeks' gestation. The progression of pelvic dilatation in both groups (12 obstructed and 86 unobstructed) was analyzed for the subset of kidneys examined in all three time periods.
At 16-23 weeks' gestation, the difference in mean pelvic diameter between obstructed and unobstructed kidneys was not statistically significant, but the difference between obstructed and unobstructed groups at 24-30 weeks' and 31-40 weeks' gestation was significant (p < .001). Renal pelvic diameter showed a much greater rise in diameter through pregnancy in the obstructed group than in the unobstructed group (p < .0003). The sensitivity of the cutoff point of 4-mm renal pelvic diameter for detecting obstruction was 76% before 23 weeks' gestation, including kidneys with a marked decrease in function postnatally; the sensitivity of a 10-mm cutoff point at 16-23 weeks' gestation was 12%. The likelihood that a fetus had renal obstruction increased with increasing diameter of the fetal renal pelvis in all three time periods.
Kidneys with significant obstruction postnatally may have no dilatation of the renal pelvis before 23 weeks' gestation. Most obstructed kidneys had pelvic diameters of less than 10 mm before 23 weeks' gestation. During pregnancy, renal pelvic diameter increases at a greater rate in kidneys that later are shown to be obstructed than in those that are not obstructed.
Aqueductal stenosis is a common cause of fetal hydrocephalus. Published studies of neonates with aqueductal stenosis have noted variable outcomes, with normal development seen in 24-86% of cases. In an attempt to better assess long-term outcomes in cases diagnosed in utero and to determine what prenatal sonographic findings might be used to predict prognosis, a retrospective analysis of patients with aqueductal stenosis was done.
Fifty-three consecutive cases of aqueductal stenosis discovered in utero at two high-risk obstetrical centers in Seattle between 1980 and 1993 were studied. Parents elected to continue pregnancy in 39 of these cases. Two months to 10 years of long-term follow-up was available in 30 patients, who form our study group. Prenatal sonograms, postnatal cranial ultrasound, and head CT and MR were evaluated. Prenatal sonographic data collected included the biparietal diameter, size of the lateral and third ventricles, the ratio of the two, and thickness of the frontoparietal cortical mantle. Medical records provided an assessment of development based on physical examination, meeting of major milestones, and neuropsychological testing. The in utero diagnosis of aqueductal stenosis was confirmed by postnatal CT, MR imaging, sonography, or autopsy.
Within the study group of 30 patients, eight died in the postnatal period and four died subsequently. Of the 22 patients with adequate postnatal follow-up, moderate or severe developmental delay was present in 16 (73%). Normal developmental milestones were met in only three (10%) of all 30 patients and in 14% of those surviving the neonatal period. Although size of the lateral and third ventricles was not a useful predictor of long-term prognosis, the ratio of the two, as well as thickness of the frontoparietal cortical mantle, was weakly associated with long-term prognosis. No correlation was found between biparietal diameter and outcome.
As compared with previous reports, prenatal diagnosis of aqueductal stenosis carries a grave prognosis. Twelve of the 30 patients died, for an overall mortality of 40%. Normal development was seen in only 10%, significantly less than in prior studies.
Evaluation of the cerebral ventricular system is a routine part of all fetal sonographic examinations. Ventriculomegaly and decreased choroid volume are indicators of poor fetal outcome, so it is important to know the normal variation of these parameters. The present study describes the normal size of the fetal lateral ventricular atrium and the normal amount of choroid plexus within the atrium during the second and third trimesters.
Six hundred eight consecutive, healthy, singleton fetuses from 13 to 42 weeks' menstrual age were examined prospectively. The atrium of the lateral ventricle was measured in the axial and coronal planes. For each axial measurement, the width of the choroid plexus was determined.
An axial atrial measurement was obtained in 88% of the fetuses, and a coronal atrial measurement was obtained in 84%. The mean measurement and one standard deviation are 6.5 +/- 1.5 mm in the axial plane and 6.6 +/- 1.5 mm in the coronal plane. Ninety-eight percent of all measured atria were at least 60% filled by choroid plexus, and in all cases the atria were at least 50% filled. Complete filling by choroid plexus occurred in 58% of cases.
This large prospective study confirms previous observations of mean atrial size. However, four standard deviations above the mean is 12 mm, suggesting currently used cutoffs for normal atrial size are too low. Other parameters, such as choroid plexus filling, may be helpful markers of normalcy in fetuses with atrial measurements between 8 and 12 mm.
Although several noninvasive techniques now exist for vascular imaging, including MR imaging, three-dimensional CT, and color-flow and duplex sonography, the gold standard to which these techniques are compared remains catheter angiography. Cut-film and digital subtraction angiography (DSA) using iodinated contrast material are the standard methods by which vascular imaging is performed. However, despite the development of low-osmolar contrast agents, premedication regimens, and careful patient selection, adverse reactions to contrast material, including idiosyncratic reactions and contrast-induced nephropathy, continue to occur in a small number of patients [1-3]. Carbon dioxide (CO2) was developed as an alternative to iodinated contrast material to avoid these problems . Once the behavior of intravascular gas, the methods of safe delivery, and the principles of successful imaging are understood, the use of CO2 as an intravascular contrast agent during DSA allows accurate imaging with little risk. Recent advances in delivery systems, postprocessing capabilities, and its extension to new vascular interventional procedures have greatly expanded the usefulness of CO2 angiography in both diagnostic and interventional vascular radiology.
Computers have greatly facilitated the processing and storage of radiologic information. Manufacturers of radiology information systems (RISs) are gradually incorporating options for interfacing their products with other computers (e.g., hospital information systems). However, a growing need exists to also interface RISs with digital radiologic equipment so that images (e.g., computed radiographs of the chest and skeleton) are automatically labeled with identification data. Such connectivity would eliminate redundant work by technologists, decrease errors in the labeling of images, and increase the consistency of patients' data within a radiology department. Unfortunately, the rapid advances in digital technology, combined with the lack of a well-defined standard for the transfer of demographic information between dissimilar systems, have delayed development of these interfaces. We have developed a widely applicable method to automatically transfer patients' demographic data from an RIS to a commercially available computed radiography system. A personal computer is configured with inexpensive programmable telecommunications software to create an interactive gateway, which eliminates the need for redundant data entry (compared with entering data once on the RIS and again on the stand-alone computed radiography system), and thus also decreases errors in the labeling of images.