Picture archiving and communication system-asynchronous transfer mode network in a midsized hospital

This article describes the pathway to full implementation of a hospital information system-picture archiving and communication system-wide area network (HIS-PACS-WAN) in a 300-bed acute care hospital, and the linking of that system to two other off-site medical centers. The PACS included direct digital capture of computed tomography (CT), magnetic resonance (MR) imaging, nuclear medicine, and ultrasonography images into an Olicon archive. Plain radiographs and fluoroscopy images were digitized manually and archived into an Olicon system. The active archive included current images on each Olicon workstation and the juke box. Long-term archiving of the images on removable optical discs, which would be loaded manually by an operator every time a request for one of these studies appeared on the operator's monitor, also was implemented. Ability to store, retrieve, and display simultaneously the physician's report of each procedure along with the images was an ultimate goal. The WAN is to be used for teleradiology and teleconferencing among the three medical centers involved in this study as well as other off-site locations. Phase I included the design and installation of the local area network (LAN) in the Department of Radiology at Olive View-UCLA Medical Center. This included the clinics and the inpatient and hospital-wide fiber-optic network and its linkage to the local telephone company. Phase II involved linkage of the Olicon workstations to imaging equipment. This implementation has been delayed significantly because of inadequate needs assessment, absence of planning for forward-compatibility to imaging equipment, and incompatibilities in DICOM conformance among vendors. Every PACS project must include an in-depth needs analysis, which should be updated yearly because of rapid turnover of technology. Although this analysis should have a heavy emphasis on clinical needs, it must incorporate the hospital-wide needs for an integrated information systems network. Integration of PACS, HIS, RIS, and a dictation/transcription system is a complex task that requires a full-time, clinically oriented project officer for successful completion.

Retroperitoneal hematoma as a complication of pudendal block. Diagnosis made by computed tomography

Images

Magnetic resonance imaging of peripartum rupture of the symphysis pubis

BACKGROUND

Peripartum pubic symphyseal rupture is diagnosed on clinical grounds. Although the diagnosis may be supported by radiography, which shows diastasis of the pubic rami, magnetic resonance imaging (MRI) can visualize the nature of the soft tissue injury.

CASE

Two puerperas thought clinically to have pubic symphyseal rupture were imaged with MRI. In addition to diastasis of the pubic rami, clefts were seen within the symphyseal cartilage, extending the entire breadth of the joint. The clefts were filled with fluid or hemorrhage, seen in T1- and T2-weighted images. The fluid was encapsulated within the joint by the surrounding ligaments. Four control normal puerperas, who had vaginal deliveries but were asymptomatic, showed none of the aforementioned findings.

CONCLUSION

MRI can visualize the soft tissue injury seen in pubic symphyseal rupture and may be used to confirm the clinical diagnosis.

Postcontrast MRI of cranial meninges: leptomeningitis versus pachymeningitis

OBJECTIVE

Our goal was to characterize the patterns of meningeal enhancement in postcontrast MR images and correlate these patterns with the clinical disorders.

MATERIALS AND METHODS

The MR scans, medical records, and laboratory findings of 83 patients, whose postcontrast MR studies of the head demonstrated meningeal enhancement, were reviewed retrospectively. The patterns of enhancement of the different layers of the meninges were divided into two types: leptomeningeal (pia and arachnoid), when enhancement of the meninges followed the convolutions of the gyri and/or involved the meninges around the basal cisterns; and pachymeningeal (dura), when the enhancement was thick and linear or nodular along the inner surface of the calvarium, falx, or tentorium without extension into the cortical gyri or basal cistern involvement. Enhancement around the basal cistern was considered leptomeningeal, since the dura-arachnoid is widely separated from the pia-arachnoid in this region. Further, the meningeal enhancement was divided into five etiologic subgroups, i.e., carcinomatous, infectious, inflammatory, reactive, and chemical. The medical history, clinical presentation, and findings on CSF analysis were used to distinguish infectious from carcinomatous meningitis. Meningeal enhancement due to surgery, shunt, or trauma was considered reactive, while ruptured cysts (dermoid or cysticercoid) or intrathecal chemotherapy were classified as chemical meningitis. Meningitis secondary to involvement by collagen vascular disease or sarcoidosis was considered to be inflammatory.

RESULTS

Thirty of the 83 subjects had carcinomatous, 28 infectious, 14 reactive, 8 chemical, and 3 inflammatory etiology for meningitis. Twenty-five cases (83%) of the carcinomatous, 14 (100%) of the reactive, 3 (100%) of the inflammatory, and 1 (12%) of the chemical meningitis subgroups demonstrated pachymeningeal enhancement, while 28 cases (100%) of the infectious meningitis and 7 (78%) of the chemical meningitis subgroups had leptomeningeal enhancement. Only five cases (17%) of the carcinomatous meningitis subgroup showed leptomeningeal enhancement. Four of these five cases were as a result of direct spread of intraparenchymal tumors or through perineural extension, rather than hematogenous involvement. Only one patient with carcinomatous meningitis demonstrated leptomeningeal enhancement without clear intraparenchymal lesion.

CONCLUSION

The recognition of various patterns of meningeal enhancement (leptomeningitis versus pachymeningitis) may help in differentiating between infectious and carcinomatous meningitis. This study demonstrated that infectious meningitis presents mostly as leptomeningitis, while carcinomatous meningitis presents as pachymeningitis.

Idiopathic hypertrophic cranial pachymeningitis: a case report

Hypertrophic pachymeningitis is a rare fibrosing inflammatory process involving dura mater and tentorium. In this report we are presenting contrast enhanced MRI findings of an unusual case of pachymeningitis which presented with a periorbital mass due to dural sinuses occlusion and retrograde filling of periorbital veins through superior sagittal sinus.

Imaging of gallbladder carcinoma

Although carcinoma of the gallbladder has a low overall prevalence, it is the most common malignant tumor of the biliary tract. Retrospectively, 59 cases of histologically proved gallbladder carcinoma were reviewed. The series consisted of 42 women and 17 men, ranging in age from 35 to 86 years. Clinical manifestations of gallbladder carcinoma include right upper quadrant pain, anorexia, weight loss, and jaundice. Radiologic findings included focal or diffuse thickening of the gallbladder wall (49%), a mass in the gallbladder fossa (37%), and an intraluminal mass (14%). Associated findings were cholelithiasis (64%), biliary duct dilatation (38%), invasion of the adjacent structures (67%), distant metastases other than those of the liver (3%), and porcelain gallbladder (4%). The histologic diagnoses were adenocarcinoma (90%) and squamous cell carcinoma (10%). Differential diagnoses include all conditions in which the gallbladder wall appears thickened. A general awareness of the radiologic features of gallbladder carcinoma enhances preoperative diagnoses.

Central nervous system tuberculosis: MRI

The MRI findings of 18 proven cases of central nervous system (CNS) tuberculosis were reviewed; 10 patients were seropositive for HIV. All had medical, laboratory, or surgical proof of CNS tuberculosis. Eleven patients had meningitis, of whom two also had arachnoiditis. Five patients had focal intra-axial tuberculomas: four brain masses and one an intramedullary spinal lesion. Two patients had focal extra-axial tuberculomas: one in the pontine cistern, and one in the spine. In all 11 patients with meningitis MRI showed diffuse, thick, meningeal enhancement. All intraparenchymal tuberculomas showed low signal intensity on T2-weighted images and ring or nodular enhancement. The extra-axial tuberculomas had areas isointense or hypointense relative to normal brain and spinal cord on T2-weighted images. Although tuberculous meningitis cannot be differentiated from other meningitides on the basis of MR findings, intraparenchymal tuberculomas show characteristic T2 shortening, not found in most other space-occupying lesions. In the appropriate clinical setting, tuberculoma should be considered.

Imaging of pregnancy-related complications

Thirty-six cases of pregnancy-related complications were studied with plain radiography, ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging alone or in combination. Among the complications diagnosed with these various techniques were venous thromboembolic disorders, deep vein thrombosis, ovarian vein thrombosis, endometritis and pyometra, HELLP syndrome (hemolysis, elevated liver enzyme levels, and low platelet counts), hepatic hematoma and rupture, fatty liver, uterine rupture, various hematomas and a foreign body, tubo-ovarian abscess, cerebral venous thrombosis, cerebral ischemia, and cerebral edema. Prompt detection and appropriate management of many of these complications could result in decreased maternal and fetal mortality and morbidity. Although US should be considered first because it can be performed bedside, does not require use of ionizing radiation, and is cost-effective, CT is superior in demonstrating the extent of the abnormality and MR imaging is best for detection of neurologic complications of pregnancy. The radiologist should select the best available method and tailor the examination according to the presumptive clinical diagnosis and the individual problem to be solved.

Leukocyte scintigraphy in the diagnosis of mycotic aneurysm

Early diagnosis of a mycotic aneurysm is critical, but often unsuspected, due to the insidious onset of symptoms related to occult infection. This study was undertaken to assess the role of leukocyte scintigraphy in establishing the diagnosis of mycotic aneurysm. The records of all patients with possible mycotic aneurysm between 1985 and 1991 were reviewed. Seven patients had leukocyte scintigraphy and computed tomography (CT), three also had magnetic resonance imaging (MRI) and three had angiography as part of the diagnostic workup. CT and MRI detected aneurysms in five of the seven patients, but CT scans were misinterpreted in two patients as indicative of abscess only. In six patients, infection could not be differentiated from thrombosis, seroma or hemorrhage by CT or MRI. Leukocyte scintigraphy was positive in all four patients with infected aneurysms; it was negative in two of the three noninfected aneurysms and equivocal in the third. Leukocyte scintigraphy provided a useful early survey that demonstrated evidence of infected aneurysms in four patients and identified other sites of infection in two patients. Leukocyte uptake complemented CT, MRI and angiographic findings distinguishing between seroma/hematoma and adjacent infection to establish a preoperative diagnosis of infected aneurysms.

Time course of satisfaction of search

"Satisfaction of search" (SOS) refers to the effect in which a second lesion remains undetected after detection of another lesion on the same radiograph. The objective of this study was to clarify our understanding of SOS by relating it to total time of inspection and time intervals before, between, and after discovery of lesions. Detection accuracy of native lesions in chest radiographs, before and after the addition of a simulated nodular lesion, was measured for ten observers. Analysis of data from this and a previous experiment showed that average perceptual accuracy of individual receiver operating characteristic curves was significantly reduced with the addition of the nodules. Plots and analyses of search time revealed that, on average, during a typical 46-second inspection of a case, simulated nodules were found at 18 seconds, native abnormalities at 25 seconds, and false positives occurred at 33 seconds. Time needed to find nodules did not depend on whether native lesions were present; time to find native lesions did not change with addition of nodules; and total search time was the same for images with one, two, or no lesions. The detection results show that the SOS effect was obtained, but that interrupting search in order to measure it also diminishes accuracy. Analysis of the time course data relates SOS to perceptual capture and strategic halting of search.

Ultrafast computed tomography in the diagnosis of aortic aneurysms and dissections

UFCT, by virtue of its 50 to 400 millisecond acquisition times, 0.75 to 1.5 mm resolution, and excellent vascular opacification, provides a rapid, minimally invasive method for assessing aortic aneurysms and dissections. During a 3.5-year period, 50 patients with suspected thoracic, thoracoabdominal, and abdominal aortic aneurysms or dissections were evaluated using the Imatron C-100 UFCT scanner. Eighteen patients had thoracic or thoracoabdominal aneurysms. 17 had thoracic or thoracoabdominal dissections, 7 had abdominal aneurysms, and in 8 no aneurysms or dissections were found. In 23 of the 35 patients with thoracic or thoracoabdominal aneurysms or dissections, the UFCT findings accurately reflected the findings at aortography, surgery, or autopsy. There was one false-positive examination. The remaining 11 patients with UFCT findings of aneurysm or dissection were followed clinically. In the 7 patients with abdominal aneurysms, 4 were confirmed by angiography or surgery, and 3 were followed clinically. Of the 8 patients with negative UFCT examinations, 2 had subsequent angiography that failed to show an aneurysm, and 6 were followed from 6 to 30 months without developing findings suggestive of aneurysm. UFCT appears to be a useful, minimally invasive technique for detecting and following aortic aneurysms and dissections.

Giant-cell tumor of the sphenoid bone: case report and review of the literature

We report the case of a 23-year-old man with a giant-cell tumor of the sphenoid bone. The radiologic manifestations consisted of an expansile mass arising from the sphenoid bone with extension into the cranial cavity and the nasopharynx. The findings with computed tomography and magnetic resonance imaging best reflected respectively the osseous and soft-tissue extent of the disease.

Satisfaction of search in diagnostic radiology

A subset of underreading errors (false-negative responses) in radiology has been attributed to "satisfaction of search," which occurs when lesions remain undetected after detection of an initial lesion. This phenomenon has not been studied in the experimental laboratory. A primary goal of this study was to develop a procedure or paradigm to study satisfaction of search. The authors measured detection accuracy for native lesions in images before and after the addition of a simulated nodular lesion. Simulated and native lesions were not spatially superimposed and the native abnormalities were physically identical with and without the nodules. Only responses related to the native lesion were analyzed. Accuracy parameters of receiver operating characteristic (ROC) curves were estimated by the method of maximum likelihood and jackknife. The average perceptual accuracy of the individual ROC curves as measured by Az and de' was significantly reduced with addition of the nodules (t = 2.364, p = 0.025, t = 2.648, p = 0.017, respectively). Az and de' parameters of the pooled ROC curve showed a similar effect (t = 1.573, p = 0.080; t = 1.934, p = 0.047, respectively). The results indicated a substantial satisfaction-of-search effect, with diminished accuracy in perception of native lesions.

Obstructive sleep apnea: diagnosis with ultrafast CT

Patients with sleep-disordered breathing often have physiologic and anatomic abnormalities of the upper airway that are demonstrable while awake. An ultrafast computed tomographic (CT) scanner was used to measure the oropharyngeal and nasopharyngeal cross-sectional areas of 11 patients with obstructive sleep apnea. Twenty-four healthy volunteers served as control subjects. The percentage of change in cross-sectional area during quiet tidal breathing was used as a measure of airway compliance. Compared with weight-matched control subjects, patients with obstructive sleep apnea had smaller oropharyngeal airways (40.4 vs 177.8 mm2) (P less than .001) and smaller nasopharyngeal airways (31.3 vs 134.2 mm2) (P less than .001). In addition, their oropharyngeal airways were significantly more compliant (75% vs 27%) (P less than .001). Patients with obstructive sleep apnea are characterized by a small, collapsible oropharyngeal airway and by nasopharyngeal airway narrowing. These abnormalities can cause sleep-disordered breathing. Ultrafast CT scanning allows rapid, noninvasive assessment of airway variables.

Arterial fibrodysplasia: a regional cause of peripheral occlusive vascular disease

The authors studied 17 cases of symptomatic arterial fibrodysplasia involving peripheral arteries without concomitant renovascular hypertension in Iranian males (age range: twenty-two to forty-five years). Affected arteries were most commonly the femoral, iliac, and popliteal, but in 2 cases the axillary and brachial arteries were also affected. Three cases were progressive. Differential diagnosis of arterial fibrodysplasia is discussed. It is concluded that this entity is the most common cause of peripheral occlusive vascular disease in younger Iranian males.

Patellofemoral joint motion: evaluation by ultrafast computed tomography

Patellofemoral maltracking is a recognized cause of peripatellar pain. Measurements of the patellofemoral relationships during active motion are not available, and clinicians currently rely on observation, palpation, and static radiographic images to evaluate the symptomatic patient. Ultrafast computed tomography (ultrafast CT) offers objective observations of the dynamic influences of muscle contraction on the patellofemoral joint as the knee is actively moved through a range of motion from 90 degrees flexion to full extension. This study reports our initial observations and establishes a range of normal values so that patients with a clinical suspicion of patellar maltracking may be evaluated.

Scoliosis caused by benign osteoblastoma of the thoracic or lumbar spine

We are reporting the cases of five patients with scoliosis caused by a benign osteoblastoma of the thoracic or lumbar spine. All five patients had pain and scoliosis as the presenting symptoms, which had lasted from six months to two years. The average curve measurement was 49 degrees. Two patients were treated by excision of the lesion, posterior spine fusion, and Harrington instrumentation and three, by excision of the lesion only. At follow-ups ranging from two and one-half to five years after treatment (average, three years and eight months), no patient had pain or recurrence of the tumor. The scoliosis was improved in the three patients who had been symptomatic for nine months or less and who had undergone excision of the tumor. The scoliosis did not improve in the two patients whose symptoms had been present for longer periods of time.