Supravalvular aortic stenosis with parafollicular cell (C-cell) hyperplasia.

Autopsy examination of a patient with well-documented supravalvular aortic stenosis and other characteristic features of the idiopathic infantile hypercalcemia syndrome revealed previously unreported hyperplasia of parafollicular cells (C cells). Immunohistochemical analysis demonstrated up to 30 calcitonin-containing cells per high power field, whereas normal glands contain only 4 to 10 cells per low power field in areas of highest concentration. The parathyroid glands were found to be normal both grossly and microscopically, whereas the bones showed thickened trabeculas, normal Haversian canals and no apparent increase in osteoblast or osteoclast activity, suggesting normal parathyroid hormone, but increased thyrocalcitonin activity. We suggest that C-cell hyperplasia has occurred in response to a persistent, rather than transient, elevation in serum calcium levels and that thyrocalcitonin function is augmented, rather than impaired in this disorder. The primary biochemical defect promoting hypercalcemia remains to be clarified, as well as the role, if any, such a defect plays in producing significant pathology in the central nervous system and in the cardiovascular, renal and skeletal systems.

False pulmonary artery catheter measurements due to the scimitar (hypogenetic lung) syndrome. Potential for iatrogenic pulmonary edema.

In an acute trauma patient with unrecognized scimitar syndrome, physiologic measurements used in patient management decisions were misleading due to the anatomic and physiologic anomalies of the syndrome. Pulmonary artery catheter measurements believed to reflect left atrial pressures were actually measuring central venous pressures because the catheter was terminating in the scimitar vein. These erroneous measurements led to overly aggressive fluid resuscitation and iatrogenic pulmonary edema. The pathologic features of scimitar syndrome are reviewed, and the mechanism for potential mismanagement of patient volume status created by aberrant pulmonary hemodynamics is discussed.

Transient hilar lymphadenopathy due to bacterial endocarditis.

Transient hilar and mediastinal lymphadenopathy accompanying right-sided bacterial endocarditis without concurrent roentgenographically-demonstrable pulmonary parenchymal abnormalities has not, to our knowledge, been previously reported. The roentgenographic finding of hilar or mediastinal lymphadenopathy should not be considered incompatible with the diagnosis of bacterial endocarditis in the appropriate clinical setting. Possible mechanisms for the development of lymphadenopathy secondary to bacterial endocarditis are discussed.

Experience with spiral computed tomography as the sole diagnostic method for traumatic aortic rupture.

BACKGROUND: Spiral computed tomographic (CT) scan is an excellent screen for aortic trauma. Traditionally, aortography is performed when injury is suspected to confirm the diagnosis. We hypothesized that it is safe and expeditious to forgo aortography when the spiral CT demonstrates aortic injury. METHODS: Retrospective review of 54 patients undergoing aortic repair from July 1994 to December 1999. Spiral CT was the initial diagnostic study in 52 patients. Pseudoaneurysm or aortic wall defect in the presence of mediastinal hematoma was considered diagnostic. Angiography, initially routine, was later performed only when requested by the surgeon, and for all "nonnegative" studies (periaortic hematoma without detectable aortic injury). RESULTS: Twenty-six patients underwent angiography before operation (group 1). Nineteen group 1 spiral CTs were unequivocally diagnostic; 7 were nonnegative and angiography was required. Twenty-eight other patients underwent repair based on spiral CT alone (group 2). There was one false-positive result in both groups. There were no unexpected operative findings. Mean time from admission to diagnosis was 5.7+/-3.4 hours for group 1 and 1.7+/-1.7 hours for group 2 (p < 0.01). CONCLUSIONS: Operating on the basis of a diagnostic spiral CT is safe and expeditious. Aortography may be reserved for those with equivocal studies.

Computed tomography of Kock and modified Kock continent ileal reservoir.

Kock or modified (Javadpour) ureteroiliostomy was performed in 5 patients following cystectomy for bladder carcinoma or exstrophy. Computed tomography was utilized to demonstrate alterations in pelvic anatomy after construction of the ileal reservoirs. Detailed evaluation of the inlet and outlet antireflux arms of the continent reservoir was possible. Appreciation of the expected alterations in pelvic anatomy accompanying the Kock or modified Kock procedure will be necessary to detect postoperative complications and to achieve early recognition of recurrent carcinoma. Potential advantages of the modified Kock ileal reservoir, as developed by Javadpour, are presented.

Intraoperative sonography of cervical spinal cord injury: results in 30 patients.

Intraoperative spinal sonography (IOSS) with a 7.5-MHz sector transducer was performed in 30 patients with cervical spine injury associated with neurologic deficits. A laminectomy (25 patients) or anterior corpectomy (five patients) during spinal surgery provided the IOSS imaging window. The surgery was performed for either spinal decompression or fixation as part of the initial care of these patients and occurred 1 to 39 days (mean, 12.4 days) after injury. Parenchymal spinal cord lesions at the level of cervical fracture or stenosis that were compatible with the initial neurologic deficits were detected by IOSS in 28 (96.5%) of 29 patients with technically adequate studies. Lesions appeared as foci of increased echogenicity and were sorted into five injury grades (0 through IV). The IOSS injury grade in each patient was determined by the maximal diameter of regions of increased echogenicity and/or cyst formation in either the sagittal or transverse image plane. The extent of initial neurologic injury and its recovery was assessed by using the ASIA motor score (0 to 100 unit scale) at admission and during follow-up. The IOSS injury grade was correlated with the initial ASIA motor score (p less than 0.009, Spearman's Rank Order Test), indicating that the IOSS echogenicity is related to the extent of initial clinical motor deficit. Regression analysis disclosed that both the IOSS injury grade and the initial ASIA score were correlated with the follow-up ASIA score (p less than 0.05 and p less than 0.001, respectively). However, the addition of the IOSS injury grade to the initial ASIA motor score did not improve the predictive ability of the follow-up ASIA motor score.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of titanium wire in cervical spine fixation as a means to reduce MR artifacts.

MR imaging of the cervical spine is valuable for assessing traumatic injuries to the spinal cord and bony ligamentous structures. MR is also useful for detecting such long-term complications of spinal cord injury as syrinx, arachnoid cyst, cord adhesion, and persistent mechanical impingement on the spinal cord or spinal nerve roots. Treatment of cervical spine injuries that are mechanically unstable entails fixation and fusion. However, previous attempts at our institution to obtain clinically useful MR images of the cervical region after posterior wire fixation have failed because of image artifacts arising from ferromagnetic stainless steel wires. Use of biocompatible titanium wire for fixation allowed undistorted imaging of the spinal cord and spinal canal adjacent to the surgical fixation in a cadaver and in eight patients.

The laterally tilted dens: a sign of subtle odontoid fracture on plain radiography.

Type III (low) odontoid fractures may be subtle on initial plain film radiographic examination. We describe a sign on the routine open-mouth view, the laterally tilted dens, which has not been previously stressed in the radiologic literature, and is an important diagnostic sign of type III fractures of the odontoid process of the axis. In a series of 82 nontraumatized patients, no odontoid angle of less than 87 degrees (3 degrees from perpendicular) was observed. In a series of type III odontoid fractures, tilting of the dens in excess of 5 degrees was present in eight (67%) of 12 cases. This may be the only readily apparent finding on the initial cervical spine series. Of eight type III odontoid fractures in which an abnormal odontoid angle was identified, it was the only definite abnormality that could be recognized prospectively in two cases (25%) and that supported very subtle findings in two other cases (25%).

Posttraumatic cerebral infarction diagnosed by CT: prevalence, origin, and outcome.

Posttraumatic cerebral infarction is a recognized complication of craniocerebral trauma, but its frequency, cause, and influence on mortality are not well defined. To ascertain this information, all cranial CT studies demonstrating posttraumatic cerebral infarction and performed during a 40-month period at our trauma center were reviewed. Posttraumatic cerebral infarction was diagnosed by CT within 24 hr of admission (10 patients) and up to 14 days after admission (mean, 3 days) in 25 (1.9%) of 1332 patients who required cranial CT for trauma during the period. Infarcts, in well-defined arterial distributions, were diagnosed either uni- or bilaterally in the posterior cerebral (17), proximal and/or distal anterior cerebral (11), middle cerebral (11), lenticulostriate/thalamoperforating (nine), anterior choroidal (three), and/or vertebrobasilar (two) territories in 23 patients. Two other patients displayed atypical infarction patterns with sharply marginated cortical and subcortical low densities crossing typical vascular territories. CT findings suggested direct vascular compression due to mass effects from edema, contusion, and intra- or extraaxial hematoma as the cause of infarction in 24 patients; there was postmortem verification in five. In one patient, a skull-base fracture crossing the precavernous carotid canal led to occlusion of the internal carotid artery and ipsilateral cerebral infarction. Mortality in craniocerebral trauma with complicating posttraumatic cerebral infarction, 68% in this series, did not differ significantly from that in craniocerebral trauma patients without posttraumatic cerebral infarction when matched for admission Glasgow Coma Score results. Thus, aggressive management should be considered even in the presence of posttraumatic cerebral infarction.

Phantom evaluation of angiographer performance using low frame rate acquisition fluoroscopy.

The authors have investigated the effect of 5 frames/s television fluoroscopy on the time required to selectively catheterize five test arteries in an angiographic phantom. Here, 5 frames/s acquisition was accomplished by sampling frames from a 30 frames/s video signal. Sampled frames were stored in a video memory which provided continuous display to the fluoroscopist between samples. The test phantom was a plastic model of an aorta with branching vessels immersed in an isodense suspension of barium in water. For four of the five vessels there was no significant difference in time required for catheter placement between 30 frames/s and 5 frames/s.

Trauma.

This article reviews the imaging evaluation and principal imaging findings associated with blunt and penetrating trauma to the urinary system. Imaging of injuries confined to the kidneys and proximal renal collecting system is examined first, followed by imaging of adrenal and lower tract injury.

CT scan evaluation of blunt hepatic trauma.

Information provided by CT scan allows for determination of the extent of liver injury and identification of other nonhepatic abdominal injuries. This information, coupled with clinical assessment, can be used to optimize management. Contrast-enhanced CT scan can monitor progression or resolution of hepatic injuries, detect complications, and guide percutaneous treatment of some complications. This article discusses CT scanning technique; classification, sites, and mechanisms of liver injury; CT scan appearance of liver injury; and complications of hepatic trauma.

Imaging diagnosis of nonaortic thoracic injury.

Chest radiographs remain the initial imaging modality to rapidly screen patients with blunt chest trauma. Spiral CT is more sensitive and specific in diagnosing most thoracic pathology seen in blunt trauma patients. This article reviews the major clinical and radiologic findings that occur with blunt injuries to the chest, excluding mediastinal vascular injuries.

Titanium wire internal fixation for stabilization of injury of the cervical spine: clinical results and postoperative magnetic resonance imaging of the spinal cord.

Nine patients with dislocation of the cervical spinal with posterior ligamentous damage were treated with posterior internal fixation using a twisted pair of 22-gauge titanium wires and iliac crest bone fusion. Fixation using the titanium wire was compared with fixation using stainless steel wire for differences in surgical insertion, long term stability of bony fusion, and postoperative magnetic resonance imaging (MRI) artifacts near the implanted wire. MRI of the cervical spine is valuable for diagnosing the acute and chronic consequences of traumatic cervical spinal injury by providing anatomic evaluation of both the spinal cord and the supporting bony/ligamentous structures in the neck. Because MRI is an accurate and sensitive noninvasive test, it is especially useful for the long-term serial assessment of the region near the cervical dislocation site to detect the sequelae of spinal cord injury, including syrinx, arachnoid cyst, cord tethering, and persistent mechanical impingement on the spinal cord or spinal roots. Previous attempts at our institution to obtain useful MRI scans of the cervical region adjacent to stainless steel wires after posterior wire fixation have failed due to marked imaging artifacts from the ferromagnetic properties of these wires. Our substitution of biocompatible titanium wire (Titanium 6 A1-4V ELI alloy, Specialty Steel and Forge, Leonia, New Jersey) for stainless steel wire produced identical immediate stabilization and ultimate bony fusion of the fracture and yielded minimal MRI artifacts overlying the immediately adjacent spinal cord and neural canal; however, the installation was technically more difficult, because of the titanium wire's greater stiffness.(ABSTRACT TRUNCATED AT 250 WORDS)

Myelographic and enhanced computed tomographic appearance of acute traumatic spinal cord avulsion.

The neuroradiological findings that revealed spinal cord transection/laceration in 6 patients with acute, blunt spinal trauma are described. Four patients suffered cervical spine injuries, and two had thoracic injuries. Initially, all patients had complete neurological deficit at the level of injury. The deficit improved in only 1 patient. On the basis of clinical history and spinal radiographs, spinal hyperflexion with distraction was the predominant mechanism of injury in our patients. Computed tomography with intrathecal contrast was performed on all patients and was always diagnostic. Visualization of intrathecal contrast material accumulating within the cord or the absence of cord shadow within the contrast column established the diagnosis in all cases. A dural tear was noted in 3 patients. Thoracic myelography was performed in 2 patients and, in both, demonstrated contrast pooling within the spinal cord at the level of the laceration. Magnetic resonance imaging was obtained in 1 patient and revealed an irregular, low-signal-intensity, intramedullary region extending to the cord surface on T1-weighted axial images. The myelographic and enhanced computed tomographic appearances of acute, traumatic spinal cord avulsion/laceration, which have been infrequently reported in the literature, are described.

Use of portable CT in the R Adams Cowley Shock Trauma Center. Experiences in the admitting area, ICU, and operating room.

The author's experience with portable CT has been positive. Nurses and clinical physicians have been pleased with this new imaging capability also, and have written testimonial letters endorsing its value. Recently, the STC extended availability of the mobile CT to the University of Maryland Hospital, an adjoining 600-bed center with numerous medical and surgical patients in ICU. They are particularly interested in assessing use of portable CT in the neonatal ICU, where patient transport outside the unit is particularly difficult and dangerous. Technical improvements for portable CT are in development. Soon, helical volume scanning will be available, allowing faster image acquisition and better two- and three-dimensional image reformations (Fig. 12). A new, more powerful x-ray tube is in development that will permit more slices to be acquired without tube cooling interruptions. Gantry translate capability coupled with a radiolucent backboard extender has the potential to permit scanning of the head, neck, spine, face, and upper torso without the patient being moved from the ICU bed. For applications in head, face, and neck surgery, a radiolucent cranial fixation device also has been developed. Other potential improvements include extended battery power for more scanning between charges, a larger tube heat unit storage for extended scanning situations, decreased system weight for easier transport, and more detector efficiency for improved image quality while maintaining significant dose reduction over conventional scanning. The capability of portable CT scanning for emergency, intensive care, and intraoperative studies exists now. The commercially marketed cost for this system is between $400,000 and $500,000. Further studies are anticipated to clarify the economic and clinical benefits of this technology.

Three-dimensional computerized tomography in the evaluation of laryngeal injury.

A comparison of diagnostic information obtained from the physical examination, conventional two-dimensional axial computerized tomography scanning (2-D CT), and three-dimensional display computerized tomography (3-D CT) was performed in five patients sustaining laryngeal trauma. Four patients had laryngeal fractures and one patient had an incompletely ossified thyroid cartilage (normal variant) simulating a fracture by 2-D CT. Three-dimensional display computerized tomography was found superior to conventional 2-D CT in assessing the presence and nature of the laryngeal injuries while correctly identifying the anatomic variant.

MR imaging of thoracic trauma.

Although MR imaging and MR angiography should not be considered a primary study for patients sustaining blunt or penetrating thoracic trauma, it has achieved importance as an ancillary problem-solving modality. In general, the authors have found MR imaging to be a useful ancillary study to confirm or exclude diaphragm injury, if spiral CT scan with reformations are equivocal; to help assess the aorta and mediastinum in cases of potential injury that are not clarified by CT scan or thoracic angiography; and to identify the true origin of trauma-related masses that may simulate thoracic neoplasms.

Le Fort fractures without mobility.

The Le Fort fracture without maxillary mobility constitutes 9 percent of maxillary fractures observed over a 3-year period. A high Le Fort (level II or III) injury exists as a one- or two-piece incomplete fracture. The degree of fracture is insufficient to permit mobility of the maxillary alveolus. Frequently, an obvious unilateral zygomatic fracture is present. Physical findings consist of bilateral eyelid ecchymosis and malocclusion. The occlusal disturbance may consist of either crossbite, open bite, maxillary rotation, or lack of proper dental intercuspation. On CT scan, fractures are best demonstrated in the posterior and medial maxillary walls at the Le Fort I level; they are most obvious unilaterally with contralateral fractures that may be subtle. Bilateral maxillary sinus fluid is consistently present on CT. Treatment usually consists of observation and traction elastics but may require mobilization of the fragments followed by open reduction and rigid fixation.

Imaging of diaphragmatic injuries.

Multiple imaging modalities are available for the preoperative diagnosis of diaphragmatic injury. Chest radiographs are the initial and most commonly performed imaging study to evaluate the diaphragm after trauma. When chest radiography is indeterminate, spiral computed tomography (CT) with thin sections and reformatted images is the next study of choice, particularly because most hemodynamically stable patients with blunt diaphragm injury will require an admission CT examination to evaluate the extent and anatomical sites of coexisting thoracoabdominal injuries. Magnetic resonance imaging is used to evaluate the diaphragm for patients with clinical suspicion but an indeterminate diagnosis after chest radiography and spiral CT.