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Biomedical subjects

J V Rogers

Publications and source records attributed to J V Rogers.

At least 19 recordsLinked to original sources

Thoracolumbar burst fractures: CT dimensions of the spinal canal relative to postsurgical improvement.

Cross-sectional spinal canal area was measured before and after surgery in 12 patients with thoracolumbar burst fractures and canal narrowing caused by retropulsed fragments. Patients were classified into Denis type A or type B. Denis type A fractures have comminution of both end-plates of the vertebral body creating multiple smaller fractures; Denis type B fractures have comminution of the superior end-plate only with a single vertical fracture line into the inferior end-plate creating larger fragments. The degree of neurologic impairment was assessed before and after surgery using the Frankel system. There was no correlation between degree of canal narrowing and degree of neurologic impairment. The degree of spinal canal narrowing reflects the final resting position of the vertebral body fragments after trauma; during trauma, greater degrees of canal impingement may have occurred. Also, significant canal narrowing may be present without pinching of the cord or cauda equina. All patients with Denis type A fractures had near-anatomic reduction of fragments out of the spinal canal by surgery; less than half of the patients with Denis type B had good reduction. There was no correlation between reduction of retropulsed fragments and subsequent neurologic improvement. However, this should not preclude surgery as a therapeutic option: Eight of 10 patients with neurologic impairment experienced some improvement in symptoms after surgery; the other two were unchanged.

Adult

Low sensitivity of sonography and cholescintigraphy in acalculous cholecystitis.

Acalculous cholecystitis is difficult to diagnose by clinical means or contrast radiography. Because sonography and cholescintigraphy have both been shown to do well in the diagnosis of calculous cholecystitis, the sensitivity of these newer imaging methods was assessed retrospectively in 33 proven cases of acalculous cholecystitis. The sensitivities to acalculous cholecystitis for sonography (67%) and for cholescintigraphy (68%) were not as high as has been reported for these tests in calculous cholecystitis. Reasons for the lower sensitivity with each test and the pathogenesis of acalculous cholecystitis are discussed.

Acute Disease

Double-contrast computed tomography of the glenoid labrum.

Imaging of glenoid labrum pathology is useful to help plan surgical repair of the dislocating shoulder. Eleven patients with suspect labrum damage were imaged with computed tomography (CT) immediately after routine double-contrast shoulder arthrography. Lesions identified included attenuation, tears, and displacement of the labrum as well as stripping and stretching of the anterior shoulder joint capsule. Surgical confirmation of pathology was available in all but one case. CT of the glenoid labrum is easy to perform, low in radiation dose, and accurate.

Adult

Single-photon emission computed tomography of the normal liver.

Single-photon emission computed tomography (SPECT) is a new imaging method that offers the advantage of cross-sectional imaging and improved contrast resolution as compared with conventional planar imaging. Preliminary SPECT studies of the liver for detection of metastatic disease are very promising. However, these studies indicate some potential pitfalls in the interpretation of the normal liver SPECT images. Experience with 58 tomographic studies obtained with a General Electric 400T rotating gamma camera is presented, with special emphasis on the areas of potential misinterpretation and on recognition of the normal anatomy as seen by this technique.

Elementary Particles

Intraoperative ultrasound detection of metastatic tumors in the central cortex.

Real-time sector ultrasonography precisely located metastatic tumors of the central motor cortex during craniotomy in two patients. In these two cases, the only surface abnormality was swelling of several overlying gyri. Intraoperative ultrasonography precisely located the 1.5- and 2.5-cm-diameter tumors to a position below a specific gyrus, enabling the surgeon to excise the tumors through small, accurately placed cortical windows. The precise location minimized exploratory probing and the size of the cortical incision required to identify and remove the tumors. This technique will have general application in similar situations when the cortical surface gives no indication of underlying tumor location. By charting the best trajectory for the surgical approach, this technique may replace a variety of stereotactic and computed tomography-guided techniques for biopsy of deep brain tumors.

Adult

Evaluation of acute right upper quadrant pain: sonography and 99mTc-PIPIDA cholescintigraphy.

A group of 75 patients with acute right upper quadrant pain was evaluated with both sonography and cholescintigraphy. Accuracy in screening for gallbladder disease was significantly greater with sonography (96%) than with cholescintigraphy (74%). For selecting patients with acute cholecystitis from this population that included acute and chronic cholecystitis as well as nonbiliary pathology, PIPIDA was less accurate (77%) than might be expected based on previous reports primarily due to false positive nonvisualization caused by chronic cholecystitis. Of patients with nonbiliary pathology, sonography was able to detect the cause of the right upper quadrant pain in 21%. Patients with acute right upper quadrant pain should first be screened with sonography. If cholescintigraphy is subsequently used for suspected acute cholecystitis, positive results should be interpreted with caution before surgery is planned.

Acute Disease

Effectiveness of CT in evaluating intrathoracic masses.

To compare the effectiveness of computed tomography (CT) with conventional radiography and conventional tomography for evaluating masses in the thorax, 168 masses, 154 of which were histologically verified, which had been examined with CT were reviewed. In 74 instances (44%) CT provided important additional information compared with conventional radiography. Compared to conventional tomography, CT added important information in 15 (23%) of 65 cases. In no case did CT fail to demonstrate pathology shown with the other two methods. Average radiation dose to the chest was 1.3 rad (0.013 Gy) with CT and 0.4 rad (0.004 Gy) with linear tomography. Although CT is associated with slightly greater radiation dose and cost, this review indicates it should be performed directly after plain film examination instead of conventional tomography when further investigation of an intrathoracic mass is indicated.

Adolescent

Real-time sonography of pleural opacities.

Fifty patients with radiographic pleural or pleural-based opacities were examined with high resolution real-time sonographic sector scanning. In 90% of cases selected for thoracentesis, fluid sufficient for diagnosis was obtained. Complex, septated pleural loculations contained an exudative effusion in 74% of the patients, while anechoic areas yielded exudative and transudative effusions with almost equal frequency. The use of real-time scanning is stressed because of greater flexibility and shorter examination time compared to compound scanning, and its utility for portable scanning on critically ill patients.

Bronchoscopy

Intracranial hemorrhage in premature infants: accuracy in sonographic evaluation.

The real-time high resolution mechanical sonographic sector scanner is a convenient and useful instrument for the detection of intracranial hemorrhage in premature infants. Experience with 27 infants with intracranial hemorrhage detected by sonography and confirmed by computed tomography (CT) or by autopsy is analyzed. The severity of the hemorrhage shown by those methods was graded by an accepted classification for standardized reporting. The extent of intraparenchymal and intraventricular hemorrhage was accurately assessed by sonography in all cases except for small amounts of blood in normal sized ventricles in five of 12 instances. Sonography also failed to detect subarachnoid hemorrhage in each of 13 cases. There were no known false-positive sonograms. From this experience the authors believe sonographic sector scanning should be the initial examination in all infants at high risk for intracranial hemorrhage. When the ventricles are of normal size, CT scanning is recommended to search for small intraventricular hemorrhage that may not be detected by sonography. For subarachnoid bleeding, CT is preferable to sonography.

Cerebral Hemorrhage

Real-time sonographic sector scanning of the neonatal cranium: technique and normal anatomy.

A commercially available wide field of view real-time mechanical sector scanner can be used to image the neonatal cranium. Because of the small transducer head size, the open anterior fontanelle can function as an acoustic window. By thus avoiding bone, higher frequency transducers may be used to improve image resolution. Infants may be scanned quickly without sedation in their isolettes in the neonatal intensive care unit. Sterility of the infant environment is maintained by placing the transducer in a surgical glove. Using this technique, detailed normal anatomy can be seen such as vascular structures, caudate nucleus, thalamus, third ventricle, cavum septum pellucidum, and the thalamocaudate notch. Angled coronal and sagittal sonographic anatomy is correlated with neonatal cadaver brain sections sliced in similar planes centered on the anterior fontanelle.

Brain

Hepatic focal nodular hyperplasia: angiography, CT, sonography, and scintigraphy.

Eleven patients with focal nodular hyperplasia of the liver underwent a combination of radiologic procedures, including sonography, computed tomography (CT), hepatic scintigraphy, and angiography. This paper describes the radiologic findings in this group of patients and reviews the current literature. In the present series, sonography was the most sensitive (100%) method for detection of focal nodular hyperplasia, while CT was able to detect only seven (78%) of nine cases. Arteriographic findings were felt to be characteristic in nine (82%) of 11 cases. Hepatic scintigraphy demonstrated normal colloid uptake in six (55%) of 11 lesions. In this series, an accurate radiologic diagnosis of focal nodular hyperplasia was made in 73% of cases. Hepatic scintigraphy is the pivotal examination. Normal colloid uptake by a focal hepatic mass is virtually diagnostic. However, in the patients in whom the colloid scan shows decreased or absent uptake, angiography may show findings diagnostic of focal nodular hyperplasia in up to 75% of cases, thus avoiding the need need for liver biopsy or surgery.

Adolescent