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Biomedical subjects

R M Quencer

Publications and source records attributed to R M Quencer.

At least 91 records · Page 5Linked to original sources
PubMed1986

Central nervous system disease in acquired immunodeficiency syndrome: prospective correlation using CT, MR imaging, and pathologic studies.

A prospective study compared the abilities of high-resolution computed tomography (HRCT) and magnetic resonance (MR) imaging in detection and evaluation of central nervous system disease in neurologically symptomatic patients with acquired immunodeficiency syndrome (AIDS). Eighteen CT scans and 19 MR images in 14 patients were compared. HRCT images with contrast material enhancement were superior to unenhanced 0.35-T MR images for differentiating a lesion from surrounding edema, discriminating between lesions in close proximity, locating lesions for biopsy, judging lesion activity, detecting small cortical lesions with minimal edema, and spatial resolution. MR imaging was superior to CT scanning in evaluation of white-matter lesions and detection of small lesions surrounded by edema. MR imaging exhibited higher contrast resolution and greater sensitivity. Complementary uses of MR and CT imaging are suggested.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Time requirements for intraoperative neurosonography.

The time requirements needed for radiologists to perform intraoperative neurosonography were analyzed. Eighty-five consecutive intracranial and spinal operative procedures were prospectively monitored, and it was found that the average length of time spent in the operating room by the radiologist was 1 hr in spinal cases and 52 min in intracranial cases; the wide range of time spent in each case depended on the complexities of the operation; only one-fifth of the radiologist's time in the operating room was spent performing the study and interpreting the sonograms; and 24% of cases were either emergencies or were performed after normal working hours. It may be helpful to take these factors into consideration when there are plans to offer the service of intraoperative neurosonography.

Brain Diseases↗
PubMed1986

MRI of the chronically injured cervical spinal cord.

Thirteen patients with prior cervical spinal cord injury resulting in quadriplegia were evaluated with magnetic resonance imaging (MRI) long after their initial injury, either because of the relatively recent onset of new and worsening neurologic symptoms or to rule our residual compression on the spinal cord or nerve roots. The results of MRI were compared with delayed metrizamide computed tomography (CT) in 10 cases, and in five of those the results were also compared with intraoperative spinal sonography. It was found that MRI more accurately demonstrated the intramedullary abnormalities in the injured spinal cord than did delayed metrizamide CT because the former could separate myelomalacia from a posttraumatic spinal cord cyst, a differentiation that was frequently difficult with delayed metrizamide CT. T2-weighted spin-echo pulsing sequences with long echo times were particularly useful in evaluating these patients.

Adolescent↗
PubMed1986

Correlative study of the computed tomographic, ultrasonographic, and pathological characteristics of cavernous versus capillary hemangiomas of the orbit.

Pathologic and ultrasonographic features of cavernous and capillary hemangiomas were correlated with the computed tomographic (CT) characteristics of these two tumors to show that these hemangiomas can be differentiated by their contrast enhancement characteristics. Specifically, all five cases of adult cavernous hemangiomas were enhanced proportionately less than extraocular muscles, whereas capillary hemangiomas were enhanced proportionately more than extraocular muscles. The capillary hemangioma that demonstrated the lowest relative enhancement was in an older child, it may have represented a more mature form of a capillary hemangioma. We correlated these CT findings with the ultrasonographic and pathologic features to explain the differences in these CT characteristics.

Adult↗
PubMed1985

Symptomatic spinal cord deformity secondary to a redundant intramedullary shunt catheter. Clinical and radiographic features.

Right arm pain, motor and sensory loss in the right arm and right facial numbness recurred in a 27 year old quadraplegic shortly after a posttraumatic spinal cord cyst (PTSCC) was shunted via a catheter into the adjacent subarachnoid space. Although shunt malfunction was clinically suspected, metrizamide computed tomography (MCT) suggested that redundancy of the catheter had caused deformity of the spinal cord. This hypothesis was confirmed at surgery when intraoperative spinal sonography (IOSS) showed that the spinal cord deformity at C1-C2 disappeared when the catheter was withdrawn. This case shows that new or recurrent spinal cord symptoms may be due to a mechanical deformity of the cord rather than shunt malfunction, that restricting the length of the shunt catheter which is used to decompress PTSCCs is important, and that IOSS is an indispensable tool for visualizing the changes in spinal cord morphology during shunting procedures.

Adult↗
PubMed1985

Central nervous system anoxic-ischemic insult in children due to near-drowning.

An analysis of admission and follow-up CT examinations of the brains of 17 children who had nearly drowned (15 of whom were comatose and two of whom were conscious on admission) indicated that a normal initial CT scan is common in the majority of comatose patients, a severe neurologic outcome may develop in spite of a normal initial CT examination, and abnormal initial or follow-up CT findings indicate the strong but not inevitable probability of a severe neurologic outcome. We conclude that when there is no head trauma, an initial CT examination is not necessary. Prediction of the clinical outcome cannot be made on the basis of the initial CT findings.

Brain Injuries↗
PubMed1985

Intraoperative spinal sonography in thoracic and lumbar fractures: evaluation of Harrington rod instrumentation.

Thirty-seven patients with thoracic and lumbar spine fractures were treated with Harrington rod instrumentation (HRI), and the progress and results of that surgery were monitored with intraoperative spinal sonography (IOSS). Adequate neural tissue decompression and spinal column alignment was achieved in less than one-half (14/31, 45%) of the patients in whom HRI was performed as the first step of the surgical procedure. As a result of these findings, further surgical maneuvers were performed which, in most cases, resulted in adequate spinal realignment and neural tissue decompression. In six patients, direct surgical reduction of displaced bone fragments was performed before HRI. Since total decompression of neural tissue may be important in patients with spinal cord or cauda equina injuries, it is recommended that IOSS be used in all cases of HRI for thoracic and lumbar spine fractures. The need to perform additional surgical maneuvers to accomplish neural tissue decompression may be obviated if intraoperative sonography shows adequate decompression with HRI alone.

Cauda Equina↗
PubMed1984

Intraoperative sonography in spinal trauma.

Intraoperative spinal sonography (IOSS) was performed in 39 spinal trauma patients. IOSS was used to detect and assess the significance of bone fragments and spinal malalignment, cord or thecal sac compression, foreign bodies, and the late complications of spinal trauma, namely post-traumatic intramedullary and subarachnoid cysts. IOSS was also used to evaluate the efficacy of reduction of vertebral fractures, guide the shunting of cysts, and differentiate myelomalacia from intramedullary cysts, thus avoiding unnecessary exploration of the spinal cord. IOSS is a safe and simple procedure that can alter surgical management. The use of IOSS during surgery performed for spinal trauma and its complications is recommended.

Adolescent↗
PubMed1984

Intraoperative spinal sonography: adjunct to metrizamide CT in the assessment and surgical decompression of posttraumatic spinal cord cysts.

Ten patients with prior spinal cord trauma were examined preoperatively by metrizamide computed tomography (CT) and were studied subsequently by intraoperative spinal sonography. On comparing intraoperative sonography with metrizamide CT, it was found that metrizamide CT tends to overestimate the size and number of posttraumatic cysts, that areas of myelomalacia on metrizamide CT correspond to areas of abnormal echogenicity on intraoperative sonography, and that intracyst septations are seen only on intraoperative sonography. By monitoring the position of the shunting catheter during surgery, intraoperative sonography can assure its proper intramedullary placement and demonstrate the successful decompression of the cyst. If no cyst is found with intraoperative sonography, further surgery is obviated. Intraoperative sonography is recommended for all cases where decompression of cord cysts is planned.

Cysts↗
PubMed1984

Normal intraoperative spinal sonography.

The normal intraoperative sonographic features of the spinal canal, spinal cord, conus medullaris, and cauda equina are described and illustrated. Important observations concerning the normal spinal cord include its highly reflective dorsal and ventral surfaces, its uniform hypoechogenicity, and the presence of a central echo. Other easily identified structures within the spinal canal include the dura-arachnoid layer, subarachnoid space, denticulate ligament, dorsal arachnoid septations, and the roots of the cauda equina. In addition the sonographic appearance of commonly encountered iatrogenically introduced material including Gelfoam, Pantopaque, cottonoid pledgets, suture material, Harrington rods, and freeze-dried dura is also demonstrated. These normal images can serve as a baseline for the interpretation of various pathologic conditions of the spinal canal and its contents as seen with intraoperative spinal sonography.

Cauda Equina↗
PubMed1984

Intraoperative spinal sonography of soft-tissue masses of the spinal cord and spinal canal.

Intraoperative spinal sonography (IOSS) was used to evaluate and monitor the progress of surgery in 18 patients with soft-tissue masses of the spinal canal and spinal cord. With intramedullary masses, IOSS showed not only the site of maximum cord enlargement so that a precise biopsy could be performed but also was able to demonstrate the zone of transition between the mass and normal cord tissue. With extradural masses and intradural extramedullary masses, IOSS showed the exact size and location of the masses and confirmed their removal and/or adequate spinal cord decompression. IOSS indicated the extent of bone removal necessary to give adequate exposure to accomplish total removal of these masses or to localize the proper level for tissue biopsy. IOSS also indicated the need to open the dura when there had been unsuspected transdural tumor spread or when bony decompression had not been sufficient to relieve the pressure on the spinal cord in tonsillar ectopia. Intraoperative spinal sonography is recommended in all cases of spinal surgery performed to resect or biopsy soft-tissue masses of the spinal canal or spinal cord.

Adult↗
PubMed1983

Posttraumatic spinal cord cysts: clinical features and characterization with metrizamide computed tomography.

Sixteen patients with posttraumatic spinal cord cysts (PTSCC) were evaluated clinically and studied with metrizamide computed tomography (MCT). These patients presented months to years following a severe spinal cord injury, usually with new or progressively worsening neurological symptoms. The development of the PTSCC was unrelated to the location, type, and severity of injury, or to the time interval from the original injury. MCT showed that these cysts occur most frequently in normal or atrophic cords, they may be multiple, they most frequently are found in the dorsal portion of the cord, and they may vary along their length in width and position within the cord. Knowledge of this radiographic morphology is crucial to the surgical planning. The location of the cysts and the mode of their enlargement are correlated with anatomic features of the spinal cord and changes in cerebrospinal fluid dynamics. Cyst-to-subarachnoid space shunting relieves the majority of symptoms.

Adolescent↗
PubMed1983

Lacrimal gland and fossa masses: evaluation by computed tomography and A-mode echography.

Although masses of the lacrimal gland and fossa are accurately localized by CT, their appearances are often similar making differentiation between various pathological entities difficult. We examined 32 patients with CT and/or standardized A-mode echography (SAE) to determine if SAE added significant information to that supplied by CT alone. Other than five cases of dermoid cysts, which were fat containing, and one case of lacrimal gland pseudotumor, which had associated uveal scleral thickening and enhancement, there was no specific CT pattern that allowed a definite diagnosis. SAE reflectivity patterns, however, allowed separation of masses into the following categories: pseudotumor/lymphoma, carcinoma/metastasis, benign mixed adenoma, lymphangioma, and dermoid cyst. We conclude that SAE is an important adjunct to CT in the diagnosis of lacrimal gland/fossa masses that are not fat containing.

Adenoma↗
PubMed1983

Nonunited ossification center of the presphenoid bone: pseudomeningioma.

Three patients are described; in two of them initial plain skull films at an outside institution were interpreted as demonstrating an anterior clinoid meningioma. Evaluation of these films along with further study of the skull base with complex motion tomography demonstrated a separate and well corticated bony structure posterior and superior to each anterior clinoid in all three cases. After review of the developmental anatomy of this region, it was concluded that these bone centers represent failure of the posterior accessory centers of the presphenoid to fuse with the orbitosphenoid. The features of these nonunited centers appear to be characteristic and should allow distinction of this developmental anomaly from a pathologic process.

Adult↗