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H Bohlman

Publications and source records attributed to H Bohlman.

13 recordsLinked to original sources
PubMed1990

Assessment of extradural degenerative disease with Gd-DTPA-enhanced MR imaging: correlation with surgical and pathologic findings.

To test whether gadolinium-DTPA-enhanced MR would increase the conspicuity of extradural degenerative disease in the previously unoperated patient, we prospectively studied a group of 30 patients with symptoms suggestive of disk disease. Surgical findings and pathologic correlations were used as an objective measure of accuracy. Gadolinium-DTPA increased the confidence of diagnosis at one of eight operated cervical levels (six patients) and changed the diagnosis from extradural degenerative disease to tumor in one patient. The mechanism of enhancement of the epidural space and peridiskal region appears to be related to accumulation of contrast material within the epidural venous plexus, as well as to epidural fibrosis associated with disk disruption and herniation. While the immediate clinical utility of gadolinium-DTPA for morphologic analysis seems limited to difficult cervical spine cases, the presence of enhancement as a marker of epidural fibrosis and attempted healing may prove to be of great importance in studying the natural history and basic pathophysiology of degenerative disk disease.

Adult↗
PubMed1990

MR imaging of the postoperative lumbar spine: assessment with gadopentetate dimeglumine.

This study defines the accuracy of gadopentetate-dimeglumine-enhanced MR imaging in patients with failed back surgery syndrome by comparing the imaging studies with surgical findings in a large patient population. From June 1988 to March 1989, 193 postoperative patients had MR imaging of the lumbar spine both with and without contrast administration. Of this group, 27 had repeat surgery at 31 levels: these patients comprise the study group. Postcontrast MR diagnoses were as follows: scar only (n = 4), disk only (n = 13), scar and disk (n = 9), and no aberrant epidural tissue (n = 5). Surgical diagnoses differed from the MR diagnoses in two patients at two levels. In one patient, disk was diagnosed on MR while osteophyte was present at surgery. In the other patient, scar only was diagnosed by MR but disk and scar were present at surgery. These data, when combined with the authors' previous experience, give pre- and postcontrast MR a 96% accuracy in differentiating scar from disk in 44 patients at 50 reoperated levels. For patients 6 or more weeks past surgery, sagittal and axial T1-weighted MR imaging before and after administration of gadopentetate dimeglumine is an effective method of evaluating the postoperative lumbar spine.

Adult↗
PubMed1988

Epidural fibrosis and recurrent disk herniation in the lumbar spine: MR imaging assessment.

Twenty patients were enrolled in a prospective study to evaluate MR imaging in the differentiation of epidural scar and herniated disk material. Fourteen patients had surgical verification of imaging findings. In 12 (86%) of these patients, the MR interpretations fully agreed with the observations at surgery. Careful integration of the findings on sagittal and axial T1-weighted images with more T2-weighted axial images was important for analysis. Anterior and lateral recess scars were hypo- or isointense on T1-weighted sequences and hyperintense on more T2-weighted sequences relative to the "parent" anulus intensity. Free fragments demonstrated a slightly hyperintense signal intensity on T1-weighted images relative to epidural fibrosis but had a similar hyperintense signal intensity on T2-weighted sequences. Prolapsed or extruded disk fragments were hypo- or isointense relative to the parent anulus on all sequences. Morphology, epidural location, mass effect, and often signal intensity were the important parameters by which scar and herniated disk could be differentiated with MR.

Adolescent↗
PubMed1988

High-resolution MR imaging of sequestered lumbar intervertebral disks.

We retrospectively reviewed the MR examinations of 20 patients with surgically documented sequestered lumbar disks (free fragments). Sixteen of 20 cases demonstrated extradural masses that were distinct from the interspace of origin and had intermediate signal on T1-weighted images but increased signal on T2-weighted images. In 12 cases there was migration of the sequestered fragment. Sequestered disks that migrated away from the interspace had an irregular, oblong appearance, while those near the interspace were round in configuration. Additionally, the interspace of origin consistently demonstrated loss of signal on T2-weighted images when compared with intact lumbar disks. Sagittal 12-weighted images best depicted the absence of a high-signal pedicle contiguous with the interspace of origin in sequestered disks. These findings were applied to a prospective group of 20 patients undergoing lumbar diskectomy. There was an 89% sensitivity, 82% specificity, and 85% accuracy for MR in distinguishing sequestered disks from other forms of lumbar disk herniation. We conclude that high-resolution MR imaging is sensitive in detecting disk disease and specific in characterizing various subtypes of extradural defects. MR uses morphology as well as changes in signal intensity to make these distinctions.

Adult↗
PubMed1987

Cervical radiculopathy: value of oblique MR imaging.

Eighteen patients with cervical radiculopathy were entered into a prospective study to compare the accuracy of surface coil magnetic resonance (MR) imaging with that of metrizamide myelography and computed tomography (CT) with metrizamide. All MR studies included tailored axial and oblique images as well as routine sagittal images. All imaging studies were evaluated for topography and type of disease. Nine of 18 patients subsequently underwent cervical surgery with an anterior interbody approach at 11 levels. The surface coil MR findings concerning disease topography and type concurred with the surgical findings at nine of 11 levels (82%). At three levels, the oblique view added important information not available on the sagittal images or clarified changes seen on the axial images. Metrizamide myelography with CT metrizamide myelography had findings concurrent with surgical findings at ten of 11 levels (91%).

Cervical Vertebrae↗
PubMed1987

Lumbar spine: postoperative assessment with surface-coil MR imaging.

A prospective study of 15 patients who were scheduled to undergo various types of lumbar spine surgery was undertaken to assess the postoperative changes observable with magnetic resonance (MR) imaging. Patients underwent imaging preoperatively, immediately postoperatively (1-10 days), and late postoperatively (2-6 months). A retrospective review of MR images obtained in 62 patients who had undergone lumbar surgery but still had low back pain was also conducted. Epidural soft-tissue change and mass effect mimicking preoperative findings were present in nine of 13 patients who underwent laminectomy and diskectomy. Mass effect improved in appearance by the late postoperative period in eight of nine patients. T2-weighted sagittal images were best in demonstrating the site of anulus disruption immediately after diskectomy, which was seen in 11 of 13 patients, and the rent resolved on the late images in eight of ten cases. Sites of foraminotomy were seen as a loss of the normal foraminal fat signal. Extensive soft-tissue changes present in the immediate postoperative period severely limit the usefulness of MR imaging in that period for evaluating persistent symptoms. The exception may be hemorrhage, as its distinctive signal on T1-weighted images makes its identification possible.

Humans↗
PubMed1987

Thoracic disk herniation: MR imaging.

The authors undertook a retrospective study to assess the role of magnetic resonance (MR) imaging in thoracic disk herniation. The initial MR images were interpreted independently of other findings. These interpretations were compared with the findings of plain and computed tomography (CT) myelography and surgery, when available. Sixteen thoracic disk herniations were confirmed with plain and CT myelography and/or surgery. Plain myelography was performed on 14 patients and showed focal ventral filling defects in nine. Results of CT myelography were equivalent to those of MR imaging with three pulse sequences (sagittal T1 and T2 weighted, axial T1 weighted) in the identification of all the abnormal levels. In two patients, the signal from the herniated disk was so low on all sequences that thoracic disk herniation had to be inferred from the mass effect on the spinal cord. Precise location of the abnormal level with body coil MR images was achieved in six of 13 patients.

Adult↗
PubMed1987

MR imaging of lumbar arachnoiditis.

To assess the usefulness of MR in defining the changes of lumbar arachnoiditis, we reviewed retrospectively the MR, plain-film myelographic, and CT myelographic findings in 100 patients referred for evaluation of failed-back-surgery syndrome. In 11 of 12 cases of arachnoiditis demonstrated by plain-film and CT myelography, an abnormal configuration of nerve roots was seen by MR. The correlated MR and CT and plain-film myelographic changes were divided into three anatomic groups: group 1 showed conglomerations of adherent roots residing centrally within the thecal sac, group 2 demonstrated roots adherent peripherally to the meninges giving rise to an "empty-sac" appearance, and group 3 demonstrated a soft-tissue mass replacing the subarachnoid space. There was one false-negative MR study. For the diagnosis of moderate to severe arachnoiditis, we found MR to correlate excellently with CT myelographic and plain-film myelographic findings.

Arachnoiditis↗
PubMed1986

Localization of foreign bodies in the spinal canal by computer-assisted biplanar digitizer.

This study is a report of the use of a computer-assisted biplane digitizer to locate shotgun pellets within the spinal canal in an incompletely paralyzed patient. It was necessary to determine if one or more shotgun pellets were located within the spinal cord of the patient. Because of the profusion of pellets it was not possible to determine which, if any, of the pellets were in the spinal canal by routine roentgenograms. The problem of determining the location of each pellet with respect to the spinal cord was resolved by the use of biplane radiography in conjunction with an x-ray digitizer and a computer program. This report presents the method for localizing foreign bodies and discusses the results of the procedure. It was concluded that the described method successfully located the position of pellets with respect to the spinal column and cord. This method may be useful for locating metallic fragments that have to be surgically removed in other patients sustaining spinal cord injury secondary to single missile wounds.

Adult↗
PubMed1986

Cervical radiculopathy: prospective evaluation with surface coil MR imaging, CT with metrizamide, and metrizamide myelography.

A prospective study was undertaken to compare the accuracy of surface coil magnetic resonance (SCMR) imaging, metrizamide myelography (MM), and computed tomography with metrizamide (CTM) in the determination of cervical radiculopathy. Surgical findings were the objective measure of accuracy. Fifty-two patients underwent all imaging studies. Studies were evaluated for disease location and type (bone vs. soft tissue). Twenty-eight patients underwent subsequent cervical surgery at 39 levels form an anterior interbody approach. Predictions made with SCMR imaging were surgically confirmed in 74% of patients, with CTM in 85%, and with MM in 67%. There was 90% agreement with surgical findings when SCMR imaging and CTM were used jointly, and 92% agreement when CTM and MM were used jointly, In general, SCMR imaging was as sensitive as CTM for identification of disease level, but not as specific for type of disease. MM was the modality least specific for disease type. The major advantage of CTM was its ability to distinguish bone from soft tissue, for which contrast material is unnecessary. SCMR imaging is a viable alternative to MM and, together with computed tomography, if needed, provides a thorough examination of the cervical region.

Adult↗
PubMedDate not supplied

MR imaging of the postoperative lumbar spine: assessment with gadopentetate dimeglumine.

This study defines the accuracy of gadopentetate-dimeglumine-enhanced MR imaging in patients with failed back surgery syndrome by comparing the imaging studies with surgical findings in a large patient population. From June 1988 to March 1989, 193 postoperative patients had MR imaging of the lumbar spine both with and without contrast administration. Of this group, 27 had repeat surgery at 31 levels: these patients comprise the study group. Postcontrast MR diagnoses were as follows: scar only (n = 4), disk only (n = 13), scar and disk (n = 9), and no aberrant epidural tissue (n = 5). Surgical diagnoses differed from the MR diagnoses in two patients at two levels. In one patient, disk was diagnosed on MR while osteophyte was present at surgery. In the other patient, scar only was diagnosed by MR but disk and scar were present at surgery. These data, when combined with the authors' previous experience, give pre- and postcontrast MR a 96% accuracy in differentiating scar from disk in 44 patients at 50 reoperated levels. For patients 6 or more weeks past surgery, sagittal and axial T1-weighted MR imaging before and after administration of gadopentetate dimeglumine is an effective method of evaluating the postoperative lumbar spine.

Adult↗
PubMedDate not supplied

Assessment of extradural degenerative disease with Gd-DTPA-enhanced MR imaging: correlation with surgical and pathologic findings.

To test whether gadolinium-DTPA-enhanced MR would increase the conspicuity of extradural degenerative disease in the previously unoperated patient, we prospectively studied a group of 30 patients with symptoms suggestive of disk disease. Surgical findings and pathologic correlations were used as an objective measure of accuracy. Gadolinium-DTPA increased the confidence of diagnosis at one of eight operated cervical levels (six patients) and changed the diagnosis from extradural degenerative disease to tumor in one patient. The mechanism of enhancement of the epidural space and peridiskal region appears to be related to accumulation of contrast material within the epidural venous plexus, as well as to epidural fibrosis associated with disk disruption and herniation. While the immediate clinical utility of gadolinium-DTPA for morphologic analysis seems limited to difficult cervical spine cases, the presence of enhancement as a marker of epidural fibrosis and attempted healing may prove to be of great importance in studying the natural history and basic pathophysiology of degenerative disk disease.

Adult↗