2 Case Studies

Case Study 1: Normal Findings

Clinical Presentation

This woman complained of variable lumbar symptoms, primarily involving the right side, while hospitalized for treatment of an unrelated problem in the foot. The pain radiated down the right posterior thigh and lateral calf to the lateral margin of the foot. Clinical examination revealed tenderness over the right sacroiliac joint.

MRI

Examination sequences

Fig. 2.1a T2 TSE, sagittal, median,
b T1 SE, sagittal, median,
c T2 TSE, axial, L3-4 (c1) and L5-S1 (c2).

Findings: This is a normal study. The annulus fibrosus and nucleus pulposus are well differentiated in both sagittal and axial slices. All lumbar disks are of normal height. There is no disk displacement. The posterior surface of the disk appears normal with a concavity at L3-4 (c1) and a hint of convexity at L5-S1 (c2). The width of the vertebral canal is normal. The facet joints appear normal.

Diagnosis: Normal findings.

Note: A concave posterior surface is a characteristic feature of all normal lumbar disks, with the exception of L5-S1, which tends to display a hint of convexity.

Treatment Rendered

In light of the clearly functional complaints without clinical neurological correlation, conservative treatment consisting of physical therapy and back training was provided.

Fig. 2.1a

Fig. 2.1b

Fig. 2.1c1

Fig. 2.1c2

Case Study 2: Monosegmental Degenerative Disk Disease

Clinical Presentation

This 22-year-old woman complained of deep sacral pain of three days' duration, without radiation into the legs. Motion in the lumbar spine was painful at the end of the range of motion in every direction, and backward bending was markedly limited. Patrick's four-part sign was positive, there were no significant neurological findings, and the Lasègue sign was negative on both sides. The clinical diagnosis was lumbar facet syndrome.

MRI

Examination sequences

Fig. 2.2a T2 TSE, sagittal, median,
b T1 SE, sagittal, median,
c T2 TSE, axial, L3-4 (c1) and L5-S1 (c2).

Findings: The nucleus pulposus and annulus fibrosus are of normal signal intensity on the T2 image, with a slight posterior height reduction and minimal posterior bulging in the L3-4 disk (a, b, ). In the axial slice, the concavity of the posterior surface of the disk is preserved (c1); see case study 1. The width of the dural sac is normal.

Diagnosis: Discrete degenerative disk disease at L3-4, with otherwise normal findings.

Clinical Course

The patient's condition improved markedly over the next few days after treatment with heat and analgesics (aspirin).

Comments

The clinical findings suggest that this patient's back pain is attributable to the facet joints of the lower lumbar segments. This is a facet syndrome. MRI is useful for the differential diagnosis, but provides no positive findings contributing to the diagnosis. On the basis of the MR image, one can rule out inflammatory and neoplastic processes in this area of the spine. MRI should be considered the imaging study of choice in future for the exclusion of such processes in young patients, whenever a study for this purpose is indicated.

Fig. 2.2a

Fig. 2.2b

Fig. 2.2c1

Fig. 2.2c2

Case Study 3: Protrusions in Segmental Degenerative Disk Disease

Clinical Presentation

This 58-year-old man complained of low back pain of three to four years' duration and the recent onset of pseudoradicular pain radiating into the posterolateral aspect of both legs. Shortly before these images were obtained, the pain had increased, with paresthesia in both legs and feet when walking, and pain on bending backward, primarily on the left side.

MRI

Examination sequences

Fig. 2.3a T2 TSE, sagittal, paramedian,
b T1 SE, sagittal, paramedian,
c T2 TSE, axial, L4-5 (c1) and L5-S1 (c2).

Findings: The signal intensity is markedly diminished in the two lower disks with only a slight reduction in height (a, b). There is mild posterior displacement of disk tissue at L4-5 and L5-S1, with only mild impression of the dural sac at L5-S1 (c2) but with a relatively intense signal in the posterior periphery of the disk (a, ). The bone marrow is of normal signal intensity.

Diagnosis: Disk degeneration with mild protrusions in the two distal segments.

Treatment Rendered

Conservative outpatient treatment to flatten the lordosis, facet joint infiltration, abdominal muscle training, relaxation in a supine position with hips and knees flexed, and Discoflex bandage.

Clinical Course

The symptoms improved slightly with conservative therapy.

Comments

The protrusions extend only to the outer layer of the annulus fibrosus (grade 2 displacement; see Fig. 1.6) and do not constitute an indication for invasive treatment, especially in light of the mild symptoms. Therapeutic measures to flatten the lumbar lordosis are indicated. Finally, the MRI study itself was not indicated, as an invasive segment-specific therapeutic procedure was not under consideration.

Fig. 2.3a

Fig. 2.3b

Fig. 2.3c1

Fig. 2.3c2

Case Study 4: L5-S1, Protrusion or Extrusion

Clinical Presentation

This 32-year-old woman complained of sacral pain variably radiating into her left and right legs, of three months' duration. The pain radiated from the buttocks across the posterior aspect of both thighs to the popliteal fossa.

The mobility of the lumbar spine was limited, especially on forward bending. Neurological examination revealed no deficit. The Lasègue sign was positive on the left at 70° and on the right at the end of the range of motion.

MRI

Examination sequences

Fig. 2.4a T2 TSE, sagittal, median,
b T1 SE, sagittal, median,
c T2 TSE, axial, L5-S1.

Findings: A circumscribed, medial posterior protrusion of the L5-S1 disk is present, accompanied by markedly diminished signal intensity and mildly diminished height. The dural sac is compressed, without displacement or compression of the nerve roots (a-c).

Diagnosis: Medial protrusion or medial subligamentous extrusion with osteochondrosis at L5-S1.

Note: The relatively thick, dark demarcation () represents what is known as the "annuloligamentous complex." Its individual component structures, which cannot be reliably distinguished from one another, include the peripheral portions of the annulus fibrosus, the posterior longitudinal ligament, the epidural membrane, and the dura mater. The definition of a disk extrusion requires perforation of the annulus fibrosus. As the annulus fibrosus cannot be reliably distinguished from the other structures listed, it is difficult to distinguish a subligamentous extrusion from a circumscribed protrusion in cases like this. In a circumscribed disk displacement, thickening of the annuloligamentous complex most likely represents portions of the annulus fibrosus and would therefore suggest a protrusion.

Treatment Rendered

Conservative therapy was provided, as no clear radicular syndrome was present.

Clinical Course

The patient's condition improved markedly with relaxation in a supine position with hips and knees flexed, application of a flexion orthosis, and local injections, especially epidural perineural injections and spinal nerve analgesia.

Comments

Direct nerve root compression was not present, so conservative therapy lasting several months was recommended. No operation should be performed in cases like this, because exposure of the medial protrusion would require strong retraction of the dural sac and nerve roots. Aside from this, the disk in question is intact. If the disk pathology should recur with reappearance of leg symptoms, intradiskal therapy, such as chemonucleolysis with chymopapain, could be considered.

Fig. 2.4a

Fig. 2.4b

Fig. 2.4c

Case Study 5: L5-S1, Protrusion and Extrusion

Clinical Presentation

This 40-year-old man complained of low back pain and left-sided sciatica of three months' duration. The band of pain corresponded to the left S1 segment. The pain was of moderate intensity; he was able to sleep at night, and he felt pain during the day only with certain movements. Examination revealed a diminished left Achilles tendon reflex and a positive Lasègue sign on the left at 60°.

MRI

Examination sequences

Fig. 2.5a T2 TSE, sagittal, left paramedian/paramedial (a1) and left paramedial/lateral (a2),
b T1 SE, sagittal, left paramedian/paramedial (b1) and left...