Reactive sclerosis: hyperintense appearance on T2-weighted magnetic resonance imaging.

Osteosclerosis is defined as increased density of bone on X-ray imaging studies. It is known that osteosclerosis appears hypointense on both T1- and T2-weighted magnetic resonance imaging sequences. In this review, we present our experience in various sclerotic skeletal pathologies that appear hyperintense on T2-weighted magnetic resonance imaging. We emphasize the possible pathophysiological mechanisms that may cause this appearance, such as bone marrow edema and/or composition of newly formed bone.

Magnetic resonance imaging in osteomalacic insufficiency fractures of the pelvis.

AIMS: To report the magnetic resonance imaging (MRI) findings of osteomalacic insufficiency fractures of the pelvis. MATERIALS AND METHODS: In all, 12 persons presenting with chronic pelvic pain and with a definitive diagnosis of osteomalacia (OM) were enrolled in this study. Radiological work-up included direct radiographs (n = 12), computed tomography (n = 5), scintigraphy (n = 12) and MRI (n = 12). The location of the insufficiency fractures and corresponding MRI appearances were evaluated. Depending on the presence or absence of signal intensity around the fractures, the lesions were grouped into active and chronic forms. RESULTS: A total of 34 insufficiency fractures were depicted on imaging studies. MRI demonstrated 33 of the lesions. All the insufficiency fractures were seen as a hypointense lines or fissures on T1- and T2-weighted and STIR MR images. There was a high frequency of insufficiency fractures at the sacrum and iliac bone (16/34, 47%). Overall, 11 chronic-type (no abnormal signal intensity around the fissure) and 22 active-type (abnormal signal intensity around the fissure) insufficiency fractures were detected by MRI. Follow-up MR examinations of 2 subjects showed that abnormal signal intensity had disappeared after appropriate treatment. CONCLUSION: The results of this study showed that the iliac and sacral bones are frequently involved in patients with OM. MRI can determine the clinical activity of the disease, and can monitor the response to treatment of the active type of insufficiency fractures.

Destructive diskovertebral lesions in ankylosing spondylitis: appearance on magnetic resonance imaging.

We report magnetic resonance imaging findings of diskovertebral lesions in a case of ankylosing spondylitis mimicking metastatic and/or infectious disease. Multiple hypointense areas were seen on T1-weighted images corresponding to hyperintense areas on T2-weighted images in dorsal, lumbar, and sacral vertebral bodies and the manubriosternal joint, with accompanying soft tissue masses. Diagnosis was achieved through biopsy, regression of the paravertebral soft tissue masses, later detection of bilateral sacroiliitis on computed tomography, and presence of histocompatibility antigen HLA-B27.

Bone marrow changes adjacent to the sacroiliac joints after pelvic radiotherapy mimicking metastases on MRI.

Radiation-induced changes in the sacroiliac joints mimicking metastases on MR images were evaluated. Twelve patients who received radiotherapy to the pelvic region due to pelvic malignancy were included in the study. All patients had undergone external beam radiation therapy to the pelvic region, and 2 patients received supplementary internal radiation. The changes in the sacroiliac joints were evaluated. Computed-tomography-guided core bone biopsy from the bone marrow was taken from their corresponding MR sections in 5 of the patients. T1 hypointense and T2 hyperintense areas with ill-defined margins in the bone marrow adjacent to the sacroiliac joints were observed in all patients. On bone scintigraphy all the lesions demonstrated increased activity. Other radiological modalities excluded fracture, soft tissue mass, and osseous destruction. Bone biopsies demonstrated peritrabecular fibrosis and inflammatory cell infiltration. Patients receiving radiotherapy to the pelvis may demonstrate T1 hypointense/T2 hyperintense, ill-defined postradiotherapeutic benign changes in the sacroiliac joints. In the absence of any other signs of disease progression and when the imaging pattern is typical, close radiological follow-up should be sufficient to rule out metastases.

Dorsolumbosacral agenesis.

Caudal regression is a rare congenital spinal anomaly characterized by partial or total agenesis of the sacral and/or lumbar spine. Sacral and/or lumbosacral agenesis has been well described. However, especially as far as MRI studies are concerned, thoracolumbosacral agenesis has rarely been reported.

Inflammation of vertebral bone associated with acute calcific tendinitis of the longus colli muscle.

We present a case of acute retropharyngeal calcific tendinitis with characteristic findings on radiographic, computed tomography, and magnetic resonance imaging (MRI). To our knowledge, this is the first acute retropharyngeal calcific tendinitis report having inflammation of both the vertebra itself and the longus colli muscle diagnosed on MRI. In patients with neck pain, acute retropharyngeal calcific tendinitis should be kept in mind in the differential diagnosis, even if these patients had vertebral pathological signals on MRI.

A case of cervical Brucella spondylitis with paravertebral abscess and neurological deficits.

Spondylitis is one of the more frequent osteoarticular complications of Brucella infection, but cervical spine involvement is rare. We report here a case of cervical Brucella spondylitis with paravertebral anterior epidural abscess which resulted in neurological deficits. The diagnosis is based on clinical history supported by Brucella serology, radiological findings and histological evidence.

Magnetic resonance imaging of bone marrow versus bone marrow biopsy in malignant lymphoma.

Bone marrow involvement is a frequent finding in malignant lymphoma. Bone marrow biopsy of the posterior iliac crest is routinely performed for staging. Abnormal magnetic resonance imaging (MRI) signals of bone marrow was also reported to be indicative of bone marrow involvement. This study included 60 patients with malignant lymphoma. Unilateral bone marrow biopsy of the posterior iliac crest was performed. MRI of lumbar spine was studied within 24 hours of bone marrow biopsy. 22 healthy controls were used for the detection of MRI objectivity during visual evaluation. In 83% of patients (50/60), biopsy and MRI results agreed completely. In two patients, histologic sections failed to show any evidence of bone marrow involvement despite abnormal MRI signals suggestive of involvement. In three patients, MRI was completely normal despite biopsy proven bone marrow infiltration. False negativity (3/60) and false positivity (2/60) rates were very low. Negative biopsy findings with positive or equivocal MRI results should not exclude bone marrow involvement and needs further evaluation with bilateral or guided biopsy. Thus, we conclude that MRI of bone marrow is a fairly sensitive, noninvasive modality and might be of potential value in detecting bone marrow infiltration in malignant lymphoid neoplasms which can be utilized as a useful adjunct to standard staging procedures.

CT and MRI in hydatid disease of cervical vertebrae.

Hydatid disease (HD) of the cervical spine is rare. A case investigated by computed tomography (CT) and magnetic resonance imaging (MRI) is presented. While CT shows the bone lesion better, MRI is superior in demonstrating compression of neural structures. The complementary use of CT and MRI in such cases is suggested.

Orbital hydatid cyst: assessment of two cases.

Two cases of unilateral proptosis due to orbital hydatid disease are reported. In both cases CT scans showed well-defined, thin-walled cystic masses whose densitometric values were similar to that of the globe.