Assessment of the Correlation between Apparent Diffusion Coefficient and Intervertebral Disk Degeneration Using 3 Tesla MRI.

The objective is to use DW-MR imaging using 3 Tesla MRI to assess the correlation between the mean ADC with degenerative disk disease (DDD). We recruited 34 subjects and used DWI-MR to image lumbar intervertebral disks. We acquired a T2W scan and DWIs. The disks were graded for DDD. Assessment of correlation between mean ADC was made. 170 disks were evaluated. The observed sample correlation between mean ADC and disk degeneration was r = 0.65 [0.55-0.73]. The observed sample correlation between mid-sagittal ADC and disk degeneration was r = 0.61 [0.51-0.70]. The differences between mean ADC of each grade were significant, except between grades 4 and 5. There is a correlation of 0.65 between the mean ADC and disk degeneration. This correlation is not strong enough to use the ADC to determine DDD in clinical settings. There was no evident difference in ADC between the studied anatomic lumbar levels.

Percutaneous needle biopsy of the spine.

The purpose of this review article is to provide a brief overview of the recent literature on the two main types of percutaneous biopsy methods done in the spinal column: fine needle aspiration biopsy (FNAB) and core needle biopsy (CNB). FNAB is the process of obtaining a sample of cells and bits of tissue for examination by applying suction through a fine needle attached to a syringe. Core needle biopsy involves extracting a cylindrical sample of tissue using a large, hollow needle. The decision for needle biopsy is a joint effort between the clinician, pathologist, radiologist, surgeon, and patient. Specific techniques and approaches with varying needle systems are described for each spinal region. Percutaneous image-guided spine biopsy is a safe and effective procedure. It is the procedure of choice in definitive diagnosis of pathologic lesions of the spine.

Periprosthetic soft tissue recurrence of chondroblastoma after attempted en bloc excision from the proximal humerus.

A case of soft tissue recurrence of chondroblastoma after attempted en bloc excision and endoprosthetic replacement is described. This tumor in the proximal humerus recurred after initial curettage and was subsequently treated by attempted en bloc excision with positive microscopic margins. The patient then presented with a large soft tissue recurrence surrounding the endoprosthesis. This periprosthetic recurrence necessitated re-excision and revision of the endoprosthesis. Recurrence is not uncommon following curettage of chondroblastoma. However, less is known about soft tissue recurrence after en bloc resection of this tumor with positive margins. A subset of chondroblastoma may exist with more locally aggressive behavior.

Cartilage metabolism in osteoarthritis and the influence of viscosupplementation and steroid: a review.

Osteoarthritis (O.A.) is the most common type of articular disease. This is an idiopathic joint disease characterized by an imbalance between synthesis and degradation of articular cartilage and subchondral bone accompanied by capsular fibrosis, osteophyte formation and variable grade of inflammation of synovial membrane. Joint lubrication is naturally provided by Hyaluronic acid in syovial fluid. Hyaluronan is present in abundance in normal young and healthy joints. In degenerative O.A. Hyaluronan is smaller in size, molecular weight and diminished in concentration. This decrease in joint lubrication and shock absorbing mechanism in O.A. can be remedied by intraarticular viscosupplementation. Alternatively the pain and secondary inflammation in O.A. can be relieved by intraarticular injection of steroids and long acting local anesthetics. Promt and effective reduction in local inflammation occurs after intra-articular injection of corticosteriod. This article reviews the cartilage metabolism in O.A., discusses the pros and cons of these treatments and provides a literature review of the studies which compare benefits and adverse reactions of viscosupplementation vs. intraarticular steroids with placebo treatment.

Imaging of osteomyelitis in the mature skeleton.

Diagnosis of acute osteomyelitis is often challenging but can be made by plain radiograph, bone scan, or MR imaging. This diagnosis may be more problematic in small bones, in diabetic or immunocompromised patients, those partially treated, post-traumatic, previous surgery, or with pre-existing marrow conditions and associated soft tissue infections. CT is the modality of choice for revealing sequestra and cortical erosions in chronic osteomyelitis. Nonenhanced and enhanced STIR or fat-saturated sequences are essential to reveal the marrow abnormality and its extension for diagnosis of subtle cases with neuropathic or other associated conditions. Combined radionuclide scintigraphy becomes necessary in complicated situations.

Lumbar spine imaging. Normal variants, imaging pitfalls, and artifacts.

Accurate recognition and reporting of spine abnormalities on MRI requires knowledge of normal anatomy and its variants. This article deals with common normal variants, points out pitfalls which may be sources of errors in interpretation and describes imaging artifacts which are essential to be recognized and not mistaken for true pathologies.

Diagnostic and therapeutic features of facet and sacroiliac joint injection. Anatomy, pathophysiology, and technique.

A diagnosis of exclusion facet syndrome is considered one of the many genuine causes of low back pain. Using careful patient selection, percutaneous facet joint block is a useful diagnostic and therapeutic procedure in the management of lumbar facet syndrome. Sacroiliac joint syndrome appears to be a more tangible entity diagnostically and more amenable to injection. This article addresses the anatomy, pathophysiology, and salient radiographic features of the apophyseal joint, and describes the procedures and techniques for facet as well as sacroiliac joint injection.

Discography 2000.

Discography is an invasive and controversial procedure that can be used as a complementary test to MR imaging or a CT myelogram prior to surgery. The examination may be performed in the prone or decubitus position. Pain provocation is the most important part of the examination. CT discography provides valuable information regarding pattern, number, extent, and degree of annular tears. Correlation of discography with cross-sectional imaging studies is reviewed and the surgical outcome is discussed.

Computed tomography of Paget disease of the skull versus fibrous dysplasia.

OBJECTIVE: Radiologists are often challenged to review CT examinations of the skull without pertinent clinical information or plain radiographs. Skull lesions of fibrous dysplasia (FD) may often be confused with Paget disease (PD). The purpose of this article is to evaluate radiographic similarities and to find the signs that can differentiate PD from FD of the skull on head CT and to describe the CT imaging features of PD and FD. DESIGN AND PATIENTS: CT scans of the skull in eight cases of PD, 18 cases of FD (13 cases of skull and facial bones, five cases of only facial bones) and 10 normals were studied retrospectively. RESULTS: Ten features were found to be similar in PD and FD and 10 other features were found to be dissimilar. The frequency of the 10 differentiating features was evaluated to determine their reliability in distinguishing one disorder from the other. The differentiating features in order of significance include: (1) "groundglass" appearance, (2) symmetry, (3) involvement of the paranasal sinuses, (4) thickness of the cranial cortices, (5) involvement of the sphenoid bone, (6) orbital involvement, (7) nasal cavity involvement, (8) presence of a soft tissue mass, (9) maxillary involvement, and (10) the presence of cyst-like changes. CONCLUSION: These 10 signs improve the radiologist's skill in differentiating FD and PD.

Radiographically ossified ganglion cyst of finger in a swimmer.

Ganglion cysts are fibrous-walled cystic lesions closely associated with joint or tendon sheaths and contain gelatinous mucinous fluid. The radiographic appearance is usually normal. Calcification or ossification in these cysts is extremely unusual. We report on an unusual appearing ganglion cyst of the little finger in a swimmer with ossification resembling myositis ossificans.

Musculoskeletal manifestations of AIDS.

Musculoskeletal manifestations in the HIV- and AIDS-infected patient are not as common as in other organ systems. A variety of musculoskeletal abnormalities are discussed in this article, including infection, arthritis, and neoplasms. A brief discussion of miscellaneous conditions, such as avascular necrosis, hypertrophic osteoarthropathy, reflex sympathetic dystrophy, and bone marrows abnormalities is also included.

The spectrum of osteoarticular and soft tissue changes in patients with human immunodeficiency virus (HIV) infection.

In 1995, the World Health Organization reported that 18 million people worldwide have been infected with the human immunodeficiency virus (HIV), with projections that this number will increase to 30 to 40 million by the year 2000. Presently, in the U.S. over 1 million persons are infected. Approximately 40,000 people become newly infected each year in the U.S., a number equivalent to those who die from acquired immunodeficiency syndrome (AIDS) yearly. AIDS is now the leading cause of death in young men aged 25 to 44, and the third leading cause of death in women aged 25 to 44. A shift in the demographic profile of those infected has been noted, with an increasing proportion of minorities, heterosexuals, and children affected. The pathogenesis of HIV infection occurs mainly through immunosuppression, which increases the host's susceptibility to numerous infections. The increased incidence of certain neoplasms in this population point to the ability of the virus either to interfere with the host's tumor surveillance ability or to interact with other agents in tumorigenesis. Certain rheumatic diseases, likely with autoimmune etiologies, are increasingly being associated with HIV. The musculoskeletal system is but one of the sites in which the radiologist must always maintain a high index of suspicion for HIV or AIDS-related disease. The spectrum of osteoarticular and soft tissue changes observed in this population is described.

Magnetic resonance imaging of primary osteosarcoma of the lumbar vertebra with metastasis to the perirenal fat.

Primary osteosarcoma of the spine not associated with any predisposing factor is rare. The authors describe a case of osteosarcoma of the lumbar spine in a 44-year-old woman with biopsy-proven ulcerative colitis. The patient underwent bone scanning, computed tomography (CT) and magnetic resonance imaging (MRI), and the authors present the first record of the MRI appearance of this disease in a vertebral body. Relative to classical osteosarcoma of long bone, this case involved a higher degree of soft-tissue ossification, which was readily visible with both CT and MRI. The patient had extensive metastasis, including metastasis to the perirenal fat, and died 10 months after presentation.

Accuracy of MRI patterns in evaluating anterior cruciate ligament tears.

The purpose of this study was to determine the different patterns of anterior cruciate ligament (ACL) tears on MRI and the prevalence and accuracy of these patterns. Images were obtained on high-tesla and low-tesla units and the results compared to determine whether field strength affects the interpretation using the grading system. In 172 patients who underwent knee MRI (109 knees with high-tesla units and 63 knees with low-tesla units) and arthroscopy, there was a total of 91 arthroscopically proven ACL tears. Five patterns of ACL tears were observed and designated as type 1 (diffuse increase in signal on T2-weighted images and enlargement of the ligament, 48%); type 2 (horizontally oriented ACL, 21%); type 3 (nonvisualization of the ACL, 18%); type 4 (discontinuity of the ACL, 11%); and type 5 (vertically oriented ACL, 2%). The positive predictive value (PPV) for type 2, 4, and 5 patterns was 100% for both field strengths: for type 3 PPV was just above 80% for both field strengths. The PPV value for type 1 was 90% for the high-tesla unit and 79% for the low-tesla, unit, which was not statistically significant. Combining the results of both field strengths, the overall sensitivity and specificity were 93% and 89%, respectively. Arthroscopic results were also used to determine the association between meniscal and ACL tears. Only 13% of ACL tears were isolated, the rest being associated with meniscal tears. Forty-five percent of medial meniscal and 50% of lateral meniscal tears were associated with an ACL tear, and 94% of ACLs were torn when both menisci were torn.

Imaging of cervical spine trauma.

The cervical spine, supporting such critical structures as the medulla, spinal cord, and cervical nerve roots, can be very challenging to image properly because of its complex structural anatomy and superimposition of bony and soft tissue parts. In this article, the use and value of the various modalities that image the cervical spine are discussed. Plain radiography remains the best screening tool in the initial evaluation of the cervical spine after trauma. Additional views, such as swimmer's, pillar and lateral flexion, and extension, often are helpful in certain circumstances.

Paget's disease of bone: review with emphasis on radiologic features, Part I.

Distinctive clinical, radiologic and pathologic features are seen in Paget's disease of bone. These distinct features can be divided into three phases; initial phase, midphase, and late phase. The clinical features may vary from patients being asymptomatic (involving a single bone) to patients having severe, multiple bone involvement with systemic disease. Radiologically, there are unique features which can differentiate Paget's disease from other bone diseases. The radiologic features follows the histologic findings on light microscopy. The correlation of the different phases with the clinical, radiologic and pathologic features of Paget's disease allows for early accurate diagnosis and treatment.

Paget's disease of bone: review with emphasis on radiologic features, Part II.

Part I discusses the correlation between the clinical, radiology and histologic features with the three phases (incipient, mid- and late phase) of Paget's disease. In this section, we will discuss in detail the radiologic features by location as well as aberrant radiographic presentations in addition to secondary tumors such as post radiation sarcomas and giant cells tumors which occur in Paget bone. Because Paget's disease generally affects people in their middle and late ages, the differential diagnosis often includes metastatic disease and the differentiation can often be quite challenging. Moreover, metastatic disease to bones afflicted with Paget's disease can further add diagnostic confusion. These critical aspects will be discussed in this section of Paget's disease of bone.

Efficacy of limited CT for nonvisualized lower cervical spine in patients with blunt trauma.

Records of 100 patients with blunt injury and nonvisualization of C7 and T1 on cross-table lateral and swimmer's views were reviewed to evaluate the usefulness of limited computed tomographic (CT) scans in "clearing" the lower cervical vertebrae of injury. CT was deemed necessary and performed in all of these cases because the lower cervical spine could not be evaluated clinically or with plain radiographs. Ninety-seven of these 100 patients had normal findings on CT and only three patients showed cervical spine fractures. All three had isolated and stable fractures. Two of these patients had "clay-shoveler" fractures at C6 and C7, respectively, and one had a single laminar fracture at C7. All three patients were conservatively treated. This study emphasizes the value of clinical correlation in the evaluation of cervical spine trauma. When deemed necessary in symptomatic patients, CT is useful to exclude skeletal injury in the lower cervical spine thus avoiding delay in the patient's workup and unnecessary hospitalization, and expediting patient discharge. Lack of pain and neurological findings in nonintoxicated, conscious, and alert patients is generally not associated with significant soft tissue or skeletal injury.

Magnetic resonance imaging of osteonecrosis and osteoarthrosis in exercising quadriplegics and paraplegics.

Degenerative bone and joint diseases that commonly accompany spinal cord injury (SCI) may be exacerbated by physical activity of the lower extremities. To determine if orthopaedic stress imposed by electrically stimulated cycling exercise is associated with osteonecrosis or osteoarthrosis in persons with chronic SCI, ten quadriplegics and paraplegics who had each undergone electrical stimulation cycle ergometry exercise two or three times weekly for longer than 1.5 years underwent magnetic resonance examinations of the femoral heads and the dominant knee. Three of the ten subjects had no evidence of meniscal or bone marrow pathologies, osteochondritis dessicans, avascular necrosis, joint effusion or accumulation or soft tissue tears. The magnetic resonance scans of six subjects were noted to have very mild effusion, slight meniscal degeneration and minimal chondromalacia patellae. Consistent patterns of bone or joint pathology were not discernible among these scans, and the positive findings did not represent threatening clinical states. The scans of one subject showed heterogenous regions of bone infarct characteristic of osteochondritis and avascular necrosis, observations that were atypical of all other subjects. No injuries consistent with the biomechanics of cycling exercise were observed in any subject. Despite the high sensitivity of magnetic resonance imaging in detecting bone and joint deterioration, significant bone and joint findings represented only 14 of 150 observations, less than previously reported in sedentary subjects with SCI. This study suggests that electrical stimulation cycle ergometry does not foster bone or joint deterioration in individuals with chronic SCI.