Prevalence of triceps tendon tears on MRI of the elbow and clinical correlation

OBJECTIVE

Triceps tendon injuries are reported to be very rare. To our knowledge, there have been no studies describing its prevalence or injury patterns on MR imaging. The purpose of this retrospective study was to determine the prevalence and patterns of triceps injuries based on a large series of consecutive MR examinations. Clinical correlation was obtained.

MATERIALS AND METHODS

From 801 consecutive elbow MR examinations over a 15-year period, 28 patients with 30 triceps tendon injuries were identified and graded as partial tendon tear and complete tendon tear. The patients' medical records were reviewed to determine age, gender, cause of tears, and management.

RESULTS

The prevalence of triceps tendon injuries was 3.8%. There were 5 women and 23 men with partial or complete tears (mean age: 46.6 years; range: 2.7 to 75.1 years). The most common injury was partial tear, found in 18 patients. There were 10 patients with 12 complete tears (2 had re-torn following surgical repair). A tear was suspected in 12 out 28 (43%) patients prior to the MRI. The most common presenting symptom was pain. The most common cause was athletic injury (8 patients [29%], including weightlifting [2 patients]). Tendon tear was found to be a complication of infection in 6 patients, and in 3 patients the tears were a complication of steroid use. Thirteen tendon tears were surgically repaired (8 of these were complete tears).

CONCLUSIONS

Triceps tendon injury is not as rare as commonly reported and may often be clinically underdiagnosed.

Imaging findings, prevalence and outcome of de novo and secondary malignant fibrous histiocytoma of bone

OBJECTIVE

To evaluate the radiographic and magnetic resonance (MR) imaging features of primary and secondary malignant fibrous histiocytoma in bone and determine the demographics, prevalence and outcome of patients with this tumor.

MATERIALS AND METHODS

A retrospective search of files from two institutions identified 28 patients with malignant fibrous histiocytoma (MFH) of bone. Microscope slides were reviewed to confirm diagnosis and identify any pre-existing lesions. Medical records were reviewed with respect to patients' demographic characteristics and outcomes.

RESULTS

Radiographic features demonstrated an aggressive osteolytic lesion with a permeative pattern of bone destruction. Periosteal reaction was seen in three of 13 lesions. T1-weighted images (T1WIs) demonstrated signal intensity iso- to slightly hyperintense to muscle. T2-weighted images (T2WIs) demonstrated mildly higher signal intensity than that of muscle. The 5-year survival rate was 53%. The tumor arose secondarily in pre-existing lesions in 43% of patients. Metastases occurred in 46% of patients during the course of the disease, with pulmonary and osseous metastases being the most common.

CONCLUSION

Secondary MFH of bone was slightly less common than primary MFH and had a prognosis similar to that of primary MFH of bone. MR imaging showed variable and somewhat unusual low to intermediate T2 signal characteristics for a radiographically malignant osteolytic lesion.

Clinical presentation and imaging of bone and soft-tissue sarcomas

The clinical presentation of bone and soft-tissue sarcomas is varied. Constitutional symptoms are rare, and although bone sarcomas tend to be painful while soft-tissue sarcomas usually are not, there are exceptions to this general rule. A high index of suspicion is required for any unexplained mass with indeterminate imaging findings. Choosing the right imaging modality is critical to the diagnosis and management of patients with suspected sarcoma, and referring clinicians have a multitude of imaging options. After discovery of a malignant-appearing bone lesion by radiography, further imaging is obtained for better characterization of the lesion (typically with magnetic resonance imaging [MRI]) and for staging (typically with computed tomography of the chest). In contrast, radiographs are rarely helpful for evaluation of soft-tissue lesions, which almost always require MRI assessment.

Estimation of a valuation function for a diabetes mellitus-specific preference-based measure of health: the Diabetes Utility Index

Preference-based measures of health (PBMH) provide 'preference' or 'utility' weights that enable the calculation of QALYs for the economic evaluations of interventions. The Diabetes Utility Index (DUI) was developed as a brief, self-administered, diabetes mellitus-specific PBMH that can efficiently estimate patient-derived health state utilities. To describe the development of the valuation function for the DUI, and to report the validation results of the valuation function. Multi-Attribute Utility Theory (MAUT) was used as the framework to develop a valuation function for the DUI. Twenty of 768 possible health states of the DUI classified as anchor states, single-attribute level states including corner states, and marker states were selected and described for preference elicitation interviews. Visual analogue scale and standard gamble (SG) exercises were used to measure preferences from individuals with diabetes recruited from primary care and community settings in and around Morgantown, WV, USA for the 20 health states defined by combinations of DUI attributes and severity levels. Data collected in the interviews were used to develop a valuation function that calculates utilities for the DUI health states and calculates attribute-level utilities. A validation survey of the valuation function was conducted in collaboration with the West Virginia University (WVU) Diabetes Institute. A total of 100 individuals with diabetes were interviewed and their preferences for various DUI health states measured. From data generated in the interviews, a DUI valuation function was developed on a scale where 1.00 = perfect health (PH) and 0.00 = the all worse 'pits' state, and adjusted to yield utilities on the conventional scale 1.00 = PH and 0.00 = dead. A total of 396 patients with diabetes who received care at WVU clinics completed a DUI mail validation survey (response rate = 33%). Clinical data consisting of International Classification of Diseases, 9th edition, diagnosis codes and glycosylated haemoglobin (HbA(1c)) values for the respondents were merged with their responses to the DUI. The utilities calculated by the scoring function of the DUI compared favourably to cardinal SG utilities for three DUI health states for which both assessments were available. The DUI utility function slightly underestimated actual SG utilities for mild and moderate health states (mean absolute difference = 0.05). There was a small but significant correlation between DUI utility scores and average past year HbA(1c) values (r = -0.30; p < 0.001). Respondents with two or more complications had significantly lower DUI utilities than those with no complications (p < 0.001) or one complication (p = 0.015). Insulin users had significantly lower DUI utilities than non-users (p < 0.001), and those with HbA(1c) values <7% had significantly higher DUI utilities than those with HbA(1c) values of >or=7% (p < 0.001). No significant association was found between DUI scores and age or sex. These results show evidence of the feasibility and validity of the DUI. Further research is suggested to demonstrate the generalizability of these findings, to study the responsiveness of the DUI, and to examine the clinical meaningfulness of DUI change scores.

Incidental tumor and tumor-like lesions around the knee

Encountering an incidental tumor or tumor-like lesion during a routine magnetic resonance imaging (MRI) of the knee is not uncommon. By far, the majority of these lesions are benign and many of them have characteristic appearances on MRI to allow a confident diagnosis. The most common, and some less common, but important incidental lesions will be discussed including bone lesions (bone cysts, subchondral fractures, enchondromas, non-ossifying fibromas, "tug" lesions, osteochondromas, bone infarcts, and prominent red marrow) and soft tissue lesions (synovial hemangiomas, intracapsular chondromas, bursae, synovitis, soft-tissue cysts, hematomas, heterotopic ossification, vascular lesions and normal variants). Gaining familiarity with the MRI appearance of these incidentally encountered lesions will be helpful in avoiding unnecessary additional tests and/or imaging.

Radiologic case study: osseous sarcoidosis

Enhance your diagnostic skills with this "test yourself" monthly column, which features a radiograph and challenges you to make a diagnosis.

Cortical scalloping and cortical penetration by small eccentric chondroid lesions in the long tubular bones: not a sign of malignancy?

OBJECTIVES

The objective of this study was to evaluate by cross-sectional imaging the prevalence and degree of cortical scalloping by small eccentric chondromas correlated with histologic diagnosis and patient history.

MATERIALS AND METHODS

From 122 patients with histologically proven enchondromas and two patients without histology but with radiologic and clinical follow-up, 11 patients with small, eccentrically located chondromas in the long bones had cross-sectional imaging available. The lesions were evaluated for location, size, presence, and degree of cortical scalloping. The patient's medical charts and microscope slides were reviewed for relevant clinical history, clinical management, and histology.

RESULTS

The chondromas ranged in size from 1.6 to 3.8 cm (mean 2.3 cm). Two lesions were located in the proximal femoral diaphysis, two in the distal femoral diaphysis, six in the distal femoral metaphysis, and one in the proximal tibial epimetaphysis. The lesions were curetted due to diagnostic uncertainty, continued pain, marked radiologic cortical penetration, or due to patient insistence on biopsy. All 11 lesions were benign, nine histologically, and two by stability over 4 and 7 years. The prevalence of cortical scalloping among eccentric chondromas was 100%. Cortical scalloping or occupancy ranged from 50 to 100% (mean 75%).

CONCLUSIONS

All small eccentric chondromas in this study were associated with an appearance of cortical scalloping of varying degree. All curetted lesions were histologically bland without nuclear atypia. Based on the benign histology of nine lesions and lack of growth of two lesions over several years, the degree of cortical scalloping is felt to be a result of lesion location within the endosteum rather than biological activity or malignancy.

Radiologic case study: diabetic myonecrosis of the posterior compartments of both thighs

Enhance your diagnostic skills with this "test yourself" monthly column, which features a radiograph and challenges you to make a diagnosis.

Cofactors for Low Serum Albumin Levels Among HIV-Infected Individuals in Southern India

Background and aims. Malnutrition and low serum albumin among human immunodeficiency virus (HIV)-infected individuals are cofactors for HIV disease progression. The present study aimed to identify the proportion of HIV-infected individuals with low serum albumin and the possible cofactors among highly active antiretroviral therapy (HAART) experienced and HAART naïve individuals. Methods. A total of 835 HIV-infected individuals (HAART-experienced, HAART-naïve) were included in the study. Results. Of the 835 individuals, 44.6% had normal (4.2-5.2 g/dL) and 55.4% had abnormal (<4.2 g/dL) albumin levels. The abnormal group had significantly lower body mass index (BMI) compared with the normal group (P = .02). Among those with abnormal albumin, 388 (84%) were HAART experienced compared with 239 (64%) with normal albumin (P < .001). Among the abnormal group, 259 (55.9%) had CD4 count <200 cells/mL as compared with 124 (33.3%) in the normal group (P < .001). Conclusions. CD4 count and lower were the major cofactors for low serum albumin among HIV-infected individuals. Therefore, serum albumin would be a useful biochemical test for HIV disease in resource-limited settings.

Does the presence of focal normal marrow fat signal within a tumor on MRI exclude malignancy? An analysis of 184 histologically proven tumors of the pelvic and appendicular skeleton

OBJECTIVE

The aim of this study was to determine if the presence of focal normal bone marrow fat signal within a tumor on magnetic resonance imaging excludes malignancy.

MATERIALS AND METHODS

One hundred eighty-four histologically proven tumors with available magnetic resonance imaging (MRI) of the appendicular skeleton and pelvis from 184 patients were collected and reviewed at two separate institutions. There were 111 malignant and 73 benign tumors. Two radiologists at each institution, blinded to the diagnosis, reviewed the MRIs independently and reported the presence or absence of normal marrow fat signal within the tumor based upon T1-weighted imaging without fat suppression and T2-weighted imaging with fat suppression and/or short inversion-time inversion recovery (STIR). Discrepancies were then reviewed in consensus to determine the presence or absence of focal normal marrow signal. For each institution, a Fisher's exact test was used to compare the frequency of focal normal marrow fat signal in benign and malignant tumors. This comparison was performed for each reader, as well as for the consensus reading at each site. Positive and negative predictive values were also calculated for each reader, as well as the consensus reading at each site. Fisher's exact test was also used to compare the frequency of intratumoral fat in benign and malignant lesions for the pooled sample. Bayes theorem was used to calculate the positive and negative predictive values for the pooled consensus data. Ninety-five percent confidence intervals were constructed for the pooled estimates using a bootstrapping algorithm.

RESULTS

There was good interobserver reliability of 95.3% and 96.7% at sites 1 and 2, respectively. There were three discrepancies (one malignant and two benign) at site 1 and four discrepancies (two malignant and two benign) at site 2. Reader consensus at site 1 identified normal marrow fat signal within 1 of 50 (2.0%) malignant and three of 14 (21.4%) benign tumors. Findings were statistically significant with a p value of 0.030. The positive predictive value (PPV) and negative predictive value (NPV) at site 1 was 81.7% and 75.0%, respectively. Reader consensus at site 2 identified normal marrow fat signal within three of 61 (4.9%) malignant and 14 of 59 (23.7%) benign tumors. Findings were statistically significant with a calculated p value of 0.004. The PPV and NPV at site 1 was 56.3% and 82.4%, respectively. For the pooled consensus, the frequency of intratumoral fat in benign lesions (17/73, 23.3%) is significantly greater than the frequency in malignant lesions (4/111, 3.6%), p < 0.001.

CONCLUSION

The presence of focal normal marrow signal within a tumor is highly suggestive of a benign tumor.

Radiologic case study. Prepatellar Morel-Lavallée lesion

Although the Morel-Lavallé lesion was originally described over 150 years ago and is a well known entity about the pelvis and femora, its occurrence in the prepatellar region has only recently been reported. While Tejwani et al asserted that prepatellar MLL and prepatellar bursitis can be readily distinguished clinically, the absence of prepatellar MLL from the literature until recently suggests that it may be under-diagnosed. Magnetic resonance imaging can be a helpful adjunct to the clinical examination in diagnosing MLL, primarily by confirming the precise extent of the fluid beyond the expected anatomic margins of the prepatellar bursa. Because both entities are initially treated in the same manner, MRI might be reserved for collections that fail to resolve following conservative therapy or in cases where the diagnosis is questioned. Serial percutaneous aspiration and sclerodesis should be considered in the management of recalcitrant collections or in the initial management of athletes depending on lesion size and range of motion.

The painful knee: choosing the right imaging test

The initial evaluation of acute knee pain should include plain radiography, which is a quick and cost-effective way to identify a wide range of problems, including fracture, degenerative changes, osteochondral defects, and effusions. Computed tomography (CT) is the test of choice to better delineate fractures in patients who have knee trauma. If the history and physical examination point to damage of the cartilage, the menisci, and the cruciate and collateral ligaments and arthroscopy is contemplated, then magnetic resonance imaging (MRI) is useful for evaluating these structures.

Iliopsoas injury: an MRI study of patterns and prevalence correlated with clinical findings

OBJECTIVES

The objective was to retrospectively determine the prevalence and patterns of iliopsoas injuries based on consecutive MRI examinations, correlated with clinical findings.

MATERIALS AND METHODS

From 4,862 consecutive MRI examinations of the hips and pelvis, 32 patients with 33 iliopsoas injuries were identified and graded as muscle strain, partial tendon tear, and complete tendon tears. These patients' medical records were reviewed to determine age, gender, and cause of symptoms.

RESULTS

The prevalence of iliopsoas tendon and myotendinous injuries was 0.66% (95% CI: 0.44-0.89). There were 18 females and 14 males whose ages ranged from 7 to 95 years (mean, 54 years). The most frequent presenting symptom was hip pain and the most frequent clinical diagnosis, an occult fracture. The most common injuries in patients under 65 years (16 patients) were muscle strains and partial tendon tears, most often due to an athletic injury. The most common injury in patients 65 years and older (16 patients) was a complete tear (8 patients, all females), 2 of which were spontaneous in origin.

CONCLUSIONS

Each grade of iliopsoas injury occurred with similar frequency. The more advanced the age of the patient, the more severe the injury. Non-athletic injuries predominated in patients 65 years and older; athletic injuries were the most common cause of iliopsoas injury in patients under 65 years.