Utility of CT-guided biopsy of suspicious skeletal lesions in patients with known primary malignancies.

OBJECTIVE: Patients with a known primary malignancy and one or more suspicious skeletal lesions are often assumed to have skeletal involvement by the known malignancy. We set out to determine how often one would be correct in making this assumption. MATERIALS AND METHODS: All CT-guided bone biopsies performed at our institution between January 2006 and January 2009 in patients with a history of a single biopsy-proven malignancy were retrospectively reviewed. Pathology results were assigned to one of three outcomes: skeletal involvement by known malignancy, newly diagnosed malignancy, or no malignancy identified. Patients categorized as no malignancy identified required repeat biopsy or stability on follow-up imaging for confirmation. RESULTS: Of 104 patients with a known primary malignancy, 11 were excluded. Of the 93 included patients, there was skeletal involvement by the known malignancy in 82 (88%), a newly diagnosed malignancy in seven (8%), and no malignancy identified in four (4%). CONCLUSION: Biopsy of a suspicious skeletal lesion in a patient with a solitary known malignancy reveals a newly diagnosed malignancy or no evidence of malignancy in 12% of patients, emphasizing the importance of biopsy.

Aberrant course of the umbilical vein in a newborn with Cornelia de Lange syndrome.

Congenital anomalies of the umbilical vein are rare. We describe an aberrant course of the umbilical vein discovered by identifying an unusual umbilical venous catheter course on abdominal radiography in a patient with Cornelia de Lange syndrome. The umbilical vein bypassed the liver to insert directly into a right pelvic vein. Use of the lateral abdominal radiograph and sonography were helpful in determining the catheter location after identifying the unusual course of the catheter on the frontal radiograph.

Upper extremity compartmental anatomy: clinical relevance to radiologists.

Malignant tumors of the upper extremity are uncommon, and their care should be referred to specialized facilities with experience treating these lesions. The Musculoskeletal Tumor Society (MSTS) staging system is used by the surgeon to determine appropriate surgical management, assess prognosis, and communicate with other healthcare providers. Magnetic resonance imaging (MRI) is employed pre-operatively to identify a lesion's compartment of origin, determine extent of spread, and plan biopsy and resection approaches. Involvement of neurovascular structures may result in devastating loss of upper extremity function, requiring amputation. Violation of high-resistance compartmental barriers necessitates more extensive surgical resection. Biopsy may be performed by the radiologist using imaging guidance. Knowledge of compartmental anatomy allows the radiologist or surgeon to use an easily excisable biopsy approach and prevent iatrogenic spread to unaffected compartments. Case examples are presented to illustrate the importance of compartmental anatomy in the management of benign and malignant upper extremity tumors.

Evaluation of the acetabular labrum at 3.0-T MR imaging compared with 1.5-T MR arthrography: preliminary experience.

Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. The purpose of this study was to prospectively compare imaging of the acetabular labrum with 3.0-T magnetic resonance (MR) imaging and 1.5-T MR arthrography. Eight patients (four male, four female; mean age, 38 years) with hip pain suspicious for labral disease were examined at both MR arthrography and MR imaging. Presence of labral lesions, paralabral cysts, articular cartilage lesions, subchondral cysts, osteophytes, and synovial herniation pits was recorded. There was arthroscopic correlation of findings in five patients. MR imaging depicted four surgically confirmed labral tears that were identified at MR arthrography, as well as one that was not visualized at MR arthrography. MR imaging helped identify all other pathologic conditions that were diagnosed at MR arthrography and helped identify one additional surgically confirmed focal articular cartilage lesion. These results provide encouraging support for evaluation with 3.0-T MR imaging over 1.5-T MR arthrography.

Sensitivity of MR arthrography in the evaluation of acetabular labral tears.

OBJECTIVE: MRI has historically provided suboptimal visualization of tears of the acetabular labrum. Degenerative fraying and underlying cartilage abnormalities can often mimic tears of the labrum on conventional MRI. Administration of intraarticular gadolinium enhances the MRI appearance of the labrum to improve detection of labral abnormalities. This study examined the improved diagnostic sensitivity of MR arthrography compared with conventional MRI and the importance of confining the study to a small field of view. MATERIALS AND METHODS: Fifty-one hips were imaged in 48 patients. Fourteen hips underwent conventional MRI with a large field of view (30-38 cm). Seven hips underwent conventional MRI with a small field of view (14-20 cm). Thirty hips underwent MR arthrography with a small field of view (14-20 cm). Labral tears were diagnosed when contrast material was identified within the labrum or between the labrum and the acetabulum, when a displaced fragment was noted, or when a paralabral cyst was identified. All study results were compared with findings at the time of hip arthroscopy. RESULTS: Conventional MRI with a large field of view was 8% sensitive in detecting labral tears compared with findings at the time of arthroscopy. Diagnostic sensitivity was improved to 25% with a small field of view. MR arthrography with a small field of view was 92% sensitive in detecting labral tears. CONCLUSION: A combination of MR arthrography and a small field of view is more sensitive in detecting labral abnormalities than is conventional MRI with either a large or a small field of view.

Lower extremity compartmental anatomy: clinical relevance to radiologists.

A thorough understanding of compartmental anatomy is necessary for the radiologist participating in the care of a patient with a lower extremity musculoskeletal malignancy. Localization of tumor to compartment of origin and identification of extracompartmental spread preoperatively are needed to correctly stage a tumor and determine the appropriate surgical management. An understanding of the locations of fascial boundaries, extracompartmental tissues, and neurovascular structures of the thigh and lower leg facilitates this diagnostic process. For the radiologist planning to biopsy a suspicious musculoskeletal lesion, consultation with the referring orthopaedic surgeon is recommended in order to jointly select an appropriate percutaneous biopsy approach. Adequate preprocedural planning ensures selection of an approach which prevents iatrogenic tumor spread beyond the compartment of origin, protects neurovascular structures, and allows complete resection of the biopsy tract and scar at the time of surgical resection without jeopardizing a potential limb-sparing procedure. Cross-sectional anatomic review and case examples demonstrate the importance of a detailed understanding of compartmental anatomy when approaching the patient with a lower extremity musculoskeletal tumor.

The effects of N(omega)-propyl-L-arginine on reperfusion injury of skeletal muscle.

N(omega)-Propyl-L-arginine (NPA) is reported to be a highly selective inhibitor of neuronal nitric oxide synthase (nNOS). This in vivo study observed its role in ischemia/reperfusion (I/R) injury in rat skeletal muscle. Our results showed that NPA infusion significantly increased vessel diameters and blood flow in reperfused cremaster muscle, and slightly increased contractile function in reperfused extensor digitorum longus (EDL) muscle. In addition, NPA treatment slightly increased I/R-mediated downregulation of nNOS and eNOS mRNA and protein levels. Although NPA showed a beneficial role in I/R injury, our in vivo data do not support NPA as a selective nNOS inhibitor. Also, our data do not provide any insight into the mechanism of NPA. Thus, the in vivo mechanism of action of NPA needs to be further identified, and the role of nNOS in skeletal muscle I/R still remains to be determined.

C1-esterase inhibitor and a novel peptide inhibitor improve contractile function in reperfused skeletal muscle.

To determine the role of inhibition of complement activation in the contractile function of skeletal muscle ischemia-reperfusion (I/R) injury, the rat extensor digitorum longus (EDL) muscles underwent 3 h ischemia and received human C1-esterase inhibitor (C1-INH, 100 IU/kg), a synthetic C1q A chain peptide with a similar inhibitory effect on activated C1 (peptide, 5 mg/kg), or human serum albumin control. Results showed a significant overall increase in tetanic contractile forces of the reperfused EDL in both C1-INH and peptide groups compared to controls. Maximum improvement occurred with peptide treatment at 120-Hz stimulation, with an increase in force from 38 +/- 4% of normal in controls to 52 +/- 4% in peptide-treated rats. There were no significant differences between C1-INH and peptide groups. Plasma C3 and C4 activities were significantly increased in both treated groups, suggesting inhibition of complement activation. Our results suggest that complement activation is involved in I/R injury, and inhibition of complement activation may therefore represent a potential therapeutic approach to reducing or preventing I/R injury.