Tumors of the Spine: When Can Biopsy Be Avoided?

Regarding osseous tumors of the spine, characteristic morphology is encountered in hemangioma of the vertebral body, osteoid osteoma (OO), osteochondroma, Paget's disease, and bone islands. In these cases, radiologic imaging can make a specific diagnosis and thereby avoid biopsy, especially when the radiologist has chosen the correct imaging modality to establish the diagnosis, such as thin-slice computed tomography in suspected OO. A benign lesion is suggested by a high amount of fat within the lesion, the lack of uptake of the contrast agent, and a homogeneous aspect without solid parts in a cystic tumor. Suspicion of malignancy should be raised in spinal lesions with a heterogeneous disordered matrix, distinct signal decrease in T1-weighted magnetic resonance imaging, blurred border, perilesional edema, cortex erosion, and a large soft tissue component. Biopsy is mandatory in presumed malignancy, such as any Lodwick grade II or III osteolytic lesion in the vertebral column. The radiologist plays a crucial role in determining the clinical pathway by choosing the imaging approach wisely, by narrowing the differential diagnosis list, and, when characteristic morphology is encountered, by avoiding unnecessary biopsies.

[Femoroacetabular impingement syndrome in adolescents-How to adivse? How to treat?] / Femoroazetabuläres Impingement-Syndrom bei Adoleszenten ­ Wie beraten? Wie behandeln?

BACKGROUND: Femoroacetabular impingement syndrome (FAIS) is a relevant cause of groin pain in adolescents. Athletes are particularly affected. OBJECTIVES: The article shall provide an evidence-based background for FAIS counseling and therapy in adolescents. MATERIAL AND METHODS: On the basis of the current literature, an overview of the prevalence and pathogenesis, evaluation and diagnostics, as well as the therapeutic recommendations for FAIS in adolescents was compiled. RESULTS AND DISCUSSION: FAIS in adolescents primarily affects physically active patients. Certain sports favor the development of FAIS. Cam impingement, pincer impingement, and combined FAIS are the most common entities in this age group. Cam morphology occurs shortly before closure of the proximal femoral growth plate. In cam impingement, the slipped capital femoral epiphysis (SCFE) must be distinguished from the primary cam morphology. SCFE requires rapid surgical treatment with stabilization of the epiphysis, while primary cam impingement can be analyzed electively, and conservative treatment is first recommended. Damage to the labrum and cartilage is regularly observed. A systematic radiological evaluation using X­rays and MRI is mandatory in order to develop an adequate treatment plan. In adolescent patients with FAIS, a conservative attempt at therapy should always be made; if this is unsuccessful, surgical repair with hip arthroscopy is indicated. The postoperative results are very good in adolescents, with a rapid improvement in symptoms, few complications, and a high return-to-sport rate.

Peripheral nerve tractography in soft tissue tumors: a preliminary 3-tesla diffusion tensor magnetic resonance imaging study.

INTRODUCTION: This diffusion tensor magnetic resonance imaging (DTI) study aimed to clarify the relationship of peripheral nerves and soft tissue tumors (STTs) in 3D to optimize subsequent treatment. METHODS: Twenty-six consecutive STT patients (histologically malignant, n=10; intermediate, n=3; and benign, n=13) underwent 3-Tesla MRI using an echoplanar DTI sequence. Deterministic tractography was performed. Fractional anisotropy (FA) values were measured within peritumoral and distant regions of interest. RESULTS: Tractography depicted the 3D course of the sciatic (n=12), femoral (n=2), tibial (n=7), fibular (n=2), median (n=1), musculocutaneous (n=1), and ulnar (n=1) nerves in a regular (n=8 of 18, 44.4%) or thinned (n=7 of 18, 38.9%) fashion. The lowest peritumoral FA values, abrupt thinning, and/or complete discontinuity of trajectories were found in 2 cases with histologically proven tumoral nerve infiltration. CONCLUSIONS: DTI clarifies the 3D topography between major peripheral nerves and STTs and may be helpful in the assessment of peripheral nerve infiltration by malignant tumors.

Tumour response of osteosarcoma to neoadjuvant chemotherapy evaluated by magnetic resonance imaging as prognostic factor for outcome.

PURPOSE: This study evaluated the feasibility of computed magnetic resonance imaging (MRI) volumetry in conventional osteosarcomas. Secondly, we investigated whether computed volumetry provides new prognostic indicators for histological response of osteosarcomas after neoadjuvant chemotherapy. METHODS: In a retrospective cohort study, data from the Vienna Bone Tumour Registry was used. MR images from 14 patients (male:female = 1.8, mean age 19 years) were analysed prior to and after neoadjuvant chemotherapy according to current therapy regimens. Histological response to chemotherapy was graded according to the Salzer-Kuntschik classification. Computed volumetry was performed for the intraosseous part, as well as the soft-tissue component and the tumour as a whole. RESULTS: In a setting of appropriate radiological equipment, the method has been considered to be well implementable into clinical routine. The mean tumour volume prior to chemotherapy was 321 (±351) ml. In good responders (n = 6), overall tumour volume decreased by 47% (p = 0.345), whereas poor responders (n = 8) showed a 19% decrease (p = 0.128). Neoadjuvant multidrug therapy remarkably changed the tumour composition. This is seen in a decrease of the mean ratio of soft-tissue to intraosseous tumour volume from 8.67 in poor responders and 1.15 in good responders to 1.26 and 0.45 (p = 0.065), respectively. Interestingly, the bony compartment of good responders showed a volume increase during neoadjuvant chemotherapy (p = 0.073). However, we did not find prognostic markers for histological tumour response to pre-operative chemotherapy. CONCLUSIONS: Separated volumetry of tumour segments revealed interesting insights into therapy-induced growth patterns. If verified in a larger study population, these results should be taken into account when planning ablative surgery.

Anatomy and variants of the triangular fibrocartilage complex and its MR appearance at 3 and 7T.

Due to the small size and complexity of its constituents, the triangular fibrocartilage complex (TFCC) has been a challenging structure for magnetic resonance (MR) imaging. Higher-field MR units, at 3T and 7T, with increased spatial resolution and the development of novel MR sequences, are promising tools for an improved visualization of the ulnocarpal complex. Anatomically, the TFCC consists of the TFC proper, the ulnomeniscal homolog, the ulnar collateral ligament, the ulnotriquetral and ulnolunate ligament, and radioulnar ligaments at the volar (palmar) and the dorsal side, as well as the sheath of the extensor carpi ulnaris tendon and the capsule of the distal radioulnar joint. This article describes the normal anatomy of the TFCC and its appearance on high-field MRI. Anatomical variants, such as the positive ulnar variance, and changes during pronation and supination are addressed.

High-resolution three-dimensional contrast-enhanced blood oxygenation level-dependent magnetic resonance venography of brain tumors at 3 Tesla: first clinical experience and comparison with 1.5 Tesla.

RATIONALE AND OBJECTIVES: To evaluate the clinical potential of high-resolution 3D contrast-enhanced blood oxygenation level-dependent MR-Venography (CE-MRV) for primary brain tumors and metastases at 3 Tesla (T) in comparison to 1.5 T. METHODS: Eighteen patients with brain tumors were examined using CE-MRV after application of a standard dose of MRI contrast agent (0.1 mmol/kg gadodiamide). CE-MRV is based on a high-resolution 3D flow-compensated gradient-echo sequence with long echo times that uses the contrast-enhanced blood oxygenation level-dependent effect. This technique was performed using the same volume coverage and acquisition time at both field strengths after performing standard imaging sequences. RESULTS: The higher spatial resolution of CE-MRV at 3 T showed more details within and around tumors than at 1.5 T. Visibility was enhanced by stronger susceptibility weighting and higher intrinsic signal-to-noise at 3 T. Compared with standard imaging protocols, additional information characterized as tubular and nontubular hypointense structures were found within or around lesions on CE-MRV images. CONCLUSIONS: Acquisition of CE-MRV data at 3 T enables spatial resolution to be increased within the same measurement time and with the same volume coverage compared with 1.5 T, thus providing more detailed information. The method may also show the potential to estimate oxygen supply of tumors, especially at high field strengths.

Effect of contrast dose and field strength in the magnetic resonance detection of brain metastases.

PURPOSE: To compare the diagnostic efficacy of a standard and cumulative triple dose of magnetic resonance (MR) imaging contrast agent in the evaluation of brain metastases using a high-field 3.0 T MR unit versus a standard field 1.5 T MR unit. METHODS: Twenty-two patients with suspected brain metastases were examined at both field strengths using identical postcontrast coronal 3D gradient echo with magnetization preparation, which was adjusted separately for each field strength. In both groups initially, iv injection of 0.1 mmol/kg body weight gadolinium chelate (gadodiamide) and thereafter, 0.2 mmol/kg body weight gadodiamide were administered. Subjective assessment of the images was performed independently by 3 neuroradiologists. Objective measurement of signal-to-noise and contrast-to-noise ratios was obtained. RESULTS: The subjective assessment of cumulative triple-dose 3.0 T images obtained the best results compared with other sequences, detecting 84 metastases, followed by 1.5 T cumulative triple-dose enhanced images with 81 brain metastases. The objective assessment confirmed those results, showing significantly higher signal-to-noise and contrast-to-noise ratios with 3.0 T than with 1.5 T. CONCLUSIONS: Cumulative triple-dose images of both field strengths were superior to standard field strengths. However, administration of gadodiamide contrast agent produces higher contrast between tumor and normal brain on 3.0 T than on 1.5 T, resulting in better detection of brain metastases and leptomeningeal involvement.

Magnetic resonance imaging contrast enhancement of brain tumors at 3 tesla versus 1.5 tesla.

RATIONALE AND OBJECTIVES: To compare the diagnostic efficacy of a standard dose of MRI contrast agent in the evaluation of primary brain tumors and metastases using a high-field 3 tesla MR unit versus a 1.5 tesla MR unit. METHODS: Sixteen patients with brain tumors were examined at both field strengths using identical axial T1-SE protocols pre- and postcontrast (0.1 mmol/kg gadolinium), and postcontrast coronal 3D GRE with magnetization preparation (MP-RAGE), which was adjusted separately for each field strength. Evaluation of the images was performed quantitatively and, in the case of T1-SE images, also by visual assessment. RESULTS: Tumor-to-brain-contrast after gadolinium administration using statistical evaluation of MP-RAGE scans was significantly higher at 3 tesla (97.5) than at 1.5 tesla (46.3). The same was true for T1-SE sequences (93.0 vs. 72.1). Signal enhancement of the lesions in T1-SE sequences was not significantly different between both field strengths. CONCLUSIONS: Administration of a gadolinium contrast agent produces higher contrast between tumor and normal brain at 3 tesla than at 1.5 tesla.

Endoscopic anterior cervical foraminotomy for unilateral radiculopathy: anatomical morphometric analysis and preliminary clinical experience.

OBJECT: Cervical radiculopathy is typically caused by posterolateral disc herniation or spondylotic foraminal stenosis, either of which may compress the ventral aspect of the nerve root. The authors undertook a study to establish the feasibility of performing an endoscopic approach for anterior cervical foraminotomy (ACFor) in a clinical setting. METHODS: Application of this method on cadavers was conducted to verify the practicability of this technique. The clinical study included 16 patients (eight men and eight women; mean age 46.6 years) all presenting with unilateral radicular symptoms (one at two adjacent ipsilateral levels), which were associated with various degrees of neck pain. Disc herniations and/or uncovertebral osteophytes were confirmed on magnetic resonance imaging and high-resolution computerized tomography scanning. A total of 17 endoscopic ACFors (one two-level procedure) were performed using a rigid glass endoscope (25 degrees angled, 3-mm diameter, 10-mm length) mounted on a tubular retractor. No major surgery-related complications were encountered. During a mean follow-up period of 13.8 months an average absolute improvement of 44% (p > 0.05) in the neck disability index score and of 96% (p > 0.05) in the visual analog scale score for radicular pain (compared with the preoperative score) was observed. During the follow-up period strength improved to normal in 84% and sensory deficit in 80% of the patients. The overall subjective patient satisfaction rate was 87.6%; the return-to-work rate after 4 weeks was 81.4%. CONCLUSIONS: The advantages of endoscopic ACFor include minimial surgical exposure, improved intraoperative visualization, direct decompression of the nerve root, and the preservation of the intervertebral disc and the motion segment.

[Imaging of tumors of the pituitary gland]. / Bildgebende Diagnostik bei Hypophysentumoren.

Macrotumors of the sella region usually involve the suprasellar and less commonly the parasellar space. The suprasellar extension of pituitary adenoma, meningeoma, craniopharyngioma, and hypothalamic or chiasmatic glioma count for the most frequent neoplastic entities. In macroadenomas of the pituitary gland invasion of parasellar spaces may occur in 6-10%. Imaging techniques are directed to increase the likelihood of surgical cure and to detect aggressive tumour invasion into surrounding tissues. A dedicated classification basing on indirect MRI signs of tumour extension has been established. With high-resolution high-field (3T) MRI the sella region may be displayed to provide better information compared to lower field strengths.

[Early arthritis: action desired - treatment required]. / Arthritis - rechtzeitig handeln heisst behandeln.

Rheumatoid Arthritis (RA) is the most prevalent inflammatory joint disease in adults and shows a destructive course in most cases. The outcome of the disease - functional decline and invalidity - necessitates an early therapy. Recent studies demonstrate that the initiation of the treatment with a disease modifying antirheumatic drug (DMARD) treatment within the first three months after the onset of symptoms is crucial for sustained improvement of prognosis as well as therapeutic success and outcome. In the early stage of the disease, the criteria for the classification of Rheumatoid Arthritis (RA) are frequently not met. Up to over 50% of the patients show an arthritis, which cannot be classified and therefore is seen as undifferentiated arthritis (UA). Early therapeutic intervention appears to prevent the chronification of the disease; thus an early and appropriate disease modifying therapy is mandatory. Age, gender, involvement of the hands, positive rheumatoid factor, as well as the detection of anti cyclic-citrullinated peptide antibodies (anti-CCP Ab) are predictors of the development of RA. Beside conventional X-rays, there are other imaging methods such as magnetic resonance tomography imaging, Power-Doppler or contrast medium enhanced sonography, which may enable the detection not only of synovitis but also of erosive lesions at very early stages. Those patients suffering from UA carry a high risk for the development of a destructive arthritis as seen in RA, and therefore should be treated with an adequate DMARD. In these cases methotrexate is still the drug of first choice.

Bone erosions and bone marrow edema as defined by magnetic resonance imaging reflect true bone marrow inflammation in rheumatoid arthritis.

OBJECTIVE: To investigate the pathologic nature of features termed "bone erosion" and "bone marrow edema" (also called "osteitis) on magnetic resonance imaging (MRI) scans of joints affected by rheumatoid arthritis (RA). METHODS: RA patients scheduled for joint replacement surgery (metacarpophalangeal or proximal interphalangeal joints) underwent MRI on the day before surgery. The presence and localization of bone erosions and bone marrow edema as evidenced by MRI (MRI bone erosions and MRI bone marrow edema) were documented in each joint (n=12 joints). After surgery, sequential sections from throughout the whole joint were analyzed histologically for bone marrow changes, and these results were correlated with the MRI findings. RESULTS: MRI bone erosion was recorded based on bone marrow inflammation adjacent to a site of cortical bone penetration. Inflammation was recorded based on either invading synovial tissue (pannus), formation of lymphocytic aggregates, or increased vascularity. Fat-rich bone marrow was replaced by inflammatory tissue, increasing water content, which appears as bright signal enhancement on STIR MRI sequences. MRI bone marrow edema was recorded based on the finding of inflammatory infiltrates, which were less dense than those of MRI bone erosions and localized more centrally in the joint. These lesions were either isolated or found in contact with MRI bone erosions. CONCLUSION: MRI bone erosions and MRI bone marrow edema are due to the formation of inflammatory infiltrates in the bone marrow of patients with RA. This emphasizes the value of MRI in sensitively detecting inflammatory tissue in the bone marrow and demonstrates that the inflammatory process extends to the bone marrow cavity, which is an additional target structure for antiinflammatory therapy.

The optimal use of contrast agents at high field MRI.

The intravenous administration of a standard dose of conventional gadolinium-based contrast agents produces higher contrast between the tumor and normal brain at 3.0 Tesla (T) than at 1.5 T, which allows reducing the dose to half of the standard one to produce similar contrast at 3.0 T compared to 1.5 T. The assessment of cumulative triple-dose 3.0 T images obtained the best results in the detection of brain metastases compared to other sequences. The contrast agent dose for dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging at 3.0 T can be reduced to 0.1 mmol compared to 0.2 mmol at 1.5 T due to the increased susceptibility effects at higher magnetic field strengths. Contrast agent application makes susceptibility-weighted imaging (SWI) at 3.0 T clinically attractive, with an increase in spatial resolution within the same scan time. Whereas a double dose of conventional gadolinium-based contrast agents was optimal in SWI with respect to sensitivity and image quality, a standard dose of gadobenate dimeglumine, which has a two-fold higher T1-relaxivity in blood, produced the same effect. For MR-arthrography, optimized concentrations of gadolinium-based contrast agents are similar at 3.0 and 1.5 T. In summary, high field MRI requires the optimization of the contrast agent dose in different clinical applications.

Elective and emergent endovascular treatment of subclavian artery aneurysms and injuries.

PURPOSE: To demonstrate our short and long-term results after transbrachial treatment of subclavian artery aneurysms and injuries with stent-grafts in elective and emergency settings. METHODS: Ten of 12 consecutive patients (6 men; mean age 63.8 years, range 38-80) were treated electively with commercially prepared endografts delivered via a transbrachial access to repair a subclavian artery aneurysm (n=3) or an injury from a misplaced central venous catheter (n=7). Two patients required emergency treatment for a ruptured atherosclerotic aneurysm in one and an unintentional arterial puncture during placement of a central venous access in the other. Stent-graft patency during follow-up was assessed by physical examination with comparison of brachial blood pressures in all patients; computed tomography angiography (CTA) was performed in available patients. RESULTS: Successful deployment of stent-grafts with sealing of the lesion was achieved in all cases. There were 2 (17%) procedural complications. One patient developed an access-site hematoma that required surgical revision. The second patient, who had a right subclavian injury, suffered an embolic cerebral infarction. The primary stent-graft patency during follow-up (mean 11.6 months) was 100%. CTA examinations in 7 patients at a mean 18 months showed strut dislocation at the thoracic outlet without luminal narrowing in 1 patient. A 50% intraluminal narrowing due to compression between the clavicle and the first rib occurred in another patient. Six patients with a mean follow-up of 23 months (range 0.3-4.5 years) are still alive with patent stent-grafts. CONCLUSIONS: Endovascular stent-graft treatment of subclavian artery aneurysms and injuries is a less invasive alternative to surgical repair. Long-term results must still be confirmed in further studies.