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Purpose: Assessment of bony fusion following anterior cervical interbody fusion (ACIF) is usually done by plain film or CT. We present the first clinical application of Cone-Beam CT (CBCT) to evaluate bony fusion after ACIF., Methods: A 56-year-old man with disc herniation at C6-C7 underwent ACIF surgery using a compressed nanocrystalline hydroxyapatite interbody device (nanOss-C, Pioneer Surgical Marquette, MI, USA) and a nanocrystalline hydroxyapatite bone graft filler (nanOss Bioactive, Pioneer Surgical Marquette, MI, USA). Imaging follow-up was performed by CBCT (NewTom 5G, QR Srl, Verona, Italy) at 1 day, 6 weeks, 3 and 9 months post-operatively. Two independent assessors quantitatively measured the greyscale changes of the bone graft filler and qualitatively evaluated the bony fusion process., Results: Quantitative analysis of the images showed a steadily increasing matrix density of the bone graft filler over the 9 months follow-up, suggesting increasing calcification. Qualitative evaluation demonstrated different stages of the bone fusion process within the disc space around the cage, at the interface between cage and endplates, and at the interface between bone graft filler and the endplates., Conclusions: CBCT provides high-resolution cross-sectional imaging of the cervical spine after ACIF. For the first time, in vivo evaluation of the bone graft filler within the centre of the circumferentially radiodense cage and detailed cross-sectional evaluation of bone fusion was achieved. Confirmation of these promising outlooks of CBCT in a large cohort of ACIF patients is needed with regard to routine clinical application and evaluation of different interbody devices.

Purpose: The purpose of this paper was to evaluate if short volumetric interpolated breath-hold examination (VIBE) sequences can be used as a substitute for T1-weighted with fat saturation (T1-FS) sequences when performing magnetic resonance (MR) arthrography to diagnose rotator cuff tears., Materials and Methods: Eighty-two patients underwent direct MR arthrography of the shoulder joint using VIBE (acquisition time of 13 s) and T1-FS (acquisition time of 5 min) sequences in the axial and paracoronal plane on a 1.0-T MR unit. Two radiologists scored rotator cuff tendons on VIBE and T1-FS images separately as normal, small/large partial thickness and full thickness tears with or without geyser sign. T1-FS sequences were considered the gold standard. Surgical correlation was available in a small sample., Results: Sensitivity, specificity, and positive and negative predictive values of VIBE were greater than 92% for large articular-sided partial thickness and full thickness tears. For detecting fraying and articular-sided small partial thickness tears, these parameters were 55%, 94%, 94%, and 57%, respectively. The simple kappa value was 0.76, and the weighted kappa value was 0.86 for agreement between T1-FS and VIBE scores. All large partial and full thickness tears at surgery were correctly diagnosed using VIBE or T1-FS MR images., Conclusion: Fast MR arthrography of the shoulder joint using VIBE sequences showed good concordance with the classically used T1-FS sequences for the appearance of the rotator cuff, in particular for large articular-sided partial thickness tears and for full thickness tears. Due to its very short acquisition time, VIBE may be especially useful when performing MR arthrography in claustrophobic patients or patients with a painful shoulder.

Introduction: This study aimed to describe the radiological aspects and procedural steps of magnetic resonance (MR) imaging-guided closed reduction for the treatment of developmental dysplasia of the hip (DDH)., Methods: Infants were positioned on a custom-made hip spica table attached to a vertically open double doughnut-shaped MR imaging unit (GE Signa SP, 0.5T) affording access to one orthopaedic surgeon and one radiologist. Standard MR imaging sequences and rapid dynamic MR imaging sequences, including fast spin-echo, fast gradient-echo and a fluoroscopic echo-planar sequence, were available. Procedural steps were described and illustrated as a guide for the radiologist actively collaborating with the orthopaedic surgeon., Results: Five separate procedural steps were defined, describing the imaging action and the radiologist's focus related to the clinical action. These procedural steps included patient positioning, static imaging to evaluate hip congruency and factors impeding reduction, dynamic stress testing and reducing the hip while using dynamic motion MR imaging sequences to visualise reduction or dislocation, cast application with intermittent imaging confirmation of the femoral head position, and postprocedural static imaging., Conclusion: The role of the radiologist was well-defined during each procedural step of the MR imaging-guided closed reduction focusing on the use of specific sequences and image interpretation. Knowledge of these procedural steps may be helpful for efficient collaboration with the orthopaedic surgeon and successful MR imaging-guided treatment of DDH.

The purpose of this article is to present a educational overview of practical tips to deal with metal artefacts in clinical musculoskeletal MRI. A brief theoretical explanation to understand the cause of metal artefacts is provided followed by a discussion on parameters to reduce these metal artefacts. Effects of adjustable parameters are demonstrated both in a volunteer with a titanium screw and a saline bag attached to the shoulder and in a in vitro experiment. These parameters include positioning of the patient with the long axis of metallic hardware parallel to B0, use of fast spin echo sequences, use of inversion recovery fat suppression, swapping phase and frequency encoding direction, use of view angle tilting, increasing the read-out bandwidth, and decreasing voxel size.

The purpose of this study was to evaluate the implementation of functional magnetic resonance imaging (fMRI) for clinical use in patients with a brain tumour in the setting of a regional hospital. Twenty-three patients underwent a fMRI examination as preoperative evaluation for a tumour adjacent to a eloquent brain area. The location and distance of the tumour relative to the fMRI activation area for this eloquent brain area was determined. Presence of postoperative neurological deficits was compared to the result of the fMRI examination. The fMRI examination was not interpretable in four of the twenty-three patients. In nine patients the eloquent brain area was located more than two centimetres from the tumour: seven showed no neurological deficit postoperatively, one patient experienced a temporary deficit, and one patient has not been operated yet. In the remaining ten patients the eloquent brain area was located less than two centimetres from the tumour: after (partial) resection of the tumour often using intra-operative cortical stimulation, six patients showed no neurological deficits, and three patients had temporary or permanent deficits. One patient was not operated. The clinical implementation of fMRI was successful in the preoperative evaluation of patients with a brain tumour and useful to plan the surgical intervention and to minimize postoperative neurological deficits.

This study demonstrates the feasibility and advantages of near real-time, multiplanar, dynamic magnetic resonance image-assisted treatment of patients with developmental dysplasia of the hip. Pathoanatomy and dynamic blocks to reduction are visualized with anatomic clarity not otherwise possible. Continuous imaging allows accurate assessment and maintenance of optimum positioning throughout the casting procedure. Patient charges for this new technique are less than standard methods of treatment, and the child receives no ionizing radiation.

Purpose: To evaluate the safety of and time required for a broad range of musculoskeletal interventional procedures performed by using magnetic resonance (MR) imaging guidance with a vertically open 0.5-T unit., Materials and Methods: Sixty-three MR imaging-guided procedures were performed. A vertically open MR unit equipped with in-room display monitors allowed interactive freehand MR guidance predominantly with fast spin-echo and gradient-echo sequences. Each procedure was classified in terms of the anatomic location, procedure type, and tissue type involved. The procedures were evaluated for success of needle placement, adequacy of tissue sampling, total procedural time, needle time, number of needle passes, and complications., Results: Procedures consisted of tissue sampling with core-needle (n = 6) or fine-needle aspiration (n = 20) biopsy, corticosteroid or contrast agent injection (n = 19), joint cyst aspiration (n = 7), and drainage (n = 11). Successful needle placement was achieved in all 63 cases. Cytologic and histologic tissue samples were sufficient for pathologic diagnosis in 24 of 26 cases. In two cases, complications occurred: transient local bleeding and a brief vasovagal episode. The mean total procedural time was 64.8 minutes; the mean needle time, 26.2 minutes; and the mean number of needle passes per patient, 1.6., Conclusion: With use of a vertically open MR unit, MR-guided interventional procedures involving bone, soft tissue, intervertebral disks, and joints are safe and sufficiently rapid for use in clinical practice.

The case of cryptogenic Escherichia coli pyogenic liver abscess in a 59-year-old Human Immunodeficiency Virus (HIV) seropositive man is reported. The initial treatment was a percutaneous drainage. As the abscess did not reduce in size, surgical drainage was planned but during surgery a necrosectomy had to be performed resulting in a partial hepatectomy. After nine months of amoxicillin-clavulanic acid treatment, drainage and highly active antiretroviral therapy, the patient recovered completely. It is expected that because of highly active antiretroviral therapy, mortality rates of surgical interventions in patients with HIV infection will decrease. Because of the increased life expectancy in persons with HIV infection, the criteria for considering surgical interventions in these patients should be broadened.

A growing fracture usually results from a skull fracture with dural tear after blunt head trauma during infancy. We present a case of child abuse with multiple growing fractures resulting from penetrating head trauma by scissors. MR imaging confirmed the presence of growing fractures and revealed a presumably post-traumatic venous anomaly (occluded left cavernous sinus and aberrant posterior venous drainage via the internal cerebral veins). Diagnosis of the growing fractures and venous anomaly was delayed until the age of 15 years. Medical expertise should be more readily available to battered children, and MR imaging is advocated in growing skull fracture to exclude associated post-traumatic brain lesions.

Objective: The purpose of this study was to determine the added diagnostic value of CT for the diagnosis of visceral angioedema., Conclusion: Thickening of the small-bowel wall and mucosa with increased contrast enhancement, depiction of more layers of the small-bowel wall than normal, prominent mesenteric vessels, ascites, and fluid accumulation in the small bowel or together in the small bowel and the colon were the most significant CT findings in three patients with visceral angioedema. Findings appear to be transient.

Bare lymphocyte syndrome (BLS) is a rare primary immune disorder characterized by defective expression of human leukocyte antigen (HLA) on lymphocytes, often resulting in extensive and recurrent multi-organ infections. We describe a previously undiagnosed case of an adult woman who presented with radiological findings of severe bronchiectases, near-total granulomatous destruction of facial bones, and osteomyelitis. Diagnosis of BLS should be considered when evaluating children with unexplained bronchiectases or adults with long history of chronic multi-organ infections.

The aims of this study were, firstly, to provide a formula (neurogenic index) based on MR characteristics used in daily routine for predicting whether a soft tissue tumor is neurogenic or not, secondly, to test prospectively the performance of this formula, and thirdly, to compare this performance with that of radiologists experienced in MR imaging of soft tissue tumors. Retrospectively, MR images of 70 neurogenic and 70 non-neurogenic soft tissue tumors were evaluated in random order by two teams of two observers each. A neurogenic index (NI) was calculated based on those MR parameters that showed no or minor interobserver variability. Subsequently, three investigators in concert used the NI in a validation group of 15 neurogenic and 22 nonneurogenic soft tissue tumors. The same team, based on their own experience, tried to differentiate in the same validation group neurogenic from non-neurogenic soft tissue tumors. This was expressed in a subjective score (SS). Sensitivity, specificity, and predictive values were calculated. NI comprised spread (intra- or extracompartmental), distribution, fluid-fluid levels, homogeneity on T2-weighted images (WI), highest signal intensity (SI) on T1WI, lowest SI on T2WI, and delineation on T2WI. In the validation group, NI had a sensitivity of 88.6%, a specificity of 52.0%, a positive predictive value (PPV) of 54.1%, and a negative predictive value (NPV) of 84.6% for neurogenic tumors. The subjective score SS was superior and had a sensitivity of 93.3%, a specificity of 77.2%, a PPV of 73.7%, and a NPV of 94.4%. Our NI was less accurate than the SS; however, the low number of false-negative diagnoses for neurogenic tumors warrants continued efforts in development of neural networks.

Objective: To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts)., Design and Patients: MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, signal intensities on T1- and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study., Results: On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody., Conclusions: Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well-defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images.

The presence of a soft tissue mass in children is of concern to parents and physicians. Fortunately, these masses are rare and usually benign or pseudotumoral. When dealing with malignant soft tissue tumors, therapeutic options and long-term survival are strongly related to the disease stage at the time of diagnosis. Therefore, when children present with indeterminate or persisting symptoms and posttraumatic, metabolic, or infectious disorders have been ruled out, one should perform dedicated imaging studies (conventional radiography, computed tomography [CT], or both; sonography; magnetic resonance [MR] imaging) to exclude the possibility of a nonpalpable soft tissue mass or to characterize the mass when present. An overview of the use of the different imaging modalities for evaluating soft tissue tumors in the pediatric patient is presented. Because of the numerous benign, malignant, and pseudotumoral soft tissue masses that are often encountered in children, clinical, histologic, and imaging features are presented as concise tables.

We report on a middle-aged woman who presented with clinical and biochemical findings of insulinoma. Preoperative evaluation by ultrasound, CT, and angiography located the pancreatic lesion but also revealed two focal liver lesions. The latter were interpreted as metastases. MR imaging with injection of superparamagnetic iron oxide particles not only localized the insulinoma but proved to be the only noninvasive technique capable to exclude presence of liver metastases preoperatively. This reversed management to minimal laparoscopic surgery. Recent literature of preoperative imaging evaluation of insulinoma and focal liver lesions is discussed.

Subcutaneous granuloma annulare (SGA) is little known to radiologists. Better knowledge of this lesion may prompt accurate diagnosis. A typical case is presented with plain radiography, ultrasound and MR imaging, and is confirmed by histology. When an otherwise healthy child presents with a rapidly growing, solitary, nontender, subcutaneous soft tissue mass, located on the scalp or extensor aspect of the limbs, that radiologically presents as an indistinct radiodense and hypoechoic mass, isointense to muscle on T1- and slightly hypointense to fat on T2-weighted MR images, without calcifications, bone involvement or extracompartmental invasion, SGA should be suspected.

The objective of this study was to evaluate the appearance and the natural evolution of desmoid tumors on MR imaging, given histologic correlation. The MR images of 30 desmoids (20 primary and 10 recurrent) in 26 patients were scored for a multiplicity of morphological parameters, signal intensity (SI) on different pulse sequences, and behavior after contrast administration. Natural evolution was evaluated in 2 primary and 3 recurrent lesions, and correlated with evolution on histologic specimens. Desmoid tumors are mostly found in muscles of shoulder and hip girdle and are often fusiform with partially ill-defined margins. Rare subcutaneous desmoids have a more stellar morphology. Variable amounts of low-SI areas are present on all sequences. On T1-weighted images (T1-WI), most lesions are near homogeneous and isointense to muscle, whereas on T2-WI they are more heterogeneous with an overall SI equal to or slightly lower than fat. Histologic correlation reveals that SI on T2-WI cannot be explained solely by cellularity. After initial growth, spontaneous evolution of desmoids is characterized by shrinking and an increase in low-SI areas on T2-WI. While distal lesions shrink, the more recent lesions in asynchronous multicentric desmoids have a tendency to develop proximally in the same limb, and should not be confused with recurrences. Fast growth, extracompartmental spread, and bone involvement are often seen in recurrences. Follow-up MR imaging of desmoids indicates natural regression of desmoids and more aggressive behavior of recurrences, which may justify a more conservative therapeutic approach.