Patellar Instability: Imaging Findings.

Patellofemoral instability results from impaired engagement of the patella in the trochlear groove at the start of flexion and may lead to pain and lateral patellar dislocation. It occurs most frequently in adolescents and young adults during sporting activities. Trochlear dysplasia, patella alta, and excessive lateralization of the tibial tuberosity are the most common risk factors for patellar instability. The main role of imaging is to depict and assess these anatomical factors and highlight features indicating previous lateral dislocation of the patella.

Crystal Diseases of the Spine.

Gout, calcium pyrophosphate deposition disease, and apatite calcifications, the three main crystal disorders, may involve the spine. These disorders can be completely asymptomatic or associated with various clinical symptoms, such as acute flares and more chronic manifestations. This article presents the typical and more unusual imaging features encountered in these disorders.

Anatomical study of the proximal tibiofibular ligaments using ultrasound.

OBJECTIVES: No description of the proximal tibiofibular (PTF) ligaments by means of high ultrasound has yet been reported in the literature. The purpose of this study was to assess whether ultrasound may allow the assessment of these ligaments. METHODS: This study was initially undertaken in three cadaveric knees, followed by an ultrasound study performed by two musculoskeletal radiologists working in consensus of 52 patients without history of trauma or surgery of the knee, and without lateral knee pain. The visibility, echogenicity, length and thickness of the PTF ligaments were assessed. RESULTS: Regarding the anterior PTF ligament, the superior bundle and the upper and lower middle bundles were clearly seen in 42.3%, 100% and 75% of the knees, respectively. Regarding the posterior PTF ligament, the superior and middle bundles were clearly seen in 88.4% and 51.9% of the knees, respectively. The echo-anatomy of these ligaments and the probe positioning allowing their best depiction were described in this study. CONCLUSION: Most of the PTF ligaments can be visualized by means of ultrasound. This possible assessment may have clinical applications, particularly in patients with lateral knee pain.

Increased Alpha Band Functional Connectivity Following the Quadrato Motor Training: A Longitudinal Study.

Quadrato Motor Training (QMT) is a new training paradigm, which was found to increase cognitive flexibility, creativity and spatial cognition. In addition, QMT was reported to enhance inter- and intra-hemispheric alpha coherence as well as Fractional Anisotropy (FA) in a number of white matter pathways including corpus callosum. Taken together, these results seem to suggest that electrophysiological and structural changes induced by QMT may be due to an enhanced interplay and communication of the different brain areas within and between the right and the left hemisphere. In order to test this hypothesis using the exact low-resolution brain electromagnetic tomography (eLORETA), we estimated the current neural density and lagged linear connectivity (LLC) of the alpha band in the resting state electroencephalography (rsEEG) recorded with open (OE) and closed eyes (CE) at three different time points, following 6 and 12 weeks of daily QMT. Significant changes were observed for the functional connectivity. In particular, we found that limbic and fronto-temporal alpha connectivity in the OE condition increased after 6 weeks, while it enhanced at the CE condition in occipital network following 12-weeks of daily training. These findings seem to show that the QMT may have dissociable long-term effects on the functional connectivity depending on the different ways of recording rsEEG. OE recording pointed out a faster onset of Linear Lag Connectivity modulations that tend to decay as quickly, while CE recording showed sensible effect only after the complete 3-months training.

NRAS(Q61K) mutated primary leptomeningeal melanoma in a child: case presentation and discussion on clinical and diagnostic implications.

BACKGROUND: Primary melanocytic neoplasms are rare in the pediatric age. Among them, the pattern of neoplastic meningitis represents a peculiar diagnostic challenge since neuroradiological features may be subtle and cerebrospinal fluid analysis may not be informative. Clinical misdiagnosis of neoplastic meningitis with tuberculous meningitis has been described in few pediatric cases, leading to a significant delay in appropriate management of patients. We describe the case of a child with primary leptomeningeal melanoma (LMM) that was initially misdiagnosed with tuberculous meningitis. We review the clinical and molecular aspects of LMM and discuss on clinical and diagnostic implications. CASE PRESENTATION: A 27-month-old girl with a 1-week history of vomiting with mild intermittent strabismus underwent Magnetic Resonance Imaging, showing diffuse brainstem and spinal leptomeningeal enhancement. Cerebrospinal fluid analysis was unremarkable. Antitubercular treatment was started without any improvement. A spinal intradural biopsy was suggestive for primary leptomeningeal melanomatosis. Chemotherapy was started, but general clinical conditions progressively worsened and patient died 11 months after diagnosis. Molecular investigations were performed post-mortem on tumor tissue and revealed absence of BRAF(V600E), GNAQ(Q209) and GNA11(Q209) mutations but the presence of a NRAS(Q61K) mutation. CONCLUSIONS: Our case adds some information to the limited experience of the literature, confirming the presence of the NRAS(Q61K) mutation in children with melanomatosis. To our knowledge, this is the first case of leptomeningeal melanocytic neoplasms (LMN) without associated skin lesions to harbor this mutation. Isolated LMN presentation might be insidious, mimicking tuberculous meningitis, and should be suspected if no definite diagnosis is possible or if antitubercular treatment does not result in dramatic clinical improvement. Leptomeningeal biopsy should be considered, not only to confirm diagnosis of LMN but also to study molecular profile. Further molecular profiling and preclinical models will be pivotal in testing combination of target therapy to treat this challenging disease.

Altered metal metabolism in patients with HCV-related cirrhosis and hepatic encephalopathy.

Dysfunctional metal homeostasis contributes to oxidative stress and neuronal damage. These have been implicated in hepatic encephalopathy pathogenesis. To investigate whether altered metal metabolism is associated with hepatic encephalopathy. Twenty-one controls and 34 HCV-cirrhotic patients (ENC/NEC patients according to presence/absence of previous overt episodes of hepatic encephalopathy) and a control group were studied. Serum iron, copper, ceruloplasmin, ceruloplasmin activity, transferrin, and ceruloplasmin/transferrin ratio were determined. Neuropsychological tests were performed by the repeatable battery of neuropsychological status. Magnetic resonance assessed basal ganglia volumes and metal deposition (pallidal index and T2*). Cirrhotic patients performed worse than controls at cognitive tests, especially ENC patients,. At biochemical analysis copper concentrations, ceruloplasmin activity and transferrin levels were lower in ENC than in NEC patients and controls (p < 0.05 and p < 0.01, respectively). Ceruloplasmin/transferrin ratio was higher in ENC compared to NEC patients (p < 0.05), and controls (p < 0.01). By brain magnetic resonance, ENC patients showed reduced caudate and globus pallidus volumes compared to controls (p < 0.05), and ENC and NEC patients an increased pallidal index compared to controls (p < 0.01). In ENC patients, ceruloplasmin activity correlated with caudate volume and pallidal index (ρ = 0.773 and ρ = -0.683, p < 0.05). Altered metal metabolism likely contributes to cirrhotic hepatic encephalopathy.

Magnetic Resonance Fiber Tracking in a Neonate with Hemimegalencephaly.

A magnetic resonance diffusion fiber tracking study in neonate diagnosed with left hemisphere hemimegalencephaly is presented. Despite diffuse morphologic deformities identified in conventional imaging, all major pathways were identifiable bilaterally with minor aberrations in vicinity of morphologic lesions.

Estimating the risk for symptomatic adjacent segment degeneration after lumbar fusion: analysis from a cohort of patients undergoing revision surgery.

PURPOSE: Aim of this study is to estimate the risk for symptomatic adjacent segment degeneration (ASD) and examine the association between spino-pelvic parameters and ASD. METHODS: 22 patients operated upon by instrumented lumbar or lumbosacral spinal fusion and re-operated upon for ASD were enrolled in the study. 83 consecutive patients with the same surgery and never re-operated upon were the controls. Pelvic incidence, sacral slope (SS), pelvic tilt (PT), and lumbar lordosis were calculated. RESULTS: Patients with ASD had significantly lower SS (p = 0.005) and higher PT values (p < 0.001). Patients with SS <39° or PT >21°, were at higher risk for symptomatic ASD (relative risk 1.73 for SS and 3.663 for PT). CONCLUSIONS: In patients re-operated upon for ASD, pelvic retroversion and hyperlordosis are the main mechanisms of compensation for the unbalanced spine. Patients with PT above 21° and SS below 39° are at higher risk for symptomatic ASD.

Inverse spatial distribution of brain metastases and white matter hyperintensities in advanced lung and non-lung cancer patients.

The aim of this study was to test by means of a voxel-based approach the hypothesis that there is a different spatial distribution of brain metastases (BM) and white matter hyperintensities (WMH) and that the presence of WMH affects the location of BM in lung and non-lung cancer patients. Two-hundred consecutive cancer patients at first diagnosis of BM were included. Images were acquired using a 1.5 Tesla MRI system (Magnetom Avanto B13, Siemens, Erlangen, Germany). Axial FLAIR T2 weighted images and gadolinium-enhanced T1 weighted images were post-processed for segmentation, co-registration and analysis. Binary lesion masks were created for WMH and BM, using Volumes of Interest. Lesion probability maps were generated and the voxel-based lesion-symptom mapping approach was used to model each voxel and to calculate a non parametric statistics (Brunner-Munzel test) describing the differences between the groups. In the lung cancer group we found higher frequency of BM in WMH- than in WMH+ patients in the occipital lobe and the cerebellum. In contrast, BM were more frequent in the right frontal lobe in WMH+ than in WMH- patients. We suggest that there exists an inverse brain spatial distribution between WMH and BM. In lung cancer patients, the presence of WMH seems to shift the distribution of BM toward locations different than what it is expected based on primary tumor.

Optimization of computed tomography (CT) arthrography of hip for the visualization of cartilage: an in vitro study.

OBJECTIVE: We sought to optimize the kilovoltage, tube current, and the radiation dose of computed tomographic arthrography of the hip joint using in vitro methods. MATERIALS AND METHODS: A phantom was prepared using a left femoral head harvested from a patient undergoing total hip arthroplasty and packed in a condom filled with iodinated contrast. The right hip joint of a cadaver was also injected with iodinated contrast. The phantom and the cadaver were scanned using different values of peak kilovoltage (kVp) and tube current (milliamp seconds, mAs). Three different regions of interest (ROI) were drawn in the cartilage, subchondral bone plate, and intraarticular contrast. The attenuation values, contrast/noise ratio (CNR), and effective dose were calculated. Two independent observers classified the quality of the contrast-cartilage interface and the cartilage-subchondral bone plate interface as (1) diagnostic quality or (2) nondiagnostic quality. RESULTS: Contrast, cartilage, and subchondral bone plate attenuation values decreased at higher kVp. CNR increased with both kVp and mAs. The qualitative analysis showed that in both phantom and cadaver, at 120 kVp and 50 mAs, the contrast-cartilage and cartilage-subchondral bone plate interfaces were of diagnostic quality, with an effective dose decreased to 0.5 MSv. CONCLUSIONS: The absolute effective dose is not directly related to the quality of images but to the specific combination of kVp and mAs used for image acquisition. The combination of 120 kVp and 50 mAs can be suggested to decrease the dose without adversely affect the visibility of cartilage and subchondral bone plate.

Extra-spinal incidental findings at lumbar spine MRI in the general population: a large cohort study.

OBJECTIVE: To determine the prevalence of clinically and non-clinically relevant extra-spinal incidental findings (IF) in patients undergoing magnetic resonance imaging (MRI) of the lumbar spine and to evaluate the rate of undetected findings in archived radiological reports. METHODS: A retrospective search of patients undergoing lumbar spine MRI from January 2006 to December 2010 was conducted. By means of randomisation, we retrospectively reviewed 3,000 lumbar spine MRI examinations. Extra-spinal abnormalities were classified according to a modified CT Colonography Reporting and Data System (C-RADS). We retrospectively compared our structured approach with the archived MRI reports as it regarded the detection of extra-spinal IF to estimate non-detection rates. RESULTS: By means of the structured approach used, extra-spinal findings were detected in 2,060 (68.6 %) of the 3,000 lumbar spine MRI examinations; 362 (17.6 %) patients had indeterminate or clinically important findings (E3 and E4) requiring clinical correlation or further evaluation. After review of the original archived radiological reports, potentially important C-RADS E3 and E4 extra-spinal IF were respectively reported in 47 of the 265 (17.7 %) and in 8 of 74 (10.8 %) patients. CONCLUSIONS: Our study shows that incidental extra-spinal findings at conventional lumbar spine MRI are common but underestimated in radiological reports.

Osteofibrous dysplasia: A case report and review of the literature.

Osteofibrous dysplasia (OFD) is a rare bone tumor affecting young individuals. The differential diagnosis between OFD and adamantinoma may be challenging in some cases on imaging. We present a case of OFD and discuss the key imaging and histological findings. We also discuss the differential diagnosis between OFD and classical adamantinoma on the basis of recent literature.

Cordarone Extravasation Inducing Volkmann's-like Syndrome.

We report a case of Volkmann's-like syndrome occurred after an extravasation of 300 mg of cordarone administrated for a cardiac arrest.The day following the extravasation, an extensive necrosis of the skin and soft tissues occurred. The patient progressively developed a retraction of the muscles of her forearm. To the best of our knowledge this is first the reported case of an acute necrosis of the soft tissue inducing a Volkmann's-like retraction of the upper limb subsequent to a cordarone extravasation. The imaging findings are provided along with a review of the literature.