Could 68 Ga-DOTA-UBI-29-41 Help Identify Chronic Osteomyelitis on PET/CT Images? A Pilot Study.

ABSTRACT: This pilot study aimed to confirm the presence of infectious agents in infection foci using PET/CT imaging with 68 Ga-DOTA-UBI (29-41) in 7 patients with chronic osteomyelitis and with indications for surgical cleaning at the site of the infection focus. The whole-body PET/CT was performed on Biograph mCT 40 PET/CT scanner (Siemens Healthineers); the image began 45-60 minutes postinjection of the radiotracer (148-260 MBq). This study demonstrated that, in 6 patients in whom the PET/CT was classified as positive for identified infectious foci, confirmed by culture of the secretion sample collected during surgery, only 1 patient in antibiotic therapy was negative.

Meniscal ramp lesions: an illustrated review.

The purpose of this review is to describe the anatomy and lesions affecting the peripheral portion of posterior horn of medial menisci (ramp lesions), along with illustrations and MRI cases. We will correlate imaging features with arthroscopic classification of ramp lesions. Also, postoperative and chronic changes related to meniscocapsular tears will be presented, as well as biomechanical consequences and treatment approach.

Demystifying MR Neurography of the Lumbosacral Plexus: From Protocols to Pathologies.

Magnetic resonance neurography is a high-resolution imaging technique that allows evaluating different neurological pathologies in correlation to clinical and the electrophysiological data. The aim of this article is to present a review on the anatomy of the lumbosacral plexus nerves, along with imaging protocols, interpretation pitfalls, and most common pathologies that should be recognized by the radiologist: traumatic, iatrogenic, entrapment, tumoral, infectious, and inflammatory conditions. An extensive series of clinical and imaging cases is presented to illustrate key-points throughout the article.

Evaluation of Posterior Cruciate Ligament and Intercondylar Notch in Subjects With Anterior Cruciate Ligament Tear: A Comparative Flexed-Knee 3D Magnetic Resonance Imaging Study.

PURPOSE: To determine if posterior cruciate ligament (PCL) and intercondylar notch (IN) morphometries and volumetrics act as risk factors for anterior cruciate ligament (ACL) tears. METHODS: A prospective case-controlled magnetic resonance imaging (MRI) study was conducted with subjects presenting noncontact knee injuries. Exclusion criteria were previous surgery, PCL tear, osteoarthritis, tumors, or infectious and inflammatory conditions. All participants underwent a flexed-knee 3-dimensional (3D) magnetic resonance imaging (MRI) to uniformly straighten PCL. MR images were independently reviewed by 2 radiologists and assessed for 2D and 3D measurements (bicondylar width; IN angle, depth, width, and cross-sectional area; PCL width, thickness, and cross-sectional area; and IN and PCL volumes). Clinical profiles were tabulated and subjects were divided into cases (ACL tear) and controls (without ACL tear). RESULTS: The study was composed of 50 cases versus 52 controls (N = 102), with a mean age of 36.8 years. There was no difference between groups (P > .05) regarding age, gender, body mass index, time from injury, Tegner score, flexion angle, limb side, intensity of injury, or familial or opposite limb history of tear. Agreement between readers ranged from substantial to almost perfect. Subjects with ACL tear presented with lower IN width, lower IN minus PCL widths, lower Notch Width Index, higher PCL/IN width proportion, higher PCL thickness, lower IN depth minus PCL thickness, and higher PCL thickness/IN depth proportion (P < .05). Moreover, higher PCL/IN cross-sectional area proportion, higher PCL volumes (OR = 9.01), and higher PCL/IN volume proportion were also found in cases. CONCLUSIONS: Our study shows that subjects with ACL tears present not only reduced IN but also larger PCL dimensions. These findings, isolated and combined, and especially PCL volume, might be suggestive as risk factors for ACL tears owing to the reduction of its space inside the IN. LEVEL OF EVIDENCE: Level III, comparative group.

Subclinical Propionibacterium acnes infection estimation in the intervertebral disc (SPInE-ID): protocol for a prospective cohort.

INTRODUCTION: Low back pain and vertebral endplate abnormalities are common conditions within the population. Subclinical infection caused by indolent pathogens can potentially lead to these findings, with differentiation between them notably challenging from a clinical perspective. Progressive infection of the intervertebral disc has been extensively associated with increasing low back pain, with Propionibacterium acnes specifically implicated with in relation to sciatica. The main purpose of this study is to identify if the presence of an infective pathogen within the intervertebral disc is primary or is a result of intraoperative contamination, and whether this correlates to low back pain. METHODS AND ANALYSIS: An open prospective cohort study will be performed. Subjects included within the study will be between the ages of 18 and 65 years and have a diagnosis of lumbar disc herniation requiring open decompression surgery. Excised herniated disc fragments, muscle and ligamentum flavum samples will be collected during surgery and sent to microbiology for tissue culture and pathogen identification. Score questionnaires for pain, functionality and quality of life will be given preoperatively and at 1, 3, 6 and 12 months postoperatively. A MRI will be performed 12 months after surgery for analysis of Modic changes and baseline comparison. The primary endpoint is the rate of disc infection in patients with symptomatic degenerative disc disease. The secondary endpoints will be performance scores, Modic incidence and volume. ETHICS AND DISSEMINATION: This study was approved by our Institutional Review Board and was only initiated after it (CAAE 65102617.2.0000.0071). Patients agreeing to participate will sign an informed consent form before entering the study. Results will be published in a peer reviewed medical journal irrespective of study findings. If shown to be the case, this would have profound effects on the way physicians treat chronic low back pain, even impacting health costs. TRIALS REGISTRATION NUMBER: NCT0315876; Pre-results.

MRI features of the anterolateral ligament of the knee.

OBJECTIVE: Evaluate the visibility and describe the anatomical features of the anterolateral ligament of the knee using MRI. MATERIALS AND METHODS: Magnetic resonance imaging examinations of the knee were independently reviewed by two musculoskeletal radiologists and assessed for the visibility of the anterolateral ligament under direct cross-referencing of axial and coronal images as complete, partial, or non-visible. Distal insertion site (tibial, meniscal), distance to lateral tibial plateau, measurements (length, width, thickness), and associated imaging findings were also tabulated. Clinical and surgical records were also reviewed. RESULTS: Seventy MRI scans from 60 consecutive subjects were included in the study. Mean age was 40 years, body mass 74.9 kg, and height 1.72 m. The subject population was 53% male, most of the knees were from the left side (51%), and chronic pain was the main clinical symptom (40%). Nine knees (13 %) had undergone previous surgery. The anterolateral ligament was identified in 51% of the knees: completely visible in 11% and partially visible in 40%. In all visible cases, the distal insertion site was identified on the tibia, with a mean distance of 5.7 mm to the plateau. A completely visible ligament had a mean length of 33.2 mm, width of 5.6 mm, and thickness of 1.9 mm [corrected]. Inter-observer agreement for ligament presence was significant (κ = 0.7). Statistical analyses showed a trend to be more visible in men, with a longer length compared with women. CONCLUSIONS: Magnetic resonance imaging clearly identifies the anterolateral ligament of the knee in slightly more than half of cases, being partially visible in most of them. In all cases, a tibial insertion is characterized.

Steroid-induced Kager's fat pad atrophy.

We report a rare case of Kager's fat pad atrophy and fibrosis in a 60-year-old woman 1 year after a steroid injection for Achilles tendinopathy. There are few published reports of steroid-induced atrophy affecting deeper layers of fat tissue. To our knowledge, this case report is the first to illustrate its features using magnetic resonance imaging. A review of the scientific literature is also presented.

How large is the lung recruitability in early acute respiratory distress syndrome: a prospective case series of patients monitored by computed tomography.

INTRODUCTION: The benefits of higher positive end expiratory pressure (PEEP) in patients with acute respiratory distress syndrome (ARDS) have been modest, but few studies have fully tested the "open-lung hypothesis". This hypothesis states that most of the collapsed lung tissue observed in ARDS can be reversed at an acceptable clinical cost, potentially resulting in better lung protection, but requiring more intensive maneuvers. The short-/middle-term efficacy of a maximum recruitment strategy (MRS) was recently described in a small physiological study. The present study extends those results, describing a case-series of non-selected patients with early, severe ARDS submitted to MRS and followed until hospital discharge or death. METHODS: MRS guided by thoracic computed tomography (CT) included two parts: a recruitment phase to calculate opening pressures (incremental steps under pressure-controlled ventilation up to maximum inspiratory pressures of 60 cmH2O, at constant driving-pressures of 15 cmH2O); and a PEEP titration phase (decremental PEEP steps from 25 to 10 cmH2O) used to estimate the minimum PEEP to keep lungs open. During all steps, we calculated the size of the non-aerated (-100 to +100 HU) compartment and the recruitability of the lungs (the percent mass of collapsed tissue re-aerated from baseline to maximum PEEP). RESULTS: A total of 51 severe ARDS patients, with a mean age of 50.7 years (84% primary ARDS) was studied. The opening plateau-pressure was 59.6 (±5.9 cmH2O), and the mean PEEP titrated after MRS was 24.6 (±2.9 cmH2O). Mean PaO2/FiO2 ratio increased from 125 (±43) to 300 (±103; P<0.0001) after MRS and was sustained above 300 throughout seven days. Non-aerated parenchyma decreased significantly from 53.6% (interquartile range (IQR): 42.5 to 62.4) to 12.7% (IQR: 4.9 to 24.2) (P<0.0001) after MRS. The potentially recruitable lung was estimated at 45% (IQR: 25 to 53). We did not observe major barotrauma or significant clinical complications associated with the maneuver. CONCLUSIONS: MRS could efficiently reverse hypoxemia and most of the collapsed lung tissue during the course of ARDS, compatible with a high lung recruitability in non-selected patients with early, severe ARDS. This strategy should be tested in a prospective randomized clinical trial.

Imbalances in regional lung ventilation: a validation study on electrical impedance tomography.

Imbalances in regional lung ventilation, with gravity-dependent collapse and overdistention of nondependent zones, are likely associated to ventilator-induced lung injury. Electric impedance tomography is a new imaging technique that is potentially capable of monitoring those imbalances. The aim of this study was to validate electrical impedance tomography measurements of ventilation distribution, by comparison with dynamic computerized tomography in a heterogeneous population of critically ill patients under mechanical ventilation. Multiple scans with both devices were collected during slow-inflation breaths. Six repeated breaths were monitored by impedance tomography, showing acceptable reproducibility. We observed acceptable agreement between both technologies in detecting right-left ventilation imbalances (bias = 0% and limits of agreement = -10 to +10%). Relative distribution of ventilation into regions or layers representing one-fourth of the thoracic section could also be assessed with good precision. Depending on electrode positioning, impedance tomography slightly overestimated ventilation imbalances along gravitational axis. Ventilation was gravitationally dependent in all patients, with some transient blockages in dependent regions synchronously detected by both scanning techniques. Among variables derived from computerized tomography, changes in absolute air content best explained the integral of impedance changes inside regions of interest (r(2) > or = 0.92). Impedance tomography can reliably assess ventilation distribution during mechanical ventilation.