Risk factors for false positive and false negative MRI in diagnosing medial and lateral meniscal tears with concomitant ACL injury.

OBJECTIVE: To determine the diagnostic performance of MRI in evaluating meniscal abnormalities in the setting of anterior cruciate ligament (ACL) injury and recognize predictors of false positive (FP) and false negative (FN) MRI diagnosis. MATERIAL AND METHODS: Four hundred twenty patients (mean age, 27.2 years; 326 males, 94 females) who underwent arthroscopy for ACL injury between January 2017 and August 2022, and had preoperative imaging within 4 months, were retrospectively included. Images were independently interpreted by two experienced musculoskeletal radiologists, noting the presence of medial and lateral meniscal tears including tear type and location. Results were correlated with arthroscopic findings. Multivariate logistic regression was implemented to study risk factors (RF) for FP and FN MRI diagnosis. RESULTS: The sensitivity/specificity/positive predictive value/negative predictive value/accuracy of MRI for medial meniscus tear was 97.5%/74.46%/65.63%/98.35%/82.15%; for lateral meniscus tear, it was 83.5%/93.70%/70.8%/94.55% /87.86%, with substantial interreader agreement. Female gender (odds ratio (OR), 0.434), posterior horn and posterior root tears (OR, 3.268/22.588), horizontal tear (OR, 3.134), and ramp lesion (OR, 4.964) were found RF for FP medial meniscus, and meniscal body tears (OR, 308.011) were found RF for FP lateral meniscus. RF for FN medial meniscus were meniscal tear at the posterior horn, body, and posterior root (OR, 12.371/123.000/13.045). CONCLUSION: MRI is an effective screening tool for meniscal tears, but less accurate in detecting all medial meniscus injuries. Gender, meniscal tear location, and type increased the risk of FP medial meniscal tear on MRI, while meniscal tear location increased the risk of FP lateral meniscus and FN medial meniscus tears.

Watch & wait - Post neoadjuvant imaging for rectal cancer.

Rectal cancer management has evolved over the past decade with the emergence of total neoadjuvant therapy (TNT). For select patients who achieve a clinical complete response following TNT, organ preservation by means of the watch-and-wait (WW) strategy is an increasingly adopted alternative that preserves rectal function and quality of life without compromising oncologic outcomes. Recently, published 5-year results from the OPRA trial demonstrated that organ preservation can be achieved in approximately half of patients managed with the WW strategy, with most local regrowth events occurring within two years. Considering the potential for local regrowth, the implementation of the WW strategy mandates rigorous clinical and radiographic surveillance. Magnetic resonance imaging (MRI) serves as the conventional imaging modality for local staging and surveillance of rectal cancer given its excellent soft-tissue resolution. This review will discuss the current evidence for the WW strategy and the role of restaging rectal MRI in determining patient eligibility for this strategy. Restaging rectal MRI acquisition parameters and treatment response assessment, including important factors to assess, pitfalls, and classification systems, will be discussed in the context of the WW strategy.

Stress Fracture of the Trapezoid in a Professional Tennis Player.

Background: Repetitive microtrauma can lead to trapezoid and second metacarpal stress fractures in racket sport players. Nontraumatic trapezoid stress fractures are rare and difficult to diagnose. To our knowledge, only 3 cases had been reported as of May 2023. We report the fourth case of a nontraumatic sports-related trapezoid stress fracture and only the second case in a tennis player. Case Report: A 29-year-old professional and right hand-dominant male tennis player presented with right hand and wrist pain for 3 weeks. He complained of dorsal wrist tenderness proximal to the base of the second metacarpal that was exacerbated by extension of the index finger. Initial radiographs were normal, but magnetic resonance imaging of the wrist showed a stress fracture of the trapezoid bone and base of the second metacarpal. The patient was treated conservatively with a wrist brace, cessation of sports activities, and modification of his training routine. The patient was asymptomatic at 1-year follow-up. Conclusion: This case highlights the relationship between trapezoid and second metacarpal stress fractures in athletes. A high index of suspicion for trapezoid stress fractures should be maintained and included in every differential diagnosis for athletes, especially racket sport players presenting with wrist pain. To avoid future injuries, clinicians should not only treat the fracture but also address the risk factors predisposing to this injury.

Split-bolus contrast injection protocol enhances the visualization of the thoracic vasculature and reduced radiation dose during chest CT.

OBJECTIVE: To investigate the visualization of mediastinal lymph nodes during thoracic CT employing a multiphasic contrast media (CM) protocol. METHODS: Institutional review board approved retrospective study consisting of 300 patients with known chest malignancy. Patients were allocated to one of two CM protocols: Protocol A, consisted of dual bolus (Phase 1:100 ml CM followed by 100 ml saline chaser) i.v. injected at 2.5 ml s-1; Protocol B employed 100 ml of CM using a multiphasic injection protocol (Phase 1 and 2:60 ml contrast and saline, followed by Phase 3 and 4:40 ml contrast and saline injected at 2.5 ml s-1) with a fixed scan delay of 70 s for each acquisition. Attenuation profiles of the thoracic arteries and veins were calculated as well as the arterio-venous contrast ratios (AVCR). Receiver operating characteristic (ROC), visual grading characteristic (VGC), and Cohen's kappa analysis were assessed. RESULTS: Arterial opacification was up to 24% (p < 0.032) higher in protocol B than A, whereas, in the veins it was significantly lower in protocol B than A, with a maximum reduction of up to 84% (p < 0.0001). There was no statistical significance between the central and peripheral pulmonary arteries [>263 Hounsfield units (HU)] in each protocol. Protocol B, demonstrated significant improvement in AVCR at various anatomical sites (p < 0.002). Radiation dose was significantly reduced in protocol B compared to A (p < 0.004). Both ROC and VGC demonstrated significantly higher Az score for protocol B compared to A (p < 0.0001) with an increased inter reader agreement from poor to excellent. CONCLUSION: Employing a multiphasic CM protocol significantly improves opacification of the thoracic vasculature and visualization of mediastinal lymph nodes during thoracic CT. ADVANCES IN KNOWLEDGE: Uniform opacification between thoracic arteries and veins increases the delineation between vasculature and lymph nodes, reduces radiation dose when employing a multiphase contrast media injection protocol.