Acute atraumatic compartment syndrome (AACS) of the foot is an uncommon, limb-threatening condition that is frequently underrecognized due to its atypical presentation and the absence of high-energy trauma. We report a case of a 32-year-old male presenting with abrupt, severe foot pain and swelling 24 h after playing in an indoor park barefoot, with no history of injury. While initial radiographs, CT, and inflammatory markers were unremarkable, physical examination demonstrated pain disproportionate to findings and increased compartmental tension. Magnetic resonance imaging (MRI) was pivotal in the diagnostic workflow, demonstrating severe diffuse enlargement, compartmental expansion, and marked edema of the abductor hallucis muscle. Laboratory evaluation post-MRI confirmed elevated creatine kinase levels consistent with rhabdomyolysis. These characteristic imaging findings prompted emergent decompressive fasciotomy, which revealed a tense medial compartment and pale musculature that successfully reperfused upon fascial release. Following surgery and aggressive hydration, the patient achieved a full recovery with preserved renal function and limb salvage. This case emphasizes that in the setting of atraumatic foot pain, MRI can provide decisive diagnostic evidence of AACS, assisting in timely surgical intervention and preventing irreversible myonecrosis or permanent neurological deficits.

MRI is central to evaluation of the post-operative knee, providing a comprehensive assessment of reconstructions, repairs, and cartilage restoration procedures. Accurate interpretation requires familiarity with operative techniques, graft biology, and the expected temporal evolution of post-operative imaging findings. This review presents a practical, imaging-based approach to contemporary knee surgery. Emphasis is placed on anterior cruciate ligament reconstruction, the renewed interest in primary repair, and common mechanisms of failure. Meniscal surgery, including repair, root repair, centralization, and transplantation, is discussed with attention to expected post-operative MRI appearances and findings suggestive of recurrent or failed repair. Finally, cartilage resurfacing and restoration techniques are reviewed using a systematic framework to assess graft infill, integration, surface congruity, and subchondral bone response. By integrating surgical context with time-dependent MRI findings, this review aims to provide radiologists with a practical framework to distinguish expected post-operative changes from complications, improving diagnostic confidence and clinical relevance of post-operative knee MRI interpretation.

Delayed-onset muscle soreness (DOMS) is a common, self-limited clinical entity resulting from ultrastructural muscle microtrauma. Despite its benign course, DOMS may clinically and radiologically mimic other muscle injuries, creating diagnostic uncertainty for clinicians and athletes. Given the increasing use of magnetic resonance imaging (MRI) in elite and recreational athletes, accurate recognition of DOMS on imaging has become essential to avoid misclassification as a structural muscle injury. Inappropriate management decisions, such as additional diagnostic workup, excessive restriction from physical activity, and delayed return to play. This review provides an overview of sport-specific patterns of musculoskeletal involvement in DOMS, emphasizing the muscle groups most frequently affected according to eccentric loading mechanisms across different sports. We also describe the imaging features, with emphasis on MRI and ultrasound (US), highlighting the key elements that help differentiate DOMS from other post-exercise musculoskeletal conditions. Important differential diagnoses discussed include muscle strain injuries, chronic exertional compartment syndrome (CECS), and exercise-related signal abnormality (ERSA). Additional conditions that may mimic DOMS on imaging, particularly in the absence of a clear clinical history, include rhabdomyolysis, inflammatory myopathies, and denervation-related muscle changes. In clinical practice, diagnostic confidence increases when imaging findings involve muscle groups associated with sport-specific biomechanical demands and correlate with the patient's activity history. Keypoints • Delayed-onset muscle soreness (DOMS) represents a form of ultrastructural muscle damage without macroscopic fiber disruption, typically developing 24-72 h after unaccustomed or intense eccentric exercise. • Magnetic resonance imaging (MRI) is the imaging modality of choice, demonstrating diffuse or multifocal muscle edema on fluid-sensitive sequences without architectural distortion or fiber discontinuity. • Sport-specific eccentric loading patterns influence the distribution of muscle involvement, reflecting the underlying biomechanical demands of different athletic activities. • Recognizing DOMS imaging patterns and differentiating them from muscle strain, exercise-related signal abnormality (ERSA), and chronic exertional compartment syndrome (CECS) is essential for prognosis, management, and safe return to sport.

Alpine skiing is associated with characteristic patterns of hand and wrist trauma, which together account for approximately 11% of all injuries in this sport. These injuries typically result from high-velocity falls, pole-related mechanisms, and collisions with infrastructure, including lift pylons and barriers. This review provides an overview of common hand and wrist injuries in alpine skiers, with emphasis on skiing-specific mechanisms, characteristic imaging findings, strengths and limitations of different imaging modalities, as well as clinically relevant implications. Although some of the described injury patterns and imaging considerations may also occur in other skiing disciplines and other sports, this review focuses specifically on alpine skiing. Discussed fractures include those of the fingers, base of the first metacarpal (Bennett and Rolando fractures), scaphoid, and distal radius. Soft-tissue injuries encompass frostbite and skiing-related injuries of ligaments, tendons, and volar plates. In most cases, conventional radiographs are the first-line imaging modality, while CT, MRI, and ultrasound are used selectively depending on the suspected injury pattern, particularly for detailed assessment of fractures, ligament integrity, and tendon injuries. An accurate evaluation of typical imaging patterns is essential for guiding treatment strategies and improving clinical outcomes. Delayed diagnosis may lead to prolonged recovery, chronic instability, post-traumatic osteoarthritis, and other secondary complications.

Subcutaneous phaeohyphomycosis is a rare opportunistic fungal infection caused by dematiaceous fungi and may clinically and radiologically mimic benign cystic or inflammatory soft tissue lesions. Imaging descriptions of this entity remain scarce. We report the case of a 60-year-old woman who presented with a slowly growing subcutaneous nodule. Ultrasound examination demonstrated a well-circumscribed hypoechoic pseudocystic lesion containing heterogeneous internal echoes and peripheral hypervascularity. Based on the imaging findings, the initial differential diagnosis included an epidermoid cyst and an inflammatory collection. Surgical excision followed by histopathological analysis revealed granulomatous inflammation containing pigmented septate fungal hyphae associated with a retained plant fragment (thorn), confirming the diagnosis of subcutaneous phaeohyphomycosis. Although the ultrasound appearance was not specific, it provided valuable characterization of lesion morphology, internal content, and vascularity, facilitating diagnostic assessment and guiding further management. This case is noteworthy because it illustrates the sonographic-pathologic correlation of a rare fungal infection associated with a retained vegetal foreign body and highlights imaging features that may increase awareness of this uncommon entity among radiologists, helping to reduce diagnostic delay and improve recognition of superficial fungal infections.

Knee injuries in snow sports are common, occurring in both professional and amateur athletes. The anatomic distribution of injuries varies significantly between alpine skiing and snowboarding, reflecting not only technical variation, but also the inherent differences in equipment between the two pastimes, including ski morphology, boots and bindings. While knee injuries, particularly to the ACL, predominate in skiing, they are relatively less common in snowboarding. Nevertheless, as snowboarding becomes increasingly popular, with more challenging terrain and jumps of higher magnitude, knee injuries including ACL tears will likely continue to increase in prevalence.