Traumatic Intracranial Hemorrhage on CT After Ground-Level Fall in Adult Patients Receiving Antithrombotic Therapy: A Retrospective Case-Control Study.

BACKGROUND. Antithrombotic medications may increase the risk and severity of traumatic intracranial hemorrhage (tICH) after minor head trauma. OBJECTIVE. The purpose of this study was to determine the frequency, distribution, and clinical course of tICH in patients receiving antithrombotic therapy who present with good neurologic status after a ground-level fall. METHODS. This retrospective study included 1630 patients (693 women and 937 men; mean age, 80.2 ± 12.7 [SD] years) who underwent head CT after presenting to the emergency department after a ground-level fall between January 1 and December 31, 2020; all patients had a Glasgow Coma Scale score of 14 or higher and no focal neurologic deficit. Patients with tICH were identified on the basis of clinical reports. In patients with tICH, images from initial head CT examinations were reviewed for characteristics of tICH, images from follow-up head CT examinations (performed within 24 hours) were reviewed for hematoma expansion, and clinical outcomes were extracted from medical records. Patients receiving antithrombotic therapy and control patients (those not receiving antithrombotic therapy) were compared. RESULTS. The antithrombotic therapy group included 954 patients (608 receiving anticoagulant therapy; 226, antiplatelet therapy; and 120, both therapies); the control group included 676 patients. A total of 63 patients (3.9%; 95% CI, 2.9-4.8%) had tICH. The antithrombotic therapy and control groups were not significantly different in terms of the frequency of tICH (4.4% vs 3.1%, p = .24), midline shift (10.0% vs 7.1%, p = .76) or regional mass effect (33.3% vs 14.3%, p = .19) on initial CT. Hematoma expansion on follow-up CT occurred in 11 of 42 patients (26.2%) in the antithrombotic group and one of 21 patients (4.8%) in the control group (p = .04). Two patients required neurosurgical intervention, and three deaths related to tICH occurred within 30 days; all five of these patients were receiving antithrombotic therapy. CONCLUSION. Antithrombotic therapy use was not associated with an increased frequency of tICH, although it was associated with an increased frequency of hematoma expansion at follow-up. CLINICAL IMPACT. In patients with good neurologic status after a ground-level fall, the findings suggest application of a similar strategy for selecting patients for initial head CT, regardless of antithrombotic therapy use; if initial head CT shows tICH, early follow-up head CT should be systematically performed in those receiving antithrombotic therapy, though it possibly should be deferred in other patients.

COVID-19 and its Mimics: What the Radiologist Needs to Know.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the current outbreak of Coronavirus disease 2019 (COVID-19). Although imaging should not be used for first-line screening or diagnosis, radiologists need to be aware of its imaging features, and those of common conditions that may mimic COVID-19 pneumonia. In this Pictorial Essay, we review frequently encountered conditions with imaging features that overlap with those that are typical of COVID-19 (including other viral pneumonias, chronic eosinophilic pneumonia, and organizing pneumonia), and those with features that are indeterminate for COVID-19 (including hypersensitivity pneumonitis, pneumocystis pneumonia, diffuse alveolar hemorrhage, pulmonary edema, and pulmonary alveolar proteinosis).

Abbreviated MRI of the foot in patients with suspected osteomyelitis.

PURPOSE: To determine the diagnostic accuracy of an abbreviated magnetic resonance imaging (MRI) protocol of the foot for the diagnosis of osteomyelitis in patients with acute foot infection. METHODS: This retrospective study evaluated adult patients (age 18 and over) visiting an academic medical center from 1 January 2013 to 31 December 2015 who were imaged with MRI for suspected acute pedal osteomyelitis. Examinations were performed utilizing the departmental standard protocol. All examinations were retrospectively interpreted by five radiologists under two protocols: a reference standard protocol consisting of all non-contrast sequences obtained at initial acquisition and an abbreviated protocol consisting of only coronal T1-weighted and sagittal T2-weighted fast multiplanar inversion-recovery (FMPIR) sequences. Interpretation of the two imaging subsets was separated in time by at least 6 weeks for each reader. Each examination was assigned a score to represent one of four diagnostic categories: normal; soft tissue infection without bone changes or bone changes specific to a non-infectious etiology; nonspecific bone marrow changes; or bone changes specific for osteomyelitis. Diagnostic accuracy of both protocols was determined based on clinical diagnosis and treatment of osteomyelitis, and histopathology when available. RESULTS: One hundred and two MRI examinations met inclusion criteria; participants ranged in age from 26 to 91 years, with a mean age of 59 years. Seventy examinations were performed for male participants (69%) and 32 for female participants (31%). Thirty-five had a confirmed diagnosis of osteomyelitis, while the remainder (n = 67) did not. An average of 6 non-contrast sequences was performed during each examination. The most common protocol (53/102 examinations) was comprised of the following 6 sequences: axial T1-weighted, axial fat-saturated proton density, sagittal T1-weighted, sagittal T2-weighted FMPIR, coronal T1-weighted, and coronal fat-saturated proton density. After patient positioning, the abbreviated protocol sequences (sagittal T2-weighted FMPIR and coronal T1-weighted) were performed in an average total of 8 min. The reference standard protocol required an average of 22 min to complete 6 sequences. Averaged across all readers, the AUC for the reference standard full protocol and the abbreviated protocols were 0.843 and 0.873, respectively. The difference in AUC between protocols was not statistically significant (p = 0.1297), with the abbreviated protocol showing a non-significantly greater AUC. CONCLUSIONS: An abbreviated MRI protocol, including only coronal T1-weighted and sagittal T2-weighted FMPIR images, is non-inferior to standard MRI protocol for the diagnosis of acute pedal osteomyelitis. It should be considered as a diagnostic alternative for reducing imaging time and improving patient access to MRI.

What to Expect When They are Expecting: Magnetic Resonance Imaging of the Acute Abdomen and Pelvis in Pregnancy.

In this article, we discuss the challenges in the diagnosis of acute abdominopelvic pain in pregnant patients, role of imaging, and advantages of MRI over other modalities. Methods consist of pictorial review. We review the differential diagnoses and illustrate the MRI findings in pregnant patients with acute abdominopelvic pain, including gastrointestinal, gynecologic, urologic, and vascular etiologies.