The purpose of this article is to review the imaging features of necrotizing fasciitis and its potential mimics. Key imaging features are emphasized to enable accurate and efficient interpretation of ...variables that are essential in appropriate management.
Necrotizing fasciitis is a medical emergency with potential lethal outcome. Dissecting gas along fascial planes in the absence of penetrating trauma (including iatrogenic) is essentially pathognomonic. However, the lack of soft-tissue emphysema does not exclude the diagnosis. Mimics of necrotizing fasciitis include nonnecrotizing fasciitis (eosinophilic, paraneoplastic, inflammatory (lupus myofasciitis, Churg-Strauss, nodular, or proliferative), myositis, neoplasm, myonecrosis, inflammatory myopathy, and compartment syndrome. Necrotizing fasciitis is a clinical diagnosis, and imaging can reveal nonspecific or negative findings (particularly during the early course of disease). One should be familiar with salient clinical and imaging findings of necrotizing fasciitis to facilitate a more rapid and accurate diagnosis and be aware that its diagnosis necessitates immediate discussion with the referring physician.
History A 54-year-old white woman with a history of rheumatoid arthritis who was taking glucocorticoids and methotrexate presented to the emergency department in December with worsening shortness of ...breath and chest heaviness for 1 week. She reported additional symptoms of weakness, headache, and arthralgia primarily involving her bilateral hands, wrist, ankles, and feet. She denied experiencing fevers, syncope or presyncope, focal neurologic deficits, chest pain, nausea, vomiting, unintentional weight loss, or recent trauma. Additional medical history included hypertension, asthma, degenerative disk disease, and migraine, all of which were reportedly controlled with medications. This patient had a smoking history of 80 pack-years, but she had quit smoking 2 months prior to presentation. She denied abuse of alcohol or recreational drugs and reported she was up-to-date on her immunizations, including those for pneumonia and flu. Family history was pertinent for breast cancer in her mother, sister, and maternal aunt. The patient reported normal findings at screening mammography and colonoscopy. A physical examination was remarkable for slightly asymmetric breath sounds, which appeared to be diminished on the right side. This patient had multiple joint deformities, most notably in the bilateral metacarpophalangeal joints. Initial electrocardiography findings and cardiac biomarkers were negative. Her complete blood count and basic metabolic profile were unremarkable. Posteroanterior and lateral chest radiographs were obtained in the emergency department. Subsequently, computed tomography (CT) of the chest was performed.
Functional neuroimaging provides means to understand the relationship between brain structure and associated functions. Functional MR (fMR) imaging can offer a unique insight into preoperative ...planning for central nervous system (CNS) neoplasms by identifying areas of the brain effected or spared by the neoplasm. BOLD (blood-oxygen-level-dependent) fMR imaging can be reliably used to map eloquent cortex presurgically and is sufficiently accurate for neurosurgical planning. In patients with brain tumors undergoing neurosurgical intervention, fMR imaging can decrease postoperative morbidity. This article discusses the applications, significance, and interpretation of BOLD fMR imaging, and its applications in presurgical planning for CNS neoplasms.
Functional neuroimaging provides means to understand the relationship between brain structure and associated functions. Functional MR (fMR) imaging can offer a unique insight into preoperative ...planning for central nervous system (CNS) neoplasms by identifying areas of the brain effected or spared by the neoplasm. BOLD (blood-oxygen-level-dependent) fMR imaging can be reliably used to map eloquent cortex presurgically and is sufficiently accurate for neurosurgical planning. In patients with brain tumors undergoing neurosurgical intervention, fMR imaging can decrease postoperative morbidity. This article discusses the applications, significance, and interpretation of BOLD fMR imaging, and its applications in presurgical planning for CNS neoplasms.
Radiomics is an emerging field in radiology that utilizes advanced statistical data characterizing algorithms to evaluate medical imaging and objectively quantify characteristics of a given disease. ...Due to morphologic heterogeneity and genetic variation intrinsic to neoplasms, radiomics have the potential to provide a unique insight into the underlying tumor and tumor microenvironment. Radiomics has been gaining popularity due to potential applications in disease quantification, predictive modeling, treatment planning, and response assessment - paving way for the advancement of personalized medicine. However, producing a reliable radiomic model requires careful evaluation and construction to be translated into clinical practices that have varying software and/or medical equipment. We aim to review the diagnostic utility of radiomics in otorhinolaryngology, including both cancers of the head and neck as well as the thyroid.
•Different immunotherapies are available for cancer treatment.•Immunotherapy can cause atypical response patterns like pseudoprogression and hyperprogression.•Radiological follow-up is the only ...definite method to assess pseudoprogression.•Common irAEs are dermatitis, enterocolitis, hepatitis, pneumonitis, and thyroiditis.
Immunotherapy has revolutionized clinical outcomes in both early-stage and advanced-stage malignancies. Immunotherapy has improved patient survival in both solid and hematologic disorders with the potential added benefit of less toxicity compared to conventional cytotoxic chemotherapy. Imaging plays a fundamental role in monitoring treatment response and assessment of immune-related adverse events, e.g. pneumonitis, colitis, etc. Familiarity with the current strategies of immune-related response evaluation and their limitations is essential for radiologists to guide clinicians with their treatment decisions. Radiologists should be aware of the wide spectrum of immune-related adverse events and their various radiological features as well as the patterns of treatment response associated with immunotherapies.
Myeloid sarcoma is a rare form of extramedullary leukemia, which can present with or without systemic leukemia. The purpose of this study was to evaluate characteristic computed tomography (CT) and ...magnetic resonance imaging (MRI) findings (including diffusion weighted imaging and susceptibility weighted imaging) of myeloid sarcoma involving the brain.
One hundred nine patients with pathologically proven myeloid sarcoma underwent pretreatment CT and MRI, which were retrospectively reviewed. Computed tomography and MRI characteristics reviewed include lesion location, shape, size, architecture, margins, ± multiplicity, ± bone destruction, pattern and degree of enhancement, ± restricted diffusion, and ± susceptibility artifact.
Twenty-five patients (14 men, 11 women; mean age, 55 years; range, 9-80 years) met the inclusion criteria. Acute myeloid leukemia with subtypes M3 (44.4%) and M5 (22.2%) were the most common. On unenhanced CT, mean lesion size was 1.9 ± 0.4 cm; 60% were intra-axial hyperdense masses, 8% were intraventricular hyperdense masses, 12% were isodense intra-axial masses, and 20% of cases were extra-axial hyperdense nodular masses. There was no observable intralesional or perilesional calcium. On MRI, mean lesion size was 2.1 ± 0.6 cm. The lesions were isointense (80%) or hypointense (20%) on T1-weighted images with homogeneous (88%) or heterogeneous (12%) enhancement. On fluid-attenuated inversion recovery and T2-weighted images, lesions were hyperintense (96%) or isointense (4%) with mild vasogenic edema. Majority (96%) of cases demonstrated restricted diffusion, whereas only a few (16%) demonstrated susceptibility artifact.
In patients with history of leukemia or myeloproliferative disorder, identification of homogenous mass hyperdense on unenhanced CT, T1 isointense, and T2/fluid-attenuated inversion recovery hyperintense with restricted diffusion and homogenous postcontrast enhancement without significant susceptibility artifact is suggestive of myeloid sarcoma.
Primary vaginal cancers are rare and account for 1–3% of all gynecologic malignancies. There are several histological subtypes that affect a wide range of the population. Imaging plays an important ...role in the diagnosis, staging, and treatment planning of vaginal cancers. This article reviews the relevant anatomy, clinical findings, imaging characteristics, and recent advances in the management of vaginal malignancies.
Anemia is an underdiagnosed clinical entity with significant mortality and morbidity. We aimed to assess whether attenuation of dural venous sinuses correlates with hemoglobin/hematocrit and to ...determine if the degree of anemia can be predicted by quantitative analysis of unenhanced computed tomography (CT) of the head.
This is an institutional review board-approved retrospective study including 500 patients who underwent emergency department investigation for potential central nervous system etiology of their symptoms with unenhanced CT head at a tertiary care center. Computed tomographic attenuation values were obtained by 2 independent readers, whereas 2 separate investigators collected clinical data. Regression analyses were performed to evaluate the strength of correlation and the predictability of anemia and its severity on unenhanced CT. Receiver operating characteristic curve analyses were performed to evaluate sensitivity, specificity, as well as positive and negative predictive values.
A total of 243 met the inclusion criteria, and attenuation values for all the dural venous sinuses were averaged and categorized according to hemoglobin values of less than 8, 8 to 10, 10 to 14, and greater than 14. Mean CT attenuation values for both readers were 36.30, 42.35, 47.99, and 53.25 Hounsfield units. Regression analysis revealed the highest positive correlation of hemoglobin/hematocrit with attenuation at the confluence of sinuses with R value of 0.63 and 0.60. The sensitivity, specificity, and negative predictive value of detecting hemoglobin of less than 10 at confluence of sinuses were 91.2%, 88.5%, and 98.6%, respectively. Interobserver agreement was found to be good (0.64) using the κ statistic.
Our study substantiates direct positive correlation between CT attenuation of dural venous sinuses and hemoglobin/hematocrit, with strongest correlation at the confluence of sinuses with good sensitivity, specificity, and negative predictive value.
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