Pathophysiology and Imaging Findings of COVID-19 Infection: An Organ-system Based Review.

BACKGROUND: COVID-19 commonly presents with upper respiratory symptoms; however, studies have shown that SARS-CoV-2 infection affects multiple organ systems. Here, we review the pathophysiology and imaging characteristics of SARS-CoV-2 infection in organ systems throughout the body and explore commonalities. OBJECTIVE: Familiarity with the underlying pathophysiology and imaging characteristics is essential for the radiologist to recognize these findings in patients with COVID-19 infection. Though pulmonary findings are the most prevalent presentation, COVID-19 may have multiple manifestations and recognition of the extrapulmonary manifestations is especially important because of the potential serious and long-term effects of COVID-19 on multiple organ systems.

Subdural extravasation of crystalloids and blood products through a scalp peripheral intravenous catheter into the subdural space of a neonate on veno-arterial extracorporeal membrane oxygenation.

We describe a rare and devastating complication of a malpositioned scalp peripheral intravenous catheter (PIV) that resulted in subdural extravasation of infused fluids and midline shift in a critically ill neonate who required extracorporeal membrane oxygenation (ECMO). Recognition of increased intracranial pressure was hindered by the hemodynamic changes of being on ECMO and only identified by routine surveillance ultrasonography. Awareness of this complication may lead providers to seek alternate sites for vascular access in such patients, and encourage closer monitoring for this complication when an alternate site is unavailable.

Early radiologic evidence of severe respiratory distress syndrome as a predictor of nasal continuous positive airway pressure failure in extremely low birth weight newborns.

OBJECTIVE: To determine whether early radiologic evidence of severe respiratory distress syndrome (RDS) is predictive of nasal continuous positive airway pressure (CPAP) failure in extremely low birth weight (ELBW) infants during the first 72 h of age. STUDY DESIGN: Retrospective analysis of 235 consecutively inborn ELBW infants who received initial support with CPAP. CPAP success (n=151) and CPAP failure (n=84) groups were designated according to outcome within the first 72 h of age. We assessed the ability of radiologic evidence of severe RDS in the initial chest radiograph, alone and in combination with other variables available in the first hours of life, to predict CPAP failure. RESULT: Severe RDS had a positive predictive value (PPV) of 0.81 (95% confidence interval (CI) 0.64, 0.92) for CPAP failure. The combination of severe RDS and gestational age (GA) ⩽ 26 weeks had a PPV of 0.92 (95% CI 0.68, 0.96). CONCLUSION: Early radiologic evidence of severe RDS is predictive of CPAP failure, especially in infants with GA ⩽ 26 weeks.

Career advancement of men and women in academic radiology: is the playing field level?

RATIONALE AND OBJECTIVES: The authors' purposes were to determine if there are gender differences in the speed of promotion and/or academic productivity in academic radiology and if this situation had changed since a previous study was performed in 1987. MATERIALS AND METHODS: Surveys were distributed to faculty members of academic radiology departments in May 1997. A total of 707 surveys were analyzed according to gender for time at rank for assistant and associate professor levels, in relation to publication rate, grant funding rate, and distribution of professional time. RESULTS: There was no difference between genders in the time at assistant professor rank. Among all current professors, women had been associate professors longer than men, but there was no difference between genders for those who had been in academic radiology for less than 15 years. There was no gender difference at any rank in the rate of publishing original articles. There was no difference in funding rates, although men had more total grant support. Male associate professors reported spending more time in administration and slightly more time in total hours at work than did their female colleagues, and male professors spent slightly more time teaching residents. Otherwise, there is no difference in how men and women at any rank spend their professional time. There are, however, lower percentages of women in tenured positions and in the uppermost levels of departmental administration. CONCLUSION: The time at rank for men and women and their rate of publication appear to have equalized. Women still are underrepresented at the uppermost levels of departmental administration, however, and are less likely than men to hold tenured positions.

CT imaging of splenic sequestration in sickle cell disease.

Pooling of blood in the spleen is a frequent occurrence in children with sickle cell diseases, particularly in the first few years of life, resulting in what is termed "splenic sequestration crisis." The spectrum of severity in this syndrome is wide, ranging from mild splenomegaly to massive enlargement, circulatory collapse, and even death. The diagnosis is usually clinical, based on the enlargement of the spleen with a drop in hemoglobin level by > 2 g/dl, and it is rare that imaging studies are ordered. However, in the patient who presents to the emergency department with non-specific findings of an acute abdomen, it is important to recognize the appearance of sequestration on imaging studies. We studied seven patients utilizing contrast-enhanced CT scans and found two distinct patterns--multiple, peripheral, non-enhancing low-density areas or large, diffuse areas of low density in the majority of the splenic tissue. Although radiological imaging is not always necessary to diagnose splenic sequestration, in those situations where this diagnosis is not immediately obvious, it makes an important clarifying contribution.

The road to success: factors affecting the speed of promotion of academic radiologists.

RATIONALE AND OBJECTIVES: The authors' purpose was to determine the factors influencing the speed of promotion of academic radiologists. MATERIALS AND METHODS: Three hundred forty-three surveys from faculty members of academic radiology departments with continuous academic careers were analyzed for time in rank at assistant and associate professor levels in relation to publication rate, grant funding rate, and distribution of professional time. Individuals promoted faster than the median time (6 years for assistant professors, 5 years for associate professors) were considered "fast track" and were compared with the remainder of the group. RESULTS: At the assistant professor level, fast track individuals had significantly higher rates of total publications and original articles than did others. At the level of associate professor, fast track individuals had significantly faster rates of publication of original articles, but no significant difference existed in total publication rate. No significant difference was found in the rate of founding of fast track individuals and others. Those with funding were not more likely to be on a fast track than those without funding. Fast track individuals spent significantly more time in administration at the assistant professor level than did other faculty, but no other significant differences were discovered in time distribution at the assistant or associate professor level. CONCLUSIONS: The rate of publishing original articles at the assistant and associate professor levels and the rate of overall publication at the assistant professor level were the most important parameters in predicting speed of promotion.

Neuroblastoma arising from the organ of Zuckerkandl: an unusual site with a favorable biologic outcome.

BACKGROUND: Prognosis in neuroblastoma has been shown to correlate with age and stage at diagnosis and site of origin. Extra-abdominal tumors (chest, neck, pelvis) do better in terms of survival than tumors arising from the upper abdomen. OBJECTIVE: We evaluated a subgroup of abdominal neuroblastomas arising near to the aortic bifurcation (commonly called organ of Zuckerkandl, O. Z.) to assess their biologic outcome and problems in diagnosis and therapy. MATERIALS AND METHODS: Sixteen O. Z. primary tumors were seen at three children's hospitals. Their clinical records and imaging studies were reviewed, including the sonographic, CT, and MRI findings. When available, MYCN amplification was noted (MYCN is the current term previously called N-MYC). RESULTS: Despite more than half of the tumors being very large, survival was the rule, with only one fatality (following multiple local recurrences). Only one patient (who survived) had bone metastases. The larger masses were usually palpated in otherwise well children, while the smaller ones were found in the course of evaluation for unrelated problems such as urinary tract infection. Intraspinal extension was common, though usually asymptomatic. MYCN amplification was absent in the four patients studied. CONCLUSIONS: Lower abdominal (O. Z.) neuroblastomas present technical problems of surgical removal, but form a group with a favorable outcome similar to cervical and thoracic primary sites. MRI was useful in delineating intraspinal extension.

Malignancies in pediatric patients with ataxia telangiectasia.

BACKGROUND: Patients with ataxia telangiectasia (AT), known to have an inherent increased susceptibility to the development of cancer, may present with malignancies that are unusual for the patient's age, are often difficult to diagnose clinically and radiographically and respond poorly to conventional therapy. MATERIALS AND METHODS: We reviewed the clinical presentation and imaging studies of 12 AT patients who developed malignancies. RESULTS: Eight of the twelve patients developed non-Hodgkin's lymphoma (CNS, thorax, bone), two developed Hodgkin's disease, and two were diagnosed with gastrointestinal mucinous adenocarcinoma. CONCLUSION: The lymphomas were commonly extra nodal, and infiltrative rather than mass-like. The recognition of the tumors was often delayed due to confusion with the known infectious complications in AT patients.

Diagnosis of pediatric tuberculosis in the modern era.

BACKGROUND: Correctly diagnosing tuberculosis (TB) in children is critical to provide appropriate treatment and to detect undiagnosed source cases. However, diagnosing TB in children may be difficult. OBJECTIVE: We sought to determine whether Amplicor, a Food and Drug Administration-approved polymerase chain reaction (PCR) assay used to detect Mycobacterium tuberculosis in sputum and computerized tomography (CT) would facilitate the diagnosis of TB in children. We also examined the applicability of the Centers for Disease Control and Prevention clinical case definition for TB. SETTING: A university-affiliated pediatric hospital in New York City. SUBJECTS: From March, 1995, to November, 1997, 27 children < 15 years of age (mean age, 3.9 years) were evaluated for suspected TB. RESULTS: M. tuberculosis was cultured from 5 of 76 (6.6%) gastric aspirate specimens, and PCR detected M. tuberculosis DNA in 3 (4.1%) of these specimens. There was poor correlation between culture and PCR because 6 specimens were discordant. CT scans were diagnostic of mediastinal or hilar adenopathy in 6 children with equivocal or negative chest radiographs and confirmed adenopathy in 8 others. Six children received alternative diagnoses. CONCLUSIONS: We conclude that the commercially available PCR technology had very limited utility in detecting M. tuberculosis from gastric aspirates, but CT scans were useful in assessing pediatric patients with suspected TB.

Cystic fibrosis. An overview.

A single gene defect in cystic fibrosis results in a spectrum of clinical presentations. Though expression is variable, the radiographic appearance reflects the underlying pathophysiology. Abnormalities of the small airways result in air-trapping; bronchiectasis and mucus plugging reflect large airway disease. These radiographic findings can be assessed and followed using varying scoring systems.

"Cold bone scans" as a sign of hemorrhagic infarcts of the spine in Gaucher's disease.

The most common form of Gaucher's disease, type 1 (chronic non-neuronopathic), results in accumulation of glucocerebroside in reticuloendothelial cells of the spleen, liver and bone marrow, with frequent occurrence of bone pain due to vaso-occlusive crisis. We report the finding of a "cold" vertebral body on bone scan in two patients with Gaucher's disease and bone crisis. Photopenia was so striking as to give the appearance of a "missing" vertebra. Concurrent plain films appeared normal. In one patient Gaucher's disease had not previously been diagnosed.

Iron overload in reticuloendothelial systems of pediatric oncology patients who have undergone transfusions: MR observations.

OBJECTIVE: Pediatric oncology patients who undergo intensive chemotherapy develop anemia caused by myeloid suppression that necessitates transfusions that, in turn, cause iron deposition in the reticuloendothelial system. We describe MR imaging of iron overload in pediatric patients who underwent such chemotherapy and who have solid and hematologic tumors. MATERIALS AND METHODS: The MR appearance of the liver, spleen, and bone marrow was evaluated in 13 children with both solid (n = 10) and hematologic (n = 3) malignant lesions using known criteria for the presence of iron deposition. Findings were correlated with transfusional history, chemotherapeutic regimens, and ferritin levels. RESULTS: MR imaging obtained after chemotherapy and transfusional therapy revealed signs of iron deposition in the liver and spleen, particularly on T2-weighted images. Bone marrow signal intensity varied among patients. Pancreatic signal intensity was normal. Ferritin levels were elevated in all patients. CONCLUSION: Reticuloendothelial system iron deposition present in follow-up MR imaging of pediatric solid and hematologic malignant lesions reflected the intensity of the chemotherapeutic regimen, the degree of myeloid suppression, and the resultant transfusional requirements. Such iron deposition appeared to have no effect on cardiac, liver, or pancreatic function.

Lumbar gibbus in storage diseases and bone dysplasias.

OBJECTIVE: The objective of this study was to review the problem of lumbar gibbus in children with storage diseases and bone dysplasias utilizing plain films and MR imaging. MATERIALS AND METHODS: Clinical histories and radiographic images in five patients with storage diseases [four mucopolysaccharidosis (MPS) and one mucolipidosis] and two with achondroplasia were reviewed. The International Skeletal Dysplasia Registry (Los Angeles, Calif.), surveyed for all patients with lumbar gibbus and skeletal dysplasias, provided 12 additional cases. RESULTS: All patients had localized gibbus of the upper lumbar spine, characterized by anterior wedging and posterior displacement of the vertebrae at the apex of the curve, producing a beaked appearance. The curve, exaggerated in the sitting or standing position, was most severe in the two patients with MPS-IV (one of whom died). Both developed severe neurologic signs and symptoms requiring surgical intervention. In four patients, MR images demonstrated the apex of the curve to be at or below the conus. Two patients demonstrated anterior herniation of the intervertebral discs at the apex of the curve, though the signal intensity of the intervertebral discs was normal. CONCLUSION: Lumbar gibbus has important neurologic and orthopedic implications, and is most severe in patients with MPS. The etiology of the gibbus with vertebral beaking is multifactorial and includes poor truncal muscle tone, weight-bearing forces, growth disturbance and anterior disc herniation. The curve is generally at or below the conus. Neurologic complications are unusual, although orthopedic problems can arise. Due to their longer survival, patients with achondroplasia or Morquio's disease are more vulnerable to eventual gibbus-related musculoskeletal complications.

Pulmonary embolism developing in patients with sickle cell disease on hypertransfusion and IV deferoxamine chelation therapy.

Pulmonary disease, including thromboembolic problems, accounts for a large portion of the morbidity of sickle cell disease. Chronic transfusion therapy is now a part of long-term treatment of sickle cell patients with stroke and chest syndrome. The resultant iron overload must be treated with chelation therapy using deferoxamine. Poor compliance with subcutaneous chelation therapy has necessitated intravenous deferoxamine treatment. We describe two patients with sickle cell disease on such a regimen, who became hypoxic as a result of pulmonary thromboembolism, secondary to venous thrombophlebitis. The thrombophlebitis and subsequent pulmonary embolism probably reflect the hypercoagulable state seen in sickle cell and are not due to the deferoxamine therapy.

Stage IVN neuroblastoma: MRI diagnosis of left supraclavicular "Virchow's" nodal spread.

Stage IV neuroblastoma is associated with high mortality; an exception are patients whose stage IV status includes distant positive nodes, but no skeletal metastases-stage IVN neuroblastoma. We describe our experience with preoperative MRI in three patients with extensive abdominal neuroblastoma without cortical bony involvement but with unsuspected metastatic involvement to the left supraclavicular (Virchow's) node. We review findings of left supraclavicular nodal spread in five earlier cases of IVN neuroblastoma.

Intrasplenic masses of "preserved" functioning splenic tissue in sickle cell disease: correlation of imaging findings (CT, ultrasound, MRI, and nuclear scintigraphy).

PURPOSE: We studied six patients with sickle cell disease (SSD), five homozygous for sickle cell anemia and one with sickle beta-thalassemia, in whom rounded intrasplenic masses proved to be preserved functioning splenic tissue. MATERIALS AND METHODS: Available images including computed tomography, ultrasonography, bone scans (Tc-99m MDP), liver spleen scans (Tc-99m sulfur colloid), and MRI were evaluated. RESULTS: The masses were low density on CT (in an otherwise calcified spleen), hypoechoic relative to the echogenic spleen on US, and had the imaging characteristics of normal spleen on MRI. They failed to accumulate Tc-99m MDP but did demonstrate uptake of Tc-99m sulfur colloid. CONCLUSION: In a patient with SSD and intrasplenic masses, proper correlation of multiple imaging modalities will establish the diagnosis of functioning splenic tissue and avoid mistaken diagnosis of splenic abscess or infarction.

Benign adenomatous kidney neoplasms in children with polycythemia: imaging findings.

PURPOSE: To correlate pathologic, computed tomographic (CT), and ultrasound (US) characteristics of nephrogenic adenofibromas and embryonal adenomas (uncommon pediatric renal tumors) in children. MATERIALS AND METHODS: Medical records and imaging and pathologic findings were reviewed in three children (aged 6 1/2, 7, and 11 years) with adenomatous renal tumors and polycythemia. Specimens were reviewed at the National Wilms Tumor Study Pathology Center (Loma Linda, Calif). RESULTS: All tumors were smaller than 3 cm in greatest dimension. They were hyperechoic on US scans and had high attenuation on unenhanced CT scans. Two patients underwent nephrectomy for initial diagnosis of Wilms tumor. The third underwent local excision. At pathologic examination, embryonal-appearing adenomatous epithelial cells were found to form tubules and papillae with abundant psammomatous calcifications. Two masses were classified as embryonal adenomas and one as nephrogenic adenofibroma. CONCLUSION: Increased attenuation on CT scans and increased echogenicity on US scans of renal adenomatous tumors are distinctive findings that may reflect the presence of tubulopapillary structures and psammomatous calcifications.

Pneumothorax as the presenting sign of Pneumocystis carinii infection in an HIV-positive child with prior lymphocytic interstitial pneumonitis.

An HIV-positive child presented with a pneumothorax secondary to cavitary Pneumocystis carinii pneumonia (PCP). Lymphocytic interstitial pneumonitis had been evident on earlier radiographs but had resolved, concurrent with a decrease in her CD4 counts, before the radiographic changes of PCP became evident. As immune function declines in HIV-positive children, the chest radiograph may paradoxically clear. In such a setting, development of focal lung disease, including pneumothorax, may herald Pneumocystis carinii infection.