Giant Cell Tumor and Giant Cell Reparative Granuloma of Bone of the Head: CT and MR Imaging Findings.

BACKGROUND: This study aimed to determine the features and differentiation of Giant Cell Reparative Granuloma (GCRG) and Giant Cell Tumor (GCT) of the head on CT and MRI. METHODS: This retrospective study included six patients with histopathology-confirmed head GCRG and 5 patients with histopathology-confirmed head GCT. All images were independently reviewed by two radiologists. The growth pattern, bone changes, MRI signal intensity, enhancement patterns and other image features were recorded. All patients received CT scans and MR images. RESULTS: All the lesions were located centrally in the bone. Osteolytic bone destruction and expansive growth patterns were observed on CT images. Four of six cases broke the cortical bone with residual cortical bone, and the last two showed a thin cortex in GCRG. Five cases broke the cortical bone with residual cortical bone in GCT. There were enhancing septations in GCT lesions on contrast- enhanced T1-Weighted Images (T1WI) while enhancing septations were not present in GCRG cases. The size of GCT lesions was larger than that of GRCG. GCRG and GCT showed iso-low signals on T1WI and iso-high signals on T2-Weighted Images (T2WI). There was a case with cystic or necrotic lesions in each of the two types of lesions. Osteolytic bone destruction and expansive growth patterns were observed in GCTs and GCRGs. CONCLUSION: The size of the GRCG lesion was smaller than that of the GCT. The presence of enhancing septations and the size of the lesion may distinguish GCTs from GCRG.

Coronavirus Disease 2019-related dyspnea cases difficult to interpret using chest computed tomography.

Patients with Coronavirus Disease 2019 (COVID-19) often have clinical characteristics, such as chest tightness and dyspnea. Continuous, unresolved dyspnea often indicates the progression of lung lesions. The mechanism that underlies the chest distress and dyspnea in patients with COVID-19 is still unclear. Chest CT has a higher sensitivity and can play an essential role in the diagnosis and treatment of the disease. However, our clinical observations showed that although some patients had significant chest distress and dyspnea, the lesions that were observed in the lungs during computed tomography were milder and not completely consistent with clinical symptoms. We analyzed the clinical characteristics, laboratory test results, and imaging findings of these patients. We found that extensive inflammation of the bilateral and respiratory bronchioles in patients with COVID-19 due to excessive activation of proinflammatory cytokines and chemotactic aggregation of T-lymphocytes at the site of inflammation are possible mechanisms underlying chest distress and dyspnea in patients with COVID-19. Short-time and lose-dose use of corticosteroid may be helpful to treat chest tightness and dyspnea in mild COVID-19 patients. Through this study, we aimed to improve our understanding of the pathogenesis of COVID-19.

CT features of SARS-CoV-2 pneumonia according to clinical presentation: a retrospective analysis of 120 consecutive patients from Wuhan city.

OBJECTIVES: To characterize the chest computed tomography (CT) findings of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) according to clinical severity. We compared the CT features of common cases and severe cases, symptomatic patients and asymptomatic patients, and febrile and afebrile patients. METHODS: This was a retrospective analysis of the clinical and thoracic CT features of 120 consecutive patients with confirmed SARS-CoV-2 pneumonia admitted to a tertiary university hospital between January 10 and February 10, 2020, in Wuhan city, China. RESULTS: On admission, the patients generally complained of fever, cough, shortness of breath, and myalgia or fatigue, with diarrhea often present in severe cases. Severe patients were 20 years older on average and had comorbidities and an elevated lactate dehydrogenase (LDH) level. There were no differences in the CT findings between asymptomatic and symptomatic common type patients or between afebrile and febrile patients, defined according to Chinese National Health Commission guidelines. CONCLUSIONS: The clinical and CT features at admission may enable clinicians to promptly evaluate the prognosis of patients with SARS-CoV-2 pneumonia. Clinicians should be aware that clinically silent cases may present with CT features similar to those of symptomatic common patients. KEY POINTS: • The clinical features and predominant patterns of abnormalities on CT for asymptomatic, typic common, and severe cases were summarized. These findings may help clinicians to identify severe patients quickly at admission. • Clinicians should be cautious that CT findings of afebrile/asymptomatic patients are not better than the findings of other types of patients. These patients should also be quarantined. • The use of chest CT as the main screening method in epidemic areas is recommended.

Splenic siderotic nodules in patients with liver cirrhosis.

The aim of this study was to investigate the interrelation between splenic siderotic nodules, hypersplenism and liver function in patients with liver cirrhosis. The splenic enhanced susceptibility-weighted angiography (ESWAN) and conventional magnetic resonance images of 33 patients with liver cirrhosis were retrospectively studied and the ESWAN images were graded. The distribution and prevalence of the image grades for patients with and without hypersplenism were evaluated. In addition, the splenic volume and the distribution of Child-Pugh and albumin scores were compared between patients with and without siderotic nodules, and the correlation between splenic volume and the ESWAN image grades were evaluated in the patients with siderotic nodules. The ESWAN images revealed splenic siderotic nodules in 24 patients. The distribution and prevalence of the ESWAN image grades were demonstrated to be significantly different (P<0.001) between patients with and without hypersplenism. Furthermore, significant differences were observed between patients with and without siderotic nodules with regard to splenic volume and the distribution of Child-Pugh and serum albumin scores (P<0.001). No significant correlation was demonstrated between splenic volume and the ESWAN image grades (P>0.05). In conclusion, a higher prevalence of splenic siderotic nodules (72.7%) was observed using the ESWAN sequence, in comparison with results from previous studies, obtained using the T1-spoiled gradient echo sequence. The presence of splenic siderotic nodules was consistent with the occurrence of hypersplenism and was interrelated with reserved liver function.

The diagnostic accuracy of TCD for intracranial arterial stenosis/occlusion in patients with acute ischemic stroke: the importance of time interval between detection of TCD and CTA.

OBJECTIVE: To evaluate prospectively the diagnostic accuracy of transcranial doppler (TCD) as an additional screening tool for intracranial arterial steno-occlusive disease against computed tomography angiography (CTA) in patients with acute ischemic stroke (AIS) if both are performed in a short time interval. METHODS: Between July 2011 and May 2012, 128 patients who were hospitalized within 24 hours of symptom onset and fulfilled the criteria for the clinical diagnosis of AIS were enrolled. Bedside detection of TCD was accomplished immediately after admission. High-resolution brain CTA was performed within 3 hours after the completion of TCD and the images were interpreted by a neuroradiologist blinded to TCD findings. The accuracy parameters of TCD against CTA were calculated after computation of true-positive, false-positive, true negative, and false-negative values. RESULTS: Among the 128 patients, there were 68 males and 60 females, aged 61.4 ± 17.5 years. The mean time interval between the detection of TCD and CTA was 89.7 (77.8) minutes. In 65% of patients, both examinations were performed with less than a half-hour interval between them. The diagnostic accuracy of TCD for different arteries showed slight distinction. Transcranial doppler demonstrated the most accurate diagnosis for middle cerebral artery (MCA), where TCD showed 35 true-positive, 0 false-negative, 1 false-positive, and 92 true-negative studies compared with CTA. Furthermore, elevated MCA velocities on TCD correlated well with the severity of intracranial stenosis detected on CTA. Vertebral artery (VA) is one of the arteries with the lowest sensitivity for TCD diagnosis (sensitivity 63.4%, specificity 96.5%, positive predictive value (PPV) 89.6%, negative predictive value (NPV) 84.8%, and accuracy 85.9%). In 20 cases (15.6%), TCD showed findings complementary to CTA (real-time embolization, collateral flow patterns, and steal phenomenon). CONCLUSIONS: Transcranial doppler shows high diagnostic accuracy against CTA if both are performed in a short time interval in evaluating intracranial arterial stenosis/occlusion in patients with AIS, especially for MCA obstruction. Transcranial doppler can also provide additional real-time dynamic findings complementary to the information provided by CTA. This can result in changes in the management in some of these patients.