CT and MR imaging findings in sinonasal schwannoma

We report a rare case of schwannoma of the sinonasal cavity, presenting with epistaxis and anosmia.     

CT and MR imaging findings of sinonasal angiomatous polyps

Objective

To characterize the CT and MR imaging findings of patients with sinonasal angiomatous polyps (SAPs) and evaluate their respective clinical value in the diagnosis of SAP.

Methods

CT and MR imaging findings of 15 patients with pathologically proven SAP were examined. Assessed image features included location, size, margin, attenuation, and change of the bony walls of the sinonasal cavity on CT, and signal intensity and enhancement pattern on MR.

Results

On CT, the SAP was mostly isoattenuated with patches of slight hyperattenuation. Most lesions caused changes in the adjacent bone, including expansile remodeling (n = 8), defect or destruction (n = 7), and hyperostosis (n = 6). All lesions examined by MR showed heterogeneous isointense signal intensity on T1-weighted images and mixed obvious hyperintense and hypointense signal intensity with linear hypointense septum internally (n = 10), and hypointense peripheral rim on T2-weighted images (n = 10). Postcontrast MR images demonstrated areas of heterogeneous and marked enhancement with an unenhanced hypointense rim and septa (n = 7).

Conclusions

CT and MR imaging have respective advantages in the diagnosis of SAP. Combined application of CT and MR examinations is necessary for patients with suspected SAP.     

MR findings in rhinocerebral mucormycosis

A case of rhinocerebral mucormycosis evaluated by magnetic resonance (MR) imaging is presented, with inflammatory changes in the paranasal sinuses and orbit. Extension of the infection into the cavernous sinus, with cavernous sinus thrombosis and internal carotid artery narrowing, was well demonstrated on pre- and postgadolinium MR images. Infarctions in the anterior choroidal artery distribution suggested intracranial invasion of basal arteries, and watershed distribution infarctions attested to the tenuousness of flow through a narrowed cavernous carotid artery. Magnetic resonance effectively demonstrated the wide array of findings possible in rhinoorbitocerebral mucormycosis.     

Spectrum of MR imaging findings in spinal tuberculosis

OBJECTIVE: We describe three patients who presented with radiographic findings of a fragment on the medial side of the tibial plateau of the knee that represented an avulsion of the deep portion of the medial collateral ligament. These findings were all associated with disruption of the posterior cruciate ligament and a peripheral medial meniscal tear-the so-called reverse Segond fracture. CONCLUSION: Avulsion fracture at the tibial insertion of the deep component of the medial collateral ligament is a rare finding. When this type of injury is diagnosed, the radiologist should consider posterior cruciate ligament injury and peripheral medial meniscal tears as possible associated findings.     

MR imaging findings in patients with bone-chip allografts

Increasing use of MR to evaluate primary bone neoplasms has stimulated numerous articles on the initial assessment of these lesions. However, scant MR literature has been written about the postoperative MR appearance. We studied the MR appearance of lesions treated by curettage followed by packing with cancellous bone-chip allograft. We retrospectively reviewed the MR scans of 18 consecutive patients treated in this way. Pathologic diagnoses of these lesions were confirmed according to commonly accepted criteria. The allograft sites showed a distinctive pattern of speckled bright signal on T1-weighted images in eight cases. Thirteen of 18 grafts showed a whorled or speckled pattern of increased signal on the T2-weighted images. Only four allograft regions had predominantly low signal on both T1- and T2-weighted images. Two of 18 patients had recurrent tumor proved by open biopsy. MR images in these cases showed areas of homogeneous signal that replaced areas of speckled hyperintensity on both T1- and T2-weighted images. In both these recurrences the tumor had signal intensity similar to that seen on the preoperative MR study. We conclude that knowledge of the MR appearance of cancellous bone chip allografts is important to avoid misinterpreting areas of high signal on T1- or T2-weighted images as areas of recurrence of tumor and/or hemorrhage.     

Incidental radiological findings suggestive of COVID-19 in asymptomatic patients

Despite routine screening of patients for coronavirus disease 2019 (COVID-19) symptoms and signs at hospital entrances, patients may slip between the cracks and be incidentally discovered to have lung findings that could indicate COVID-19 infection on imaging obtained for other reasons. Multiple case reports and case series have been published to identify the pattern of this highly infectious disease. This article addresses the radiographic findings in different imaging modalities that may be incidentally seen in asymptomatic patients who carry COVID-19. In general, findings of COVID-19 infection may appear in computed tomography (CT), magnetic resonance imaging, positron emission tomography-CT, ultrasound, or plain X-rays that show lung or only apical or basal cuts. The identification of these characteristics by radiologists and clinicians is crucial because this would help in the early recognition of cases so that a rapid treatment protocol can be established, the immediate isolation to reduce community transmission, and the organization of close monitoring. Thus, it is important to both the patient and the physician that these findings are highlighted and reported.     

Skeletal coccidioidomycosis: imaging findings in 19 patients

 Objective. The objective of this study was to describe the distribution and radiologic appearance of skeletal coccidioidomycosis in 19 documented cases. Design and patients. Medical records of 19 patients (17 men, 2 women; age range 17–62 years, mean age 34 years) with clinically confirmed skeletal coccidioidomycosis were retrospectively reviewed. The patients were studied with plain radiography (n=19), skeletal scintigraphy (n=6), computed tomography (CT) (n=5), and magnetic resonance imaging (MRI) (n=1). Results. Multiple lesions were seen in 11 of 19 patients (58%). Of a total of 46 lesions, 27 (59%) were described as punched-out lytic, 10 (22%) as permeative/destructive, and 9 (17%) as involving a joint and/or disk space. Lesions were identified in almost every bone (with the exception of the facial bones, ulna, carpus, and fibula) and were most commonly found in the axial skeleton (20 of 46; 43%). Conclusion. Skeletal coccidioidomycosis is frequently multicentric and may involve almost any bone. The axial skeleton is the most common site of involvement. Lesions are usually well demarcated but may present with an ill-defined border and permeative type of bone destruction, especially in the spine. Joint involvement is not uncommon. Plain radiographs are effective in the initial evaluation of bones and joints, scintigraphic studies can identify disseminated disease, and CT and MRI are effective in determining soft tissue involvement and spinal abnormalities.     

Radiation myelopathy in over-irradiated patients: MR imaging findings

The objective of this work is to report the MRI findings in patients with radiation myelopathy due to accidental local over-irradiation syndrome. Eight patients (seven males and one female) were suffering from over-irradiation syndrome as a result of treatments from a malfunctioning linear electron accelerator. The mean accidental estimated dose was 136 Gy delivered to the “open-neck” (seven cases) and to the thoracic wall (one case), during a mean of 5.4 sessions (range 1–9 sessions). Paresthesia and weakness in the upper extremities were the earliest symptoms (87.5 %), with evolution to paralysis in all patients. No patient is alive (mean survival time 64 days). In all cases MRI was negative for neurologic lesions in the acute phase ( < 90 days from irradiation; Radiation Therapy Oncology Group scoring system). Late signs of radiation myelitis manifested as high-intensity signals on T2-weighted images in three patients, and as Gd-DTPA enhancement of T1-weighted images in one case. Autopsies performed on four patients who died in acute phase showed morphologic alterations in white matter: edema in 75 %, and necrosis and glial reaction as well as obliterative vasculitis in all cases. In cases of over-irradiation, MRI may be normal in acute phase even if the patients have severe neurologic deficit, as positive MRI findings appear only in delayed radiation myelitis. Received 25 March 1996; Revision received 3 July 1996; Accepted 4 September 1996     

新型冠状病毒肺炎初诊临床特征及高分辨率CT影像表现

目的 探讨新型冠状病毒肺炎(COVID-19)患者初诊临床特征及胸部高分辨率CT(HRCT)影像表现。方法 回顾性搜集2020年1月20日至28日武汉大学人民医院经临床及核酸检测确诊的141例COVID-19患者,男77例,女64例,中位年龄49(9, 87)岁。分析141例COVID-19患者的临床特征、实验室检查指标以及胸部HRCT影像学表现。结果 141例COVID-19患者实验室检查发现白细胞计数降低38例(26.95%)、淋巴细胞比率降低71例(50.35%)。141例COVID-19患者中发热(>37.5 ℃) 139例(98.58%)、咳嗽106例(75.18%)、头痛11例(7.80%)、咳痰41例(29.08%)、胸闷93例(65.96%)、呼吸道以外症状主要有腹泻等4例(2.84%)。141例COVID-19患者HRCT均有异常,52例(36.88%)胸部HRCT图像表现为磨玻璃影(GGO)和斑片影,以胸膜下分布为主;23例(16.31%)GGO合并局灶实变影;27例(19.15%)小片状模糊影;20例(14.18%)大片状实变影;48例(34.04%)支气管血管束增粗和血管穿行征;5例(3.55%)有空气支气管征象;7例(4.96%)小结节影;5例(3.55%)纤维化、网格影或条索影;7例(4.96%)双侧胸腔积液,4例(2.84%)纵隔或双侧肺门淋巴结肿大。结论 COVID-19的临床特征及HRCT影像表现多样,在COVID-19特定的流行病学背景下,应及时开展胸部HRCT扫描,对疾病做出早期预警。     

Abdominal imaging in COVID-19

Initially thought of as a respiratory infection, coronavirus disease-2019 (COVID-19) is now recognized as a complex disease with a wide clinical spectrum, including digestive involvement. While several studies have evaluated chest imaging findings in COVID-19, few papers have looked at the abdominal imaging features of these patients. Liver, biliary, pancreas and bowel involvement have been reported in COVID-19 infected patients. In this review, we aim to summarize currently available data related to abdominal imaging techniques in COVID-19, in accordance with relevant clinical and laboratory workup of these patients. Underlying mechanisms, indications and imaging findings related to COVID-19 are discussed based on published data. Also, practice points for clinicians are highlighted in order to adequately recognize digestive-related injuries of severe acute respiratory syndrome coronavirus 2 infection. While there’s been a steady accumulation of data with respect to abdominal imaging findings in COVID-19, currently available recommendations are based on limited research. There is a wide spectrum of abdominal imaging findings in COVID-19, which includes hepato-biliary, pancreatic and luminal pathology.     

Review of radiographic findings in COVID-19

The purpose of this study is to review the published literature for the range of radiographic findings present in patients suffering from coronavirus disease 2019 infection. This novel corona virus is currently the cause of a worldwide pandemic. Pulmonary symptoms and signs dominate the clinical picture and radiologists are called upon to evaluate chest radiographs (CXR) and computed tomography (CT) images to assess for infiltrates and to define their extent, distribution and progression. Multiple studies attempt to characterize the disease course by looking at the timing of imaging relative to the onset of symptoms. In general, plain CXR show bilateral disease with a tendency toward the lung periphery and have an appearance most consistent with viral pneumonia. Chest CT images are most notable for showing bilateral and peripheral ground glass and consolidated opacities and are marked by an absence of concomitant pulmonary nodules, cavitation, adenopathy and pleural effusions. Published literature mentioning organ systems aside from pulmonary manifestations are relatively less common, yet present and are addressed in this review. Similarly, publications focusing on imaging modalities aside from CXR and chest CT are sparse in this evolving crisis and are likewise addressed in this review. The role of imaging is examined as it is currently being debated in the medical community, which is not at all surprising considering the highly infectious nature of Severe Acute Respiratory Syndrome coronavirus 2.     

Brain MR imaging findings in two patients with Alpers'' syndrome

We describe the magnetic resonance (MR) imaging findings in two patients with the clinical diagnosis of progressive neuronal degeneration of childhood with liver disease (Alpers' syndrome). One patient showed atrophy of both occipital lobes, and one patient showed high signal intensity in deep gray matter nuclei and diffuse atrophy. Although the imaging findings were nonspecific, they correlated well with the patients' clinical findings.     

Ovarian carcinoma in patients with endometriosis: MR imaging findings

OBJECTIVE: Various types of malignancy can develop in patients with endometriosis. Enhancing mural nodules have been reported as an imaging characteristic of malignant transformations. We evaluated contrast-enhanced MR imaging to determine the optimum sequence to reveal mural nodules and other characteristics of malignant transformations. MATERIALS AND METHODS: We examined 10 patients with pathologically proven ovarian adenocarcinoma in endometriosis and 10 patients (the control group) with ovarian endometrioma suggestive of malignant transformation on the basis of sonographic findings. We analyzed the size and nature of the endometriomas in each patient. We compared four types of contrast-enhanced MR imaging to determine which sequence best revealed mural nodules. RESULTS: In the malignant and control groups, 80% of the cysts with findings suggestive of malignant transformation showed unilateral disease or larger endometrial cysts on the suggestive side than on the contralateral side. High signal intensity on T1-weighted images and low signal intensity on T2-weighted images relative to the myometrium were observed only in two of 10 malignant endometrial cysts and in all control cysts. All malignant endometriomas had small mural nodules with low signal intensity on T1-weighted contrast-enhanced images. Only three benign endometriomas had mural nodules and none of them enhanced. The enhancement of mural nodules was easily seen on dynamic subtraction imaging. CONCLUSION: On the basis of our findings, endometrial cysts with malignant transformation rarely show low signal intensity on T2-weighted images and usually have enhancing mural nodules. Because the enhancement of mural nodules is often difficult to evaluate on conventional T1-weighted images, dynamic subtraction imaging can be valuable.     

Elbow MR imaging findings in patients with synovial fringe syndrome

Objective

To describe imaging findings in patients with synovial fringe (SF) syndrome of the elbow and to compare with a control population.

Materials and methods

Nine patients (5 men, 4 women) whose mean age was 35.7 years were diagnosed with SF syndrome and had undergone preoperative elbow MRI. The radiohumeral (RH) plica was assessed for thickness, cross-sectional area, coverage of one third or more of the radial head, blunting of the free edge, and T2 signal intensity abnormality. Other abnormalities of the RH joint were also assessed, including adjacent articular cartilage defects, subcortical bone marrow signal abnormality in the capitellum, and synovitis. Results were compared with 15 control patients who were asymptomatic laterally and posteriorly.

Results

Mean thickness and cross-sectional area of the RH plica were 1.8 mm and 19.4 mm² respectively in controls, compared with 2.5 mm and 21.9 mm² respectively in symptomatic patients. No statistically significant differences in the distribution of the mean thickness or cross-sectional area of the RH plica were found between the two groups. However, 67% of SF syndrome patients had a RH plica thickness greater than 2.6 mm compared with only 13% of controls (p?=?0.021). Other abnormalities of the RH plica occurred more frequently in patients with SF syndrome compared with controls, but were not statistically significant.

Conclusion

In patients presenting with posterolateral pain or mechanical symptoms in the elbow, RH plica thickness greater than 2.6 mm on elbow MRI examinations may help identify patients with SF syndrome.