Unusual Malignant Solid Neoplasms of the Kidney: Cross-Sectional Imaging Findings

Malignant kidney neoplasms are the most frequently encountered solid kidney masses. Although renal cell carcinoma is the major renal malignancy, other solid malignant renal masses should be considered in the differential diagnosis of solid renal masses that do not contain a macroscopic fatty component. In this pictorial essay, we present the imaging findings of a primitive neuroectodermal tumor, primary liposarcoma of the kidney, primary neuroendocrine tumor, leiomyosarcoma, synovial sarcoma, malignant fibrous histiocytoma, sclerosing fibrosarcoma and renal metastasis of osteosarcoma.     

骨恶性间叶瘤的影像学表现(附4例病例报告并文献复习)

目的:探讨骨恶性间叶瘤的影像学表现,以提高影像诊断水平,减少误诊。方法:回顾性分析经手术病理证实的4例骨恶性间叶瘤患者的X线、CT及MRI表现,其中X线平片检查4例,CT和MRI各检查2例。结果:骨恶性间叶瘤的主要影像学表现为:①软组织肿块:形态不规则,直径多>10 cm,边缘清楚或模糊,肿块内有钙化、骨化,CT显示肿块内有脂肪组织,MR T_1WI上肿块呈等、低信号,T_2WI呈混杂高信号,CT增强扫描示肿块不均匀强化;②骨质改变:呈浸润性斑片状骨质破坏,部分破坏边缘有硬化,MR T_1WI呈低信号,T_2WU呈混杂高信号,骨膜反应少见;③骨破坏程度与软组织肿块大小不成比例。结论:骨恶性间叶瘤影像学表现有一定特征,影像检查有助于本病的诊断和鉴别诊断。     

Extrapulmonary Tuberculosis: Imaging Features Beyond the Chest

The purpose of this pictorial review is to illustrate the various imaging findings of extrapulmonary tuberculosis. Manifestations of cardiac, central nervous system, head and neck, musculoskeletal, abdominal, genitourinary, and breast tuberculosis will be discussed. Extrapulmonary tuberculosis presents a difficult diagnostic challenge for the radiologist and requires a high index of suspicion, particularly in high-risk populations.     

肿瘤样钙质沉着症的临床和影像学分析

目的:探讨肿瘤样钙质沉着症的临床及影像学表现,提高本病的影像诊断水平.方法:回顾性分析6例经手术病理证实的肿瘤样钙质沉着症的临床及影像学资料.6例均行X线平片检查,2例行MRI检查.结果:6例患者主要临床表现为关节附近无痛性肿块,多发肿块2例,单发肿块4例.主要X线表现为关节周围团块状软组织钙化.MRI表现:T1WI上呈结节状不均匀低信号,T2WI上呈不均匀高信号.X线和MRI均显示邻近关节结构正常.结论:肿瘤样钙质沉着症的典型影像学表现为不侵及关节的软组织内多发钙化性肿块,平片和MRI有助于本病的诊断和鉴别诊断.     

Neuroimaging Findings in Patients with COVID-19: A Systematic Review and Meta-Analysis

ObjectiveCentral nervous system involvement in coronavirus disease 2019 (COVID-19) has been increasingly reported. We performed a systematic review and meta-analysis to evaluate the incidence of radiologically demonstrated neurologic complications and detailed neuroimaging findings associated with COVID-19.Materials and MethodsA systematic literature search of MEDLINE/PubMed and EMBASE databases was performed up to September 17, 2020, and studies evaluating neuroimaging findings of COVID-19 using brain CT or MRI were included. Several cohort-based outcomes, including the proportion of patients with abnormal neuroimaging findings related to COVID-19 were evaluated. The proportion of patients showing specific neuroimaging findings was also assessed. Subgroup analyses were also conducted focusing on critically ill COVID-19 patients and results from studies that used MRI as the only imaging modality.ResultsA total of 1394 COVID-19 patients who underwent neuroimaging from 17 studies were included; among them, 3.4% of the patients demonstrated COVID-19-related neuroimaging findings. Olfactory bulb abnormalities were the most commonly observed (23.1%). The predominant cerebral neuroimaging finding was white matter abnormality (17.6%), followed by acute/subacute ischemic infarction (16.0%), and encephalopathy (13.0%). Significantly more critically ill patients had COVID-19-related neuroimaging findings than other patients (9.1% vs. 1.6%; p = 0.029). The type of imaging modality used did not significantly affect the proportion of COVID-19-related neuroimaging findings.ConclusionAbnormal neuroimaging findings were occasionally observed in COVID-19 patients. Olfactory bulb abnormalities were the most commonly observed finding. Critically ill patients showed abnormal neuroimaging findings more frequently than the other patient groups. White matter abnormalities, ischemic infarctions, and encephalopathies were the common cerebral neuroimaging findings.     

Pelvic Solitary Plasmacytoma: Computed Tomography and Magnetic Resonance Imaging Findings with Histopathologic Correlation

ObjectiveTo describe the imaging features of pelvic solitary plasmacytoma and to correlate them with the pathologic grade.ResultsThe imaging features of pelvic solitary plasmacytoma revealed 3 different types: multilocular type (n = 5), unilocular type (n = 2) and complete osteolytic destruction type (n = 3) on computed tomography and MRI. Pathologically, the tumors were classified into low, intermediate and high grades. Features such as multilocular change, perilesional osteosclerosis, slight expansion, local bone cortex disruptions and masses inside bone destruction, often suggest a low-grade solitary plasmacytoma; complete osteolytic destruction, huge soft tissue mass, and osseous defects imply a higher pathologic grade.ConclusionPelvic solitary plasmacytoma has various imaging manifestations, while a slight expansile osteolytic feature with multilocular change or homogeneous enhancement highly suggests its diagnosis. The distinctive imaging features of pelvic solitary plasmacytoma are well correlated to the pathologic grade.     

骨原发性恶性纤维组织细胞瘤影像诊断

目的探讨骨原发性恶性纤维组织细胞瘤(BMFH)影像表现及诊断要点。方法回顾性分析6例经病理确诊为BMFH的X线、CT及MRI表现。结果4例侵犯单骨,2例侵犯多骨。溶骨型4例,混合型2例。股骨下端3例,肱骨上端1例,楔骨1例,横突1例,共侵犯12个骨骼。6例均有骨及骨皮质明显破坏,以溶骨性破坏为主,2例病灶周围有轻度骨硬化。全部病例均有软组织肿块,巨大肿块2例,局限性肿块4例,1例肿块内可见散在小钙化影。全部病例未见骨膜反应,3例合并病理性骨折。结论原发性BMFH好发于长骨干骺端或骨端,多见于股骨下端及胫骨上端。虫蚀状或大片状溶骨性骨质破坏,巨大软组织肿块,无骨膜反应,是其影像学特点,诊断需密切结合临床和病理。     

Utility of Postmortem Autopsy via Whole-Body Imaging: Initial Observations Comparing MDCT and 3.0T MRI Findings with Autopsy Findings

Objective

We prospectively compared whole-body multidetector computed tomography (MDCT) and 3.0T magnetic resonance (MR) images with autopsy findings.

Materials and Methods

Five cadavers were subjected to whole-body, 16-channel MDCT and 3.0T MR imaging within two hours before an autopsy. A radiologist classified the MDCT and 3.0T MRI findings into major and minor findings, which were compared with autopsy findings.

Results

Most of the imaging findings, pertaining to head and neck, heart and vascular, chest, abdomen, spine, and musculoskeletal lesions, corresponded to autopsy findings. The causes of death that were determined on the bases of MDCT and 3.0T MRI findings were consistent with the autopsy findings in four of five cases. CT was useful in diagnosing fatal hemorrhage and pneumothorax, as well as determining the shapes and characteristics of the fractures and the direction of external force. MRI was effective in evaluating and tracing the route of a metallic object, soft tissue lesions, chronicity of hemorrhage, and bone bruises.

Conclusion

A postmortem MDCT combined with MRI is a potentially powerful tool, providing noninvasive and objective measurements for forensic investigations.     

The performance of MRI in detecting subarticular bone erosion of sacroiliac joint in patients with spondyloarthropathy: A comparison with X-ray and CT

Objective

To assess the sensitivity and specificity of detecting subarticular bone erosion of sacroiliac (SI) joint in patients with spondyloarthritis (SpA) using MRI three-dimensional water selective balanced steady-state free precession sequence (3D-WS-bSSFP) and T1-weighted (T1W) sequence.

Materials and methods

Radiography, CT and MRI of SI joint from 43 SpA patients were retrospectively analyzed. MRI examination sequences include T1W, short tau inversion recovery (STIR) and 3D-WS-bSSFP. Two radiologists, blinded to clinical data, independently determined bone erosion at bilateral sacral and iliac sides of the SI joint on radiography, CT, T1W and 3D-WS-bSSFP respectively. X² test was used to compare the sensitivity of detecting bone erosion among different diagnostic methods.

Results

Of the 86 sacral and 86 iliac articular surfaces from the 43 cases, radiography, CT, MRI T1W and 3D-WS-bSSFP showed the presence of bone erosion in 40, 74, 50 and 71 articular surfaces respectively. CT and MRI 3D-WS-bSSFP demonstrated similar sensitivity (x² = 0.11, P = 0.74), and both were superior to radiography (x² = 15.17, P < 0.01 and x² = 12.78, P < 0.01, respectively) and T1W (x² = 7.26, P < 0.01 and x² = 5.62, P < 0.05). Using CT diagnosis as the gold standard, the sensitivity and specificity of detecting bone erosion for MRI 3D-WS-bSSFP and T1W sequences were 91.8%, 96.9%, and 60.8%, 94.9% respectively.

Conclusion

MRI 3D-WS-bSSFP sequence is associated with short scanning time, zero ionizing radiation, high sensitivity and specificity of displaying the subarticular bone erosion of SI joints in patients with SpA. Therefore, it can be considered an alternative to CT.     

The Abdominal Wall Lumps and Bumps: Cross-Sectional Imaging Spectrum

This article focuses on the cross-sectional imaging spectrum of abnormalities that affect the abdominal wall, with emphasis on magnetic resonance imaging (MRI). Cross-sectional imaging is valuable for diagnosing and evaluating the extent of abdominal-wall masses. With the increasing use of MRI, it is often possible to reach a diagnosis or narrow the differential diagnosis, thereby guiding effective management. Neoplastic and non-neoplastic pathologies will be illustrated, and the distinctive imaging characteristics of these entities will be highlighted.     

Imaging in acute stroke

Stroke is a syndrome characterized by a sudden neurological deficit caused by intracranial hemorrhage or ischemia. Computed tomography (CT) maintains a primary role in the evaluation of patients with acute stroke. The optimal magnetic resonance imaging (MRI) protocol in acute stroke includes diffusion-weighted imaging (DWI) to show acute ischemic lesion and MR perfusion study to estimate brain perfusion. Careful selection of patients for a thrombolytic therapy is crucial to improve safety and efficacy.     

骨斑点症的影像学表现(附6例报告及文献复习)

目的:提高对骨斑点症的影像学认识.方法:对6例患者均行全身骨X线检查,4例行CT与MRI检查.结果:6例患者发病均较广泛并双侧对称,病灶呈大小不等的圆形,类圆形硬化结节.大部分病灶位于骨松质内,并与骨小梁走行一致,少部分位于骨皮质内.相邻关节软骨无异常改变.结论:骨斑点症X线、CT、MRI表现均具有特异征象,可明确诊断.     

静脉窦血栓形成的CT和MR影像特点

目的：研究静脉窦血栓形成（ＶＳＴ）的ＣＴ和ＭＲ特点。方法：对１７例ＶＳＴ的ＣＴ和ＭＲ特点进行回顾性影像分析，重点研究ＶＳＴ与皮层下多发性脑内血肿（ＳＣＭＨ）的联系，诊断与鉴别诊断。结果：ＳＣＭＨ在ＶＳＴ中出现率为１００％（１７／１７）。９例ＶＳＴ病例ＭＲ随访显示血肿、水肿和静脉窦内血栓进行性吸收，血肿周围可见规则完整的含铁血黄素沉积圈。结论：ＣＴ上急性ＳＣＭＨ是ＶＳＴ很强的一个诊断指征。ＭＲ可以进一步除外瘤卒中，发现静脉窦内血栓，以明确ＶＳＴ的诊断     

Imaging Findings of Follicular Dendritic Cell Sarcoma: Report of Four Cases

Follicular dendritic cell sarcoma is a rare malignant neoplasm and little is known about its radiological features. We present here four cases of follicular dendritic cell sarcomas and we provide the image characteristics of these tumors to help radiologists recognize this entity when making a diagnosis.     

Lead synovitis: The important role of radiology on diagnosis and follow-up: Case report

We present the case report of a 67-year-old man with a history of a firearm injury on the left upper extremity 35 years ago. Lead synovitis and imaging features are reviewed, emphasizing radiology''s crucial role in diagnosing and following this condition.     

亨廷顿病的影像学表现

目的 报道亨廷顿病的影像学表现. 资料与方法 分析1例经基因检测证实的亨廷顿病患者CT、MRI、氢质子磁共振波谱(1H-MRS)、正电子发射体层成像(PET/CT)影像学表现,并复习文献. 结果 头颅CT及MRI提示双侧尾状核萎缩,侧脑室前角扩大.尾状核头部最大直径、壳核最大直径值减低、双尾状核比率和双额角比率值增高.1H-MRS出现异常乳酸峰并提示基底节区N-乙酰天门冬氨酸/肌酸值减低,胆碱复合物/肌酸值增高.PET/CT示双侧基底节代谢减低. 结论 1H-MRS代谢异常及PET/CT基底节区代谢减低有助于诊断亨廷顿病.