Necrotizing fasciitis: an urgent diagnosis

Necrotizing fasciitis (NF) is a rare, life-threatening soft-tissue infection and a medical and surgical emergency, with increasing incidence in the last few years. It is characterized by a rapidly spreading, progressive necrosis of the deep fascia and subcutaneous tissue. Necrotizing fasciitis is often underestimated because of the lack of specific clinical findings in the initial stages of the disease. Many adjuncts such as laboratory findings, bedside tests—e.g., the “finger test” or biopsy—and imaging tests have been described as being helpful in the early recognition of the disease. Imaging is very useful to confirm the diagnosis, but also to assess the extent of the disorder, the potential surgical planning, and the detection of underlying etiologies. The presence of gas within the necrotized fasciae is characteristic, but may be lacking. The main finding is thickening of the deep fasciae due to fluid accumulation and reactive hyperemia, best seen on magnetic resonance imaging.     

Eosinophilic fasciitis: spectrum of MRI findings

OBJECTIVE: Our objective was to describe the spectrum of MRI features of eosinophilic fasciitis. CONCLUSION: MRI findings in eosinophilic fasciitis are characteristic and consist of abnormal fascial signal intensity and enhancement, both of which are directly proportional to disease activity. MRI provides a useful aid for diagnosis and a marker for disease activity and response to treatment.     

Nodular fasciitis: correlation of MRI findings and histopathology

OBJECTIVE: To compare the histopathology of nodular fasciitis (NF) with the magnetic resonance imaging (MRI) findings in order to evaluate the basis of the MR signal characteristics. DESIGN AND PATIENTS: Ten patients with NF, nine females and 1 male, with an age ranging from 13 to 58 years (mean 26.8 years) were studied. MRI findings, available in all 10 patients, were compared with the histopathology in nine patients, and an area-to-area comparative study of the whole specimen section histopathology and MRI was performed in two patients. RESULTS: On the basis of an excisional biopsy or resection specimen, the nine lesions were classified into myxoid ( n=4), cellular ( n=3) and fibrous ( n=2) subtypes. Four myxoid lesions with a subcutaneous location showed a homogeneous SI comparable with muscle on T1-weighted images, high SI on T2-weighted images, and had homogeneous enhancement. One cellular lesion presented with homogeneous, slightly higher SI than muscle on T1-weighted images and inhomogeneous, high SI on T2-weighted images. Alcian blue stain of the whole specimen section revealed the lesion had two parts corresponding to different enhancement patterns on MRI. The blue-stained myxoid part showed markedly diffuse enhancement, while the non-stained cystic space had only peripheral enhancement. Two other cellular lesions had the same appearance on both T1- and T2-weighted images and showed inhomogeneous, diffuse enhancement. One fibrous subtype lesion presented with inhomogeneous, overall slightly higher SI than muscle on T1-weighted images, lower SI at the periphery and high SI in the center on STIR images and only peripheral enhancement. Microscopy and CD-31 staining of the lesion showed more extracellular matrix, with poor vascularity in the center and more collagenous matrix with higher vascularity at the periphery. CONCLUSION: Although similar findings were found in some lesions, the large histologic variability of NF hampers the definition of a prototype of NF on MRI. However, the MRI appearance of the myxoid subtype is rather characteristic. Histologic findings reflect the different SI characteristics and enhancement pattern on MRI.     

Atypical presentation of Lhermitte-Duclos disease: preoperative diagnosis with MRI

Summary In a 35-year-old man with clinical features mimicking acute subarachnoid hemorrhage, MRI demonstrated bilateral Lhermitte-Duclos disease.     

MRI volumetry for the preoperative diagnosis of trigeminal neuralgia

To assess whether quantitative measuring methods can help improve the reliability of MRI-based evaluations of the pathological role of a neurovascular conflict between an artery and the trigeminal nerve. In a prospective study, magnetic resonance images were obtained from 62 patients with unilateral facial pain and 50 healthy test subjects. In coronal T1- and T2-weighted sequences volume measurements were performed by regions of interest and compared intraindividually (healthy versus affected side in the patient populations and right versus left side in the group of test subjects) and on the basis of the different clinical pictures (t test for dependent and independent samples, p<0.05). In patients with trigeminal neuralgia, the affected nerve showed a smaller volume than the trigeminal nerve on the healthy side (p<0.001). Such a volume difference was noted neither in the other patients nor in the healthy test subjects. Quantitative MRI measurements allow a pathological neurovascular conflict to be distinguished from a nonpathological condition where an artery is in close proximity to the trigeminal nerve. The measured volume difference between the healthy and the affected nerve in patients with neuralgia is indicative of trigeminal nerve atrophy resulting from damage to the nerve.     

MRI for diagnosis and monitoring of patients with eosinophilic fasciitis

OBJECTIVE: The objective of this study was to describe MRI findings in patients with eosinophilic fasciitis (EF) and to correlate clinical and laboratory findings with the MRI findings. MATERIALS AND METHODS: Six patients with histologically proven EF underwent MRI at the time of diagnosis and after therapy (15 MRI examinations). Unenhanced T1-weighted, T2-weighted, and STIR sequences were performed using a 1.5-T MRI system. In addition, all patients were imaged with contrast-enhanced T1-weighted sequences. MRI findings, clinical findings, and laboratory parameters were retrospectively reviewed. RESULTS: At the time the six patients presented, all eight MRI examinations revealed symmetric thickening and hyperintensity of the superficial muscle fasciae of the thigh, calves, or arms on unenhanced T1-weighted, T2-weighted, or STIR sequences, with strong enhancement after administration of IV contrast agent. In seven of the eight MRI examinations, similar signal changes were also present in the deep muscle fasciae. After treatment, the fascial abnormalities found on MRI disappeared on six of eight MRI examinations performed in five patients-a rate that correlated well with the clinical findings. In one patient with EF involvement of the thigh, the MRI abnormalities showed partial remission, which also correlated well with the clinical findings. CONCLUSION: In EF, MRI reveals characteristic findings including thickening, signal abnormalities, and contrast enhancement of the superficial and, to a lesser extent, deep muscle fasciae. MRI is useful for establishing the diagnosis, guiding the choice of biopsy site, and assessing treatment response.     

应力性骨折的早期低场强MRI与DR诊断分析

目的：通过对应力性骨折的DR与低场强MRI表现的对比,及分析应力性骨折的解剖学和生物力学特征,提高对应力性骨折早期的低场强MRI诊断的准确性。方法：回顾性分析经临床随访或病理证实29例不同部位应力骨折患者的MRI及DR图像。结果：29例中,胫骨12例（中上段为主）,股骨下段3例,胫骨上段和股骨下段同时发病3例,髂骨、耻骨、坐骨及股骨头颈部、股骨上段各2例,跖骨2例,腓骨中上段2例。MRI均可见骨髓腔内斑片状不均匀长T1、长T2水肿信号,范围远较DR片广泛,边界模糊;7例骨皮质周围见环形或半环形长T1、长T2骨膜水肿信号;6例可见隐匿骨折线;冠、矢状位表现为髓腔内斜形或横形线条状长T1、短T2信号影,其中骨皮质中断4例;10例可见骨皮质增厚,呈长T1、短T2信号;软组织肿胀呈弥漫性长T1、长T2信号。结论：MRI能够更敏感地发现早期应力性骨折,为诊断和判断骨折愈合情况提供更多信息。     

腰部浅筋膜炎48例CT、MRI诊断结果分析

 目的 探讨CT及MRI在腰部浅筋膜炎诊断上的应用,进一步提高对腰部浅筋膜炎影像学表现的认识。方法 收集2018年1-12月经临床及影像学确诊的48例腰部浅筋膜炎患者的CT及MRI扫描结果,进行两种影像学检查的回顾性对比分析。其中男23例,女25例,年龄21～64岁,平均44岁。均行腰椎CT及腰椎MRI检查。CT检查常规行1 mm重建,并做矢状位MPR。MRI检查采用1.5T超导磁共振成像系统,扫描节段同CT,采集矢状位T₁WI序列、矢状位T₂WI序列、横轴位T₂WI序列及矢状位T₂_TIRM序列图像。结果 CT观察到异常37例,对腰部浅筋膜炎的检出率为77.1%,可见到腰部浅筋膜明显增粗呈网状、絮状,边界模糊不清;MR观察到异常48例,对腰部浅筋膜炎检出率为100%。MR上观察到片状型浅筋膜炎8例,条状型浅筋膜炎26例;积液型浅筋膜7例;混合型浅筋膜炎7例。结论 CT及MRI对腰部浅筋膜炎的诊断均有重要意义,其中MR可列为首选检查。     

脑包虫病的MRI表现及诊断

目的 分析脑包虫病的MRI特征性表现.方法 回顾性分析18例经手术病理证实脑包虫病患者的MRI表现,总结脑包虫病的MRI诊断与鉴别诊断要点.结果 18例脑包虫病患者中囊性包虫病和泡型包虫病各9例.囊性包虫病表现为脑内大小不等的圆形长T1、长T2信号病灶,内部信号均匀一致,液体衰减反转回复(FLAIR)序列扫描其内囊液信号可被抑制;DWI序列病灶为低信号;6例病灶周围无水肿带,3例破裂包虫囊肿病灶周围有水肿带;6例病灶见囊壁显示,3例病灶囊壁显示不明显;增强扫描3例破裂包虫囊肿有环形强化,6例病灶无强化;泡型包虫病表现为脑内多发等T1、短T2簇状异常信号,病灶周围通常有类似脑肿瘤样的水肿带.病灶T2WI信号似"煤炭样"黑色的低信号,内见无数密集稍高信号的小囊泡影,小囊泡直径约1～10 mm为其特征性表现.DWI序列病灶为低信号;Gd-DTPA增强扫描后病灶均见不规则的异常环形强化.2例脑灌注成像病变为低灌注改变.结论 MRI以多方位、多参数成像的优势显示脑包虫更准确,术前诊断率更高,对临床诊治具有重要意义.     

Necrotizing fasciitis with fatal outcome: a report of two cases

Two cases of sudden and unexpected death due to necrotizing fasciitis are presented with a short overview of this rare disease with special reference to pathological features and causative and epidemiological factors. One case occurred as a complication of liposuction surgery, and the second presented after minor trauma. Based on the autopsy findings and an interdisciplinary approach, medico-legal evaluation provides a substantial basis for later court hearings in such cases.     

Necrotizing fasciitis of the knee following primary total knee arthroplasty

Necrotizing fasciitis is a rare, life-threatening and rapidly spreading soft-tissue infection that results in necrosis of the muscle, fascia and surrounding tissue. It can be result of a polymicrobial synergistic infection or a streptococcal infection. The authors report a case of necrotizing fasciitis occurring in the knee of a 65-year-old woman following an uneventful primary total knee arthroplasty and resulting in above-the-knee amputation. Having in mind severe infections like necrotising fasciitis, one should be aware of the possibility of such postoperative complications especially in patients with risk factors even in routine procedures like a total knee arthroplasty.     

肛瘘的术前MRI表现与手术结果的对照分析

目的 探讨术前MRI检查对肛瘘诊断及分型的价值.方法 回顾性分析经手术证实的36例肛瘘患者的临床资料及MRI表现,并与手术结果对照分析,总结肛瘘的MRI表现特点及应用价值.结果 36例肛瘘手术显示内口42个,主瘘管45条、瘘管分支15条,外口42个,脓肿16个.与手术结果对照,MRI显示肛瘘内口的准确率为90.5%(38/42个),显示瘘管分支的准确率为80%(12/15条),显示主瘘管、外口及脓肿的准确率均为100%.按照Parks分型,MRI分型符合率为88.9%(32/36例).结论 MRI能准确显示肛瘘内、外口的位置,瘘管的数量及走行,能够对肛瘘进行准确分型.     

MR imaging findings in granular cell tumor of the neurohypophysis: a difficult preoperative diagnosis

Granular cell tumor is a rare neoplasm arising within the neurohypophysis. We describe the MR imaging findings in two symptomatic patients. In one patient with history of panhypopituitarism, MR images showed a large sellar and suprasellar mass. The other patient presented with acute loss of vision in her left eye, and MR images showed a suprasellar mass with compression of the optic chiasm. Received: 18 November 1999; Revised: 5 April 2000; Accepted: 10 April 2000     

Meningioma in the pineal region: preoperative diagnosis with CT, MRI, and angiography

We report a case of pineal region meningioma. The nature of the tumor was correctly diagnosed mainly from the angiographic findings, which enabled us to avoid unnecessary irradiation therapy. Retrospective readings of the CT and MR findings also indicated that the tumor arose apart from the pineal body and appeared to be attached to the dura at the falcotentorial junction. The differential diagnosis of pineal region tumors is discussed.     

肝门区肿瘤的MRI诊断和术前评估

目的 探讨MRI在肝门区肿瘤诊断和术前评估中的价值。方法 肝门区肿瘤42例，其中肝门区肝细胞癌(HCC)12例，肝门区胆管癌(HC)22例，肝门区转移性病变8例。MR检查包括平扫、磁共振胰胆管成像(MRCP)和连续动态增强。连续动态增强为2次注射对比剂，首次经静脉团注钆喷替酸葡甲胺(Gd—DTPA)约10ml，行全肝动态增强扫描，延迟至15min后，追加对比剂15～20ml(0．15～0．20mml／kg)行三维动态增强磁共振血管成像(3D DCE MRA)。MRI表现与手术、病理进行对照。结果 (1)HCC的强化曲线以I、Ⅱ型为主(10／12，83．3％)，HC的强化曲线以Ⅲ、Ⅳ型为主(21／22，95．4％)，8例肝门转移病变的强化曲线呈多样化。(2)HCC组24支门静脉中，3支(12.5%)门静脉侧壁虫噬样侵犯，4支(16．7％)门静脉癌栓；HC组44支门静脉中，5支(11．4％)局部管壁受侵，8支(18．2％)向心性缩窄，11支(25．0％)门静脉闭塞；肝门转移病变组仅1例门静脉右支缩窄。(3)术前MRI对肝门肿瘤能否切除总的评估准确率为85．2％(33／42)，HCC组评估准确率为83．30%(10／12)，HC组评估准确率为86．4％(19／22)。结论 MR平扫、MRCP结合连续动态增强对肝门肿瘤的鉴别诊断和术前评估有较高的准确率。