乳腺脂肪坏死的临床及影像研究进展

<正>乳腺脂肪坏死是一种少见的乳腺良性疾病，本质是乳腺内液化坏死脂肪组织引起的肉芽肿性炎症。其临床及影像表现多样，部分与乳腺癌相似，容易误诊而导致不必要的穿刺或手术。因此，准确的术前影像诊断对临床治疗具有重要的指导价值。本文对乳腺脂肪坏死的临床、病理及影像表现进行综述。1乳腺脂肪坏死的临床特征与分类乳腺脂肪坏死是一类非化脓性炎性病变，发病率约为0.6%，占乳腺良性病变的3%^[1]，多见于中老年妇女，     

MRI测量人腹部脂肪组织

目的:评估MRI测量腹部脂肪组织的价值.方法:2例女性肥胖者行腹部磁共振T1WI扫描,应用Photoshop软件,分别用手动分析方法和快速分析方法对腹腔脂肪、皮下脂肪和腹部脂肪进行系列处理.手动分析方法计算15层图像,而快速分析方法测量平脐1层图像.比较两种方法测量腹部脂肪组织的易操作性、速度和适用范围.结果:快速分析腹部脂肪方法操作性强,手动分析方法计算1例图像的腹部脂肪约需2～3 h,而快速分析法需约8 min.手动分析方法适用范围广.结论:MRI腹部脂肪扫描可以用来研究正常人体脂肪组织分布规律及某些病理状态下的再分布,预计手动分析方法和快速分析方法各有不同适用范围.     

脂肪栓塞综合征及其影像学表现

脂肪栓塞(fat embolism,FE)是由于循环血流中出现的脂滴阻塞于小血管所致的栓塞,常见于长骨骨折、严重脂肪组织挫伤或脂肪肝挤压伤时,脂肪细胞破裂,游离出的脂滴经破裂的小静脉进入血流而引起脂肪栓塞,脂肪栓塞的后果取决于脂滴的大小和多少以及全身受累的程度.脂肪栓塞综合征(fat embolism syndrome,FES)是血循环内的脂肪栓塞导致的以神经系统异常、呼吸衰竭及斑点状皮疹为主要表现的综合征,最常见的栓塞部位有肺、脑及皮肤.脂肪栓塞临床症状和检查无特异性,确诊率低、死亡率高.早期诊断脂肪栓塞可降低死亡率,减少额外费用.CT及MRI检查可以早期发现肺部及脑部病变,尤其是MRI已成为评估脑脂肪栓塞(cerebral fat embolism,CFE)最敏感的检查技术.笔者现就脂肪栓塞的流行病学、病理生理机制和临床表现进行综述,重点介绍肺及脑脂肪栓塞的影像表现.     

腹腔局灶性脂肪坏死的典型影像学征象及其鉴别诊断

腹腔局灶性脂肪坏死是一种临床常见的腹部脂肪病变,常以腹痛为首发症状就诊。大部分腹腔局灶性脂肪坏死是一种自限性疾病,临床处理方法与其他急腹症不同,需要依靠影像学方法及时诊断并区分鉴别,避免不必要的手术和过度治疗。笔者主要结合临床病例探讨腹腔局灶性脂肪坏死的典型影像学征象及其主要鉴别诊断。     

成人股骨头缺血坏死的治疗新进展

股骨头缺血性坏死(avascular necrosis of femoral head,ANFH)是临床常见难治性疾病,它是由不同病因引起的股骨头血运障碍导致骨细胞、骨髓造血细胞和脂肪细胞坏死的病理过程.     

应用屏气T_1 WI的腹部脂肪交互阈值容积分析

目的：使用屏气T1WI探索一种可行有效的测定腹部脂肪的方法。方法：具有高对比度的T1加权梯度回波MR序列可区分腹部的脂肪组织与非脂肪组织。常使用相控阵表面线圈以期获得高的信躁比。线圈敏感性的不均一会导致图像信号的不均匀，因此，为了测定腹部脂肪容积必须使用自动算法来校正信号强度。在对图像直方图分析的基础上界定一阈值来区分脂肪组织与非脂肪组织。使用阈值自动区分的方法就可直接测出脂肪的容积，最后使用交互式选择分开腹内脂肪和皮下脂肪。     

腹部脂肪分布与冠心病的相关性研究

目的 :研究腹部脂肪分布与冠心病的相关性。材料和方法 :选择有心血管检查记录 ,且腹部CT检查无器质性病变的男性 2 3例 ,根据其是否合并冠心病分为A、B两组 (A组为冠心病组 ,B组为非冠心病组 )。选择平扫期的腹部经过脐平面一层图像 ,分别测定两组该层图像腹部脂肪组织总面积 (ATA)和腹内脂肪组织面积 (VTA) ,计算出VTA/ATA ,并记录超体重者例数。结果 :两组间超体重者无显著差别 ,而VTA/ATA在两组间有差别。结论 :CT定量测定腹部脂肪分布(VTA/ATA)是一种检查肥胖的有效手段 ,VTA/ATA值≥ 0 .45可判断或预测冠心病。     

乳腺脂肪坏死的X线表现及病理对照研究

目的 探讨乳腺脂肪坏死的X线表现及病理基础，提高对脂肪坏死的认识。方法 回顾性分析经手术、病理证实的91例（其中2例为双侧乳腺脂肪坏死，共93个病变。）脂肪坏死X线表现，并与病理结果对照。结果 主要X线表现：（1）无任何异常X线发现14例（15．4％）；（2）脂性囊肿6例（6．6％）；（3）表现为肿物20例（22．0％），其中1例为双侧乳腺脂肪坏死；（4）表现为小结节13例（14．3％）；（5）脂肪层内星芒影、斑片影、索条影混杂出现28例（30．8％），其中1例为双侧乳腺脂肪坏死；（6）脂肪层内索条影交织呈网状5例（5．5％）；（7）结构不良者5例（5．5％）。分布部位：（1）位于脂肪层内55例；（2）向脂肪层突出或位于脂肪层与腺体交界处13例，常规位摄片位于脂肪层与腺体交界处的脂肪坏死，切线位投照有利于将病变显示于脂肪层内；（3）位于腺体之间9例；（4）乳腺平片未见异常发现14例。病理表现：（1）脂性囊肿是病变早期的特征性X线表现。（2）脂肪层内不均匀密度肿物影或小结节影为病变中期的特征性表现，反应了纤维组织逐渐替代了液化坏死的脂肪组织。（3）脂肪层内或浅层腺体内局限星芒状致密影以及不规则的网状影最常见，是病变后期的特征性表现。反应了坏死脂肪组织被吸收，周围残留部分纤维组织。通常不同病理时期的X线表现常同时出现。结论 乳腺X线摄影对于脂肪坏死具有重要诊断价值。     

不典型肾血管平滑肌脂肪瘤的CT诊断

肾血管平滑肌脂肪瘤（RAML）是肾脏最为常见的良性肿瘤,大部分病例中因其含有脂肪组织得以诊断明确。但其中少数可仅含少量脂肪或无脂肪组织其影像学表现和肾癌极为相似,常常误诊。作者收集我院2009年收治的11例RAML病例,共12个病灶,所有病例均经手术病理证实,通过分析其CT影象学特征,旨在提高其诊断率,现报道如下。     

乏脂肪性肾血管平滑肌脂肪瘤的CT诊断

肾血管平滑肌脂肪瘤（angiomyolipoma,AML）,又称错构瘤,是肾脏较常见的良性肿瘤,由于含有脂肪组织,绝大多数诊断不难。但少数脂肪含量甚少或无脂肪组织的病例,其影像表现不典型,极易误诊。笔者搜集经手术病理证实的6例乏脂肪性肾AML共8个病灶,以探讨此病的CT影像特征。     

Imaging manifestations of abdominal fat necrosis and its mimics

Intraabdominal fat is a metabolically active tissue that may undergo necrosis through a number of mechanisms. Fat necrosis is a common finding at abdominal cross-sectional imaging, and it may cause abdominal pain, mimic findings of acute abdomen, or be asymptomatic and accompany other pathophysiologic processes. Common processes that are present in fat necrosis include torsion of an epiploic appendage, infarction of the greater omentum, and fat necrosis related to trauma or pancreatitis. In addition, other pathologic processes that involve fat may be visualized at computed tomography, including focal lipohypertrophy, pathologic fat paucity (lipodystrophies), and malignancies such as liposarcoma, which may mimic benign causes of fat stranding. Because fat necrosis and malignant processes such as liposarcoma and peritoneal carcinomatosis may mimic one another, knowledge of a patient's clinical history and prior imaging studies is essential for accurate diagnosis.     

Intraabdominal fat necrosis

The processes that course with intraabdominal fat necrosis often manifest with acute or subacute abdominal pain; these clinical findings can be caused by various conditions, including epiploic appendagitis, omental infarction, encapsulated fat necrosis, mesenteric panniculitis, appendicitis, diverticulitis, and certain neoplasms. In this context, although the anatomic location of the pain and accompanying symptomatology can help orient the diagnosis, there is a risk of unnecessary surgery. Imaging tests like ultrasonography and especially computed tomography are essential for diagnosing intraabdominal fat necrosis. Radiologists must be familiar with the characteristic findings for all the conditions that can cause acute or subacute abdominal pain to ensure appropriate management and prevent unnecessary surgery.     

Extrahepatic, nonneoplastic, fat-containing lesions of the abdominopelvic cavity: spectrum of lesions, significance, and typical appearance on multidetector computed tomography

Fat may be noted in a diffuse or focal manner in a variety of nonneoplastic abdominopelvic conditions. The specific signature of macroscopic fat on computed tomography along with the usually characteristic findings of these entities makes the diagnosis of most of these conditions relatively straightforward. In the intestinal tract, the "fat halo sign" usually arises in the context of subacute to chronic bowel wall inflammation. Excess fat in the renal sinus may occur with renal sinus lipomatosis or "replacement lipomatosis of the kidney." Some cases of "pancreatic lipomatosis" may culminate in steatopancreatitis and ultimately neoplastic transformations. "Fibrofatty mesenteric proliferation" is a characteristic feature of Crohn disease. In the setting of the acute abdomen, accurate diagnosis of fat-containing lesions (epiploic appendagitis or omental infarction) from other causes of the acute abdomen is critical. Mesenteric panniculitis is 1 of the causes of the "misty mesentery." Juxtacaval fat deposition is a benign process that has the potential to be confused with more serious conditions. More diffuse fat deposition (abdominal or pelvic lipomatosis) has the potential to become symptomatic by causing mass effect upon the adjacent structures. Fat can also be seen in a variety of postoperative/iatrogenic conditions or abdominal wall/diaphragmatic hernias.     

Variable appearances of fat necrosis on breast MRI

OBJECTIVE: The purpose of this article is to illustrate the varying appearances of fat necrosis on MRI. CONCLUSION: Fat necrosis may mimic malignancy with varying appearances on MRI. Suspicious morphologic and kinetic features may be present, necessitating biopsy to exclude new or recurrent breast cancer.     

Fat necrosis of breast: a potential pitfall in breast MRI

Fat necrosis is a benign nonsuppurative inflammatory process of adipose tissue. Occasionally fat necrosis may mimic a breast cancer clinically, mammographically, and sonographically. There have been some previous reports on the MR imaging of the fat necrosis. In some MR findings of fat necrosis, it was difficult to distinguish it from malignant lesions. We report a case of fat necrosis presenting the irregular enhancement with the non-enhancing area of central areas on MRI.     

Intramedullary fat globules related to bone trauma: a new MR imaging finding

Objective

The purpose of this study is to describe intraosseous fat globules related to bone trauma that are detectable with magnetic resonance imaging (MRI), to define the relationship of this finding to fracture and bone contusion, to establish the frequency and associated findings. A proposed pathogenesis is presented.

Materials and methods

We retrospectively reviewed 419 knee MRI examinations in patients with a history of recent injury and MRI findings of fracture or bone contusion. As a control population, 268 knee MRI examinations in patients without MRI findings of recent bone injury were also reviewed.

Results

Eight of 419 (1.9 %) patients with acute or subacute knee injury with positive findings of osseous trauma on MRI demonstrated intraosseous fat globules. The mean age of patients with fat globules was greater than that of those without fat globules, and the finding was more commonly seen in women. Fat globules were hyperintense to the normal fatty marrow present elsewhere in the bone on TI-weighted imaging and had a surrounding halo of high signal intensity on fluid-sensitive imaging.

Conclusions

Intramedullary fat globules related to bone injury visible on MRI are thought to be due to coalesced fat released by the necrosis of fatty marrow cells. The pathogenesis is supported by histologic studies of fat globules related to osteomyelitis, bone contusions and fractures. As the medullary cavity of long bones in older patients contains more fat than hematopoetic bone marrow, it is likely that this finding is more common with advancing age.     

Fat Necrosis after Conserving Surgery and Interstitial Brachytherapy and/or External-Beam Irradiation in Women with Breast Cancer

PURPOSE: To investigate the incidence of fat necrosis, breast tissue fibrosis and breast pain after conserving surgery and accelerated partial-breast irradiation (APBI, group A), whole-breast external-beam irradiation (EBRT, group B), or EBRT combined with an interstitial boost (EBIB, group C) in women with breast cancer. PATIENTS AND METHODS: 85 patients who received breast-conserving therapy from 02/2000 to 03/2002 were analyzed. 30 patients received EBRT, 33 patients APBI, and 22 patients EBIB. Median follow-up was 35.5, 35.0, and 37.5 months, respectively. Fat necrosis was detected and rated by mammograms, fibrosis and pain were clinically rated with the LENT-SOMA scores. RESULTS: The incidence of fat necrosis was 15.3% for all patients; and 15.2%, 20.0%, and 9.0% for groups A, B, and C, respectively. The 3-year fat necrosis-free survival probability was 83%, 76%, and 95% (difference not significant). The mean time to first diagnosis of fat necrosis was 25.6, 26.2, and 26.0 months. No patient needed surgical intervention because of fat necrosis-related pain. Fibrosis was present in 27.3%, 63.3%, and 77.3% (p < 0.001), breast pain in 9.0%, 33.4%, and 18.1% (p < 0.05). CONCLUSION: Asymptomatic fat necrosis is a common finding after both percutaneous and interstitial irradiation after breast-conserving surgery. This analysis did not support the hypothesis that APBI with multicatheter implants leads to higher rates of fat necrosis, fibrosis, or pain.     

Traumatic fat necrosis of male breast

Fat necrosis is a benign nonsuppurative inflammatory process that most commonly occurs in female breast. It is a rare condition in male breast. There are very few reports in the literature. There is a wide range of manifestations of fat necrosis and can mimic breast cancer clinically and radiologically. We report a case of fat necrosis of the breast in a 57-year-old man.     

Abdominal fat: standardized technique for measurement at CT

The authors estimated abdominal fat distribution on the basis of measurements at computed tomography (CT). The attenuation range for fat tissue was defined as the interval within the mean plus or minus 2 SDs considered to be individual variation. Fat areas found with this method were closely correlated with those obtained by means of the computed planimetric method or with a fixed attenuation range from -190 to -30 HU as the standard of reference. Although the average CT numbers obtained with different scanners were distributed widely, the calculated fat areas were almost identical. This method might be a practical and standardized method at CT.     

Seat belt injury of the breast: MR mammographic follow-up

Fat necrosis of the breast is a benign inflammatory process that most commonly occurs as the result of breast trauma. The radiographic and clinical significance of fat necrosis of the breast is that it may mimic a malignancy. We report mammographic, sonographic and MR imaging findings and evolution of the lesions located along the seat-belt line in a case of fat necrosis of the breast after a car accident.