颈肩部纤维组织源性肿瘤的MR和CT诊断

目的 分析颈肩部促结缔组织增生性成纤维细胞瘤及侵袭性纤维瘤病的MR、CT特征，重点讨论MRI表现的病理基础。方法 分析手术病理证实有MR或CT影像资料的颈肩部促结缔组织增生性成纤维细胞瘤4例及侵袭性纤维瘤病3例的影像表现，并与病理对照。结果 （1）4例促结缔组织增生性成纤维细胞瘤均位于颈部肌间隙中，类圆形，边界大部分清晰，1例在MRI上见包膜样改变。CT平扫为均匀低密度（2例）及等低密度夹杂改变（1例），增强后肿块强化不明显，密度改变与平扫时一致。肿瘤在T1WI上为均匀等信号（1例）或等低信号混杂改变（1例）；T2WI上2例信号相似于邻近的肌肉，不均匀伴有结节样的低信号或略高信号；增强扫描，病灶强化不明显，仍以等肌肉信号为主，伴有灶性低或略高信号。（2）3例侵袭性纤维瘤病均起源于肌肉本身，长梭形生长，长径与所侵犯的肌肉走向一致，边缘均不规则。CT平扫为等肌肉密度、边界不清晰的肿块（2例）；MRT1WI为均匀等信号的占位，边界不清晰（3例）；T2WI见夹杂条状或结节状低信号的稍高信号（2例）或均匀高信号（1例）；增强扫描肿块均明显强化，条状或结节状的低信号影及不规则的边界显示更加清晰，2例见边缘爪样浸润改变。结论 好发于不同年龄的促结缔组织增生性成纤维细胞瘤和侵袭性纤维瘤病都为纤维来源的软组织肿瘤，但影像改变完全不同，这与其不同的病理基础密切相关。MRI的诊断及鉴别诊断作用明显优于CT。     

胚胎发育不良性神经上皮肿瘤的影像诊断

目的 探讨颅内胚胎发育不良性神经上皮肿瘤（DNT）的影像学表现，评价CT和MRI对该类肿瘤的诊断价值。方法 经手术病理证实的胚胎发育不良性神经上皮肿瘤8例，回顾分析其CT（5例，另3例未行CT检查）及MR表现，并与手术、病理相对照。结果 本组8例11个病灶，其中2例为多发病灶。颞叶6个病灶（6／11），顶叶、额叶、脑干及小脑各1个病灶，同时累及额颞叶者1例。所有病灶均位于皮层或部分病灶同时累及皮层下白质。5例CT平扫中，3例呈较均匀低密度；1例在低密度病灶中尚可见等密度小结节灶；1例可见边缘小斑块状钙化。8例MR平扫，T1WI，病灶均呈低信号，部分可见多个小囊状更低信号区。病灶外形欠规则呈多结节融合的脑回状或局部脑回不同程度扩大呈皂泡样隆起。T2WI除钙化斑呈低信号外，余均呈均匀高信号。1例可见病灶局部颅骨内板受压呈轻微弧形改变。2例行液体抑制反转恢复序列（FLAIR），所有病灶均呈略高信号；2例行质子密度加权成像（PDW），病灶呈均匀略高信号；1例尚行扩散加权成像（DWI），病灶显示等信号。增强检查，除1个病灶轻微强化外，余病灶均未见增强表现。3个病灶边界欠清晰，余病灶均可见清晰边界。2个病灶显示轻微瘤周水肿，余病灶均未见瘤周水肿表现。结论 胚胎发育不良性神经上皮肿瘤（DNT）的影像学表现具有一定的特征性，仔细分析并结合病史可大大提高该类肿瘤的诊断正确率。     

MR imaging after aneurysmal subarachnoid hemorrhage and surgery: a long-term follow-up study.

BACKGROUND AND PURPOSE: We assumed that patients with surgically treated aneurysmal subarachnoid hemorrhage (SAH) might have more lesions than those revealed by CT that could be visible on MR images. METHODS: We conducted a retrospective study of a series of 147 patients with aneurysmal SAH who were treated surgically within 3 days of the onset of SAH. One hundred four patients (mean age, 48.8 years) underwent MR imaging studies 2.1 to 5.6 years (mean, 3.3 years) postoperatively. RESULTS: Eighty-four (81%) patients presented a total of 152 areas of increased signal intensity on T2-weighted images, consistent with infarction; 48% of the patients had lesions in the frontal lobes. CT performed 3 months postoperatively revealed hypodense areas on the scans of only 57% of the patients and showed lesions in the frontal lobes of only 16% of the patients. CONCLUSION: Patients who undergo early surgery for aneurysmal SAH have more lesions than are revealed by CT. The difference is remarkable, especially in the frontal lobes.     

MR imaging and proton spectroscopy of the brain in posttraumatic cortical blindness

Magnetic resonance (MR) imaging and localized proton MR spectroscopy of the occipital lobes were performed in a patient with cortical blindness following brain trauma. Computed tomography (CT) scans and MR images of the visual cortex were normal in the acute stage. Six weeks after the trauma, MR images showed cortical lesions in both occipital lobes, while the spectra showed elevated lactate and decreased N-acetyl aspartate levels relative to those of healthy volunteers. One year later, visual acuity had improved and follow-up studies revealed an increase in the ratios of N-acetyl aspartate to choline and creatine. These results demonstrate that parenchymal lesions may develop in brain regions that appear normal at CT and MR imaging during the acute stage after trauma. Metabolic changes can be observed in these areas by means of localized proton MR spectroscopy.     

胚胎发育不良性神经上皮瘤的CT和MRI表现特征

目的 分析胚胎发育不良性神经上皮瘤(DNT)的CT和MRI表现特征,以提高该病的诊断准确性.方法 对经手术病理证实的10例DNT的CT和MR材料进行回顾性分析.结果 10例均位于幕上,局限于皮层或以皮层为主,呈类圆形、分叶状、楔形或不规则状假囊肿样.T_1WI呈低信号,T_2WI呈高信号,FLAIR像见完整或不完整高信号"环征"及分隔,其他部分呈等偏低信号,DWI上呈低或等偏低信号,波谱表现NAA轻度降低.增强后7例病变无强化,3例病变内呈轻度不均匀强化,无病变周围水肿及占位效应,病灶边界大部分清晰,其中1例病灶无明显边界.2例CT扫描病变均呈低密度改变,其中1例病灶内有条状钙化.结论 DNT在影像学上表现较具特征性,有助于术前正确诊断.     

CT and MRI in tuberculous sternal osteomyelitis: a case report

We report a 58-year-old male patient presenting with a 1-year history of presternal swelling and pain. Plain radiography revealed increased soft tissue density anterior to the body of the sternum, which showed cortical sclerosis. Computed tomography (CT) demonstrated ring-enhancing hypodense soft tissue masses surrounding the sternum, whose anterior and posterior cortices were markedly thickened. On three-phase technetium bone scintigraphy, the left side of the sternum showed increased radiotracer uptake and the central part of the bone was photopenic. The bone marrow of the sternum and peristernal soft tissue lesions were hypo- and hyperintense on T1- and T2-weighted magnetic resonance (MR) images, respectively, and showed marked enhancement postgadolinium. Treatment included both surgical intervention and medical therapy.     

CT and MR findings of brain aspergillosis

CT and MR findings of a case of brain aspergillosis with histopathologic correlation are reported. On both CT and MR images, there were multiple lesions in the corticomedullary junction (CMJ) that appeared to disrupt the cortical sulci and that were not enhanced by intravenous contrast material. In most of these lesions, there were centrally located structures that were enhanced by intravenous contrast material and that appeared to be continuous from markedly enhanced adjacent dilated cortical vessels. Histopathologic examination of the autopsy specimen showed multiple hemorrhagic infarcts in the CMJ with remaining dilated cortical vessels that had been thrombosed by aspergillus hyphae.     

腹、盆部巨大淋巴结增生的影像学表现

目的 分析腹、盆部巨大淋巴结增生的影像学表现特点，以期提高对这种少见病的认识。方法 回顾性分析10例经病理证实的腹、盆部巨大淋巴结增生的临床及影像学特点。本组患者年龄18～56岁，平均40岁。其中男7例，女3例。9例位于腹部，1例位于盆腔。4例既有CT也有MRI检查，4例仅有CT检查，2例仅有MRI检查。将影像学结果与临床和病理结果进行对照。结果 10例中局限性9例，弥漫性1例。局限型9例病理诊断均为透明血管型，表现为单发肿块6例，单个较大肿块周围伴有小的子灶3例。CT平扫与肌肉相比呈等密度；动态增强多数病变（5／7例）在动脉期和延迟扫描均持续高度强化，强化程度接近大动脉。MRI平扫与肌肉相比T1WI表现为低信号或等信号，T2WI呈高信号，动态增强扫描病灶的强化方式与CT一致。4例肿块（直径〉5cm）增强扫描内部见裂隙状和放射状的CT低密度区和MRI低信号区，病理证实为较多纤维成分。弥漫型1例为浆细胞型，表现为腹膜后多个软组织结节，轮廓光整，明显强化。结论 腹、盆部Castleman病的影像学表现与病理类型密切相关。局限透明血管型巨大淋巴结增生的特点是单发肿块或单发较大肿块周围伴有小的子灶，强化密度与信号接近大动脉，较大肿块内部增强后可出现裂隙状或放射状CT低密度和MRI低信号区。     

Limbic lobe of the human brain: evaluation with turbo fluid-attenuated inversion-recovery MR imaging

PURPOSE: To determine whether brain cortices have different signal intensities on turbo fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) images. MATERIALS AND METHODS: Coronal 5-mm-thick turbo FLAIR MR images in 56 neurologically normal patients (27 male and 29 female patients; age range, 12-73 years; mean age, 47 years) were evaluated retrospectively. Cortical signal intensities in the amygdala, hippocampus, cingulate gyrus, subcallosal area, insula, temporal lobe, parietal lobe, and occipital lobe were graded relative to cortical signal intensity in the frontal lobe. Contrast-to-noise ratios were compared for each cortical area. RESULTS: Increased signal intensity was frequently seen in the amygdala, hippocampus, cingulate gyrus, and subcallosal area, regardless of patient age. Signal intensities of temporal, parietal, and occipital cortices were similar to that of frontal cortex, and signal intensity of the insula was slightly higher than that of frontal cortex. There were no significant differences with respect to sex and laterality, whereas significant differences were found among cortical regions (P <.01). The contrast-to-noise ratios of the amygdala, hippocampus, cingulate gyrus, and subcallosal area were significantly greater than those of all other gray matter structures (P <.05). CONCLUSION: On turbo FLAIR images, high signal intensities of cortices of the limbic lobe are frequently seen in neurologically normal brain. These findings should not be considered abnormal.     

Giant cell tumors of the tendon sheath may present radiologically as intrinsic osseous lesions

The purpose of this study was to explain radiographic features of giant cell tumors of the tendon sheath (GCTTS), in particular, osseous extension, by correlating imaging findings with histology in order to increase the accuracy of radiological diagnosis. In a series of 200 consecutive osseous (pseudo) tumors of the hand, on radiography, six patients presented with an intrinsic osseous lesion caused by a histologically confirmed neighboring GCTTS. Available radiographs, computed tomography (CT), and contrast-enhanced magnetic resonance (MR) images were correlated with histology. Radiography showed osseous lesions consisting of well-defined cortical defects in four (one of whom also demonstrated cortical scalloping) and a slightly expansile, well-defined osteolytic lesion in two patients. MR obtained in four patients showed the extraosseous tumor invading/eroding bone and causing cortical scalloping (three and one patients, respectively). Extension depicted on MR was confirmed on the two available resection specimens. All lesions were polylobular (cauliflower or mushroom like) and neighbored tendon sheaths. Dense collagen and hemosiderin-loaded macrophages explained the high CT attenuation and the low MR signal intensity on T2-weighted images that was observed in all four MR and in all two CT scans. The high density of proliferative capillaries explained the marked enhancement observed in all four patients with gadolinium (Gd)-chelate-enhanced MR imaging. GCTTS is a soft tissue (pseudo) tumor that may invade bone and as a consequence mimick an intrinsic osseous lesion on radiographs. In such cases, specific MR and CT features that can be explained by histological findings can be used to suggest the correct diagnosis.     

Metastatic liver tumor from cystic ovarian carcinomas: CT and MRI appearance.

OBJECTIVE: The initial and follow-up CT and MRI images of ten patients with hepatic metastases from ovarian tumors were retrospectively analyzed to establish their features and sequential changes in appearance. MATERIALS AND METHODS: Ten patients with hepatic metastasis from ovarian tumors received initial and follow-up CT and MRI examinations. Six patients were followed up every two to three weeks before surgical tumor resection. Both CT and MR images were analyzed by two radiologists. RESULTS: A total of fourteen lesions were detected by CT and MRI in 10 patients. All 14 lesions were demonstrated as areas of marked hyperintensity on T2-weighted MRI. Eleven cyst-like tumors were demonstrated as round or oval low density lesions on CT and as areas of hypointensity on T1-weighted imaging. Three lesions were shown as solid masses with slightly low attenuation at the initial CT examination and slightly low or iso-intensity areas on T1-weighted imaging, and these lesions showed early peripheral globular enhancement and delayed enhancement on contrast-enhanced CT and MR imaging. Cystic formation was observed two to three weeks later after initial study in all the 3 solid lesions. Rapid subcapsular effusion, which showed obvious enhancement on delayed Gd-DTPA enhanced MR imaging, was observed in two patients. CONCLUSION: The hepatic metastatic tumor from cystic ovarian carcinoma may manifest as a well-defined cystic lesion or as a solid mass, and the solid mass shows delayed enhancement on contrast-enhanced CT and MR imaging. Furthermore, rapid cystic formation and rapid subcapsular extension is frequently seen.     

CT and MR imaging of postnecrotic liver scars

Four cases of postnecrotic liver scar were examined by dynamic CT or MR imaging or both. Postnecrotic scars appeared as low-density areas on plain CT, showed marked and prolonged enhancement on single level dynamic CT, and became isodense on postcontrast scan. On T2-weighted images, postnecrotic scar were as hyperintense as the spleen. Postnecrotic liver scar is an example of localized attenuation or intensity difference not corresponding to mass lesion. It should be distinguished from mass lesions associated with lobar or segmental attenuation (or intensity) difference of the liver as well as nonmass lesions such as irregular fatty infiltration, radiation hepatitis, and hepatic infarction.     

原发性脑淋巴瘤的CT及MRI诊断

目的探讨原发性脑淋巴瘤的CT及MRI影像学特征。方法对20例经手术病理证实的脑淋巴瘤患者的CT及MRI影像学表现进行回顾性分析。结果20例脑淋巴瘤患者17例单发，3例多发，共有24个病灶。其中，CT及MRI图像有以下特点：a）瘤灶多为单发，幕上多见，多为圆形或不规则形；b）CT平扫多呈等或略高密度，无钙化，MR T1WI呈略低或等信号，T2WI呈等或略高信号，瘤周水肿及占位效应相对较轻；c）CT及MRI增强扫描病灶多呈均匀明显强化，亦可不均匀呈环形或花瓣样强化。结论脑原发性淋巴瘤影像表现缺少特征性，确诊主要依靠病理检查。     

Aggressive fibromatosis of the prevertebral and retropharyngeal spaces: MR and CT characteristics.

A 47-year-old man had aggressive fibromatosis, and CT and MR showed a large, multilobulated soft-tissue mass within the prevertebral and retropharyngeal spaces. On CT, the lesion was slightly higher in attenuation than adjacent muscle; on MR, it was intermediate between muscle and fat on unenhanced T1-weighted images, isointense with fat on intermediate-weighted images, hyperintense relative to fat on T2-weighted images, and markedly enhanced after administration of gadopentetate dimeglumine. Multiple small focal and linear areas of decreased signal intensity that did not enhance with gadopentetate dimeglumine were observed on all pulse sequences.     

胚胎发育不良性神经上皮瘤的CT和MRI表现

目的:探讨胚胎发育不良性神经上皮瘤(DNET)的CT和MRI表现。方法:回顾性分析6例经手术病理证实的DNET的MRI和CT资料。6例均行常规MRI检查,其中4例行液体衰减翻转恢复(FLAIR)序列和扩散加权成像(DWI),3例行MR波谱检查。6例中5例行CT平扫。结果:6例中5例为单发,1例为弥漫性。病灶均位于或主要位于皮层区,单发者呈倒三角型表现。肿瘤以囊性成分为主,于CT平扫上均为低密度影,1例可见钙化;其MRI表现为T1WI低信号,T2WI高信号,FLAIR序列上病灶边缘和分隔呈高信号改变,增强扫描示病灶实质结节或分隔有轻度强化,病灶周围均未见水肿。结论:瘤周无水肿、倒三角征和瘤内分隔为PNET的特异性影像学表现,其影像学表现有助于临床诊断和治疗。     

CT and MR characteristics of hibernoma: six cases

PURPOSE: The purpose of this study was to describe the computed tomography (CT) and magnetic resonance (MR) imaging findings of hibernoma. MATERIALS AND METHODS: We retrospectively evaluated imaging findings of CT and MR examinations of six patients (three men and three woman, aged 27-48 years) with histopathological diagnosis of hibernoma. RESULTS: On CT examination, the lesions were slightly hyperdense, and on T1- and T2-weighted MR images, they were isointense or slightly hypointense compared to the subcutaneous fat. All of these lesions showed contrast enhancement and one out of the six lesions had internal linear septations. CONCLUSION: Hibernoma has a wide spectrum of CT and MR imaging findings, which should be considered in differential diagnosis, especially with other lipomatous lesions.     

儿童脑神经母细胞瘤的CT、MRI和病理分析

目的 :探讨儿童脑神经母细胞瘤的CT、MRI表现及和病理的关系。方法 :对 9例经组织病理学证实的脑神经母细胞瘤进行回顾性分析 ,研究肿瘤的CT及MRI影像学特征。结果 :9例神经母细胞瘤中 ,4例肿瘤位于右侧额叶 ,1例位于左侧额叶 ,3例位于右侧颞叶并累及同侧额叶 ,1例位于左侧顶叶。 9例肿瘤均呈囊实性肿块 ,边界清楚 ,5例有钙化。肿瘤实质性部分CT平扫呈略高密度 ,MRT1WI呈等或稍低信号 ,T2 WI呈等或稍高信号 ,增强后肿瘤实性部分和囊性部分的壁明显强化。结论 :神经母细胞瘤是儿童期少见的恶性肿瘤 ,常发生钙化、囊变、坏死。肿瘤实性部分CT平扫密度通常高于脑灰质 ,MRT1WI呈等或稍低信号 ,T2 WI呈等或稍高信号。     

Serial CT and MR imaging of carmustine wafers

BACKGROUND AND PURPOSE: A new option in the treatment of recurrent malignant glioma is surgical placement of chemotherapy-laden biodegradable wafers. We describe the CT and MR appearance of chemotherapy wafers in patients after surgery for recurrent malignant glioma METHODS: Eighteen patients had carmustine (BCNU) wafers implanted during reoperation for malignant glioma; three patients had empty, placebo wafers placed. The 21 patients had a total of 22 CT and 57 MR imaging studies. Repeat CT studies were conducted for up to 6 months, the MR studies for up to 1 year. Examinations were evaluated for attenuation on CT scans, signal abnormalities on MR images, and changing appearance during the follow-up period. Enhancement characteristics were also assessed. RESULTS: On CT scans, 13 of 16 acute (<7 days) cases showed linear high-attenuation wafers, with three showing low attenuation. On MR images, all T1 and T2 studies performed in the acute stage showed decreased signal of the wafers. Eight of 15 studies showed a transient increase in T1 only at about 2 months. Wafers decreased in conspicuity on both CT and MR studies after 2 months. The wafers did not enhance. One postoperative tumor showed a transient increase in edema and increased enhancement at 5 weeks. The presence or absence of BCNU within the wafers did not change their appearance. CONCLUSION: BCNU wafers have a characteristic appearance: in the first 7 days after implantation they are linear, usually of increased attenuation on CT scans, and always show decreased signal on MR images; they do not enhance, and become less conspicuous after 2 months.     

Epithelioid hemangioendothelioma of the liver: imaging findings with pathologic correlation.

Hepatic epithelioid hemangioendothelioma is a rare malignant neoplasm that has nonspecific clinical signs and symptoms and can be difficult to diagnose on the basis of biopsy results. Radiologists may suggest the diagnosis of this slowly progressive neoplasm by recognizing its characteristic radiologic features. We correlated images from CT (13), sonography (nine), and MR (six) with pathologic findings in resected whole livers (eight) and biopsy specimens (five) from 13 patients 25-58 years old. Gross pathologic examination showed a repetitive pattern of multiple solid tumor nodules, in a predominantly peripheral distribution, with coalescence as individual nodules exceeded 4 cm. Tumor nodules had a hyperemic rim. Lesions adjacent to the capsule often produced capsular retraction. These findings correlated well with imaging findings. On CT, the lesions were of low attenuation, peripherally based, and with capsular retraction or flattening in nine (69%) of 13 patients. Unenhanced CT scans showed superior conspicuity over contrast-enhanced CT scans (9/13, 69%) and showed the extent of lesions more accurately in all cases (13/13, 100%). In nine patients, lesions had a peripheral enhancement pattern of alternating attenuation values correlating with the hyperemic rim at pathologic evaluation. On sonograms, the tumors were solid and predominantly hypoechoic. On MR, tumor signal was low on T1-weighted and high on T2-weighted images, with a low-signal halo present around many of the lesions. CT, sonographic, or MR findings of coalescent peripheral hepatic masses with capsular retraction are highly suggestive of hepatic epithelioid hemangioendothelioma.     

肝脏局灶性结节增生的螺旋CT和MRI诊断

目的 :分析肝脏局灶性结节增生 (FNH)平扫和动态增强的螺旋CT、MRI表现 ,提高FNH诊断符合率。方法 :对 13例经手术病理证实的FNH影像学表现进行回顾性分析。螺旋CT检查 8例 ,MRI检查 6例 ,其中 1例同时做CT和MRI检查。结果 :8例CT平扫病灶均呈低密度 ,均匀或不均匀。增强动脉期扫描除中心疤痕外 ,所有病灶均有明显均匀强化 ,其中 4例还可见到病灶中心或周边增粗、扭曲的动脉。门脉期和延迟期扫描 4例呈略高密度、4例病灶呈等密度或略低密度 ,4例伴有中心疤痕者均有延迟强化。MRI检查 6例 ,病灶均呈不均匀略长或等T1及T2 信号 ,增强动脉期呈明显强化 ,门脉期及延迟期呈等或略高强化 ,4例MRI平扫显示中央瘢痕者有延迟强化。结论 :平扫和动态增强螺旋CT、MRI能较全面显示FNH的病理特征和血供特点 ,明显地提高与其它富血管恶性肿瘤的鉴别诊断能力