Apparent diffusion coefficient of subcutaneous epidermal cysts in the head and neck comparison with intracranial epidermoid cysts

RATIONALE AND OBJECTIVES: Subcutaneous epidermal cysts and intracranial epidermoid cysts are pathologically identical. Although diffusion-weighted imaging (DWI) studies of intracranial epidermoid cysts have been numerously reported, those of subcutaneous epidermal cysts have not been sufficiently investigated. Our hypothesis for this study is that the apparent diffusion coefficient (ADC) values of subcutaneous epidermal cysts and intracranial epidermoid cysts are not different. This study was intended to evaluate the ADC of subcutaneous epidermal cysts of the head and neck in comparison with that of intracranial epidermoid cysts. MATERIALS AND METHODS: The MR studies were performed in 14 patients with head and neck subcutaneous epidermal cysts and 10 patients with intracranial epidermoid cysts using line scan DWI (LSDWI). The ADC was measured and compared between the two types of cyst. RESULTS: The ADC values (mean +/- SD) were 0.81 +/- 0.14 x 10(-3) mm(2)/s in subcutaneous epidermal cysts and 1.06 +/- 0.12 x 10(-3) mm(2)/s in intracranial epidermoid cysts. A significant difference was found in ADC values between the two types (P = .0019). CONCLUSION: Our preliminary study has shown that the ADC provides useful information regarding tissue characterization of subcutaneous epidermal cysts. However, the ADC of subcutaneous epidermal cysts was significantly lower than that of intracranial epidermoid cysts.     

Apparent diffusion coefficient measurements within intracranial epidermoid cysts in six patients

The purpose was to determine whether a strong decrease in apparent diffusion coefficient (ADC) within epidermoid cysts (ECs) is actually responsible for their bright signal intensity on diffusion-weighted (DW) trace images. We studied six patients with surgically proven ECs in whom ADC calculation from T2-weighted DW-EPI-SE data were performed within the ECs and within the deep white matter and cerebrospinal fluid (CSF) as references. All ECs displayed highest signal intensity on the DW trace images. ADC values ranged from 1,280 to 807 x 10(-6) mm(2)/s within cysts (with a mean value of 1,070), from 849 to 698 x 10(-6) mm(2)/s within white matter (with a mean value of 764) and from 3,370 to 2,980 x 10(-6) mm(2)/s within CSF (with a mean value of 3,185). ECs exhibited slightly higher ADC values than white matter, and not the strongly decreased ones which would have been expected if diffusion-weighting were the prominent mechanism for bright signal intensity of the ECs on DW images. However, the EC ADC values are much lower than those of the CSF. Other mechanisms must therefore be involved, i.e. the T2 shine-through effect. Reduced ADC is not the only explanation of the EC bright signal intensity on the DW trace images.     

Syringomyelia in association with posterior fossa cysts

This paper presents three patients with a triad of syringomyelia, midline posterior fossa cysts, and hydrocephalus. In the first patient, the clinical presentation was related to spinal cord cavitation, and the cranial anomalies were unexpected. In cases 2 and 3, the brain anomalies dominated the clinical picture, and syringomyelia was unexpected. These cases show that an examination of the whole neuraxis is as important in patients with midline posterior fossa cysts as it is in patients with developmental syringomyelia or Chiari I malformation.     

Seminal vesicle cysts: association with adult polycystic kidney disease

Adult polycystic kidney disease (APKD) is associated with cyst formation in the kidney, liver, pancreas, esophagus, ovary, uterus, and brain. Four patients with APKD (aged 45-65 years) with computed tomographic evidence of seminal vesicle cysts are described. All seminal vesicles contained cystic masses with attenuation values of 0-30 HU. Seminal vesicle thickness was 3-4 cm (normal, 1.5 cm). High-attenuation walls separated the cysts, which were 3-35 mm in diameter. All patients had typical renal stigmata of APKD. None had cysts elsewhere, except one patient with hepatic cysts. Postmortem examination in one patient confirmed the seminal vesicle cysts as well as APKD. It is likely that a basement membrane defect allows cyst formation in multiple organs, presumably including the seminal vesicles. Because of the association of seminal vesicle cysts with ipsilateral urogenital anomalies, and because only 60% of patients with APKD have a relevant familial history, the kidneys of patients with cross-sectional imaging evidence of seminal vesicle cysts should also be studied.     

Intramuscular rotator cuff cysts: association with tendon tears on MRI and arthroscopy

OBJECTIVE: This study was designed to explore the relationship between intramuscular cysts and rotator cuff tendon tears. CONCLUSION: Intramuscular cysts are strongly associated with rotator cuff tendon tears. Identification of such a cyst should prompt a search for a rotator cuff tear. Findings on MR arthrography and surgery suggest that a delaminating component of the rotator cuff tear may lead to the development of these cysts and may explain the occasional discrepancy between location of tears and location of cysts.     

胸腺神经内分泌肿瘤的MSCT表现与其病理分级的相关性

目的 探讨胸腺神经内分泌肿瘤(NETs)的MSCT表现与其WHO病理组织学分级的相关性.方法 回顾性分析经病理证实的16例胸腺NETs的MSCT表现,并依据2015年WHO病理组织学分级将其分为中低级别、高级别进行相关性分析.结果 本组病例中低级别8例,高级别8例.本组病例肿瘤位置、大小、形态、钙化、心包增厚、心包积液、胸膜增厚、胸腔积液、纵隔脂肪线消失、肿块-肺界面(MPI)增厚呈尖角或锯齿状差异均无统计学意义,其中淋巴结转移有统计学意义.增强后,不同级别肿瘤中线状强化血管影差异有统计学意义,但坏死囊变、周围血管侵犯差异无统计学意义.结论 不同级别胸腺NETs的MSCT表现有一定特征性,并且对其级别预测有一定帮助.     

Characteristic association between K-ras gene mutation with loss of heterozygosity in X-ray-induced thymic lymphomas of the B6C3F1 mouse

PURPOSE: To elucidate the characteristics of radiation carcinogenesis, the spectra of K- and N-ras oncogene mutations, loss of heterozygosity (LOH) and their association in X-ray-induced thymic lymphomas (TL) were determined by comparing with those of N-ethyl-N-nitrosourea (ENU)-induced and spontaneously occurring TL. MATERIALS AND METHODS: TL that arose in untreated, X-ray-irradiated and ENU-treated B6C3F1 mice were examined both for K- and N-ras mutations by PCR-SSCP and DNA sequencing and for LOH by PCR with polymorphic microsatellite markers. RESULTS: (1) ras gene mutations were found in a proportion of TL from X-ray-exposed (approximately 20%) and ENU-treated (30-40%) mice while no ras gene mutations were found in spontaneous TL. N-ras mutations were rare. (2) The spectrum of ras gene mutations was diverse and seemed to differ little between X-ray-induced and ENU-induced TL, even though there was a higher frequency of ras mutations in ENU-induced TL that clustered to K-ras codon 12. (3) The X-ray-induced TL showing K-ras mutation were associated with LOH on chromosome 6, while those showing no K-ras mutation were associated with high frequency of LOH on chromosomes 4, 11 and 12. CONCLUSION: These results demonstrate that, in the B6C3F1 mouse TL, X-ray-induced lymphomagenesis showed both the co-expression, yet low occurrence of allelic imbalance on chromosome 6 and K-ras mutation, and exclusive expression of frequent allelic imbalance on chromosomes 4, 11 and 12 and K-ras mutation.     

胸腺上皮肿瘤WHO病理分型与CT特征的相关性

目的：探讨胸腺上皮性肿瘤（TETs）的WHO病理分型与CT表现的相关性,以提高其CT诊断及临床诊疗水平。方法：回顾性分析经穿刺活检或手术病理证实的66例TETs患者的CT影像学表现。所有患者均行胸部CT平扫及增强扫描,均经组织病理学及细胞免疫组化检查并进行WHO组织病理分型,分析TETs各种组织学类型的CT特征。结果：66例TETs中男39例,女27例,年龄6～77岁。病理分型：A型5例（7．6％）,AB型15例（22．7％）,B1型13例（19．7％）,B2型10例（15．2％）,B3型10例（15．2％）及胸腺癌13例（19．7％）。A、AB、B1型胸腺瘤均呈圆形或类圆形,而80．0％的B3型胸腺瘤及92．3％的胸腺癌呈不规则形;大部分（92．4％）胸腺肿瘤呈中度强化。80．0％B3型胸腺瘤及100％胸腺癌有包膜破坏并侵犯邻近结构;40．0％的B3型胸腺瘤及61．5％的胸腺癌出现心包和（或）胸膜腔积液;随着肿瘤病理分级的增加,周围结构受侵的发生率亦随之升高,分别为15．4％（B1）、40．0％（B2）、80．0％（B3）及100％（胸腺癌）。TETs组织学分类与侵袭危险度CT分级之间存在显著相关性（rs=0．736,P〈0．01）。结论：不同WHO病理分型的TETs的cT表现具有一定特征性,TETs的CT特征反映了其侵袭危险性及组织病理学分型。     

Prevalence and characteristics of paratracheal air cysts and their association with emphysema in a general population

Background

To evaluate the prevalence and characteristics of paratracheal air cysts and their association with emphysema and gender in a general population using low-dose computed tomography scanning of the chest.

Materials and methods

We retrospectively enrolled a total of 924 patients (584 women, 340 men; mean age, 59.73 years; range, 37–89 years) who had received low-dose computed tomography scanning for health examination during the period January 1, 2010 to June 30, 2010. Computed tomographic images were evaluated for the presence of paratracheal air cysts. If paratracheal air cysts were identified, the lungs were reconstructed as a three-dimensional model on a commercial workstation. An emphysema index, an objective quantification of the extent of emphysematous changes on CT imaging, was defined as the percentage area of lung with attenuation values below −950 Hounsfield units.

Results

A total of 60 patients with paratracheal air cysts were included in this study (estimated prevalence, 6.5%; 12 men, 48 women; mean age, 59.85; range 45–89 years). Emphysema index differed significantly between genders (P < 0.0001). The prevalence of paratracheal air cysts in men was significantly lower than that in women (P = 0.005); however, the emphysema index in patients of both genders showed no evidence of emphysema. The majority (95%) of paratracheal air cysts were at the level of the seventh cervical to the second thoracic vertebrae.

Conclusion

The presence of paratracheal air cysts is a common condition in general populations and should not be misdiagnosed as abnormal paratracheal free air. Paratracheal air cysts are more common in woman than in man. In our study, there is no patient with paratracheal air cysts has CT evidence of emphysema.     

不典型胸腺瘤和胸腺癌的临床与CT表现比较

目的 探讨不典型胸腺瘤(B3型胸腺瘤)和胸腺癌(C型胸腺瘤)在临床和CT表现上的异同.方法 搜集经手术切除、按2004年WHO胸腺上皮肿瘤分类标准分类,并有完整CT资料的B3型(30例)和C型(17例)胸腺上皮肿瘤,对其包括预后在内的临床资料和CT图像做回顾性分析.2组患者年龄和肿瘤横断面最长径的比较采用独立样本t检验;对于性别、有无重症肌无力、手术方法及2组间肿瘤边缘、形态、有无坏死和钙化、肿瘤的强化形式和程度以及对周围纵隔脂肪、胸壁、大血管、纵隔胸膜、心包和胸壁的侵犯情况,是否存在纵隔淋巴结肿大、胸膜种植转移、胸水和远处转移等采用Fisher精确概率法检验.对于2组患者预后情况则采用Kaplan-Meier法进行生存分析.结果 (1)临床:B3型患者[平均年龄(43±15)岁]较C型[(56±11)岁]年轻(t=-2.905,P=0.006);90.0％ (27/30) B3型合并有重症肌无力症状,而C型仅5.9％( 1/17),差异有统计学意义(P=0.000);B3型肿瘤的完整切除率(80.0％,24/30)高于C型(11.8％,2/17,P=0.001);70.6％( 12/17)C型患者于术后2年内死亡,B3型中仅20.0％ (5/30)在术后2～9年内死亡;5年生存率C型为14.7％,B3型为94.7％,差异有统计学意义(P =0.000).(2)CT表现:C型肿块的长径为(6.4±2.1) cm,大于B3型的(4.6±2.3)cm(t=-2.778,P=0.008);C型边缘多为不规则形状( 13/17,76.5％),而B3型则多为分叶状(18/30,60.0％,P=0.019);C型(15/17例,88.2％)较B3型(17/30,56.7％)更容易发生肿瘤坏死(P =0.049);在增强扫描中与B3型比较,92.8％ (13/14)C型表现为不均匀强化(P=0.042);同时C型更易发生大血管侵犯(15/17,P=0.001)和远处转移(8/17,P=0.028).结论 B3型和C型胸腺瘤在临床、预后及CT表现有一定差异,有助于作出区别.     

Characteristic association between K- ras gene mutation with loss of heterozygosity in X-ray-induced thymic lymphomas of the B6C3F1 mouse

Purpose : To elucidate the characteristics of radiation carcinogenesis, the spectra of K- and N- ras oncogene mutations, loss of heterozygosity (LOH) and their association in X-ray-induced thymic lymphomas (TL) were determined by comparing with those of N -ethyl- N -nitrosourea (ENU)-induced and spontaneously occurring TL. Materials and methods : TL that arose in untreated, X-ray-irradiated and ENU-treated B6C3F1 mice were examined both for K- and N- ras mutations by PCR-SSCP and DNA sequencing and for LOH by PCR with polymorphic microsatellite markers. Results : (1) ras gene mutations were found in a proportion of TL from X-ray-exposed (~20%) and ENU-treated (30-40%) mice while no ras gene mutations were found in spontaneous TL. N- ras mutations were rare. (2) The spectrum of ras gene mutations was diverse and seemed to differ little between X-ray-induced and ENU-induced TL, even though there was a higher frequency of ras mutations in ENU-induced TL that clustered to K- ras codon 12. (3) The X-ray-induced TL showing K- ras mutation were associated with LOH on chromosome 6, while those showing no K- ras mutation were associated with high frequency of LOH on chromosomes 4, 11 and 12. Conclusion : These results demonstrate that, in the B6C3F1 mouse TL, X-ray-induced lymphomagenesis showed both the co-expression, yet low occurrence of allelic imbalance on chromosome 6 and K- ras mutation, and exclusive expression of frequent allelic imbalance on chromosomes 4, 11 and 12 and K- ras mutation.     

经阴道与经腹腔镜行良性卵巢囊肿剥除术的对比分析

目的：探讨经阴道手术和腹腔镜手术治疗良性卵巢囊肿的临床疗效及利弊。方法：回顾性分析比较2006年9月-2008年12月我院43例行经阴道剥除术和同期94例行腹腔镜下剥除术的良性卵巢囊肿患者的I}缶床资料。结果：两组患者术中出血量、术后排气时间差别均无显著性意义（P〉0．05）。经阴道卵巢囊肿剥除术手术时间、术后住院日均短于经腹腔镜手术者,差别有显著性意义（P〈0．05）。结论：经阴道手术和腹腔镜手术各有利弊,均为较理想的微创术式,应根据患者的具体情况进行选择。     

胸腺上皮肿瘤的MSCT-手术-病理对照分析

_目的：对胸腺上皮肿瘤的 MSCT-手术-病理进行对照分析,为术前诊断、分期、治疗方式的选择及预后评价提供依据。方法：对84例经病理确诊为胸腺上皮肿瘤患者的临床、病理及影像学资料进行回顾性对照分析。结果：胸腺上皮肿瘤大多（64．3％,54/84）位于中线一侧,多呈椭圆形（66．7％,56/84）,部分边缘可见肿块-肺界面（MPI）增厚呈尖角或锯齿征（46．4％,39/84）及肿瘤的肿块-大血管心脏面（MCI）呈灌铸式生长（44．0％,37/84）,内部可见钙化灶、坏死及囊变区,少数可见大血管侵犯（15．5％,13/84）、胸膜或心包结节（14．3％,12/84）、胸腔或心包积液（13．1％,11/84）及纵隔淋巴结肿大（13．1％,11/84）,极少发生肺转移（2．4％,2/84）。MCI 呈灌铸式生长诊断胸腺上皮肿瘤侵犯邻近心脏大血管的敏感度为54．5％,特异度为87．0％。MPI 增厚呈尖角或锯齿状诊断胸腺上皮肿瘤侵犯邻近纵隔-肺的敏感度为63．6％,特异度为91．7％。结论：MSCT 能准确显示胸腺上皮肿瘤的内部结构、邻近组织侵犯及胸膜、肺转移。