Recent topics related to nephrogenic systemic fibrosis associated with gadolinium‐based contrast agents

Nephrogenic systemic fibrosis is a progressive, potentially fatal, multiorgan‐system fibrosing disease related to exposure of patients with renal failure to gadolinium‐based contrast agents used in magnetic resonance imaging. Between 1997 and 2007, more than 500 cases of nephrogenic systemic fibrosis in patients with severe renal insufficiency (glomerular filtration rate less than 30 mL/min/1.73 m²) were reported, and no known cases of nephrogenic systemic fibrosis have occurred in patients with a glomerular filtration rate of more than 30 mL/min/1.73 m² without acute kidney injury. Additional major risk factors are use of high‐dose and specific gadolinium‐based contrast agents, a pro‐inflammatory state. Although the mechanism of nephrogenic systemic fibrosis is unclear and there is no consistently‐effective therapy, nephrogenic systemic fibrosis is an entity that can be eliminated by observing recent recommended guidelines for gadolinium‐based contrast agents and nephrogenic systemic fibrosis. This article reviews current knowledge about nephrogenic systemic fibrosis and focuses mainly on how to prevent it.     

Accuracy of ultrasonography and magnetic resonance imaging in the diagnosis of non-palpable testis

BACKGROUND: Studies were needed to evaluate the accuracy of ultrasonography (US) and magnetic resonance imaging (MRI) for diagnosing non-palpable testis, and to study the clinical usefulness of US and MRI before surgical exploration. METHODS: Fifty-six patients with non-palpable testis aged 1--12 years were examined between 1993 and 2002. Forty-six patients (55 non-palpable testes) underwent US. Forty patients (47 non-palpable testes) were examined using MRI. Both US and MRI were used in 29 patients (34 non-palpable testes). We used Fisher's exact probability test to compare the results of these graphic examinations with the surgical or laparoscopic findings for the non-palpable testis. RESULTS: Ultrasonography had a sensitivity of 76%, a specificity of 100%, and an accuracy of 84% in the diagnosis of non-palpable testis, whereas MRI had a sensitivity of 86%, a specificity of 79%, and an accuracy of 85%. CONCLUSIONS: There were no statistically significant differences in the accuracy rates of US and MRI for diagnosing non-palpable testis. Laparoscopy or inguinal exploration should be performed even if these graphic examinations demonstrate the absence of a testis, because some patients with a non-palpable testis were found to be false negatives. We recommend US as the first step after clinical examination, and MRI could be performed when the US findings are negative preoperatively for a non-palpable testis.     

衰老大鼠睾丸间质细胞形态学观察

目的通过对老年SD大鼠睾丸间质组织学和Leydig细胞超微结构的观察,探讨老年大鼠性腺功能减退的机制.方法测定3月龄和24月龄SD大鼠血清睾酮水平,并进一步对不同年龄大鼠睾丸间质和Leydig细胞进行光镜和电镜检查.结果老年大鼠血清T浓度显著低于青年大鼠;老年大鼠睾丸色泽灰暗、质地松弛;睾丸间质中成纤维细胞增生明显而Leydig细胞数量减少,单个Leydig细胞变小,并出现退行性改变;hCG刺激8d后,青年和老年大鼠两组睾丸形态学均无明显变化.结论老年大鼠的Leydig细胞出现明显的形态学异常,可能与睾酮合成功能减退有关.     

The effect of experimental cryptorchidism on the phosphorus NMR spectrum of the rat testis

Magnetic resonance (MR) spectroscopy of the cryptorchid rat testis was used to test whether changes in the MR spectra of the rat testis might be a more sensitive indicator of changes in the metabolic status of germ cells in the testis rather than simply the cell types present. Testes of adult Wistar rats before and during 42 days of experimental cryptorchidism were investigated by in-vivo ³¹P MR spectroscopy. Results were compared to MR studies of the synchronized developing testis. The testicular phospho-monoester/ATP (PM/ATP) ratio was dependent only on the cell types present, and showed the same characteristics for each cell type present in the degenerating testis as in the developing testis. The testicular phosphodiester/ATP (PD/ATP) ratio decreased rapidly when the number of round and elongated spermatids was reduced. Similar effects, although less pronounced, were seen in the developing testis. The pH decreased rapidly after cryptorchidism, and was related inversely to the PM/ATP ratio, which was also observed in the developing testis. This study demonstrates that MR spectroscopy monitors the cell types present in the rat testis rather than its metabolic status.     

环状与线状分子结构钆螯合物增强MRI评价前列腺增生的对照研究

目的分析MRI对比剂环状分子结构钆螯合物钆特酸葡胺对前列腺增生的增强效果。方法回顾性分析75例前列腺增生多期动态增强(DEC)和延迟期增强MRI表现,分为观察组[Gatedotera(钆特酸葡胺)组,20例]、对照组1[Magnevist(钆喷酸葡胺)组,15例]、对照组2[Consun(钆喷酸葡胺)组,16例]和对照组3[Omniscan(钆双胺)组,24例]。比较各组间前列腺增生结节基础信号强度、最大信号强度、增强幅度、达峰时间、DEC曲线上升斜率。以闭孔内肌信号强度、图像噪声为参考,比较延迟期增生结节实质强化程度、实质CNR、包膜强化程度、包膜CNR及包膜显示清晰度的差异。结果各组间达峰时间差异有统计学意义(F=3.812,P=0.014),观察组达峰时间明显短于对照组2(P=0.021),对照组2达峰时间明显长于对照组1(P=0.011)及对照组3(P=0.023);包膜强化程度及包膜CNR差异均有统计学意义(P均0.05),观察组包膜强化程度明显高于对照组2(P=0.005)及对照组3(P=0.047),包膜CNR明显高于对照组1(P=0.016)、对照组2(P0.001)及对照组3(P0.001);且各组间MR增强扫描延迟期包膜显示清晰度差异有统计学意义(χ~2=127.86,P0.010)。其余指标各组间总体及两两比较差异均无统计学意义(P均0.05)。结论环状分子结构钆螯合物MRI对比剂增强效果与线状分子结构钆螯合物对比剂相仿,且显示包膜效果更优。     

Case of mesothelioma of the tunica vaginalis testis with characteristic findings on ultrasonography and magnetic resonance imaging.

A case of mesothelioma of the right tunica vaginalis testis in a 32-year-old man is reported. Trans-scrotal ultrasonography revealed hydrocele and multiple nodular masses measuring 1.0-4.5 cm in size attached to the parietal vaginal layer. Magnetic resonance imaging demonstrated more clearly nodular masses with irregular surfaces lined on the hydrocele cavity. Histologic diagnosis of the tumor when orchiectomized was mesothelioma. The patient has been free of disease for approximately 3 years since the treatment.     

The effect of LH and copulation on the number of spermatozoa in the rat testis

In the present work we have re-examined our previous observations concerning the hormonal control of spermiation. We have applied a method which consists in the treatment of testicular homogenates by a detergent and subsequent counting of the resistant sperm heads. The results show that both LH administration and copulation are able to produce a significant diminution of the number of spermatozoa contained in the rat testis.     

MR磁化传递对比成像观察新生儿轻度窒息

目的观察MR磁化传递对比(MTC)成像在轻度窒息新生儿中的应用价值。方法对15例轻度窒息新生儿(Apgar评分10分,病例组)及25名正常新生儿(对照组)采集脑常规T1WI、3D-T1WI和T1WI-MTC,计算脑磁化率(MTR),配准于标准新生儿脑模板后行统计分析。采用3dRegAna对病例组MTR与Apgar评分进行回归分析。结果相比对照组,病例组右颞极、左颞下回、左额上回、右缘上回、右眶额皮质、左额中叶、右额中回及左上额叶MTR显著降低;右梭状回、右顶叶下回、右枕中回、右颞中回、右颞下回、右颞上极、右楔叶、右角回、右舌回及右颞上回MTR显著增加。回归分析显示,病例组左中央后回、右颞下叶(前)、右额中回、右颞上极、左眶额皮质及右颞下叶(后)MTR与Apgar评分呈正相关,右壳核、右眶额皮质、左杏仁核、右颞下回、左舌回、右舌回、左颞中回、左枕中回、延髓及右梭状回呈负相关。组间MTR差异有统计学意义、且病例组MTR与Apgar评分呈正相关脑区为右额中叶、右颞极,呈负相关脑区则为右舌叶及右梭状回。结论 MR MTC成像能检出轻度窒息新生儿缺血缺氧脑区;缺血缺氧主要导致新生儿右侧脑损害。     

全身性非特异性免疫反应对大鼠睾丸几种酶活性的影响

为确定全身性非特异性免疫反应对大鼠睾丸功能的影响而进行此项研究。动物经１０天碳粒注射,睾丸内ＬＤＨ总活性、ＬＤＨｘ活性比,以及琥珀酸脱氢酶、酸性磷酸酶、非特异性酯酶、酸性酯酶等酶的活性,经酶组织化学染色、生物化学检测,以及凝胶电泳分析等显示,它们在活性强度、活性分布以及同工酶谱等方面均发生了明显改变。动物血皮质酮水平明显变化。实验结果提示：一个单纯性的全身性非特异性免疫反应可对睾丸的功能造成明显损     

定量磁化率成像评估脑部钆沉积

钆对比剂(GBCA)是含顺磁性金属钆离子的螯合物,可通过增加T1WI信号强度(SI)而提高病灶与正常组织的对比度,常用于颅脑增强MR检查;而接受(尤其多次接受)GBCA增强检查者可出现脑部钆沉积,常见于大脑苍白球(GP)及齿状核(DN)。定量磁化率成像(QSM)评估钆沉积较T1WI更敏感,且定量优势更显著。本文对QSM检测GBCA脑部沉积研究进展进行综述。     

Effects of amlodipine on ischaemia/reperfusion injury in the rat testis

The aim of this study was to examine the effects of amlodipine (AML) in rat testicular torsion/detorsion damage. In this study, rats were divided into eight groups: (i) sham; (ii) testicular ischaemia, 2 h of ischaemia; (iii) testicular ischaemia/reperfusion (I/R), 2 h of ischaemia followed by 2 h of reperfusion; (iv) ischaemia + AML (5 mg kg^?1) administered 30 min before ischaemia; (v) ischaemia + AML (10 mg kg^?1) administered 30 min before ischaemia; (vi) and (vii) I/R + AML (5 mg kg^?1) and I/R + AML (10 mg kg^?1) administered 1.5 h after the induction of ischaemia, respectively, and at the end of a 2‐h ischaemia period and a 2‐h reperfusion period applied; and (viii) sham + AML (10 mg kg^?1). Significant decreases in levels of superoxide dismutase and glutathione were observed in ischaemia and reperfusion groups when compared with healthy controls. These antioxidant levels increased in AML groups while malondialdehyde levels significantly decreased. While increases in tumour necrosis factor‐alpha and transforming growth factor‐beta levels were found in the torsion and detorsion groups, significant decreases in the levels of these inflammatory cytokines were observed in the treatment groups. These results demonstrate that AML significantly produced protective effects on testis tissue damage that occurs in the torsion/detorsion model via biochemical, histopathological and molecular pathways.     

Apparent diffusion coefficient values of normal testis and variations with age

The usefulness of diffusion-weighted magnetic resonance imaging （DWI） in the evaluation of scrotal pathology has recently been reported. A standard reference of normal testicular apparent diffusion coefficient （ADC） values and their variations with age is necessary when interpreting normal testicular anatomy and pathology. We evaluated 147 normal testes using DWI, including 71 testes from 53 men aged 20-39years （group 1）, 67 testes from 42 men aged 40-69 years （group 2） and nine testes from six men older than 70years （group 3）. DWI was performed along the axial plane, using a single shot, multislice spin-echo planar diffusion pulse sequence and b-values of 0 and 900 s mm-2. The mean and standard deviation of the ADC values of normal testicular parenchyma were calculated for each age group separately. Analysis of variance （ANOVA） followed by post hoc analysis （Dunnett T3） was used for statistical purposes. The ADC values （x 10-3 mm2s-1） of normal testicular tissue were different among age groups （group 1：1.08 ± 0.13; group 2：1.15 ±0.15 and group 3：1.31± 0.22）. ANOVA revealed differences in mean ADC among age groups （F= 11.391, P〈 0.001）. Post hoc analysis showed differences between groups 1 and 2 （P= 0.008） and between groups 1 and 3 （P= 0.043）, but not between groups 2 and 3 （P= 0.197）. Our findings suggest that ADC values of normal testicular tissue increase with advancing age.     

Effects of oral zinc administration on long‐term ipsilateral and contralateral testes damage after experimental testis ischaemia–reperfusion

The purpose of this study was to examine potential long‐term post‐torsion changes that can occur in the histopathology, biochemistry and spermatogenesis of both torsioned and nontorsioned opposite testes. The study also determines the effect of zinc (Zn) administration on the testicular torsion/detorsion (T/D) damage on both testes. Forty‐eight male rats, divided equally into eight groups: (SHAM), (SHAM+,Zn+), (T/D+, Zn? 1 month), (T/D+,Zn? 2 months), (T/D+,Zn? 3 months), (T/D+,Zn+ 1 months), (T/D+,Zn+ 2 months), (T/D+,Zn+ 3 months), have been used. Drug administration was carried out by adding 100 μg (0.016 ml/rat) Zn per rat to drinking water in related groups. Testicular damage decreased superoxide dismutase (SOD) and glutathione (GSH) and increased malondialdehyde (MDA) in the testis tissues of rats, while Zn administration increased SOD and GSH and decreased MDA in the testis tissues in comparison with the SHAM group. The beneficial effect of zinc sulphate was more evident on the nonrotated testis than the rotated testis. In the histopathological study, a significant decrease in torsion and detorsion injuries was observed in the treatment groups compared to the torsion and detorsion groups. We found a protective effect of zinc sulphate on oxidative stress as a result of T/D injuries in rats, especially for the nonrotated testis; results were supported histopathologically.     

纳米级超声造影剂研究进展

超声是疾病诊治最重要的手段之一,造影剂的应用显著增加了超声敏感性。纳米级造影剂不仅能从血管外溢出实现血管周围组织显像,且生物相容性、易修饰性及稳定性均比微米级造影剂更好。以生物标记物修饰纳米级造影剂表面,通过配体与受体的相互反应与目标组织特异性结合,可靶向释放负载药物或基因,促进分子成像水平诊断及治疗肿瘤、炎症等疾病。本文对纳米级超声造影剂研究进展进行综述。     

Interpreting contrast imaging to plan breast surgery

Background

Contrast enhanced mammography (CEM) and magnetic resonance imaging (MRI) are more accurate than conventional imaging (CI) for breast cancer staging. How adding CEM and MRI to CI might change the surgical plan is understudied.

Methods

Surgical plans (breast conserving surgery (BCS), wider BCS, BCS with diagnostic excision (>1BCS), mastectomy) were devised by mock-MDT (radiologist, surgeon and pathology reports) according to disease extent on CI, CI + CEM and CI + MRI. Differences in the mock-MDT's surgical plans following the addition of CEM or MRI were investigated. Using pre-defined criteria, the appropriateness of the modified plans was assessed by comparing estimated disease extent on imaging with final pathology. Surgery performed was recorded from patient records.

Results

Contrast imaging modified mock-MDT plans for 20 of 61(32.8%) breasts. The addition of CEM changed the plan in 16/20 (80%) and MRI in 17/20 breasts (85%). Identical changes were proposed by both CEM and MRI in 13/20 (65%) breasts. The modified surgical plan based on CI + CEM was possibly appropriate for 6/16 (37.5%), and CI + MRI in 9/17, (52.9%) breasts. The surgery performed was concordant with the mock-MDT plan for all 10 patients where the plans could be compared (BCS 1, >1 BCS 2 and mastectomy 7).

Conclusion

Adding CEM or MRI to CI changed mock-MDT plans in up to one third of women, but not all were appropriate. Changing surgical plans following addition of contrast imaging to CI without biopsy confirmation could lead to over or under-treatment.     

Evaluation of gadolinium‐enhanced T1‐weighted magnetic resonance imaging in the preoperative assessment of local staging in rectal cancer

Aim The aim of this study was to determine whether gadolinium‐enhanced T1‐weighted magnetic resonance (MR) sequence is beneficial in the preoperative assessment of tumour and nodal staging in patients with primary rectal cancer. Method Eighty‐eight patients with primary rectal cancer underwent preoperative MR imaging, followed by surgical resection. Two radiologists independently reviewed (i) T2‐weighted MR images (T2WI); (ii) gadolinium‐enhanced T1‐weighted MR images (T1 + Gd); (iii) MR combined with T2WI and T1 + Gd for the prediction of tumour and nodal stage compared with histopathologic findings as the end point. Differences in the diagnostic performance of T2WI only, T1 + Gd image only and combined T2WI and T1 + Gd MR images were analyzed by comparing areas under receiver operating characteristic curves (Az) for each reader. Interobserver agreement was also calculated. Results There was no significant difference in the Az values of T2WI only, T1 + Gd image only and combined T2WI and T1 + Gd images for the prediction of tumour staging (Az of T2WI, T1 + Gd and combined MR images for reader 1, 0.80, 0.76 and 0.85; reader 2, 0.83, 0.82 and 0.87) and nodal staging (Az for reader 1, 0.73, 0.73 and 0.81; reader 2, 0.79, 0.80 and 0.83). Interobserver agreement for the prediction of tumour staging was moderate to substantial, while only fair agreement was noted for the prediction of nodal staging. Conclusion Gadolinium‐enhanced T1‐weighted MRI did not increase the diagnostic yield for tumour and nodal staging, and may be omitted in the MR protocol for preoperative assessment of primary rectal cancer.