Thrombus localization by using streptokinase containing vesicular systems

Our research focused on the preparation of vesicular drug delivery systems, such as liposomes, noisomes, and sphingosomes, for achieving slow release of entrapped proteins in the circulation to increase half-life, to mask immunogenic properties, and to protect against loss of enzymatic activity. We prepared, characterized, and monitored the biodistribution of three types of vesicular systems (liposomes, niosomes, and sphingosomes) containing streptokinase. For biodistribution stuides, radiolabelled streptokinase dispersions were injected into the ear vein of female rabbits in the weight of 2.5-3 kg weight. Following the application, rabbits were sacrificed, then organs of these animals were removed and radioactivity of organs was measured by well-type gamma counter. The comparison of the biodistribution results of the free streptokinase with the streptokinase vesicles showed that incorporation of the enzyme into the vesicles changed the biodistribution of the drug and by the entrapment of the streptokinase in the vesicles, thrombus uptake and imaging quality were improved.     

In vivo photoacoustic imaging of blood vessels with a pulsed laser diode

Photoacoustic imaging is a hybrid imaging modality that is based on the detection of acoustic waves generated by absorption of pulsed light by tissue chromophores such as hemoglobin in blood. For this technique, usually large and costly Q-switched Nd:YAG lasers are used. These lasers provide a pulse energy of at least several milliJoules. In search of alternative light sources, we investigated the use of a small and compact pulsed laser diode to image blood vessels. We proved that a pulsed laser diode can be applied for imaging blood vessels in vivo.     

A review of 3 current radiosurgery systems

BACKGROUND: Stereotactic radiosurgery and fractionated stereotactic radiotherapy have become widespread techniques applied to the treatment of a variety of intracranial lesions. Rapid evolution of new technologies has now enabled clinicians to treat tumors outside the cranium and down the spinal axis. This review compares 3 commercially available systems in widespread use throughout the world. METHODS: Literature review and interviews with practitioners in the United States were performed to establish data for a comparative analysis of the Gamma Knife (Elekta, Sweden), Novalis (BrainLabs, Germany), and CyberKnife systems (Accuray, Sunnyvale, CA). Cost analyses were deliberately excluded because of the need for detailed cost-benefit analysis beyond the scope of the review. RESULTS: An unbiased comparative analysis was not possible because of the lack of objective data from a standard metric for these systems. Despite this shortcoming, disparate features of each system were compared and contrasted. CONCLUSION: A careful assessment of each system, including its operational features, capabilities, and yearly capacity must be weighed against the composition of the radiosurgery team, the case mix of the practice, and the objectives of the clinical unit to yield the best fit.     

Technetium-99m sestamibi kinetics in reperfused canine myocardium

The purpose of the current study was to clarify the myocardial kinetics of technetium-99m sestamibi when the latter is administered during reperfusion. Sestamibi has in the past been given to patients following thrombolytic therapy to document reperfusion and assess salvage. However, the factors which affect sestamibi kinetics during reperfusion are not clearly defined. In this study the left circumflex coronary artery was occluded for 2 h in six dogs (group 1) and for 3 h in six dogs (group 2), followed by reperfusion. Five additional dogs were not reperfused (group 3). Sestamibi was administered during reperfusion in groups 1 and 2, and during ongoing occlusion in group 3. Regional myocardial sestamibi activity was monitored for 3 h using miniature implanted radiation detectors and gamma camera imaging. Group 1 dogs had no infarcts, group 2 had moderate infarcts (mean: 13.9%), and group 3 had large infarcts (mean: 25.2%). Three-hour fractional myocardial clearances were significantly greater for reperfused infarcted (group 2) (0.23±0.02 SEM) and for nonreperfused infarcted myocardium (group 3) (0.24±0.02) compared to control (0.10±0.01) and reperfused non-infarcted myocardium (group 1) (0.07±0.02;P<0.01). Quantitative image analysis demonstrated a significant reduction in the left circumflex/left anterior descending count ratios from initial to final scans for group 2 (0.74±0.03 to 0.65±0.03,P<0.05), and a trend towards a reduction in the count ratios from initial to final scans for group 3 (0.38±0.04 to 0.30 ±0.04;P = 0.06). Thus, probe-derived myocardial sestamibi kinetics following reperfusion do differentiate non-infarcted from infarcted myocardium. Although the detection of accelerated clearance can be demonstrated by quantitative analysis of gamma camera images in dogs, this may be technically difficult in clinical situations.     

MRI findings in cerebral fat embolism

The purpose of this retrospective study was to demonstrate the MRI features of cerebral manifestations in patients with fat embolism syndromes in comparison with cerebral CT (CCT). Magnetic resonance imaging was performed according to standard protocols revealing multiple small non-confluent hyperintense intracerebral lesions larger than 2 mm on proton-density and T2-weighted images to various extents in three of four patients with clinically suspected cerebral fat embolism. Cerebral CT was negative in all patients. Our findings confirm that MRI can detect cerebral fat embolism with a higher sensitivity than CCT. Thus, MRI should be the first choice for imaging of cerebral fat embolism. Received 28 November 1997; Revision received 9 March 1998; Accepted 30 March 1998     

不同影像方法对射频消融治疗肝癌疗效的评价

目的通过对射频消融治疗肝癌前后的B超、CT和MRI的比较,探讨不同影像方法对射频消融治疗肝癌疗效评价的意义。方法对100例肝癌患者进行了B超引导下经皮射频消融（PRFA）治疗。患者治疗前行B超、MRI或CT检查;治疗后1个月复查MRI或CT,每个月进行肿瘤标记物和B超检查。结果100例中,PRFA治疗前34例行CT检查;治疗后14例行CT复查,其中5例肿瘤区域呈现较原肿瘤更低的密度,动态增强无强化,9例肿瘤部分区域有强化。66例患者PRFA治疗前行MRI检查,T1加权像为低信号,T2加权像为相对高信号,动态增强扫描后动脉期强化,门脉期强化减弱。治疗后,全组有86例患者复查MRI,44例肿瘤T1加权像为等或高信号,T2,肌权像为等或低信号,动态增强无异常强化;42例肿瘤T1加权像呈不均匀等低混杂信号,T2,加权像部分呈相对高信号,动态增强有强化。结论增强CT扫描可以显示出残存肿瘤;MRI的T1、T2加权像及Gd-DPTA动态增强的信号变化,能够更好地反映肿瘤的坏死或残存状况,血清肿瘤标记物阳性者术后转阴并MRI（或CT）显示肿瘤呈完全凝固性坏死,可作为PRFA治疗肝癌的临床治愈标准。     

肝动脉化疗栓塞术后胆管损伤的影像学研究

目的观察经导管肝动脉化疗栓塞术（TACE）治疗肝脏恶性肿瘤后继发胆管损伤的影像学表现。方法1240例患者行TACE2680次,18例于TACE术后3周～3个月出现胆管损伤。18例TACE前后均行CT和超声波检查,14例行MRI,15例行血管造影。对18例不同类型的肝脏恶性肿瘤TACE术后胆管损伤的发生率、影像学表现及导致胆管损伤的高危因素进行回顾性分析。结果肝转移性肿瘤TACE术后胆管损伤的发生率为8．8％（13／148）,肝细胞性肝癌（HCC）胆管损伤的发生率为0．5％（5／1092）。影像学表现为局灶性胆管扩张4例,多灶性肝段-亚段胆管扩张8例,巨大囊性病灶或胆汁瘤6例。胆管损伤区肝叶-段呈进行性萎缩6例。分析结果显示,TACE术后胆管损伤多发生于无肝硬变者的肝转移瘤患者（P〈0．01）;同时,使用铂类制剂与碘油乳化行TACE以及肿瘤为少血供型（P均〈0．01）,也是高危因素。结论TACE后可出现局灶性、多灶性胆管扩张和胆汁瘤等胆管损伤表现;无肝硬变者是TACE后造成胆管损伤的主要危险因素。     

Low birth weight and psychiatric morbidity; stability and change between adolescence and young adulthood

Background

Being born with low birth weight is a risk factor for psychiatric morbidity.Few longitudinal studies have included diagnostic assessment and followed subjects into adulthood.

Aim

To assess stability and change in psychiatric morbidity between adolescence and young adulthood in low birth weight subjects, and explore whether screening in adolescence can predict subsequent psychopathology in these groups.

Study design

Prospective geographically based follow-up study of two low birth weight groups and a control group born between 1986 and 1988, assessed at 14 (T1) and 20 (T2) years of age.

Subjects

Thirty eight subjects born preterm with very low birth weight (VLBW: ≤ 1500 g), 43 born at term but small for gestational age (SGA: < 10th percentile) and 64 controls with normal birth weight participated.

Outcome measures

Mental health was assessed using diagnostic psychiatric interview at both study points supplemented with the Achenbach System of Empirically Based Assessment and Children's Global Assessment Scale at T1.

Results

There was a trend towards increasing morbidity from T1 among VLBW (p = 0.086) and a significant increase among SGA (p = 0.003) participants. Supplementary assessment at T1 discriminated satisfactory between persons with and without psychiatric disorders at T2 (area under ROC curve: 0.66 to 0.89), but was most effective in the VLBW group.

Conclusion

High psychiatric morbidity continued into young adulthood in the VLBW group and increased significantly in the SGA group. Screening in adolescence can be used to detect individuals at risk especially among those born at very low birth weight.     

Is a routine voiding cystourethrogram necessary in children after the first febrile urinary tract infection?

Aim: The aim of this study was to estimate the value of identifying vesicoureteral reflux (VUR) on a voiding cystourethrogram (VCUG) and the benefit of VUR management according to imaging strategies at the first febrile urinary tract infection (UTI). Methods: Children aged 1–144 months (n = 618) with the first febrile UTI admitted at our hospital from 2000 to 2009 were enrolled. In all patients, renal sonogram (US), ^99mTc‐dimercaptosuccinic acid (DMSA) renal scanning and VCUG were performed. Retrospective analyses per patient and per renal unit were performed. Results: Abnormal US or DMSA scans had a sensitivity of 100% and a negative predictive value (NPV) of 100% to detect high‐grade reflux. In hydronephrotic kidneys, DMSA scanning had a sensitivity of 88.2% and a NPV of 97.1% to detect high‐grade reflux. Conclusion: Routine VCUG is not required after the first febrile UTI in patients with normal US or normal DMSA scan. Even if the US reveals hydronephrosis, routine VCUG is not necessary if the DMSA findings are normal. It is recommended that children who did not receive both a DMSA scan and VCUG after the first febrile UTI should be followed up over the long term.     

Brain ultrasound findings in neonates treated with intrauterine transfusion for fetal anaemia

Background

The main causes of severe fetal anaemia are red-cell allo-immunization, parvo B19 virus infection and feto-maternal haemorrhage. Treatment consists of intrauterine transfusion (IUT). Neuro-imaging studies in surviving neonates treated with IUT are scarce.

Aims

To assess if neonates treated with IUT for fetal anaemia are at risk for cerebral injury, report the incidence and severity of brain ultrasound (US) abnormalities and explore the relation between brain US findings and perinatal parameters and neurological outcome.

Patients and methods

Brain US scans of neonates born alive between 2001 and 2008 with at least one IUT were retrospectively reviewed and classified as normal, mildly or moderately/severely abnormal. Incidences of abnormalities were calculated for full-term and preterm neonates. Presence and severity of abnormalities were related to clinical and IUT related parameters and to neurological outcome around 2 years of age (adverse: moderate or severe disability; favourable: normal or mild disability).

Results

A total of 127 neonates (82 born preterm) were included. Median number of IUTs was 3 (range 1–6) and of brain US 2 (1–6). Median gestational age and weight at birth were 36.6 (26.0–41.1) weeks and 2870 (1040–3950) g. In 72/127 (57%) neonates ≥ 1 abnormality was seen on brain US, classified as moderate/severe in 30/127 (24%). Neurological outcome was adverse in 5 infants. Presence of brain US abnormalities was not significantly related to any of the perinatal parameters or to neurological outcome.

Conclusions

Neonates undergoing IUT for fetal anaemia are at high risk of brain injury.