Visualisation of non-invasive coronary bypass imaging: 4-row vs. 16-row multidetector computed tomography

The purpose of this study was to investigate the image quality of coronary artery bypass graft visualization in 4- and 16-row multidetector CT using multiple imaging reformations. Material and Methods: One hundred sixteen patients underwent CT examination of the heart after receiving CABG. Group A (n=58) received 4-row MDCT; group B (n=58) received 16-row MDCT. Various bypass types such as LITA to LAD and venous grafts to the RCA and RCX were included in the study. A five-point Likert scale was used to grade image quality. Each bypass was reviewed under different imaging reformations: thin slap maximum intensity projection (MIP thin), multiplanar reformation (MPR) and volume rendering technique (VRT). Special attention was paid to the delineation of the distal anastomosis. Interobserver correlation was determined. Results: From 289 bypass grafts examined, 279 (96.54%) were classified as patent and 10 (3.46%) as not patent. Except for the distal anastomosis, 16-row MDCT showed significantly better results for all segments of bypasses. Comparison of reformations within group A and B showed that MIP thin (P<0.05) and VRT (P<0.05) displayed better visualization as compared to MPR. Conclusion: Significantly better imaging of all bypass types is possible using 16-row MDCT as compared to 4-row MDCT. Assessment of the distal anastomosis yields no difference between 4- and 16-row technology.This revised version was published online in October 2004 with a correction to the article title.     

Vitamin D Status in the North African Population: a Review

Even though the North African countries are located in one of the sunniest place in the world, several North African studies from there proved a high prevalence of hypovitaminosis D in men and women. The objectives of the present review are to summarize the existing literature on vitamin D status and to list the main predictors of hypovitaminosis D in North African population. We searched Medline/PubMed, Cochrane, CINAHL, Embase, Scopus, and Springerlink for the published data on vitamin D in North African countries. The identified articles had to meet all the following criteria: human clinical outcomes rather than animal experiments, a cross-sectional or longitudinal study and quantitative information on vitamin D status in North Africa must be included. Several studies proved a high prevalence of hypovitaminosis D in North African men and women. Also, these studies reported that determinants of vitamin D status were the culture of avoiding the sun, the wearing of the veil for women, the pigmented skin, the lack of vitamin D supplementation in the aliments, the breastfeeding for 2 years. This review on vitamin D status in North Africa indicates a high prevalence of vitamin D insufficiency in men and women (among all age groups).     

激光介入治疗大鼠不同大小肝转移癌的实验研究

[目的]比较在大鼠肝转移癌模型进行激光治疗不同大小肝肿瘤的疗效.[方法]在20只雄性WAG大鼠肝包膜下种植CC531结直肠癌肝转移癌细胞混悬液(d 0,1×106/0.1 m1),种植术后13 d时进行磁共振检查(MRI),测量肿瘤体积V1.将动物按照肿瘤体积V1大小分为A组(较小肿瘤:0.05～0.06 cm3)和B组(较大肿瘤:0.10～0.12cm3),d 14时,采取中腹切开术,将激光头插入肿瘤病灶中央并进行激光治疗(Nd:YAG激光,1064 nm,2W,5min),d 28时再次进行磁共振检查以确定肿瘤体积V2变化,比较肝肿瘤体积生长率V2/V1.[结果]在A组,肿瘤术前和术后平均体积分别为(0.05±0.003)cm3和(0.23±0.016)cm3;在B组,肿瘤术前和术后平均体积分别为(0.11±0.006)cm3和(0.68±0.037)cm3.A组和B组肝肿瘤体积生长率V2/V1分别为4.31±0.19和6.11±0.14,和B组相比,A组的肿瘤生长明显较慢(t-test,P<0.01).[结论]激光治疗不同大小的肝转移癌之后,较大肝癌的生长速度比较小者更快.     

Navigation-based needle puncture of a cadaver using a hybrid tracking navigational system

PURPOSE: The purpose of this study was to determine the puncture accuracy of a navigational system, Medarpa, in a soft tissue environment using augmented overlay imaging. MATERIALS AND METHODS: Medarpa is an optical electromagnetic tracking system, which allows tracking of instruments, the radiologist's head position, and the transparent display. The display superimposes a computed tomography scan of a cadaver chest on a human cadaver in real time. In group A, needle puncture was performed using the Medarpa system. Three targets located inside the cadaver chest were selected. In group B, the same targets were used to perform standard computed tomography-guided puncture using a single-slice technique. A total of 42 punctures were performed in each group. Postpuncture computed tomography scans were made to verify needle tip positions. RESULTS: Mean deviation from targets was 8.42 mm +/- 1.78 mm for group A and 8.90 mm +/- 1.71 mm for group B. No significant difference was found between group A and B in any target (P > 0.05). No significant difference was found between the targets of the same group (P > 0.05). Procedural time for 42 punctures was 160 minutes in group A versus 289 minutes in group B (P < 0.05). CONCLUSION: Needle puncture in a soft tissue environment using the navigational system Medarpa can be reliably performed and matches the accuracy achieved by a computed tomography-guided puncture technique.     

Tierexperimentelle Untersuchungen zur Effektivitat der transarteriellen Chemoembolisation （TACE） unter Einsatz von Bletilla striata

Zusammenfassung Evaluierung der Effektivit?t von Bletilla striata bei transerteriellen Chemoembolisation (TACE) im Kleintiermodell. Nach subkapsul?rer Implantation (Tag 0) eines soliden Morris Hepatoms (2 mm³) bei ACI-Ratten (n=30) wurden am 13. Tag die Tumorvolumina (V1) magnettomographisch bestimmt. Im Anschlu erfolgten nach Laparatomie die retrograde Katheterisierung der Arteria gastroduodenalis und die Anwendung folgender Therapieprotokolle: (A) TACE (0.1 mg Mitomycin C+0,1 mL Lipiodol)+Bletilla striata (1,0 mg) (n=10); (B) TACE (Bletilla striata (1,0 mg)+Ligatur (n=10); (C) TACE allein (Kontrollgruppe,n=10). Zur Effektivit?tsbeurteilung der unterschiedlichen Therapieprotokolle erfolgte am 28. Tag eine erneute magnettomographische Bestimmung der Tumorvolumina (V2). Das durschschnittliche Tumorvolumen der Gruppen A, B und C vor und nach interventioneller Therapie betrug 0,0355 cm³ und 0, 2248 cm³, 0,0374 cm³ und 0,0573 cm³ sowie 0,0380 cm³ und 0,3674 cm³. Das errechnete durchschnittliche Verh?ltnis (V2/V1) betrug 6,28, 1,53 sowie 9,14. Im Vergleich zur Kontrollgruppe C konnte somit für Therapiegruppe B eine signifikant (P<0,01) geringere Tumorvolumenzunahme im Beobachtungszeitraum ermittelt werden, w?hrend zwischen Gruppe A und Gruppe C keine statistisch signifikanten (P>0,05) Unterschiede im Tumorwachstum festgestellt werden konnten. Das Wachstum der induzierten Lebertumoren konnte unter Behandlung mittels TACE+Bletilla striata +Ligatur im Tiermodell statistisch signifikant im Vergleich zur Kontrollgruppe gehemmt werden.

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QIAN Jun, male, born in 1967, M. D., Associated Professor     

A multiplex polymerase chain reaction method for rapid pneumococcal serotype determination in childhood empyema

Nonvaccine serotypes are increasingly responsible for pneumococcal empyema. We developed a one-step polymerase chain reaction for identifying all serotypes covered by the 13-valent conjugate vaccine. Over 1 year, we identified serotypes 19A (n = 6), 1 (n = 2), 3 (n = 1) and 7F/A (n = 2), both in culture-positive and culture-negative pleural fluid from 11 children with empyema.     

Variables affecting the risk of pneumothorax and intrapulmonal hemorrhage in CT-guided transthoracic biopsy

The influence of various variables on the rate of pneumothorax and intrapulmonal hemorrhage associated with computed tomography (CT)-guided transthoracic needle biopsy of the lung were evaluated retrospectively. One hundred and thirty-three patients underwent CT guided biopsy of a pulmonary lesion. Two patients were biopsied twice. Variables analyzed were lesion size, lesion location, number of pleural needle passes, lesion margin, length of intrapulmonal biopsy path and puncture time. Eighteen-gauge (18G) cutting needles (Trucut, Somatex, Teltow, Germany) were used for biopsy. Pneumothorax occurred in 23 of 135 biopsies (17%). Chest tube placement was required in three out of 23 cases of pneumothorax (2% of all biopsies). Pneumothorax rate was significantly higher when the lesions were located in the lung parenchyma compared with locations at the pleura or chest wall (P < 0.05), but all pneumothorax cases which required chest tube treatment occurred in lesions located less than 2 cm from the pleura. Longer puncture time led to an increase in pneumothorax rate (P < 0.05). Thirty-seven (27%) out of 135 biopsies showed perifocal hemorrhage. Intrapulmonal biopsy paths longer than 4 cm showed significantly higher numbers of perifocal hemorrhage and pneumothorax (P < 0.05). Significantly more hemorrhage occurred when the pleura was penetrated twice during the puncture (P < 0.05). Lesion size <4 cm is strongly correlated with higher occurrence of perifocal hemorrhage (P < 0.05). Lesion margination showed no significant effect on complication rate. CT-guided biopsy of smaller lesions correlates with a higher bleeding rate. Puncture time should be minimized to reduce pneumothorax rate. Passing the pleura twice significantly increases the risk of hemorrhage. Intrapulmonal biopsy paths longer than 4 cm showed significantly higher numbers of perifocal hemorrhage as well as pneumothorax.     

Accuracy of biopsy needle navigation using the Medarpa system—computed tomography reality superimposed on the site of intervention

The aim of this work was to determine the accuracy of a new navigational system, Medarpa, with a transparent display superimposing computed tomography (CT) reality on the site of intervention. Medarpa uses an optical and an electromagnetic tracking system which allows tracking of instruments, the radiologist and the transparent display. The display superimposes a CT view of a phantom chest on a phantom chest model, in real time. In group A, needle positioning was performed using the Medarpa system. Three targets (diameter 1.5 mm) located inside the phantom were punctured. In group B, the same targets were used to perform standard CT-guided puncturing using the single-slice technique. The same needles were used in both groups (15 G, 15 cm). A total of 42 punctures were performed in each group. Post puncture, CT scans were made to verify needle tip positions. The mean deviation from the needle tip to the targets was 6.65±1.61 mm for group A (range 3.54–9.51 mm) and 7.05±1.33 mm for group B (range 4.10–9.45 mm). No significant difference was found between group A and group B for any target (p>0.05). No significant difference was found between the targets of the same group (p>0.05). The accuracy in needle puncturing using the augmented reality system, Medarpa, matches the accuracy achieved by CT-guided puncturing technique.