Unsuspected swallowing of a partial denture

We report a case of a swallowed partial denture in a 51-year-old man who presented with progressive dysphagia, odynophagia, and fevers. Imaging studies were initially interpreted as supraglottitis with laryngeal inflammation, which was confirmed by direct visualization with flexible endoscopy. Despite appropriate therapy, the patient's symptoms persisted and rigid laryngoscopy was performed, which revealed a partial denture in the hypopharynx and upper esophagus. The subtle imaging appearance of a swallowed denture is discussed.     

前牙重度磨耗伴游离端牙列缺损固定-活动联合修复的临床应用

目的评价采用固定-活动联合修复前牙重度磨耗伴游离端牙列缺损重建咬合关系的临床效果。方法对28例前牙重度磨耗伴游离端牙列缺损的患者,前牙进行完善根管治疗,后牙先以活动可摘局部义齿重建后牙咬合关系和牙合间距离,经过不断调整、观察2～3个月后,采用前牙桩核烤瓷连冠修复,后牙根据最后确定的垂直高度采用附着体义齿修复。结果 28例前牙重度磨耗伴游离端牙列缺损经过咬合重建序列治疗,采用固定-活动联合修复后,患者面下1/3高度均得到恢复,面部丰满美观,关节无疼痛和弹响,前牙烤瓷冠牢固、美观,游离端附着体义齿固位良好,咀嚼效能高,无卡环,义齿美观舒适,恢复了垂直距离,确定了咬合关系。结论固定-活动联合修复是治疗前牙重度磨耗伴游离牙列缺损患者的一种有效可行的修复方法。     

单个后牙缺失伴远端基牙倾斜的树脂黏结固定桥修复研究

目的 观察树脂黏结固定桥(RBFPD)修复下颌单个后牙缺失合并桥基牙倾斜患者的临床效果,并总结其适应证和设计特点.方法 选择2002-2003年在解放军总医院口腔科就诊的典型下颌单个后牙缺失、远端基牙近中倾斜的患者18例,所有患者基牙倾斜度不超过50°,基牙无明显松动,牙周无异常.根据基牙倾斜和模型观测结果,设计(牙合)支托和固位体的位置和形态,义齿选择普通钛合金烤瓷或钻铬合金烤瓷修复,并在修复体完成后进行5年随访.随访时进行临床检查、X线片检查并询问患者主观感受.结果 远端倾斜基牙平均倾斜33°.随访5年后,2例修复病例修复体脱落,其余义齿功能良好,牙周无明显炎症.基牙以及桥体下方牙龈无明显红肿,X线片示基牙牙周间隙无异常,患者对于修复体的外观及使用情况满意.5年期间修复体的成功率为88.9%.结论 对于伴有基牙倾斜的单个后牙缺失,采用树脂黏结固定桥进行修复的效果可靠,并具有磨牙少、基牙无需进行根管治疗等优点.     

Feasibility of a fixed scan delay technique using a previous bolus tracking technique data for dynamic hepatic CT

Objective

To compare the quality of contrast enhancement and hepatic CT images acquired using bolus tracking technique at two different time points and those acquired with fixed scan delay technique using a previous bolus tracking data.

Materials and methods

Fifty patients who underwent 3 different hepatic CT exams (25-s fixed injection of 600 mg iodine (I)/kg or 100 mL of 370 mg I/mL nonionic contrast medium) were enrolled. The first and second exams were performed with a bolus tracking technique. The third exam was performed with a fixed scan delay technique using the first exam data. Differences in attenuation values in the abdominal organs were examined and evaluated visually on hepatic arterial phase images.

Results

There was no significant difference in the mean 50-HU threshold times between the first and second bolus tracking exams with intra-patient differences between them (1.3 ± 0.9 s). No significant intra-patient differences were noted in organ attenuation and visual evaluation on hepatic arterial phase images between the 3 exams.

Conclusion

The fixed scan delay technique using a previous bolus tracking data is feasible for hepatic CT exams to follow up hepatocellular carcinoma.     

用铸造支架式设计制作局部义齿修复治疗老年牙缺损

目的 总结针对老年复杂牙列缺损,采用铸造支架可摘局部义齿的设计制作经验和体会,为临床局部义齿的修复治疗作借鉴.方法 对1998年以来门诊病案中老年复杂牙列缺损542例的义齿修复治疗病例,按照缺牙类型、部位施行铸造支架式设计进行分析总结.结果 542例的义齿修复治疗病例,按照缺牙类型、部位,采用铸造义齿支架个别设计修复义齿,分别设计了后牙低间隙缺牙铸造金属围墙强化义齿,牙齿重度磨耗设计金属(牙合)垫、金属塑料混合垫义齿,牙周病伴随缺牙设计铸造牙列式夹板义齿,食物嵌塞设计防嵌器.其中36例进行两年随访,31例义齿使用正常,4例卡环折断,经重新设计修复体铸造支架获得满意效果,患者戴用义齿情况良好,能很快适应,复诊率低,义齿的强度也有不同程度的提高.采用义齿个别设计铸造支架式可摘局部义齿修复各类缺牙,可较好地解决牙列重度磨耗、食物嵌塞、牙周疾患等问题.结论 针对老年牙列缺损伴有垂直距离过低、重度磨耗、食物嵌塞以及牙周病患者,采用铸造围墙式义齿、(牙合)垫式义齿、防嵌器和铸造牙列式夹板义齿可以取得良好的临床效果.     

临时性血管分流术在肢体主要血管损伤中的应用及疗效

目的探讨临时性血管分流术在肢体主要血管损伤中的应用及疗效。方法23例肢体主要血管损伤,其中肢体完全缺血15例。2例在6小时内、14例在6～8小时、7例在8～12小时时限内先后2次进行各约10分钟的临时性血管分流术。结果损伤血管良好修复,通畅率100%。所有肢体成活,无感染、肾衰并发症。小腿胫前肌大部分坏死1例,经扩创人工皮覆盖,换药1个月治愈。随访10～15个月,平均12个月,血管损伤的疗效评定标准:优10例,良10例,可3例,优良率87%。结论临时性血管分流术能最早提供缺血肢体有效血循环,是肢体主要血管损伤早期保肢治疗的一种良好方法,且操作简单,疗效可靠。     

"Black bone" MRI: a partial flip angle technique for radiation reduction in craniofacial imaging

The potential harmful effects of ionising radiation continue to be highlighted. Radiation reduction techniques have largely consisted of low-dose techniques rather than a shift to non-ionising methods of imaging. CT scanning is frequently employed for imaging the craniofacial skeleton despite being one of the key anatomical regions for radiation protection in view of the radiosensitive lens and thyroid gland. We describe a low flip angle gradient echo MRI sequence which provides high image contrast between bone and other tissues but reduces the contrast between individual soft tissues. This permits the "black bone" to be easily distinguished from the uniformity of the soft tissues. While maintaining a repetition time of 8.6 ms and an echo time of 4.2 ms, the flip angle which provided optimised suppression of both fat and water was identified to be 5°. The biometric accuracy of this sequence was confirmed using a phantom to obtain direct anatomical measurements and comparable CT scanning. The average discrepancy between black bone MRI measurements and direct anatomical measurements was 0.32 mm. Black bone MRI therefore has the potential to reduce radiation exposure by replacing CT scanning when imaging the facial skeleton, with particular scope for imaging benign conditions in the young.     

隐形义齿材料结合铸造部件在可摘局部义齿再修复中的应用

目的探讨隐形义齿材料结合铸造部件在可摘局部义齿再修复中的临床应用效果。方法对已做可摘局部义齿修复、但对义齿的前部金属卡环易显露影响美观而要求重做的患者,采用隐形义齿材料结合铸造部件进行再修复,再修复患者21例,共制作修复体27件,进行6～24个月的随访观察,评价临床应用效果。结果 25件义齿取得满意疗效,成功率为92.6%。2件义齿修复失败,其中1件基托折断,1件人工牙脱落。结论对美观要求高的患者应用隐形义齿材料结合铸造部件进行再修复是一种可行的修复方法。     

A comparison of fixed and variable kVp technique protocols for film-screen mammography

Mammographic image quality, contrast and dose for a variable tube potential (kVp) technique protocol for film-screen mammography have been investigated. In this protocol, the tube potential is increased for larger breast thicknesses. Comparisons were made with fixed kVp protocols, in which the tube potential is kept constant and the breast thickness compensated for by prolonging the exposure ("fixed kVp" protocol). All measurements were performed on a mammography unit with a molybdenum target and filter. Image quality was quantified by image contrast, image detail detection and the minimum detectable dimension of low contrast objects. It was demonstrated that for a compressed breast thickness of less than about 40 mm, varying the tube potential had a negligible effect upon dose but a significant effect upon image quality. For a compressed breast thickness greater than about 60 mm, the effect of the tube potential upon image quality was much reduced; however, the effect upon dose was significantly greater. The variable kVp protocol takes advantage of this feature to yield a significantly lower dose for thicker breasts with a small reduction in image quality, often only within experimental uncertainty. For an exposure under automatic exposure control, increasing the tube potential from 26 kVp to 30 kVp for a breast of a reference tissue composition (50% adipose and 50% glandular) with a compressed thickness of 60 mm reduced the mean glandular dose from 6 mGy to 3.9 mGy (-35%), but increased the minimum detectable dimension of a low contrast mass from 0.8 (+/- 0.1) mm to 1.1 (+/- 0.1) mm. Adopting a variable kVp protocol led to a median patient mean glandular dose per film of 2.7 mGy, nearly independent of compressed breast thickness. In our survey, the mean age of women presenting for mammography is younger and the mean compressed breast thickness is less than reported from screening centres. This suggests that there will be a higher proportion of denser, glandular tissue in the breasts incorporated within this survey than for surveys from screening centres. The clinical use of the variable kVp protocol allows the extraction from patient data of separate changes in breast composition which are due to patient age and breast thickness. It is concluded that the reference breast tissue composition is not an accurate representation of the women presenting at this centre.     

Teleradiology Uppsala-Sydney for nighttime emergencies: preliminary experience

BACKGROUND: The development of digital imaging systems for radiology in combination with the possibility to transfer large quantities of data over the Internet has increased the interest in teleradiology. Transferring nighttime examinations to an evaluation center in a daytime zone may provide improved patient security, better working hours for radiologists, and reduced costs for emergency radiological services. PURPOSE: To evaluate the time required for transferring radiological information from Uppsala (Sweden) to Sydney (Australia). MATERIAL AND METHODS: A radiologist in Sydney reported on radiological examinations performed in Uppsala. The time required for downloading 75 examinations and returning 24 reports was registered. RESULTS: Downloading was completed in <60 min for all conventional radiological examinations, but only 44% of computed tomography (CT) examinations with >65 images. Reports were completed in <10 min. Turnaround time was directly related to the time required for downloading the images. The Sydney report was available in Uppsala within 30 min of the in-house report in 79% of examinations. CONCLUSION: The main challenge for emergency teleradiology is the time required for downloading large volumes of data over the Internet.     

Interventional radiology in renal emergencies: a pictorial essay

Emergency Radiology - Renal emergencies necessitate prompt diagnosis and management to stop active bleeding and retain kidney function. Causes of renal emergencies can be classified into traumatic,...     

Imaging of acute gastric emergencies: a case-based review

The stomach is one of the most frequently imaged organs in the body with dedicated and incidental inclusion in chest imaging modalities. Gastric emergencies often present clinically with non-specific abdominal, nausea, and vomiting. As such, imaging plays a critical role in early identification and treatment of a myriad of gastric emergencies. The goal of this paper is to showcase gastric emergencies as they appear on multimodality imaging.     

Cone beam computed tomography for dental and maxillofacial imaging: technique improvement and low-dose protocols

Objective

The aim of this study was to evaluate images quality and radiation doses of Cone Beam Computed Tomography (CBCT) for dental and maxillofacial imaging testing five different acquisition protocols.

Methods

Dose measurements of different acquisition protocols were calculated for Pax Zenith three-dimensional (3D) Cone Beam (Vatech, Korea) and for conventional orthopantomography (OPT) and cephalometric skull imaging Ortophos (Sirona Dental Systems, Bernsheim, Germany). The absorbed organ doses were measured using an anthropomorphic phantom loaded with thermoluminescent dosimeters at 58 sites related to sensitive organs. Five different CBCT protocols were evaluated for image quality and radiation doses. They differed in FOV, image resolution, kVp, mA, acquisition time in seconds and radiation dose. Measurements were then carried out with the orthopantomograph. Equivalent and effective doses were calculated.

Results

The reference protocol with large FOV, high resolution quality images, 95 kVp, 5 mA and acquisition time of 24 s resulted in a DAP value of 1556 mGy cm² instead the protocol with reduced kVp from 95 to 80 kVp translated into a value of DAP inferior to 35% (from 1556 to 1013 mGy cm²). Going from a high resolution to a normal resolution, there was a reduction of the acquisition time to 15 s which allowed further dose reduction of approximately 40% (628 mGy cm²); this protocol resulted in a value of effective dose of 35 microSievert (μSv). Moreover, the effect of changing FOV has been evaluated, considering two scans with a reduced FOV (160 × 140  and 120 × 90 mm, respectively).

Conclusions

CBCT low-dose protocol with large FOV, normal resolution quality images, 80 kVp, 5 mA and acquisition time of 15 s resulted in a value of effective dose of 35 microSievert (μSv). This protocol allows the study of maxillofacial region with high quality of images and a very low radiation dose and, therefore, could be proposed in selected case where a complete assessment of dental and maxillofacial region is useful for treatment planning.

     

An innovative method for neuraxis radiotherapy using partial transmission block technique

Whole CNS (neuraxis) radiotherapy is an important part of therapy for certain CNS tumours which seed via the CSF. Many, if not the majority, of these predominantly young patients are cured but the neuropsychometric, neuroendocrine and growth morbidity of neuraxis radiotherapy on children by conventional methods may be considerable; patients receiving such therapy at an early age often are eventually in the educationally subnormal category. Recent radiobiological data support the concept that all aspects of CNS radiation tolerance are heavily dependent on daily fraction size. We describe a new radiotherapy technique that allows lower daily fraction sizes to be delivered to the neuraxis without prejudicing the total dose to the neuraxis or primary area and without prolonging the overall treatment time. Published radiobiological data support the concept that all the major morbidities attributed to conventional neuraxis radiotherapy will be reduced by the currently described technique without reducing tumour control rates.     

CT-guided multi-catheter insertion technique for partial breast brachytherapy: reliable target coverage and dose homogeneity

PURPOSE: To evaluate the feasibility and dosimetric reliability of a CT-guided method of catheter insertion for accelerated partial breast brachytherapy (APBB). MATERIALS AND METHODS: From 1995 to 2002, 77 patients were treated with APBB using a multi-catheter low-dose-rate or high-dose-rate approach. Within that timeframe, 29 patients with early stage invasive breast cancer were treated with high-dose-rate partial breast brachytherapy and had CT scans of the brachytherapy implant available for analysis. Initially, catheter insertion was accomplished in the operating room at the time of lumpectomy using standard free-hand insertion techniques under fluoroscopic guidance and subsequent orthogonal film dosimetry. To improve the efficiency and quality of the technique, the procedure was moved to the departmental CT-simulation suite where the catheters were placed with CT guidance. Basic guidelines of needle insertion and implant construction were followed to assure appropriate intercatheter and interplanar spacing that allowed optimal dosimetric coverage of the target volume. Target volumes were delineated and a treatment plan generated using a 3D planning system (Varian Brachyvision). PTV 1 cm was defined as the lumpectomy cavity plus 1 cm and PTV 2 cm as the lumpectomy cavity plus 2 cm. Target coverage goals were set as delivery of 100% of the prescribed dose to >95% of PTV 1 cm and >90% of the dose to >90% of PTV 2 cm. Dose homogeneity index (DHI) was defined as (V150%-V100%/V100%) with a goal of achieving >0.75. Fifteen patients were treated using the initial method and 14 patients using the CT-guided technique. Targets were retrospectively entered in the initial group and dose volume histogram analysis completed on all patients. The ability of each technique to achieve the target coverage and homogeneity goals was compared. RESULTS: With the change from traditional techniques to a CT-guided technique, the percentage of patients satisfying all dosimetric goals increased from 42% to 93%. Mean dose coverage (defined as the percentage of PTV 2 cm receiving 90% of the prescribed dose) increased from 89% to 95% (p=0.007) and the mean DHI increased from 0.77 to 0.82 with the new technique (p < 0.005). CONCLUSIONS: Reproducible target coverage and dose homogeneity were achieved with CT-guided catheter insertion and 3D planning software. Catheters can be optimally placed with intraoperative CT evaluation and 3D planning software allows improved implant visualization resulting in optimized dosimetry. Improvements in target coverage and DHI may translate into optimized local control and improved cosmesis with a corresponding reduction in the risk of complications.     

锁骨骨折内固定术三种麻醉方法的临床经济学评价

目的 采用成本效果分析方法对锁骨骨折内固定手术患者三种麻醉方法作出临床经济学评价。方法随机将144例患者分为3组,Ⅰ组臂丛加颈浅丛神经联合阻滞,Ⅱ组臂丛神经阻滞,Ⅲ组颈浅丛神经阻滞。分别计算出三种麻醉方法的成本和效果,作出成本效果比较。结果单病例成本而言,单纯颈浅丛神经阻滞成本最低,锁骨骨折位于锁骨外2／3时单纯臂丛神经阻滞平均成本最低,锁骨骨折位于锁骨内1／3时单纯颈浅丛神经阻滞平均最低。结论从临床经济学角度来看,锁骨骨折位于锁骨外2／3时首选单纯臂丛神经阻滞,锁骨骨折位于锁骨内1／3时首选单纯颈浅丛神经阻滞。     

A new technique for the postmortem detection of tooth-coloured dental restorations

Identification of unknown bodies is mainly made by dental examination and comparison with accurate dental records. Therefore it is necessary to examine the jaws carefully and to locate every tooth-coloured dental restoration. Overlooking dental fillings can make positive identification impossible. The technique described prepares the natural dental hard tissue by etching with 37% phosphoric acid. In the next step an indicator colours the roughened dental tissue but not the polished restoration material. In this way all 15 tested dental restoration materials could be detected with high sensitivity. Received: 18 November 1997