Dose-image optimisation in digital radiology with a direct digital detector: an example applied to pelvic examinations

In diagnostic radiology increasing attention has been focused on dose reduction while maintaining a clinically good image quality. With the use of digital detectors balancing dose vs image quality is done differently than in film-screen radiography, since dose and image brightness are uncoupled in digital imaging. In this study a new direct digital detector (flat-panel detector) was used in a dose-image optimisation of a simulated pelvic examination. X-ray images were taken with a direct digital detector (DDD), of the pelvic of a phantom using varying tube current (varying stochastic noise). The entrance surface dose was measured for each image. These images were scored by two radiologists according to EU guidelines. A dose comparison was made with an older PCR system (storage phosphor plates). With decreasing tube current the noise in the images increased and the image with the lowest dose and still acceptable image quality was identified. The results showed that the entrance surface dose using the DDD decreased from 1.4 mGy (PCR value) to 0.48 mGy (DDD standard settings). Through the optimisation the dose could be further decreased to 0.24 mGy while still maintaining an acceptable image quality. A substantial dose reduction was obtained with this new direct digital detector. This simple but efficient optimisation approach is easily applicable to other examinations and both DDD and storage phosphor plate detectors.     

保留盆腔植物神经的广泛性子宫切除术治疗子宫颈癌的初步研究

目的 探讨保留盆腔植物神经的广泛性子宫切除术(NSRH)治疗宫颈癌的可行性,并评估其改善术后膀胱功能的效果.方法 选择接受手术治疗的临床分期为Ⅰ b1～Ⅱa期的宫颈癌患者44例,分为两组.研究组22例患者接受NSRH手术,术中在处理主韧带、宫骶韧带、深层的膀胱宫颈韧带及阴道旁组织时,保留盆腔内脏神经、腹下神经、下腹下神经丛及其膀胱支;对照组22例患者接受经典的广泛性子宫切除手术(即Piver Ⅲ类子宫切除术).对比两组患者的术中及术后并发症发生情况.结果 研究组术中出血量为(550±241)ml,对照组为(475±284)ml,两组比较,差异无统计学意义(P>0.05);研究组手术时间为(329±43)min,对照组为(272±56)min,两组比较,差异有统计学意义(P<0.01).术后第8天,研究组及对照组中残余尿量<100 ml的患者比例分别为68%及18%,两组比较,差异有统计学意义(P<0.01);研究组留置尿管时间(8～23 d,中位时间8 d)与对照组(8～32 d,中位时间20 d)比较,差异有统计学意义(P<0.01).两组患者均无严重的手术相关性损伤及病理切缘不净的情况发生.结论 NSRH治疗早期子宫颈癌安全、可行,且能明显改善患者术后的膀胱功能.     

Computerized tomography in the evaluation of the soft tissue component of bony lesions of the pelvis

Three cases are presented in which lesions of the bony pelvis with extraosseous soft tissue components are evaluated using computerized tomography. In each instance, computerized tomography provided precise anatomic localization of bony lesions and clearly depicted the extent of associated extraosseous masses. In all cases, the clarity of anatomic detail obtained suggests that computerized tomography represents an important new methodology for evaluation of the soft tissue component of bony lesions of the pelvis.     

Selective arterial embolisation in aneurysmal bone cysts

Summary The treatment of three cases of aneurysmal bone cyst by selective arterial embolism is described. Two cases had involvement of the pelvis and one of the knee. The 2-year follow up has been promising. Radiologically the lesion has been arrested with increased density of the cyst wall and intra-cystic trabecular new bone formation. Pain relief has been complete and up to now no surgical treatment has been required.

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Résumé Présentation de l'évolution clinique et radiologique de trois cas de kyste osseux anévrysmal, deux localisés au bassin et le troisième au genou, traités par embolisation artérielle sélective. Les résultats, avec 2 ans de recul, sont encourageants. Radiologiquement la lésion paraît stabilisée avec densification des parois et apparition de travées d'os nouveau à l'intérieur du kyste. Les douleurs ont complétement disparu et jusqu'à présent aucun geste chirurgical n'a été nécessaire.

     

FDG-PET uptake in occult acute pelvic fracture

The role of FDG-PET in the diagnosis of bone metastases remains unsettled, although it is hoped that PET scans will add specificity to or replace bone scintigraphy. We report a case in which an acute traumatic fracture presented with a level of uptake generally considered indicative of neoplasm. It is important to recognize that increased FDG-PET activity in bone should not be accepted as definitive evidence of metastatic disease.     

Primary lung carcinoma metastatic to a solitary fibrous tumor

We report the case of a 78-year-old man with a 2 month history of newly diagnosed metastatic lung adenocarcinoma, who presented with a left gluteal soft tissue mass. Histological examination of the mass revealed a solitary fibrous tumor containing metastases from adenocarcinoma.     

Unusual sites of lymph node metastases and pitfalls in their detection

This pictorial review discusses and illustrates unusual sites of lymph node metastases and their mimics.     

From normal to abnormal MR findings within three weeks in a solitary pelvic Langerhans histiocytosis

We present a histologically proven case of pelvic Langerhans histiocytosis (eosinophilic granuloma) which showed abnormality on MR imaging 3 weeks after a normal MR examination mimicking an infection.