[Craniocerebral trauma: magnetic resonance imaging of diffuse axonal injury]. / Schädel-Hirn-Trauma : MRT bei diffuser axonaler Verletzung.

CLINICAL/METHODICAL ISSUE: Acceleration-deceleration rotational brain trauma is a common cause of disability or death in young adults and often leads to a focal destruction of axons. The resulting pathology, axonal shear injury is referred to as diffuse axonal injury (DAI). The DAI-associated lesions occur bilaterally, are widely dispersed and have been observed in the surface and deep white matter. They are found near to and far from the impact site. STANDARD RADIOLOGICAL METHODS: When DAI is clinically suspected, magnetic resonance imaging (MRI) is the method of choice for further clarification, especially in patients where cranial computed tomography (CT) is inconspicuous. METHODICAL INNOVATIONS: To investigate the presence of DAI after traumatic brain injury (TBI), a multimodal MRI approach is applied including the common structural and also functional imaging sequences. PERFORMANCE: For structural MRI, fluid-attenuated inversion recovery (FLAIR) weighted and susceptibility contrast imaging (SWI) are the sequences mainly used. The SWI technique is extremely sensitive to blood breakdown products, which appear as small signal voids at three locations, at the gray-white interface, in the corpus callosum and in the brain stem. Functional MRI comprises a group of constantly developing techniques that have great potential in optimal evaluation of the white matter in patients after craniocerebral trauma. These imaging techniques allow the visualization of changes associated with shear injuries, such as functional impairment of axons and decreased blood flow and abnormal metabolic activity of the brain parts affected. ACHIEVEMENTS: The multimodal MRI approach in patients with DAI results in a more detailed and differentiated representation of the underlying pathophysiological changes of the injured nerve tracts and helps to improve the diagnostic and prognostic accuracy of MRI. PRACTICAL RECOMMENDATIONS: When DAI is suspected multimodal MRI should be performed as soon as possible after craniocerebral injury.

Feasibility of cerebral MRI in non-sedated preterm-born infants at term-equivalent age: report of a single centre.

AIM: MRI is gaining in importance as an imaging tool for brain development and injury in preterm infants. The aim of this study was to evaluate the feasibility of performing MRI in non-sedated preterm-born infants at term-equivalent age (TEA). METHODS: A total of 89 infants born before 32 gestational weeks were recruited. Infants were scanned without sedation. Duration of the entire examination including scan repetition and interruptions was registered. RESULTS: Of the 89 infants, 56 (63%) underwent MRI at TEA. Out-patients required a significantly shorter total MR examination time than did in-patients (32 ± 12 vs. 54 ± 10 min, p < 0.01). Of the 56 infants, 39 (69.6%) were examined without interruption. Only four (7.2%) of the 56 scans were unusable because of motion artefacts. Mean duration of all scans was 36 ± 14 min. In cases with no interruptions, sessions were completed within 32 ± 12 min; MR sessions with interruption lasted 45 ± 13 min. CONCLUSION: A well-trained team is indispensable in obtaining best-quality images as a prerequisite for good counselling. From our experience, we worked out a guideline to ensure that scans in stable non-sedated preterm-born infants at TEA run smoothly and provide high-quality images.

[Non-Hodgkin lymphoma of the lacrimal gland]. / Non-Hodgkin-Lymphom der Tränendrüse.

BACKGROUND: Non-Hodgkin lymphoma is a systemic disease and various organs can therefore be affected. Ocular manifestations of non-Hodgkin lymphomas are possible but involvement of the eyelids or lacrimal glands are uncommon. CASE REPORT: A 63-year-old female patient suffered from a painless upper eyelid swelling of the left eye for 3 weeks. The anterior and posterior parts of the eyes showed no pathologic signs and X-ray examination of both orbits revealed no pathologic findings. Magnetic resonance imaging and computer tomography of the head revealed a neoplasm of the left lacrimal gland and also of the left parotid gland. The histologic examination revealed a recurrent non-Hodgkin lymphoma. CONCLUSIONS: The causes of eyelid swellings can be multiple, however, painless swellings may also be caused by neoplasms. In the case described here it was interesting that behind a painless eyelid swelling even a systemic disorder was hidden, i.e. a recurrence of a non-Hodgkin lymphoma, which was localized in the lacrimal gland.

[Radiation exposure in single slice and multi-slice spiral CT (a phantom study)]. / Untersuchungen zur Strahlenexposition bei der Einzelschicht- und Mehrschicht-Spiral-CT (eine Phantom-Studie).

PURPOSE: The purpose of study was to compare patient dose applying singleslice- and multislice-spiral CT. METHODS: The examinations were performed with a singleslice-spiral CT (Highspeed Advantage; GE Medical Systems; Milwaukee, USA) and with a multislice CT systems (LightSpeed QX/i GE Medical Systems; Milwaukee, USA). For the determination of the radiation exposure (absorbed dose) a selection of most executed protocols (thorax-helical, abdomen-helical, petrous bone-axial, head-axial) were simulated using an Alderson Rando Phantom. The dose was determined by means of lithiumfluorid-thermoluminiscence dosimeters (TLD-GR 200). RESULTS: For thorax and abdomen protocols higher energy dose values could be found using a multislice CT. On the average the energy dose values were increased by 2.6 on an average in relation to single slice spiral CT. The energy dose values of the multisclice CT using head protocols could be reduced by 30% in relation to single slice spiral CT due to suitable parameter selections. The energy dose applying a petrous bone protocol resulted in an average increase by a factor 1.5 using a multislice CT. CONCLUSION: Using the new multislice CT technique protocol strategies must be optimized regarding the patient doses. Users can operate critically in the sense of the radiation protection only if they are aware of the occurring dose amounts to the patient.

[Acute diagnosis of spinal trauma]. / Akutdiagnostik des Wirbelsäulentraumas.

Most traumatic spinal injuries result from a high-energy process and are accompanied by other injuries. Following the CCSPR study, the presence of all low-risk factors (simple trauma mechanism, fully conscious, ambulatory at any time since trauma, neck rotation exceeding 45 degrees bilaterally) obviates the need to acutely image the cervical spine. Imaging is indicated in all other patients. Emergency spiral CT should be performed as the first imaging method in high-risk and moderate-risk patients; only in low-risk patients should conventional radiography be performed and trusted as the sole modality. The AO classification according to Magerl et al. is used for the subaxial spine, whereas the upper cervical spine should be classified separately because the anatomy is different at each level. Radiological evaluation of traumatic spinal injuries should be done systematically using the "ABCS" scheme.

Isolated right-sided varicocele as a salvage pathway for portal hypertension.

Retrograde blood flow can occur in the testicular veins and in the pampiniformis plexus in the absence of valves or if the valves are incompetent, resulting in tortuosity and dilatation of the veins. These abnormal alterations in the anatomy of the veins, termed varicoceles, are associated with infertility in the male. Most varicoceles occur on the left. We report the case of a rare isolated right-sided varicocele in a male evaluated for infertility in whom extensive work-up revealed venous anomalies and a spontaneous porto-systemic shunt. In such cases, standard approaches to infertility treatment are fruitless.

[Stress fractures in athletes]. / Stressfrakturen bei Athleten.

Stress fractures may pose a diagnostic dilemma for radiologists since they are sometimes difficult to demonstrate on plain films and may simulate a tumour. They were first described in military personnel and professional athletes. Recently, there is an increasing incidence in the general population due to increasing sportive activities. Stress fractures occur most often in the lower extremities, especially in the tibia, the tarsal bone, the metatarsal bone, the femur and the fibula. In the upper extremities, they are commonly found in the humerus, the radius and the ulna. Some fractures of the lower extremities appear to be specific for particular sports, for example, fractures of the tibia affect mostly distance runners. Whereas stress fractures of the upper extremities are generally associated with upper limb-dominated sports. A correct diagnosis requires a careful clinical evaluation. The initial plain radiography may be normal. Further radiological evaluation could be performed by means of computerised tomography, magnetic resonance imaging and bone scanning. The latter two techniques are especially helpful for establishing a correct initial diagnosis.

[Transperineal sonography in anorectal disorders]. / Transperineale Sonographie bei rektoanalen Erkrankungen.

AIM: Magnetic resonance imaging, computed tomography, endorectal and endoanal sonography are used for imaging of inflammatory and neoplastic conditions of the lower rectum, the anus and the perineum. These methods, however, have their limitations regarding accuracy, cost-effectiveness, and availability in the acute setting. Pain may be a limiting factor when introducing a probe into the anus. Percutaneous transperineal sonography is an acknowledged method for diagnosing anorectal malformations in children and infants and for diagnosis of prostatic disease. Until today, only limited reports regarding the value of transperineal sonography for evaluation of diseases of the lower rectum, the anus and the perianal region in adults are available. PATIENTS AND METHODS: Between 1997 and 2000 a total of 44 patients underwent transperineal sonography including B-mode and colour Doppler sonography for imaging anorectal structures using 3.5 MHz sector arrays and 7 MHz linear arrays. The lesions were also investigated using colour Doppler imaging. During examination the patient is positioned on his side. Orientation landmarks are the pubic symphysis and the prostate gland in men and the vagina in women. RESULTS: The spectrum of diseases of the current study population (44) included perianal fistulas (10), pararectal abscesses (7), fistulas with abscess (7), perianal inflammation without abscess (1), rectal (6) and anal carcinomas (3) and metastasis of a leiomyosarcoma (1). In 10 cases digital examination of the anus and rectum was not possible because of intense pain. In 34 patients (85 %) sonographic findings were confirmed by intraoperative diagnosis. CONCLUSION: Transperineal sonography proved to be an inexpensive, easily available diagnostic tool that may help in detecting a variety of pathological conditions of the lower rectum, the anus, and the perianal region.