Development of a protocol for standardized use of a water-soluble contrast agent with polyethylene glycol in post-mortem CT angiography.

Computed tomography angiography (PMCTA) is increasingly used in postmortem cases. Standardized validated protocols permit to compare different PMCTA images and make it more easily to defend a case in court. In addition to the well-known technique by Grabherr et al. (2011) which is using paraffin oil as a carrier substance, water-soluble polyethylene glycol 200 (PEG200) can be used in combination with the contrast agent Accupaque® 300. As to date, there exists no standardized protocol for the use of this contrast agent mixture, the aim of this study was to develop a protocol using it. Between 2012 and 2022, 23 PMCTA with PEG200 and Accupaque®300 were performed at the University Centre of Legal Medicine Lausanne (Switzerland) and the Institute of Forensic Medicine Munich (Germany). The images obtained were evaluated regarding the opacification of the vessels and possible artefacts. The best image quality was obtained with a mixing ratio of 1:15 (Accupaque®300:PEG200) and a perfusion volume of 1000 ml in the arterial, 1400 ml in the venous and 350 ml in the dynamic phase. The infusion rates described by Grabherr et al. were confirmed for the three phases. Overall, the opacification of the vessels was diagnostically sufficient. In 13 cases no opacification of the right coronary artery was observed due to a stratification artefact. By using the PMCTA protocol with PEG200 as a carrier, a good overall image quality can be achieved. This protocol offers the possibility to standardize PMCTA with PEG200.

Pediatric postmortem CT angiography: validation of vascular access for PMCT angiography in stillbirths, babies and toddlers.

PURPOSE: The use of angiography in postmortem CT angiography (PMCTA) has several advantages. In adults, femoral vascular access is well established. Due to the small and specific anatomy in fetuses and infants, the technique has to be adapted, especially regarding the vascular access. The aim of this study was to evaluate vascular access for pediatric PMCTA (pedPMCTA). MATERIALS AND METHODS: Ten pedPMCTAs were performed in stillbirths, babies, and one toddler. A femoral approach by cannulation of the femoral artery and vein, an umbilical approach by cannulation of the umbilical vessels, and an intraosseous approach by an intraosseous needle were evaluated by handling and resulting imaging. RESULTS: The insertion of a cannula with a size of 18-20 G in the femoral vessels was possible in babies. An umbilical access with peripheral venous cannulas with a size of 14-20 G was feasible in stillbirths and newborns. An intraosseous access is advisable as equal alternative to umbilical and in cases where a femoral access is not possible. The most significant problem with the vascular access is the extravasation of contrast media, but this can be reduced significantly with practice. CONCLUSION: When performing pedPMCTA, an umbilical vascular access is recommended if an umbilical cord with open vessels is still present. Otherwise, a bone marrow access should be preferred in the presence of an arteriovenous shunt or if only the venous system needs to be shown. If that is not the case, the femoral access with the possibility to separate venous and arterial scan should be used.

Realistic three-dimensional imaging of injuries in forensic medicine - Survey-based method comparison of CRT and VRT.

OBJECTIVE: A comparison between Cinematic Rendering Technique (CRT) and Volume Rendering Technique (VRT) in cases with postmortem CT-angiography (PMCTA) was carried out. METHODS: For different injuries seen in PMCTA, a VRT and a CRT image of exactly the same pathological section was generated. Two questionnaires were created, one with CRT and one with VRT reconstructions, with the same questions per 3D-image. The questionnaires were sent to forensic pathologists, lawyers and police officers. In total eleven different injuries had to be analyzed. RESULTS: In total 109 questionnaires were answered fully. Of these returnees, 36 stated that they were forensic pathologists. Seventy-three people were assigned to the group of medical laypersons, in the study this group consists mainly of police officers, judges and lawyers. Between the two software programs CRT and VRT that were compared, no significant difference could be identified in any of the participating groups with regard to the assessment of the life-threatening nature of the injury images shown. When asked about the comprehensibility of pathology, there was a significant difference in favour of CRT. This advantage was apparent to named medical laypersons and to forensic pathologists. CONCLUSIONS: The study showed a positive trend that CRT may be more understandable than VRT. Not only the medical laypersons, but also the forensic physicians found CRT to be beneficial.

Diagnosis of recurrent laryngeal nerve palsy after thyroidectomy: a systematic review.

BACKGROUND: Recurrent laryngeal nerve palsy (RLNP) is a recognised possible complication after thyroid surgery. It may present with a variety of symptoms, such as voice change and respiratory symptoms. However, it may remain undetected and the true incidence may be under-reported. The aim of this study was to determine the reported incidence of temporary and permanent palsy after thyroid surgery using different vocal assessment methods. METHODS: A Medline search was performed. A systematic review was undertaken which included 27 articles and 25,000 patients. RESULTS: The average incidence of temporary RLNP after thyroid operations is 9.8% and the incidence of permanent RLNP is 2.3%. The RLNP rate varied according to the method of examining the larynx and ranged from 26% to 2.3%. Most of the reviewed studies recommend a follow-up period up to 1 year to assess and evaluate RLNP. CONCLUSION: Our study has identified that different methods are used to diagnose RNLP and that a wide variety of reported RLNP rates exist. We propose establishment of a 'gold standard' for assessing the voice after thyroidectomy to reduce reporting bias.

Thyroid lymphoma and airway obstruction - is there a rationale for surgical management?

BACKGROUND: The current management of thyroid lymphomas (TL) includes the combined use of chemotherapy and radiotherapy, with surgery mainly confined to diagnosis through an open biopsy following ultrasound-guided fine-needle aspiration cytology (US-FNAC). AIMS: To analyse the clinical presentation and methods of diagnosis of TL, its pitfalls and the management of these tumours presenting with compression symptoms and airway obstruction. METHODS: A retrospective review of nine patients diagnosed with TL at Guy's and St Thomas Hospital NHS Foundation Trust in London over the past 5 years. RESULTS: Nine consecutive patients were identified with the diagnosis of TL, and seven (78%) of them being women and with a mean age of 65 years. All patients presented with an anterior neck mass while four (44.4%) presented with stridor and vocal cord palsy. Two (22.2%) presented with a hoarse voice, dysphagia, and only one patient had a B symptom of weight loss. FNAC was diagnostic in three patients (33.3%) and a report of multi-nodular goitre in one patient. There was clinical suspicion of TL in three patients (33.3%). Of the three patients presenting with stridor, two had an open biopsy followed by the initiation of dexamethasone therapy and resolution of symptoms within 48 h. One patient had a partial thyroidectomy following a suspected diagnosis of multi-nodular goitre from US-FNAC. One patient required tracheostomy for airway management. CONCLUSION: Diagnosis of TL may be difficult. However, US-FNAC is useful in raising the suspicion of a TL. Open biopsy is still the definitive diagnostic tool of choice. In the emergency setting of airway obstruction, once definitive diagnosis is achieved, dexamethasone therapy and endotracheal intubation for airway management are all that is required for optimal management strategy. Surgical intervention has no role except for providing tissue for diagnosis.

4 years' experience of head and neck tuberculosis in a south London hospital.

In a south London department of otorhinolaryngology and head and neck surgery, 33 cases of tuberculosis were diagnosed in 4 years. The most common presentation was cervical adenitis (58%) and in some cases the initial investigations suggested malignant disease. Most of the patients were of non-British origin but none proved to be HIV seropositive. Fine-needle aspiration was positive for tuberculosis in 7 of 19 patients. 21 patients required a surgical procedure for diagnosis.