Worth the risk? Contemporary indications, yield and complications of lumbar punctures in a metropolitan Australian health service.

BACKGROUND: Performing lumbar punctures carries a risk of harm to the patient, but the information cerebrospinal fluid provides often makes this procedure necessary. Clinicians in the Australian setting would benefit from having more information on these procedures, in order to help them in a risk versus benefit analysis. AIMS: To describe the contemporary indications, cerebrospinal fluid findings and complications of lumbar punctures in a metropolitan Australian health service. METHODS: Retrospective electronic medical records audit of lumbar punctures performed on 525 adults within three acute hospitals between 1 July 2018 and 30 June 2019. Main outcome measures include frequency of indication for lumbar puncture by category, normal versus abnormal cerebrospinal fluid for each category, and frequency, severity and type of complications of lumbar punctures. RESULTS: Of 525 adult lumbar punctures that were assessed in this study, 466 were performed for a diagnostic indication. The most common diagnostic indications were acute severe headache (156 procedures; 33.5%) and encephalopathy (128 procedures; 27.5%). The yield of abnormal results varied by indication category, with the above indications yielding abnormal results in 85 (54.5%) and 72 (56.3%) cases respectively. A complication was recorded in 54 (10.3% of total) procedures. The majority (45; 8.6%) of complications were minor in severity and most frequently consisted of post-dural puncture headache (PDPH). CONCLUSIONS: In the era of an increased reliance on high quality neuroimaging, lumbar puncture has a high diagnostic yield with a low rate of major complications. The most common complication is PDPH, which is mild and self-limiting in most cases.

Effect of a clinical flowchart incorporating Wells score, PERC rule and age-adjusted D-dimer on pulmonary embolism diagnosis, scan rates and diagnostic yield.

OBJECTIVE: To assess the association between the use of a flowchart incorporating Wells score, PERC rule and age-adjusted D-dimer and subsequent imaging and yield rates of computed tomography pulmonary angiogram and nuclear medicine ventilation perfusion scans being ordered in the ED for the assessment of pulmonary embolism. METHODS: A flowchart governing ED pulmonary embolism investigation was introduced across three EDs in Melbourne, Australia for a 12 month period. Comparison of pulmonary embolism imaging rates and yield with the preceding 12 months was performed. RESULTS: A total of 1815 pre-implementation scans were performed compared with 1116 scans post-implementation. Because of growth in patient attendances over this time, this equated to an imaging rate of 14.5 per 1000 presentations pre-implementation and 8.6 per 1000 presentations post-implementation (P < 0.001). Overall pulmonary embolism imaging yield rates rose from 9.9% to 16.5% (P < 0.001). A total of 179 pre-implementation pulmonary embolisms were identified, with an incidence of 1.4 per 1000 presentations. This compared to 184 pulmonary embolisms post-implementation, with an incidence of 1.4 per 1000 presentations (P = 0.994). CONCLUSION: The introduction of a clinical flowchart incorporating Wells score, PERC rule and age-adjusted D-dimer was associated with an increase in ED computed tomography pulmonary angiogram and nuclear medicine ventilation perfusion yield rate from 9.9% to 16.5% across the three enrolment hospitals when investigating possible pulmonary embolism. This corresponded to a 40% relative reduction in pulmonary embolism imaging. Diagnosis rates remained unchanged and no cases of missed pulmonary embolism attributable to the flowchart were identified.

Mitochondrial disease: an uncommon but important cause of diabetes mellitus

Mitochondrial diseases are rare, heterogeneous conditions affecting organs dependent on high aerobic metabolism. Presenting symptoms and signs vary depending on the mutation and mutant protein load. Diabetes mellitus is the most common endocrinopathy, and recognition of these patients is important due to its impact on management and screening of family members. In particular, glycemic management differs in these patients: the use of metformin is avoided because of the risk of lactic acidosis. We describe a patient who presented with gradual weight loss and an acute presentation of hyperglycemia complicated by the superior mesenteric artery syndrome. His maternal history of diabetes and deafness and a personal history of hearing impairment led to the diagnosis of a mitochondrial disorder. Learning points: •• The constellation of diabetes, multi-organ involvement and maternal inheritance should prompt consideration of a mitochondrial disorder. •• Mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes (MELAS) and maternally inherited diabetes and deafness (MIDD) are the most common mitochondrial diabetes disorders caused by a mutation in m.3243A>G in 80% of cases. •• Metformin should be avoided due to the risk of lactic acidosis. •• There is more rapid progression to insulin therapy and higher prevalence of diabetic complications compared to type 2 diabetes. •• Diagnosis of a mitochondrial disorder leads to family screening, education and surveillance for future complications. •• Superior mesenteric artery syndrome, an uncommon but important cause of intestinal pseudo-obstruction in cases of significant weight loss, has been reported in MELAS patients.

Perfusion-Derived Dynamic 4D CT Angiography Identifies Carotid Pseudo-Occlusion in Hyperacute Stroke.

BACKGROUND: Differentiation between true acute tandem occlusion involving the extracranial internal carotid artery (ICA) from pseudotandem occlusion with a patent extracranial ICA has important prognostic and therapeutic implications. We explored the utility of perfusion-derived 4-dimensional CT angiogram (4D-CTA) in identifying carotid pseudo-occlusion in a single-center pilot study. METHODS: Acute stroke patients with delayed antegrade ICA flow on 4D-CTA despite an apparent tandem occlusion on conventional single-phase CTA were prospectively identified over a 2.5-year period (2013-2015). RESULTS: Eight patients were identified. Delayed antegrade intracranial flow from the apparently occluded ICA was detected up to 50 seconds after contrast administration on 4D-CTA. The distal intracranial ICA was the most common site of true occlusion. Reconstruction of the 4D-CTA images required an additional processing time of 2-3 minutes. CONCLUSIONS: 4D-CTA is a novel noninvasive technique that can identify carotid pseudo-occlusion in the acute stroke setting. Our preliminary findings suggest that 4D-CTA can be easily incorporated into an existing acute stroke neuroimaging protocol.

Case Study: Giant Cell Arteritis with Vertebral Artery Stenosis.

In giant cell arteritis (GCA), involvement of the vertebral arteries is rare with reported rates of 3%-4% for ischemic events secondary to vertebral artery stenosis or occlusion for those patients with GCA. This case study describes a patient who initially presented with acute onset of vertigo but was also found to have transient, side-alternating upper limb neurological findings. While initial imaging showed no vascular abnormalities, it was not until GCA was eventually confirmed with a temporal artery biopsy that the initial scans were shown to have bilateral narrowing of the vertebral arteries. While rare, vertebral artery involvement is an important complication to consider in the setting of GCA due to the high rate of associated mortality, despite immunosuppressive therapy.

Time-Resolved 4-Dimensional Computed-Tomography Angiography Can Correctly Identify Carotid Pseudo-Occlusion.

Correct identification of symptomatic high-grade internal carotid artery stenosis from low-grade or total chronic occlusion is critical for patient selection for urgent carotid endarterectomy. Carotid pseudo-occlusion is a flow-related artifact on noninvasive imaging that can lead to an incorrect diagnosis of total internal carotid artery occlusion, thereby denying an eligible patient for appropriate surgical treatment. We present an 82-year-old man with a symptomatic critical internal carotid artery, which was detected on time-resolved 4-dimensional computed-tomography angiography, whereas single-phase computed-tomography angiography, magnetic resonance angiography, and Doppler ultrasonography suggested apparent occlusion. To our understanding, the use of 4-dimensional computed-tomography angiography to identify carotid pseudo-occlusion has not been previously reported.

The changing face of radiology: from local practice to global network.

Rapid advances in communications and computing technology have opened up new opportunities for clinical teleradiology. The quality of teleradiology reporting, when carried out properly, is on par with onsite reporting, and offers the potential for increased accuracy and improved patient outcomes. Local and international industry organisations and professional bodies are creating standards, policies and protocols for every aspect of teleradiology in response to concerns about the use of this technology. The key factor for the long-term success of teleradiology has been identified as a commitment to ensuring duty of care to patients (encompassing high-quality service and patient safety) is the first priority. Evidence indicates that increased use of teleradiology will be a step forward if managed well, but requires a commitment to excellence, patience and perseverance.