Magnesium implants in orthopaedic surgery create a diagnostic conundrum: A radiology case series and literature review.

During a routine post-operative orthopaedic radiograph reading session, repeated unusual radiographic soft tissue and bone appearances became evident. It was discovered that these patients had received biodegradable magnesium implants which have recently been introduced into orthopaedic clinical practice. To the untrained eye, the combination of peri-metallic bone resorption with associated soft tissue gas, could easily be mistaken for post-operative infection. The aim of this study is to properly characterise the radiographic post-operative appearances of biodegradable magnesium orthopaedic hardware. We retrospectively evaluated radiographs of all patients who underwent magnesium screw implantation for fractures over a 6 month period. Four patients, mean age of 9.75 (range: 6-15) years who underwent magnesium screw fixation following fracture were included in the study. Follow up duration was 100 days (range: 75-122) with a mean of 2.5 postoperative radiographs being performed per patient during this period. All cases demonstrated post-operative peri-metallic radiolucency which developed around the magnesium screws on x-ray, which subsequently resorbed over time. Peri-metallic soft tissue gas was observed in all patients. In two cases, magnesium implants fractured. As the use of biodegradable metal implants becomes more common, it is important for radiologists to be aware of their imaging characteristics. Prior to reporting a case, it would be prudent to know if biodegradable screws have been utilised and whether there exists a clinical concern for post-operative infection in patients with these particular implants, in which case it would be critical not to dismiss peri-prosthetic radiolucencies and soft tissue gas as merely a sequela of the natural metal degradation process.

Can smoking cause impotence? a radiological retrospective cohort study comparing internal pudendal artery calcification on CT in male smokers versus non-smokers.

BACKGROUND AND AIMS: This retrospective cohort study evaluated the degree of pelvic inflow and internal pudendal artery (IPA) calcification in male smokers versus non-smokers. As erectile dysfunction (ED) is strongly associated with IPA vascular, we wanted to investigate radiologically if there was a statistically significant difference in the degree of IPA calcification in smokers and potentially be a contributing factor in the cause of ED. METHODS: CT studies of 100 men aged between 40 and 60 years of age were blindly reviewed and assigned a calcium score of their vascular calcification levels. We compared scores of 50 smokers versus 50 non-smokers. The Mann Whitney U test statistic was used to test for a statistical difference in calcification score between the smoking and non-smoking groups. RESULTS: Results show a statistically significant association between smoking and pelvic inflow and IPA calcification. The Mann Whitney U test demonstrated a statistically significant higher calcium score in the smoking group (mean = 4.8, SD 3.7), versus the non-smoking group, (mean = 1.8, SD 1.9) (U = 701.5, p < 0.05). CONCLUSIONS: This research is the first of its kind based on an extensive literature review. The association between vascular calcification and smoking is well established, in addition to the direct relationship of IPA calcification and ED. This unique study has demonstrated an increased rate of IPA calcification in smokers with a potential inferred association with ED. Findings represent a novel and useful deterrent for health authorities to include in anti-smoking campaigns.

Safely increasing nephro-ureteric stent exchange intervals, resulting in significant cost savings for the interventional radiology suite, a 2-year experience in a tertiary referral centre.

AIM: To evaluate the nephro-ureteric stent (NUS) insertion and exchange practice in a tertiary referral cancer centre, and determine the safety and compliance with current guidelines. We also reviewed if increasing exchange time interval from 6 to 12 weeks was safe, and if this could be adopted into our local guidelines. METHODS: A retrospective review was performed covering 24 months from January 2017 to December 2018. All NUS insertions and exchanges performed in that period were analysed, including the number of exchanges the patient underwent, the time between subsequent exchanges, and the screening time. We also reviewed the indications for stent insertion, possible causes for failed stent exchange, and factors which led to significant delays in stent exchanges for some patients. A scatterplot of screening time versus time in situ was derived and correlation analysis performed using the Pearson coefficient. RESULTS: Thirty-two patients underwent de novo NUS insertion during the period, and 102 NUS exchanges were performed. The interval between stent exchanges ranged from 1 to 40 weeks, with a mean of 12.3 weeks (SD = 8.96 weeks). Screening time ranged from 33 s to 17 min, with a mean of 3 min 50 s (SD = 3 min 35 s). There were 100 successful exchanges, and two failed exchanges, accounting for 1.9% of total exchanges. In both failed cases, the reason for failed exchange was due to a prolonged period between exchanges (6 months in both cases). The reason for delay for stent exchange was due to non-attendance for scheduled appointments. There was a weakly positive correlation coefficient of 0.06 (screening time versus time period between insertions); however, this was not statistically significant (p = 0.81). CONCLUSION: In this retrospective review, we have demonstrated that the recommended 6-week period between stent exchanges is unnecessary in the vast majority of cases, and that a longer interval between NUS exchanges, e.g. 8-12 weeks, is safe for the patient, and reduces screening time. This reduction in procedures also provides a significant potential saving to the radiology department in both monetary expense and limited angiography suite time.

CT-determined sarcopenia as a predictor of post-operative outcomes in patients undergoing an emergency laparotomy.

PURPOSE: Emergency laparotomy has a high reported thirty-day mortality, ranging from 11 to 15%. Current peri-operative risk assessment tools may poorly estimate the risk of perioperative mortality. We sought to determine if CT-determined sarcopenia may be a useful predictor of post-operative outcomes in patients undergoing an emergency laparotomy. METHODS: A retrospective review of a prospectively maintained database of consecutive adult patients who underwent an emergency laparotomy at our institution was performed. Post-operative mortality (90-day mortality), admission to HDU or ICU and APACHE-II scores were recorded for these patients. Sarcopenia was calculated by determining psoas area and density at the level of the third lumbar vertebra. The lowest quartile was determined to be sarcopenic. Univariate statistical analysis investigated associations between sarcopenia and these outcome measures. RESULTS: Eighty patients were included in the study following application of exclusion criteria. Thirty-eight were male. The 90-day mortality rate was 11%. Compared to their non-sarcopenic counterparts, sarcopenic patients were significantly more likely to have died by 90 days post-operatively (χ2 = 9.51, p = 0.002) and to require admission to either the HDU or ICU in the post-operative period (χ2 = 10.62, p = 0.001). CONCLUSIONS: CT determined sarcopenia is significantly associated with 90-day mortality and post-operative admission to HDU or ICU in patients undergoing an emergency laparotomy. The future development of a validated scoring tool incorporating sarcopenia could help to better select out those patients who will require higher levels of post-operative care as well as identifying those for whom surgery may not confer a survival benefit and be deemed futile.

Natural growth pattern of sporadic renal angiomyolipoma.

BACKGROUND: Surveillance of sporadic renal angiomyolipomas is a growing issue for physicians and radiologists. Current treatment recommendations favor active surveillance. However, the evidence underlying these is based on small case series, which also typically include angiomyolipomas associated with tuberous sclerosis. PURPOSE: To evaluate the natural growth pattern of sporadic renal angiomyolipomas in patients without tuberous sclerosis. MATERIAL AND METHODS: A retrospective review was performed in three separate tertiary referral centers. A keyword search of each institutions PACS history was performed. Inclusion criteria were angiomyolipomas > 1 cm in size, three years of follow-up, and lesions requiring treatment before reaching three years of follow-up. Exclusion criteria included a diagnosis of tuberous sclerosis, pregnancy, prior treatment with embolization without any prior imaging, and lesions which were treated on presentation. Growth of the angiomyolipomas was evaluated on the basis of maximum dimension on initial and follow-up images. RESULTS: Sixty-three patients were identified in total, with 64 lesions eligible for inclusion. The majority of patients were women (55/63). The mean age at which the angiomyolipomas discovered was 56.4 years. Mean total growth was 0.085 mm and mean follow-up was 65.5 months. At initial measurement, the mean maximum dimension of the lesions in our cohort was 2.08 cm. After follow-up, this was 2.16 cm. The average rate of growth was 0.015 cm per year. CONCLUSION: Sporadic angiomyolipomas exhibit minimal, if any, natural growth. Current surveillance strategies could be relaxed.

The impact of the introduction of artificial intelligence in radiology and its potential legal implications in the UK and Ireland.

Artificial intelligence (AI) has been defined as a branch of computer science dealing with the capability and simulation of a machine to imitate intelligent human behaviour. Diagnostic radiology, being a computer-based service, is unsurprisingly at the forefront of the discussion of the use of AI in medicine. There are however differing schools of thought regarding its use; namely, will AI eventually replace the radiologist? Or indeed will it ever be fully capable of replacing radiology as a speciality, but rather be used as an aid to the profession whereby a human's input will always be required? Furthermore, what will the legal implications of AI in radiology mean to the profession? Who will be liable for missed diagnoses? Is it possible that the introduction of AI to radiology will in fact make the profession busier?

The urachus revisited: multimodal imaging of benign & malignant urachal pathology.

The urachus is a fibrous tube extending from the umbilicus to the anterosuperior bladder dome that usually obliterates at week 12 of gestation, becoming the median umbilical ligament. Urachal pathology occurs when there is incomplete obliteration of this channel during foetal development, resulting in the formation of a urachal cyst, patent urachus, urachal sinus or urachal diverticulum. Patients with persistent urachal remnants may be asymptomatic or present with lower abdominal or urinary tract symptoms and can develop complications. The purpose of this review is to describe imaging features of urachal remnant pathology and potential benign and malignant complications on ultrasound, CT, positron emission tomography CT and MRI.

Quantification of the impact of interventional radiology in the management of acute pancreatitis.

OBJECTIVES: Interventional radiology plays a central role in the management of complicated acute pancreatitis, contributing to image-guided drainages, treating haemorrhagic complications and maintaining the patency of the biliary tree. In addition, many of these patients require long-term venous access for antibiotics or parenteral feeding. The aim of this study was to evaluate the role and level of involvement of the interventional radiology in this sub-group of patients. METHODS: This was a single-centre retrospective review of all admissions for acute pancreatitis over a 5-year period. Each case was assessed to determine whether radiological intervention was utilised. RESULTS: Our review included 401 patients. A total of 18.7% (75/401) of patients required vascular access procedures and 18.4% (74/401) required image-guided drainage. A total of 1.2% (2/401) patients had embolisation procedures performed. The embolisation procedures were performed to treat a pseudoaneurysm that had formed. Overall, 20.9% (84/401) of patients were referred to the interventional radiology department for a procedure; a majority of these patients were referred for multiple procedures over the course of their admission. The patients in the 'severe pancreatitis' category had a total of 154 procedures performed, which was 65.5% of the total procedures. On average, the patients who underwent multiple interventional procedures tended to have a longer admission and more complex disease. CONCLUSION: The diagnosis and treatment of complicated acute pancreatitis is heavily dependent on the interventional radiology department. A substantial proportion of patients with pancreatitis required radiological intervention as part of their management, the proportion of which increased significantly in complex disease.

Colorectal intussusception secondary to primary rectal melanoma: A novel case report.

INTRODUCTION: Intussusception in adults is a rare condition, accounting for just 5% of all cases. Approximately 50% of cases of large intestine intussusception occur due to a malignant neoplasm. We present here a novel case report of colo-rectal intussusception arising secondary to a primary rectal melanoma. PRESENTATION OF CASE: We present the case of an 85 year-old patient, who underwent a colonoscopy for investigation of weight loss and altered bowel habit. At colonoscopy, a pigmented polypoid mass was visualised in the upper third of the rectum. The lesion was causing colo-rectal intussusception. Initial biopsies of the specimen stained positive for S-100. The patient had an MRI (magnetic resonance imaging) pelvis, which demonstrated a mass at the rectosigmoid junction, which was diffusely high signal on the fat sat T1 weighted sequence. The patient proceeded to a laparoscopic anterior resection and had an uncomplicated post-operative course. The resected specimen was sent for pathological analysis. The morphological and immunohistochemical profile was consistent with malignant melanoma. There was no evidence of cutaneous melanoma following a full skin examination. DISCUSSION: Rectal melanoma is a rare condition. We present a novel case report of colo-rectal intussusception arising secondary to rectal melanoma. CONCLUSION: This is a rare entity. This patient's pre-operative MRI and biopsy samples suggested this lesion was a rectal melanoma, which was subsequently confirmed on analysis of the resected specimen. Surgical resection of such neoplasms should be attempted where possible.

Computed tomographic evaluation of the thymus-does obesity affect thymic fatty involution in a healthy young adult population?

OBJECTIVE: To determine a relationship between increased body mass index (BMI) and fatty involution of the thymus in subjects aged between 20 and 30 years. METHODS: CT images of 94 patients aged between 20 and 30 years were reviewed. Quantitative thymic mean attenuation was recorded and qualitative thymic attenuation was assigned to 1 of 4 possible grades. BMI and subcutaneous fat thickness were documented. Correlations between thymic attenuation, and BMI and subcutaneous fat thickness were assessed using linear regression models. Differences in thymic attenuation in overweight vs normal weight patients were assessed using t-test and Pearson Χ2 analysis. RESULTS: Low mean thymic attenuation values were associated with higher patient BMI (p = 0.024). Normal weight patients had a mean quantitative thymic attenuation of 15.5 Hounsfield unit and overweight patients had a mean quantitative thymic attenuation of -16.4 Hounsfield unit (p = 0.0218). There was a significant association between increasing subcutaneous fat thickness and reduced mean quantitative thymic attenuation (p < 0.0001). There was also a significant difference in subcutaneous fat thickness when comparing qualitatively assessed thymic Grade 0 with grades 2 and 3 (p = 0.027 and 0.001 respectively); and Grade 1 with Grade 3 (p = 0.001). CONCLUSION: In patients between 20 and 30 years old, the degree of thymic fatty infiltration is related to BMI. Advances in knowledge: Multidetector CT can assess fatty involution of the thymus gland. This retrospective study demonstrates a relationship between BMI and thymus gland fatty involution. Subjects with increased subcutaneous fat have decreased mean thymus gland attenuation.

Combined Vertebral Augmentation and Radiofrequency Ablation in the Management of Spinal Metastases: an Update.

OPINION STATEMENT: Spinal metastases are the most commonly encountered tumour of the spine, occurring in up to 40% of patients with cancer. Each year, approximately 5% of cancer patients will develop spinal metastases. This number is expected to increase as the life expectancy of cancer patients increases. Patients with spinal metastases experience severe and frequently debilitating pain, which often decreases their remaining quality of life. With a median survival of less than 1 year, the goals of treatment in spinal metastases are reducing pain, improving or maintaining level of function and providing mechanical stability. Currently, conventional treatment strategies involve a combination of analgesics, bisphosphonates, radiotherapy and/or relatively extensive surgery. Despite these measures, pain management in patients with spinal metastases is often suboptimal. In the last two decades, minimally invasive percutaneous interventional radiology techniques such as vertebral augmentation and radiofrequency ablation (RFA) have shown progressive success in reducing pain and improving function in many patients with symptomatic spinal metastases. Both vertebral augmentation and RFA are increasingly being recognised as excellent alternative to medical and surgical management in carefully selected patients with spinal metastases, namely those with severe refractory pain limiting daily activities and stable pathological vertebral compression fractures. In addition, for more complicated lesions such as spinal metastasis with soft tissue extension, combined treatments such as vertebral augmentation in conjunction with RFA may be helpful. While combined RFA and vertebral augmentation have theoretical benefits, comparative trials have not been performed to establish superiority of combined therapy. We believe that a multidisciplinary approach as well as careful pre-procedure evaluation and imaging will be necessary for effective and safe management of spinal metastases. RFA and vertebral augmentation should be considered during early stages of the disease so as to maintain the remaining quality of life in this patient population group.

Risk Stratification in Multinodular Goiter: A Retrospective Review of Sonographic Features, Histopathological Results, and Cancer Risk.

PURPOSE: In the management of thyroid nodules, although the potential for malignancy exists, there is also the potential for overtreatment of subclinical disease. Although the TI-RADS (Thyroid Imaging-Reporting and Data System) system outlines a risk stratification score based on suspicious ultrasound findings, it has not been universally accepted. Many TI-RADS 2 or 3 patients proceed to fine needle aspiration biopsy (FNAB), potentially unnecessarily. The aim of the study was to identify whether lesions within a multinodular goiter (MNG) without suspicious features can be followed with ultrasound rather than biopsied as is recommended for single nodules. METHODS: Pathology records were retrospectively analysed for proven MNGs over a 5-year period. A total of 293 cases were identified. FNAB, prebiopsy ultrasound images, and reports were identified for each case. Images were reviewed and assessed for sonographically suspicious criteria guided by TI-RADS. Logistic regression was applied to determine if any sonographic features were associated with neoplasia. Odds ratios with 95% confidence intervals were calculated. RESULTS: Of 293 samples, 14 (4.7%) were neoplastic. Having no suspicious features conferred an average risk of 0.0339 (95% confidence interval: 0.02831-0.04087) of neoplasia. Risk of neoplasm significantly increased by having 1 and >1 suspicious feature (P < .001). Regarding cytological results, of 237 patients with Thy-2 cytology, 159 were followed up and 8 had a neoplasm. CONCLUSION: Ultrasound can be used to estimate risk of neoplasia in MNG. In the absence of suspicious radiological findings, follow-up with ultrasound rather than FNAB may be appropriate in patients who have a low clinical suspicion for neoplasia.

Evaluation of Knee Pain in Athletes: A Radiologist's Perspective.

Lower limb injuries account for most of all injuries suffered by athletes and the knee joint accounts for over half of these. The etiology of knee pain is multifactorial; a good history focusing on the mechanism of injury and the chronicity of pain is extremely useful in correlating with radiologic findings and establishing a clinically meaningful diagnosis. This review article will discuss several important and common causes of acute and chronic knee pain in athletes, focusing on their mechanism of injury and site of pain as well as their salient imaging findings.