Iliocaval stenting for May-Thurner syndrome: Initial experience.

The aim of this report is to describe our experience in endovascular treatment of May-Thurner syndrome. We report three cases of iliocaval stenosis treated endovascularly at our institution. We included three patients age range from 41 to 85 years with two presenting with acute deep vein thrombosis and associated limb swelling and one with chronic lower limb symptoms. We reviewed the technical success, complications, and stent patency on follow-up, latter was monitored be serial imaging. The three cases of iliocaval stenosis were treated with endovascular stenting with follow-up imaging follow-up period ranged from 6 to 13 months (mean 5.6 months) with two out of the three cases maintaining stent patency. One case was complicated by intraprocedural reopening of previously venous bleed. Clinical symptoms resolved with no recurrence in two out of three cases. One case experienced symptomatic in-stent thrombosis following endovascular treatment. Endovascular treatment of iliocaval stenosis appears effective in immediate technical success. Periprocedural attention to anticoagulation and stent position are important in preventing in-stent restenosis.

Gouty tophus: Unusual case of nasal lump.

Chronic tophaceous gout is a common disease but rarely found in the head and neck region. Here we report a case of a middle aged male who presented with a mass over the right side of the nasal bridge. CT of the paranasal sinuses revealed a tophi lesion in the right nasal bridge with erosion of the underlying nasal bone. The mass was excised and histologically confirmed to be a gouty tophus. This case report illustrates how a common disease presented in an uncommon location could pose a diagnostic challenge.

Endovascular treatment of iatrogenic superior mesenteric arteriovenous fistula resulting in recurrent abdominal ascites.

Superior mesenteric arteriovenous fistulas (AVFs) are rare and are usually caused by previous bowel surgery or blunt abdominal trauma. Patients may be asymptomatic, have non-specific symptoms of abdominal pain, nausea and vomiting or present with symptoms of portal hypertension; some patients may present years after initial surgery or trauma. Traditionally, superior mesenteric AVFs are treated by surgical ligation. However, percutaneous endovascular treatment has become increasingly popular in recent years. Different options of endovascular treatment include coil embolisation, covered stent and vascular plugs. There is a risk of coil migration with coil embolisation and covered stents may cause abnormal vessel straightening. Vascular plugs allow the fistula to be treated with fewer devices and have minimal risk of migration. Newer devices such as microvascular plugs have the added advantage of being able to be delivered through microcatheters or diagnostic catheters. The smaller profile of the microvascular plug also allows it to navigate through tortuous vessels. We report a case of a 77-year-old patient presenting with recurrent abdominal ascites three years after small bowel resection. CT and angiogram demonstrated a superior mesenteric AVF, which was successfully treated with a combination of microvascular plug and coil. He remained relatively asymptomatic four months after treatment.

Olfactory Dysfunction in Coronavirus Disease 2019 Patients: Observational Cohort Study and Systematic Review.

BACKGROUND: Olfactory dysfunction (OD) has been reported in coronavirus disease 2019 (COVID-19). However, there are knowledge gaps about the severity, prevalence, etiology, and duration of OD in COVID-19 patients. METHODS: Olfactory function was assessed in all participants using questionnaires and the butanol threshold test (BTT). Patients with COVID-19 and abnormal olfaction were further evaluated using the smell identification test (SIT), sinus imaging, and nasoendoscopy. Selected patients received nasal biopsies. Systematic review was performed according to PRISMA guidelines. PubMed items from January 1, 2020 to April 23, 2020 were searched. Studies that reported clinical data on olfactory disturbances in COVID-19 patients were analyzed. RESULTS: We included 18 COVID-19 patients and 18 controls. Among COVID-19 patients, 12 of 18 (67%) reported olfactory symptoms and OD was confirmed in 6 patients by BTT and SIT. Olfactory dysfunction was the only symptom in 2 patients. Mean BTT score of patients was worse than controls (P = .004, difference in means = 1.8; 95% confidence interval, 0.6-2.9). Sinusitis and olfactory cleft obstruction were absent in most patients. Immunohistochemical analysis of nasal biopsy revealed the presence of infiltrative CD68+ macrophages harboring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen in the stroma. Olfactory dysfunction persisted in 2 patients despite clinical recovery. Systematic review showed that the prevalence of olfactory disturbances in COVID-19 ranged from 5% to 98%. Most studies did not assess olfaction quantitatively. CONCLUSIONS: Olfactory dysfunction is common in COVID-19 and may be the only symptom. Coronavirus disease 2019-related OD can be severe and prolonged. Mucosal infiltration by CD68+ macrophages expressing SARS-CoV-2 viral antigen may contribute to COVID-19-related OD.

Metal artifact reduction by monoenergetic extrapolation of dual-energy CT in patients with metallic implants.

PURPOSE: The objective of this study is to assess artifact reduction and image quality using dual-energy computed tomography (DECT) and metal artifact reduction techniques in patients with metallic implants. METHODS: Forty patients with metallic implants, who had targeted CT performed by DECT during March to September 2018, were prospectively recruited. Post-processing with monoenergetic extrapolation at 70 and 150 keV was performed. Forty matched controls with metallic implants with single-energy CT (SECT) performed were selected. Attenuation value, noise, and signal-to-noise ratio (SNR) at the site of maximal artifact were measured at muscle and fat areas. Image quality of three sets of images (70 keV, 150 keV, and SECT) was assessed by two independent reviewers using a 5-point Likert-type scale. Statistical analysis of measured values, Likert-type scales, and radiation doses (volume CT dose index (CTDIvol)) of DECT and SECT were performed with Mann-Whitney U test. RESULTS: As compared to SECT, high keV reconstruction of DECT show (1) significantly higher values within muscle and fat surrounding the implant (DECT vs. SECT-muscle: -96 Hounsfield units (HU) vs. -405 HU, fat: -115 HU vs. -301 HU; p < 0.001), (2) significantly lower mean image noise (75 HU vs. 129 HU; p = 0.02), and (3) higher SNR (-0.8 vs. -4.3; p < 0.001). In addition, image quality of high keV reconstruction was rated superior to the other two groups on Likert-type scales ( p < 0.001). The mean radiation doses (CTDIvol) were comparable between DECT and SECT (14.2 mGy vs. 19.3 mGy; p = 0.08). CONCLUSION: For patients with metallic implants, monoenergetic extrapolation of DECT at high keV can reduce metal artifacts, increase SNR, and improve qualitative image quality at comparable radiation dose.

Case 237: Renal Cell Carcinoma with Osseous Metaplasia.

History A 47-year-old man presented with palpitations and decreased exercise tolerance. A peripheral blood smear revealed anemia, thrombocytopenia, and blast cells, and a diagnosis of acute myeloid leukemia was made. Immunohistochemistry revealed positivity for cluster of differentiation (or CD) markers, which have been reported to be associated with an increased risk of extramedullary leukemic involvement. Thus, contrast material-enhanced computed tomography (CT) of the thorax, abdomen, and pelvis was requested to enable exclusion of any extramedullary extension of leukemia. Unenhanced and contrast-enhanced nephrographic phase CT was performed. Follow-up CT 3 months later showed minimal interval change in the lesion (images not shown).

Prognostic nomogram for refining the prognostication of the proposed 8th edition of the AJCC/UICC staging system for nasopharyngeal cancer in the era of intensity-modulated radiotherapy.

BACKGROUND: The objective of this study was to develop a nomogram for refining prognostication for patients with nondisseminated nasopharyngeal cancer (NPC) staged with the proposed 8th edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system. METHODS: Consecutive patients who had been investigated with magnetic resonance imaging, staged with the proposed 8th edition of the AJCC/UICC staging system, and irradiated with intensity-modulated radiotherapy from June 2005 to December 2010 were analyzed. A cohort of 1197 patients treated at Fujian Provincial Cancer Hospital was used as the training set, and the results were validated with 412 patients from Pamela Youde Nethersole Eastern Hospital. Cox regression analyses were performed to identify significant prognostic factors for developing a nomogram to predict overall survival (OS). The discriminative ability was assessed with the concordance index (c-index). A recursive partitioning algorithm was applied to the survival scores of the combined set to categorize the patients into 3 risk groups. RESULTS: A multivariate analysis showed that age, gross primary tumor volume, and lactate dehydrogenase were independent prognostic factors for OS in addition to the stage group. The OS nomogram based on all these factors had a statistically higher bias-corrected c-index than prognostication based on the stage group alone (0.712 vs 0.622, P <.01). These results were consistent for both the training cohort and the validation cohort. Patients with <135 points were categorized as low-risk, patients with 135 to <160 points were categorized as intermediate-risk, and patients with ≥160 points were categorized as high-risk. Their 5-year OS rates were 92%, 84%, and 58%, respectively. CONCLUSIONS: The proposed nomogram could improve prognostication in comparison with the TNM stage group. This could aid in risk stratification for individual NPC patients. Cancer 2016;122:3307-3315. © 2016 American Cancer Society.

Proposal for the 8th edition of the AJCC/UICC staging system for nasopharyngeal cancer in the era of intensity-modulated radiotherapy.

BACKGROUND: An accurate staging system is crucial for cancer management. Evaluations for continual suitability and improvement are needed as staging and treatment methods evolve. METHODS: This was a retrospective study of 1609 patients with nasopharyngeal carcinoma investigated by magnetic resonance imaging, staged with the 7th edition of the American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) staging system, and irradiated by intensity-modulated radiotherapy at 2 centers in Hong Kong and mainland China. RESULTS: Among the patients without other T3/T4 involvement, there were no significant differences in overall survival (OS) between medial pterygoid muscle (MP) ± lateral pterygoid muscle (LP), prevertebral muscle, and parapharyngeal space involvement. Patients with extensive soft tissue involvement beyond the aforementioned structures had poor OS similar to that of patients with intracranial extension and/or cranial nerve palsy. Only 2% of the patients had lymph nodes > 6 cm above the supraclavicular fossa (SCF), and their outcomes resembled the outcomes of those with low extension. Replacing SCF with the lower neck (extension below the caudal border of the cricoid cartilage) did not affect the hazard distinction between different N categories. With the proposed T and N categories, there were no significant differences in outcome between T4N0-2 and T1-4N3 disease. CONCLUSIONS: After a review by AJCC/UICC preparatory committees, the changes recommended for the 8th edition include changing MP/LP involvement from T4 to T2, adding prevertebral muscle involvement as T2, replacing SCF with the lower neck and merging this with a maximum nodal diameter > 6 cm as N3, and merging T4 and N3 as stage IVA criteria. These changes will lead not only to a better distinction of hazards between adjacent stages/categories but also to optimal balance in clinical practicability and global applicability.