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.

3D dissimilar-siamese-u-net for hyperdense Middle cerebral artery sign segmentation.

The hyperdense middle cerebral artery sign (HMCAS) representing a thromboembolus has been declared as a vital CT finding for intravascular thrombus in the diagnosis of acute ischemia stroke. Early recognition of HMCAS can assist in patient triage and subsequent thrombolysis or thrombectomy treatment. A total of 624 annotated head non-contrast-enhanced CT (NCCT) image scans were retrospectively collected from multiple public hospitals in Hong Kong. In this study, we present a deep Dissimilar-Siamese-U-Net (DSU-Net) that is able to precisely segment the lesions by integrating Siamese and U-Net architectures. The proposed framework consists of twin sub-networks that allow inputs of left and right hemispheres in head NCCT images separately. The proposed Dissimilar block fully explores the feature representation of the differences between the bilateral hemispheres. Ablation studies were carried out to validate the performance of various components of the proposed DSU-Net. Our findings reveal that the proposed DSU-Net provides a novel approach for HMCAS automatic segmentation and it outperforms the baseline U-Net and many state-of-the-art models for clinical practice.

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.

Predictors of the success and failure of emergency pelvic artery embolisation for primary postpartum haemorrhage: a 12-year review.

INTRODUCTION: This study aimed to identify predictors of the outcome and clinical efficacy of emergency pelvic artery embolisation (PAE) for primary postpartum haemorrhage (PPH) and to assess the post-embolisation fertility of PAE patients in a regional hospital setting. METHODS: A 12-year retrospective study of patients undergoing emergency PAE was conducted at a regional acute general hospital. Clinical and procedural parameters, clinical outcomes and post-embolisation pregnancy success rates were analysed. RESULTS: There were 47,221 deliveries at the hospital during the study period, of which 33 patients required urgent PAE for primary PPH. The technical success rate of embolisation was 97.0% (n = 32). Clinically adequate haemostasis was achieved by a single embolisation procedure in 24 (72.7%) patients; the remaining eight eventually required surgery to achieve cessation of bleeding. Among the parameters studied, multivariate logistic regression analysis showed that pre-embolisation platelet count (p = 0.036) and maternal age (p = 0.019) were the only significant independent predictors of embolisation failure. Only two patients successfully conceived after PAE, although one of them had an ectopic pregnancy. CONCLUSION: Emergency PAE is an effective measure to arrest life-threatening bleeding in patients with primary PPH. As low pre-embolisation platelet count and advanced maternal age are associated with higher odds of embolisation failure, careful post-embolisation monitoring may be required for such patients. Embolisation also allows subsequent pregnancy. However, further studies are required to assess the outcomes of post-embolisation pregnancies.

An unusual case of gastric cancer presenting with breast metastasis with pleomorphic microcalcifications.

Breast metastasis from gastric carcinoma is rare. We present a case of right breast mass with microcalcification in which the diagnosis of poorly differentiated adenocarcinoma from the stomach was made after a biopsy. Pleomorphic microcalcification was noted in the ill-defined breast mass, which is a rare feature in breast metastasis. Since breast metastasis usually signifies advanced metastatic disease, differentiating primary breast cancer from metastasis is important for appropriate treatment.

Diagnostic challenge of lipomatous uterine tumors in three patients.

Lipomatous uterine tumors are uncommon benign neoplasms, with incidence ranging from 0.03% to 0.2%. They can generally be subdivided into two types: pure or mixed lipomas. A third group of malignant neoplasm has been proposed, which is liposarcoma; however, this is very rare. In this article, we report three patients having lipomatous uterine tumors, including one uterine lipoma and two uterine lipoleiomyomas. All our patients are postmenopausal women, which is the typical presenting age group. They did not have any symptoms and the tumors were only found incidentally on imaging. However, in some patients, symptoms may uncommonly occur. If symptoms occur, these are similar to those of leiomyoma. We illustrate the imaging features of the tumors in our patients with ultrasound, computed tomography (CT) scan and magnetic resonance imaging (MRI). The tumor typically appears as a well-defined homogenously hyperechoic lesion on ultrasound. It shows fat density on CT scan and signal intensity of fat on MRI. MRI is the modality of choice because of its multiplanar capability and its ability to demonstrate fat component of the lesion, as illustrated in our cases. We also discuss the importance of differentiating lipomatous uterine tumors from other lesions, especially ovarian teratoma which requires surgical intervention. Despite the rarity and the common asymptomatic nature of the tumors, we believe that this series of three cases demonstrates a review of a rare tumor which provides important knowledge for patient management.