Assessment of material identification and quantification in the presence of metals using spectral photon counting CT.

Spectral Photon Counting Computed Tomography (SPCCT), a ground-breaking development in CT technology, has immense potential to address the persistent problem of metal artefacts in CT images. This study aims to evaluate the potential of Mars photon-counting CT technology in reducing metal artefacts. It focuses on identifying and quantifying clinically significant materials in the presence of metal objects. A multi-material phantom was used, containing inserts of varying concentrations of hydroxyapatite (a mineral present in teeth, bones, and calcified plaque), iodine (used as a contrast agent), CT water (to mimic soft tissue), and adipose (as a fat substitute). Three sets of scans were acquired: with aluminium, with stainless steel, and without a metal insert as a reference dataset. Data acquisition was performed using a Mars SPCCT scanner (Microlab 5×120); operated at 118 kVp and 80 µA. The images were subsequently reconstructed into five energy bins: 7-40, 40-50, 50-60, 60-79, and 79-118 keV. Evaluation metrics including signal-to-noise ratio (SNR), linearity of attenuation profiles, root mean square error (RMSE), and area under the curve (AUC) were employed to assess the energy and material-density images with and without metal inserts. Results show decreased metal artefacts and a better signal-to-noise ratio (up to 25%) with increased energy bins as compared to reference data. The attenuation profile also demonstrated high linearity (R2 >0.95) and lower RMSE across all material concentrations, even in the presence of aluminium and steel. Material identification accuracy for iodine and hydroxyapatite (with and without metal inserts) remained consistent, minimally impacting AUC values. For demonstration purposes, the biological sample was also scanned with the stainless steel volar implant and cortical bone screw, and the images were objectively assessed to indicate the potential effectiveness of SPCCT in replicating real-world clinical scenarios.

A Tangled Autoimmune Trio: Multiple Sclerosis, Systemic Lupus Erythematosus and Antineutrophil Cytoplasmic Antineutrophil Cytoplasmic Antibody Vasculitis.

The coexistence of multiple autoimmune diseases in the same individual is unusual and has received little attention in the literature. We present a young female patient with multiple sclerosis, systemic lupus erythematosus, and biopsy-proven renal proteinase 3 antineutrophil cytoplasmic antibodyassociated vasculitis who responded well to intravenous rituximab clinically and serologically.

Comprehensive description of the prevalence, serological and clinical characteristics, and visceral involvement of systemic sclerosis (scleroderma) in a large cohort from the United Arab Emirates Systemic Sclerosis Registry.

Systemic sclerosis is an autoimmune condition characterized by a wide range of clinical presentations. Registries may serve to expand understanding about systemic sclerosis and aid in patient care and follow-up. The objective of this study was to analyze the prevalence of systemic sclerosis in a large cohort from the United Arab Emirates Systemic Sclerosis Registry and find the significant similarities and differences between the different subsets. All scleroderma patients in the United Arab Emirates were included in this multicenter national retrospective analysis. Data on demographics, comorbidities, serological characteristics, clinical aspects, and treatment were collected and analyzed, highlighting the most common traits identified. A total of 167 systemic scleroderma patients from diverse ethnic backgrounds were enrolled. Overall, 54.5% (91/167) of the patients were diagnosed with diffuse cutaneous systemic sclerosis, and 45.5% (76/167) with limited cutaneous systemic sclerosis. The prevalence of systemic sclerosis was 1.66 per 100,000 for the total registry and 7.78 per 100,000 for United Arab Emirates patients. Almost all patients in the diffuse cutaneous systemic sclerosis and limited cutaneous systemic sclerosis groups tested positive for the immunofluorescence antinuclear antibody. Antibodies against Scl-70 were significantly more associated with diffuse cutaneous systemic sclerosis, whereas anticentromere antibodies were significantly more associated with the limited cutaneous systemic sclerosis group (p < 0.001). Sclerodactyly, shortness of breath, and digital ulcers were more common in diffuse cutaneous systemic sclerosis patients compared with the limited cutaneous systemic sclerosis subtype in terms of clinical symptoms and organ involvement. Telangiectasia was much more common in the limited cutaneous systemic sclerosis group. Furthermore, diffuse cutaneous systemic sclerosis patients had more lung fibrosis (interstitial lung disease) than limited cutaneous systemic sclerosis patients (70.5% vs 45.7%), and pulmonary arterial hypertension was twice as common in limited cutaneous systemic sclerosis patients as it was in diffuse cutaneous systemic sclerosis patients. Local registries are paramount to understanding the clinical/serological characteristics of scleroderma. This study emphasizes the importance of raising disease awareness and distinguishing between the various systemic sclerosis subsets to implement patient-tailored strategies for early detection, better management, and higher quality of care.

Lower back pain as a manifestation of acute gouty sacroiliitis: Utilization of dual-energy computed tomography (DECT) in establishing a diagnosis.

Gout is the most common inflammatory arthritis which initially presents as a monoarthritis that usually favours peripheral joints namely the 1st MTP. It was reported in the literature to rarely involve the axial joint, such as the sacroiliac joint, and often mimics seronegative spondyloarthritis (SpA). Gout is a male disease and after menopause the risk in females is equal to males. Previous reports describe male patients developing gout involving the SI joint. We report a lady with a history of gout presenting with acute onset lower back pain. MRI of the sacroiliac joints revealed unilateral sacroilitis. With the help of Dual-Energy Computed Tomography (DECT) which is a newer imaging technique, a diagnosis of gout involving the sacroiliac joint was established. Gout involving the sacroiliac joints is rare, however it should be considered in the differential diagnosis in patients with unilateral sacroilitis given the similarity in presentation to SpA. Utilization of newer imaging modalities including DECT can highly guide in establishing a diagnosis and providing the correct treatment.

Hereditary Angioedema Type II: First Presentation in Adulthood with Recurrent Severe Abdominal Pain.

A 27-year-old Emirate man presented to Cleveland Clinic Abu Dhabi emergency department with a 4 year history of recurrent episodes of severe swellings affecting different parts of his body. He used to get 2 swelling episodes every week affecting either his face, hands, feet or scrotum and severe abdominal pain twice a week. Abdominal CT scan and a colonoscopy showed bowel wall oedema. There was no family history of similar complaint or of hereditary angioedema (HAE). Complement studies confirmed the diagnosis of HAE type II. He was commenced on danazol 100 mg twice daily and his symptoms resolved. This case report highlights the importance of considering HAE in patients with recurrent unexplained abdominal pain even in the absence of positive family history of HAE.

Cutaneous metastatic lung cancer detected with 18F-FDG PET.

A 48-year-old male smoker presented with a chief complaint of persistent cough for three months. A CT scan revealed only a large right paratracheal mass. The plan was to obtain histological confirmation of suspected lung cancer via bronchoscopy and mediastinoscopy. A whole body 18F-FDG (2-deoxy-2-[18F]fluoro-D-glucose) PET Scan was ordered for staging and localization of the most accessible biopsy site. There was a large, intense hypermetabolic focus corresponding to the paratracheal lesion seen on CT, as well as a lesion in the right adrenal gland. There was also a superficial, subcutaneous hypermetabolic lesion in the mid-back. The subcutaneous lesion, which previously had not been noted, was biopsied and proved to be metastatic adenocarcinoma consistent with the lung primary. This case illustrates the clinical utility of reporting soft tissue abnormalities, which may provide an alternative, more readily accessible location for biopsy that is both safer and less expensive than bronchoscopy or mediastinoscopy.

Usefulness of electron beam computed tomography for diagnosis of an anomalous origin of a coronary artery from the opposite sinus.

The ectopic origination of a coronary artery from the opposite sinus is a rare condition, often discovered as an incidental finding during invasive catheter angiography performed for the evaluation of atherosclerotic coronary artery disease. Although most patients lack hemodynamic significance, a small fraction of these anomalies have been associated with sudden cardiac death and ischemic complications. The exact anatomic definition of the anomalous coronary artery and its course, especially in relation to the ascending aorta and the pulmonary trunk, is therefore crucial for every imaging modality that attempts coronary artery visualization. To underline the potential of 3-dimensional electron-beam computed tomography as an important complement to invasive angiography in the delineation of anomalous coronary arteries, this study focused on the potentially malignant ectopic contralateral origination of a coronary artery.

Three-dimensional noninvasive contrast-enhanced electron beam tomography angiography of the kidneys: adjunctive use in medical and surgical management.

OBJECTIVE: To indicate the use of 3D electron beam computerized tomography angiography (EBCTA) for renal artery lesions, vascular variants that are crucial to detect before surgery, especially partial nephrectomy and extension of the intravascular tumor. METHODS: Forty patients (30 men, 10 women, age range 13-82, mean age 54.2) underwent EBCT (GE-Imatron, C 150 ultrafast CT scanner) of the renal arteries. It is essential to review the axial images for all necessary information before the 3D technique is performed. RESULTS: Maximum intensity projection (MIP) and volume rendering (VR) images were excellent in demonstrating stenosis of the renal arteries. Accessory and main renal arteries were easily depicted, and stenosis has been shown. In our study, among 40 renal angiography patients, 21 had stenosis of the renal arteries with different percentages. A total of 12 accessory renal arteries (five left, seven right) were detected. EBCT, with its 3D techniques, was found to be accurate and useful for renal vascular anatomy as a noninvasive test to delineate renal tumors and renal anatomy prior to nephron sparing surgery because it is known to conserve normal renal parenchyma adjacent to tumor. CONCLUSION: EBCT, with its noninvasive VR and MIP techniques, is easy to apply and is functional and accurate for neoplasms, renal vascular anatomy and renal artery stenosis.

Multicentric giant cell tumor of the fourth and fifth metacarpals with lung metastases.

Giant cell tumors of bone (GCTB) are generally benign neoplasms, but recently, some authors consider them to be low-grade malignant neoplasms because they have a relatively high rate of recurrence and at least some potential for metastases. The majority of GCTB are unifocal, and less than 1 % are multicentric. We report a rare case of a multicentric GCTB arising simultaneously in the non-dominant fourth and fifth metacarpals of a 25-year-old female. The patient underwent ray amputation of the two involved digits, and the surgical margins were histologically negative for tumor. The tumor had the classic histologic appearance of a benign GCTB. A year after the amputation, the patient developed pulmonary metastasis which was treated with pulmonary lobe resection. She is currently over 2.5 years postsurgical treatment of the primary lesion with no evidence of local recurrence or distant metastasis.

Multimodality diagnostic imaging of diffuse esophageal leiomyomatosis.

A case of diffuse esophageal leiomyomatosis is presented, with emphasis on the imaging findings across multiple contemporary diagnostic modalities. This entity represents a rare presentation of uncommon benign smooth muscle tumors of the esophagus. The characteristic clinical, histologic, and multimodality imaging findings may distinguish this benign tumor from its malignant counterpart leiomyosarcoma and from achalasia.

Congenital coronary anomalies in adults: comparison of anatomic course visualization by catheter angiography and electron beam CT.

The objective of this study was to compare the anatomic course of anomalous coronary arteries by axial and three-dimensional volume-rendered electron beam computed tomography (EBCT) angiography and X-ray catheter angiography (CAG). We performed a blinded study where patients who previously underwent CAG with (n = 14) and without (n = 14; age- and gender-matched controls) anomalous coronary anatomy were studied with EBCT coronary angiography. Forty to 50 EKG-triggered 3 mm overlapping axial slices were acquired with 2 mm table movement within one breath hold during the i.v. injection of 140 cc of nonionic iodinated contrast (4 ml/sec). The axial source images and volume-rendered three-dimensional reconstructions were evaluated for the presence, type, and course of coronary anomalies and the results were compared to those of CAG. All normal and anomalous coronary arteries were identified by both modalities in all subjects. Identified anomalies include single coronary artery (n = 3), left-sided right coronary artery (n = 3), right-sided left main coronary artery (n = 3), anterior descending coronary artery (n = 2), circumflex coronary artery (n = 2), and separate left-sided ostia for left anterior descending and circumflex coronary arteries (n = 1). In five cases, there was discrepancy in the course of the anomalous vessels between the two modalities. Consensus reading among cardiologist and radiologists favored the interpretation of EBCT over catheter angiography. Noninvasive EBCT coronary angiography compares well with CAG in identifying anomalous coronary arteries and may provide confirmatory evaluation of their precise anatomic relationships to the heart and great vessels.

Atherosclerosis and vascular calcification are independent predictors of left ventricular hypertrophy in chronic haemodialysis patients.

BACKGROUND: Accelerated atherosclerosis and vascular calcification are common in chronic haemodialysis (HD) patients. In this study, we aimed to investigate the relationship between left ventricular hypertrophy (LVH) in HD patients and atherosclerosis and vascular calcification measured by electron beam computed tomography (EBCT). METHODS: In a cohort of 118 HD patients (52 male, 66 female, mean age: 46+/-13 years), we measured biochemical parameters, including BUN, creatinine, albumin, haemoglobin, C-reactive protein and fibrinogen levels, and performed echocardiography, high-resolution B-mode carotid ultrasonography and EBCT in 85 of them. The degree of stenosis was measured at four different sites (communis, bulbus, interna and externa) in both carotid arteries. Carotid plaque scores were calculated by summing the degrees of stenosis measured at all locations. RESULTS: LVH was detected in 89 of the patients (75%). Plaque-positive patients had higher left ventricular mass index (LVMI) than plaque-negative patients (175+/-59 vs 143+/-46 g/m2, P = 0.003). LVMI was correlated with systolic blood pressure (r = 0.62, P<0.001), pulse pressure (r = 0.58, P<0.001), haemoglobin levels (r = - 0.25, P = 0.008), carotid plaque score (r = 0.32, P = 0.001) and coronary (CACS) and aortic wall calcification score (AWCS) (r = 0.34, P = 0.002 and r = 0.43, P<0.001, respectively). Multiple linear regression analysis (model r = 0.76) showed the independent factors related to LVMI to be systolic blood pressure, pulse pressure, CACS and presence of carotid plaques. CONCLUSION: Extra-coronary atherosclerosis and vascular calcification are associated with LVH in HD patients. Whether the treatment of atherosclerosis or vascular calcification may cause regression of or even prevent LVH in HD patients remains to be seen.