Significant unfavorable geometrical changes in ascending aorta despite stable diameter at follow-up.

OBJECTIVE: The clinical importance of following up on the ascending aortic diameter lies in the fundamental presumption that wall pathology eventually manifests as a change in shape. However, the diameter describes the vessel locally, and the 55 mm criterion fails to prevent most dissections. We hypothesized that geometric changes across the ascending aorta are not necessarily imprinted on its diameter; i.e. the maximum diameter correlates weakly and insignificantly with elongation, surface stretching, engorgement, and tortuosity. METHODS: Two databases were interrogated for patients who had undergone at least 2 ECG-gated CT scans. The absence of motion artifacts permitted the generation of exact copies of the ascending aorta which then underwent three-dimensional analysis producing objective and accurate measurements of the centreline length, surface, volume, and tortuosity. The correlations of these global variables with the diameter were explored. RESULTS: Twenty-two patients, 13 male and 9 female, were included. The mean age at the first and last scan was 63.7 and 67.1 y, respectively. The mean diameter increase was approximately 1 mm/y. There were no dissections, while 7 patients underwent preemptive surgery. The yearly change rate of the global variables, normalized to height if applicable, showed statistically insignificant, weak, or negligible correlation with diameter increments at follow-up. Most characteristically, a patient's aorta maintained its diameter, while undergoing 1 mm/y elongation, 151 mm2/(y·m) stretching, 2366 mm3/(y·m) engorgement, and 0.02/y tortuosity. CONCLUSION: Maximum diameter provides a local description of the ascending aorta and cannot fully portray the pathological process across this vessel. Following up the diameter is not suggestive of length, surface, volume, and tortuosity changes.

Rapid Progression of Angiosarcoma in a Man with a Left Psoas Muscle Hematoma and a Recent EVAR of Abdominal Aorta.

Angiosarcoma is a rare type of soft tissue cancer with several clinical presentations and a poor prognosis. We present a case of a 75-year-old man who was admitted due to anemia and fatigue. The patient had undergone an endovascular repair (EVAR) of a 9 cm infrarenal aneurysm of the abdominal aorta two months ago. A computed tomography (CT) scan of the abdomen on admission indicated a Type-II endoleak and a large hematoma of the left psoas muscle with multiple sites of intramuscular extravasation. Osseous metastases were found at the head of the left femoral head and at the iliac bones. A CT guided biopsy of the femoral head revealed an angiosarcoma of unknown primary site a few days after the patient had died from intra-alveolar hemorrhage caused by lung metastases.

Massive pericardial effusion without cardiac tamponade due to subclinical hypothyroidism (Hashimoto's disease).

CONTEXT: Hypothyroidism is a significant cause of pericardial effusion. However, large pericardial effusions due to hypothyroidism are extremely rare. Hormone replacement therapy is the cornerstone of treatment for hypothyroidism and regular follow-up of patients after initiation of the therapy is indicated. Herein, the case of a 70-year-old woman with a massive pericardial effusion due to Hashimoto's disease is presented. ISSUES: A 70-year-old female from a rural village on the island of Crete, Greece, was admitted to our hospital due to a urinary tract infection. She was under hormone replacement therapy with levothyroxine 100 µg once a day for Hashimoto's disease. Two years previously, the patient had had an episode of pericarditis due to hypothyroidism and had undergone a computed tomography-guided pericardiocentesis. The patient did not have regular follow-up and did not take the hormone replacement therapy properly. On admission, the patient's chest X-ray incidentally showed a possible pericardial effusion. The patient was referred for echocardiography, which revealed a massive pericardial effusion. Beck's triad was absent. Thyroid hormones were consistent with subclinical hypothyroidism: thyroid-stimulating hormone (TSH) 30.25 mIU/mL (normal limits: 0.25-3.43); free thyroxin 4 0.81 ng/dL (normal limits: 0.7-1.94). The patient had a score of 5 on the scale outlined by the European Society of Cardiology (ESC) position statement on triage strategy for cardiac tamponade and, despite the absence of cardiac tamponade, a pericardiocentesis was performed after 48 hours. The patient was treated with 125 µg levothyroxine orally once daily. LESSONS LEARNED: This was a rare case of an elderly female patient from a rural village with chronic massive pericardial effusion due to subclinical hypothyroidism without cardiac tamponade. Hypothyroidism should be included in the differential diagnosis of pericardial effusion, especially in a case of unexplained pericardial fluid. Initiation of hormone replacement therapy should be personalised in elderly patients. TSH levels >10 mU/L usually require therapy with levothyroxine in order to prevent adverse events. Rural patients usually do not have regular follow-up after the initiation of hormone replacement therapy. Pericardial effusions due to hypothyroidism grow slowly and subclinical hypothyroidism rarely shows signs and symptoms and can be underdiagnosed. The ESC position statement on triage strategy for pericardial diseases is a valuable clinical tool to estimate the necessity for pericardial drainage in such cases.

Multifocal bone and bone marrow lesions in children - MRI findings.

Polyostotic bone and bone marrow lesions in children may be due to various disorders. Radiographically, lytic lesions may become apparent after loss of more than 50% of the bone mineral content. Scintigraphy requires osteoblastic activity and is not specific. MRI may significantly contribute to the correct diagnosis and management. Accurate interpretation of MRI examinations requires understanding of the normal conversion pattern of bone marrow in childhood and of the appearances of red marrow rests and hyperplasia. Differential diagnosis is wide: Malignancies include metastases, multifocal primary sarcomas and hematological diseases. Benign entities include benign tumors and tumor-like lesions, histiocytosis, infectious and inflammatory diseases, multiple stress fractures/reactions and bone infarcts/ischemia.

Innovation diffusion modeling: the deterministic, stochastic and chaotic case.

The field of innovation diffusion modeling showed a tremendous growth process during the last decades. Numerous qualitative and quantitative studies have been presented followed by significant applications in various scientific fields. This review paper explores the main quantitative developments on innovation diffusion and the gradual progress from the original deterministic models to their stochastic and chaotic alternatives. Related applications are presented.