398 research outputs found
18F-FDG PET/CT demonstrated renal and hepatic cyst infection in a patient with autosomal dominant polycystic kidney disease
Infection of renal or hepatic cyst is a serious complication of autosomal dominant polycystic kidney disease (ADPKD) and early diagnosis is crucial for the correct management. We report a case of 64-year-old male with ADPKD, who required renal transplantation some years before, with recent recurrent episodes of fever and abdominal pain, who underwent 18F-FDG PET/CT twice at 18 months intervals, after not conclusive conventional imaging studies (CT, ultrasonography). 18F-FDG PET/CT has proven to be a useful method for the diagnosis of renal and hepatic cyst infection in a patient with ADPKD and for the subseÂquent management
Ultra-low-voltage self-body biasing scheme and its application to basic arithmetic circuits
The gate level body biasing (GLBB) is assessed in the context of ultra-low-voltage logic designs. To this purpose, a GLBB mirror full adder is implemented by using a commercial 45 nm bulk CMOS triple-well technology and compared to equivalent conventional zero body-biased CMOS and dynamic threshold voltage MOSFET (DTMOS) circuits under different running conditions. Postlayout simulations demonstrate that, at the parity of leakage power consumption, the GLBB technique exhibits a significant concurrent reduction of the energy per operation and the delay in comparison to the conventional CMOS and DTMOS approaches. The silicon area required by the GLBB full adder is halved with respect to the equivalent DTMOS implementation, but it is higher in comparison to conventional CMOS design. Performed analysis also proves that the GLBB solution exhibits a high level of robustness against temperature fluctuations and process variations
A Sub-kT/q Voltage Reference Operating at 150 mV
We propose a subthreshold CMOS voltage reference operating with a minimum supply voltage of only 150 mV, which is three times lower than the minimum value presently reported in the literature. The generated reference voltage is only 17.69 mV. This result has been achieved by introducing a temperature compensation technique that does not require the drain-source voltage of each MOSFET to be larger than 4kT/q. The implemented solution consists in two transistors voltage reference with two MOSFETs of the same threshold-type and exploits the dependence of the threshold voltage on transistor size. Measurements performed over a large sample population of 60 chips from two separate batches show a standard deviation of only 0.29 mV. The mean variation of the reference voltage for VDD ranging from 0.15 to 1.8 V is 359.5 μV/V, whereas the mean variation of VREF in the temperature range from 0°C to 120°C is 26.74 μV/°C. The mean power consumption at 25 °C for VDD = 0.15 V is 26.1 pW. The occupied area is 1200 μm2
Incidental thyroid 99mTc-MDP uptake in a patient affected by differentiated thyroid cancer
We report a case of incidental uptake of 99mTc-methylene diphosphonate in the thyroid in a 62-year-old female with a history of breast cancer treated with quadrantectomy, chemotherapy and radiotherapy, who underwent total-body-bone scintigraphy during follow up. Planar scintigraphy was followed by neck SPECT-CT that demonstrated an area of increased tracer uptake in the neck at the left lobe of the thyroid. Neck ultrasonography showed a nodule corresponding to SPECT-CT finding and the ultrasound-guided fine needle aspiration documented the presence of papillary carcinoma. The patient underwent total thyroidectomy and ipsilateral lymphadenectomy; histological examination confirmed the presence of a papillary carcinoma and the patient underwent ablation therapy with iodine-131
Image-based biomechanical models of the musculoskeletal system
Finite element modeling is a precious tool for the investigation of the biomechanics of the musculoskeletal system. A key element for the development of anatomically accurate, state-of-the art finite element models is medical imaging. Indeed, the workflow for the generation of a finite element model includes steps which require the availability of medical images of the subject of interest: segmentation, which is the assignment of each voxel of the images to a specific material such as bone and cartilage, allowing for a three-dimensional reconstruction of the anatomy; meshing, which is the creation of the computational mesh necessary for the approximation of the equations describing the physics of the problem; assignment of the material properties to the various parts of the model, which can be estimated for example from quantitative computed tomography for the bone tissue and with other techniques (elastography, T1rho, and T2 mapping from magnetic resonance imaging) for soft tissues. This paper presents a brief overview of the techniques used for image segmentation, meshing, and assessing the mechanical properties of biological tissues, with focus on finite element models of the musculoskeletal system. Both consolidated methods and recent advances such as those based on artificial intelligence are described
Primary nasal-ethmoid choriocarcinoma detected by 18F-FDG PET/CT: a rare tumor with complete remission
Choriocarcinoma is a highly malignant and rare tumor characterized by secretion of the beta-subunit-of-humanchoriogonadotropin (β-HCG). We report a case of primary nasal choriocarcinoma with good response to chemotherapy. A 36-years-old woman gravida 0 and with history of 4 spontaneous abortion, in December 2018 referred to Otorhinolaryngology Department for repeated episodes of epistaxis. Cervical Magnetic Resonance Imaging (MRI) revealed a tumor mass involving right nasal cavity, right ethmoid, sphenoidal and maxillary sinuses. For a differential diagnosis between metastatic gestational choriocarcinoma and primary choriocarcinoma in January 2019 she underwent 18Fluorine-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG-PET/CT) scan that demonstrated intense uptake only in the nasal-ethmoid tumor mass showed by MRI. This was suggestive of primary nasal-ethmoid choriocarcinoma she received 3 courses of BEP – regimen and after β-HCG was reduced to 500 mIU/mL and 18F-FDG-PET/CT scan showed a decreased uptake in tumor mass but the appearance of a new uptake in cervical lymph node which was analysed and reported as metastatic localization of choriocarcinoma. Therefore she was treated with 2 cycles of TIP-regimen. Subsequents 18F-FDG-PET/CT and MRI showed a complete tumor remission. This case proved the fundamental role of PET/CT to make diagnosis of primitive choriocarcinoma and to exclude the hypothesis of distant metastasis
Incidental double neurinoma detected by 18F-choline PET/CT scan in a prostate cancer patient.
Incidental 18F-FDG PET/CT bilateral breast uptake due to carcinoma
We report a case of 71-year-old female patient, previously treated with chemotherapy and surgical resection of sigmoid tract of the large bowel for adenocarcinoma (pT3N1M0), who underwent a 18F-FDG PET/CT for a suspicious hepatic lesion detected at CT scan during follow-up. 18F-FDG PET/CT showed no abnormal uptake in the liver both at 60 minutes and 120 minutes after injection but revealed a pathological uptake in two breast nodules, (one localized in upper-internal-quadrant of the right breast and the other in the upper-external-quadrant of the left breast). The patient underwent breast MRI, which confirmed the suspicious nature of both lesions; subsequently she underwent a trucut biopsy of both lesions witch demonstrated a bilateral localization of papillary carcinoma (both lesion were classified as pT1c). The patient underwent bilateral mastectomy and the final biopsy confirmed the presence of breast cancer, while bilateral sentinel nodes biopsy showed no lymph-nodes metastases
Evolution of indeterminate hepatocellular nodules at Gd-EOB-DPTA-enhanced MRI in cirrhotic patients
To retrospectively analyze the evolution of indeterminate hepatocellular nodules in cirrhotic patients on serial Gd-EOB-DPTA-enhanced MRI, and to identify predictors of HCC development
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