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1.
Nat Commun ; 13(1): 2235, 2022 Apr 25.
Article in English | MEDLINE | ID: mdl-35468880

ABSTRACT

Existing circuit camouflaging techniques to prevent reverse engineering increase circuit-complexity with significant area, energy, and delay penalty. In this paper, we propose an efficient hardware encryption technique with minimal complexity and overheads based on ferroelectric field-effect transistor (FeFET) active interconnects. By utilizing the threshold voltage programmability of the FeFETs, run-time reconfigurable inverter-buffer logic, utilizing two FeFETs and an inverter, is enabled. Judicious placement of the proposed logic makes it act as a hardware encryption key and enable encoding and decoding of the functional output without affecting the critical path timing delay. Additionally, a peripheral programming scheme for reconfigurable logic by reusing the existing scan chain logic is proposed, obviating the need for specialized programming logic and circuitry for keybit distribution. Our analysis shows an average encryption probability of 97.43% with an increase of 2.24%/ 3.67% delay for the most critical path/ sum of 100 critical paths delay for ISCAS85 benchmarks.

2.
Korean J Pediatr ; 58(8): 294-300, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26388894

ABSTRACT

PURPOSE: It is difficult to differentiate between central precocious puberty (CPP) and premature thelarche (PT) in girls. The aim of this study was to investigate the diagnostic usefulness of pelvic ultrasonography to distinguish between CPP and PT in girls with early breast development. METHODS: This study included girls with early breast development who visited the clinic between January 2012 and December 2013. Clinical, laboratory, and pelvic ultrasonographic data were evaluated. CPP and PT were confirmed using the gonadotropin-releasing hormone stimulation test. RESULTS: A total of 248 girls aged 7-8 years were included, among whom 186 (75.0%) had CPP and 62 (25.0%) had PT. The uterine length, transverse diameter, fundus, volume, and cross-sectional area were significantly larger in the CPP group (uterine length, 2.45±0.50 cm vs. 2.63±0.49 cm, P=0.015; uterine volume, 0.95±0.62 cm(3) vs. 1.35±0.76 cm(3), P<0.001). However, there were no differences in the fundus/cervix ratio and ovarian measurements. In receiver operating characteristic analysis, a uterine volume of at least 1.07 cm(3) was the most predictive parameter for CPP with an area under the curve of 0.670 (95% confidence interval, 0.593-0.747). CONCLUSION: Uterine measurements by pelvic ultrasonography in girls with early pubertal development were significantly larger in the CPP group. However, the diagnostic value of ultrasonographic parameters was not high because of a considerable overlap of values between the two groups. Therefore, pelvic ultrasonography in combination with clinical and laboratory tests may be useful to distinguish between CPP and PT in girls.

3.
J Clin Neurosci ; 21(4): 596-600, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24412294

ABSTRACT

We compared the accuracy for localizing arterial occlusion sites between delayed-phase computed tomography angiography (CTA) and arterial-phase CTA in acute stroke patients with large vessel occlusion. Institutional Review Board approval was obtained, and informed consent was waived. For patients treated with intra-arterial thrombolysis within a 6 hour window between January 2009 and November 2011, we retrospectively assessed the arterial occlusion sites of pre-treatment, delayed-phase and arterial-phase CTA and compared these with digital subtraction angiography (DSA) findings. The positive predictive value for detection of vessel occlusion for both CTA methods was derived using DSA as a reference standard. The outcomes were compared using the McNemar test. Inter-observer disagreement within each modality was assessed using the Kendall W test. Among 73 patients treated with intra-arterial thrombolysis, 24 (32.9%) underwent both arterial-phase and delayed-phase CTA, and 66 (90.4%) underwent arterial-phase CTA only. For 24 patients undergoing both arterial-phase and delayed-phase CTA, the delayed-phase CTA detected concordant occlusion sites with DSA in 21 patients, yielding a positive predictive value of 87.5%, whereas the arterial-phase CTA detected this in 14 patients, for a positive predictive value of 58.3% (p=0.013). When discordant with DSA, arterial-phase or delayed-phase CTA indicated occlusions in more proximal sites than DSA. Delayed-phase CTA more precisely localized the occlusion site than arterial-phase CTA in acute stroke patients with large vessel occlusion. Thus, delayed-phase CTA findings could guide neurointerventionists in selecting intra-arterial thrombolysis modalities.


Subject(s)
Cerebral Angiography/methods , Stroke/diagnostic imaging , Tomography, X-Ray Computed/methods , Aged , Angiography, Digital Subtraction , Carotid Artery, Common/diagnostic imaging , Carotid Artery, Internal/diagnostic imaging , Female , Humans , Male , Middle Aged , Reperfusion/methods , Reproducibility of Results , Retrospective Studies , Stroke/drug therapy , Stroke/surgery , Surgery, Computer-Assisted/methods , Thrombolytic Therapy
4.
Clin Imaging ; 36(5): 553-8, 2012.
Article in English | MEDLINE | ID: mdl-22920361

ABSTRACT

In three-dimensional (3D) CT colonography (CTC), a wider viewing angle provides a larger field of view. The purpose of this study was to investigate the polyp detection rate and time efficiency of unidirectional 240°-angle 3D CTC compared with bidirectional 120°-angle CTC. CTC data sets of 40 patients were reviewed by two readers using the two methods. The unidirectional 240°-angle CTC showed a performance in polyp detection similar to the bidirectional 120°-angle CTC with improved time efficiency.


Subject(s)
Colonic Polyps/diagnostic imaging , Colonography, Computed Tomographic/methods , Colonic Polyps/pathology , Colonoscopy , Feasibility Studies , Female , Humans , Imaging, Three-Dimensional/methods , Male , Middle Aged , Retrospective Studies
5.
Korean J Radiol ; 12(2): 261-5, 2011.
Article in English | MEDLINE | ID: mdl-21430946

ABSTRACT

Lymphangioleiomyomatosis (LAM) is a rare idiopathic disease and this is characterized by a proliferation of abnormal smooth muscle cells in the lungs and in the lymphatic system of the thorax and retroperitoneum. The female genital tract is rarely affected by LAM. We report here on the CT and MR imaging findings of extensive LAM involving the uterus and pelvic cavity, and this was seen as multiple cystic uterine and parauterine masses with internal hemorrhage in a young female with tuberous sclerosis complex.


Subject(s)
Adnexal Diseases/diagnosis , Lymphangioleiomyomatosis/diagnosis , Magnetic Resonance Imaging , Tomography, X-Ray Computed , Uterine Neoplasms/diagnosis , Adnexal Diseases/diagnostic imaging , Adnexal Diseases/surgery , Adult , Diagnosis, Differential , Female , Humans , Hysterectomy , Lymphangioleiomyomatosis/diagnostic imaging , Lymphangioleiomyomatosis/surgery , Tuberous Sclerosis/diagnosis , Tuberous Sclerosis/diagnostic imaging , Tuberous Sclerosis/surgery , Uterine Neoplasms/diagnostic imaging , Uterine Neoplasms/surgery
6.
Korean J Radiol ; 11(5): 553-9, 2010.
Article in English | MEDLINE | ID: mdl-20808700

ABSTRACT

OBJECTIVE: The purpose of this study was to evaluate any improvement in the quality of abdominal CTs after the utilization of the nationally based accreditation program. MATERIALS AND METHODS: Approval was obtained from the Institutional Review Board, and informed consent was waived. We retrospectively analyzed 1,011 outside abdominal CTs, from 2003 to 2007. We evaluated images using a fill-up sheet form of the national accreditation program, and subjectively by grading for the overall CT image quality. CT scans were divided into two categories according to time periods; before and after the implementation of the accreditation program. We compared CT scans between two periods according to parameters pertaining to the evaluation of images. We determined whether there was a correlation between the results of a subjective assessment of the image quality and the evaluation scores of the clinical image. RESULTS: The following parameters were significantly different after the implementation of the accreditation program: identifying data, display parameters, scan length, spatial and contrast resolution, window width and level, optimal contrast enhancement, slice thickness, and total score. The remaining parameters were not significantly different between scans obtained from the two different periods: scan parameters, film quality, and artifacts. CONCLUSION: After performing the CT accreditation program, the quality of the outside abdominal CTs show marked improvement, especially for the parameters related to the scanning protocol.


Subject(s)
Accreditation , Quality Improvement , Radiography, Abdominal/standards , Tomography, X-Ray Computed/standards , Humans , Republic of Korea , Retrospective Studies
7.
Korean J Radiol ; 11(5): 560-5, 2010.
Article in English | MEDLINE | ID: mdl-20808701

ABSTRACT

Intrahepatic bile duct adenoma is a rare benign epithelial hepatic tumor derived from bile duct cells. We report the imaging findings of a patient with bile duct adenoma, which appeared as a small heterogeneously enhancing mass with focal small cystic change on CT and MRI. Follow-up images at seven months showed a slight increase in tumor size, which could be partly explained by intratumoral hemorrhage on pathologic examination. Although rare, bile duct adenoma should be considered as a differential diagnosis of a small hypervascular tumor located in the periphery of liver. Focal cystic change and intratumoral hemorrhage may occur.


Subject(s)
Adenoma, Bile Duct/diagnosis , Bile Duct Neoplasms/diagnosis , Hamartoma/diagnosis , Adenoma, Bile Duct/surgery , Bile Duct Neoplasms/surgery , Contrast Media , Female , Hamartoma/surgery , Hepatectomy , Humans , Magnetic Resonance Imaging , Middle Aged , Tomography, X-Ray Computed
8.
Abdom Imaging ; 35(2): 212-4, 2010 Apr.
Article in English | MEDLINE | ID: mdl-19283428

ABSTRACT

Giant hepatic artery aneurysm is a very rare vascular lesion, but can be detected incidentally during abdominal imaging. We report the sonographic and computed tomography (CT) features of a giant hepatic artery aneurysm in a 52-year-old woman presenting with vague abdominal discomfort. This report illustrates that a giant hepatic artery aneurysm can manifest as an incidental large mass in the porta hepatis, and we discuss the role of sonography and CT in the diagnosis of the lesion and review the natural history and clinical presentation of hepatic artery aneurysm.


Subject(s)
Aneurysm/diagnostic imaging , Hepatic Artery/diagnostic imaging , Diagnosis, Differential , Female , Humans , Incidental Findings , Middle Aged , Tomography, X-Ray Computed , Ultrasonography, Doppler, Color
9.
Radiographics ; 29(2): 495-507, 2009.
Article in English | MEDLINE | ID: mdl-19325061

ABSTRACT

Hydrosalpinx is a common adnexal lesion that may occur either in isolation or as a component of a complex pathologic process (eg, pelvic inflammatory disease, endometriosis, fallopian tube tumor, or tubal pregnancy) that leads to distal tubal occlusion. On magnetic resonance (MR) images, hydrosalpinx appears as a fluid-filled C- or S-shaped tubular structure that arises from the upper lateral margin of the uterus. Although hydrosalpinx is most often seen on ultrasonographic images, it also may be delineated on multiplanar MR images. MR imaging also may be useful for determining the cause of a hydrosalpinx or its associated adnexal process by characterizing the nature of the contents of the dilated tube. Tubal fluid with high signal intensity on T1-weighted images is suggestive of hematosalpinx associated with endometriosis and tubal pregnancy. A thickened wall of a dilated fallopian tube that displays variable or heterogeneous signal intensity may be indicative of pyosalpinx as a component of a tubo-ovarian abscess. The presence of an enhancing solid mass within a dilated tube is suggestive of fallopian tube carcinoma, whereas enhancement of the dilated tubal wall surrounding a saclike cystic mass may be indicative of a tubal pregnancy. Understanding the pathogenesis and clinical manifestations of conditions associated with hydrosalpinx may aid in the timely diagnosis of complex adnexal masses at MR imaging, enabling avoidance of unnecessary procedures.


Subject(s)
Fallopian Tube Diseases/pathology , Fallopian Tubes/pathology , Image Enhancement/methods , Magnetic Resonance Imaging/methods , Adult , Female , Humans , Middle Aged
10.
Int J Oral Maxillofac Implants ; 23(6): 1089-94, 2008.
Article in English | MEDLINE | ID: mdl-19216278

ABSTRACT

PURPOSE: This study aimed to measure the numbers of viable bone cells present in autogenous drilling dust (ADD) and mandibular particulated bone (MPB) and to histomorphometrically compare the effects of the combined use of resorbable membranes and ADD or xenografts for the treatment of dehiscence-type defects around implants. MATERIALS AND METHODS: The left mandibular premolars were extracted from 4 adult beagle dogs. After a 3-month healing period, 4 standardized bone defects were prepared on each mandible, and 1 implant was placed per defect. The 4 sites in each dog were allocated to 4 different treatment groups: 1 site received ADD alone (ADD); 1 site received a Cytoplast membrane supported by ADD (ADD+CP); 1 site received BioCera alone (BC); and the final site received a Cytoplast membrane supported by BioCera (BC+CP). Each animal received a series of 3 bone labels. Three months following these regenerative surgeries, animals were sacrificed and histomorphometric examinations were carried out. In addition, in 3 of the 4 dogs at the time of regenerative surgery, ADD was obtained using implant drills (group 1), MPB was obtained using a fissure bur and rongeur (group 2), and 1.0 cm3 of each was then cultured. Cultured cell counts and osteocalcin synthesis analysis using reverse transcription-polymerase chain reaction were performed on cells from these 2 groups at 4 and 9 weeks after regenerative surgery. Alkaline phosphatase activity (ALP) was measured at 9 weeks in both groups. RESULTS: MPB revealed greater cell counts than ADD after 4 and 9 weeks. Cells stained positively for ALP and osteocalcin in both groups. Fluorescence microscopy showed 22.4% bone formation with ADD+CP, 17.8% with BC+CP, 13.1% with ADD, and 6.4% with BC at 8 weeks. Bone regeneration heights were 2.0 mm with AD, 1.9 mm with ADD+CP, 1.7 mm with BC+CP, and 1.3 mm with BC. Bone regeneration areas measured 1.0 mm2 with ADD, 0.9 mm2 with ADD+CP, 0.6 mm2 with BC+CP, and 0.3 mm2 with BC. Bone-to-implant contacts were 53.1% with ADD, 46.6% with ADD+CP, 44.1% with BC, and 33.7% with BC+CP. CONCLUSIONS: ADD appears to be a useful material for closing dehiscence-type defects, and the use of a membrane was not found to affect bone formation during the treatment of dehiscence-type defects around implants in this study. However, larger studies are needed before fully endorsing its widespread use.


Subject(s)
Absorbable Implants , Bone Regeneration/physiology , Bone Transplantation/methods , Dental Implants/adverse effects , Guided Tissue Regeneration/methods , Mandible/surgery , Membranes, Artificial , Surgical Wound Dehiscence/surgery , Transplantation, Heterologous , Alkaline Phosphatase/analysis , Animals , Bone Density/physiology , Cell Count , Cell Survival , Cells, Cultured , Coloring Agents , Dogs , Fluorescent Dyes , Microscopy, Fluorescence , Osteocalcin/analysis , Osteocytes/pathology , Osteocytes/transplantation , Osteogenesis/physiology , Time Factors , Transplantation, Autologous
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