Ct Scan Research Papers - Academia.edu (original) (raw)

Subarachnoid hemorrhage (SAH) is a medical emergency which can lead to death or severe disability. Misinterpretation of computed tomography (CT) in patients with SAH is a common problem. How to improve the accuracy of diagnosis is a great... more

Subarachnoid hemorrhage (SAH) is a medical emergency which can lead to death or severe disability. Misinterpretation of computed tomography (CT) in patients with SAH is a common problem. How to improve the accuracy of diagnosis is a great challenge to both the clinical physicians and medical researchers. In this paper we proposed a method for the automatic detection of SAH on clinical non-contrast head CT scans. The novelty includes approximation of the subarachnoid space in head CT using an atlas based registration, and exploration of support vector machine to the detection of SAH. The study included 60 patients with SAH and 69 normal controls from clinical hospitals. Thirty patients with SAH and 30 normal controls were used for training, while the rest were used for testing to achieve a testing sensitivity of 100% and specificity of 89.7%. The proposed algorithm might be a potential tool to screen the existence of SAH.

Primary colorectal lymphoma is a very uncommon disease; therefore, it has received little attention in the radiology literature. Moreover, imaging features of newly described pathologic subtypes have not been reported such as low-grade... more

Primary colorectal lymphoma is a very uncommon disease; therefore, it has received little attention in the radiology literature. Moreover, imaging features of newly described pathologic subtypes have not been reported such as low-grade B-cell lymphoma arising from mucosa-associated lymphoid tissue and peripheral T-cell lymphoma that involves colorectal area. We retrospectively reviewed double-contrast barium enema and CT scans in the patients with primary colorectal lymphoma. In this article the radiologic appearances of primary colorectal lymphoma are categorized into focal lesion and diffuse lesion. Focal lesion includes polypoid mass, circumferential infiltration with smooth mucosal surface, circumferential infiltration with extensive ulceration, cavitary mass, mucosal nodularity, and mucosal fold thickening. Diffuse lesion includes diffuse ulcerative lesion and diffuse nodular lesion. Peripheral T-cell lymphomas that involve the colon manifested as either a diffuse or focal segmental lesion and showed extensive mucosal ulceration. These findings are similar to those of Crohn's disease or tuberculous colitis and are different from those of previously reported colorectal lymphoma. Low-grade B-cell lymphoma arising from mucosa-associated lymphoid tissue manifest as multiple mucosal nodularity. The imaging features of primary colorectal lymphoma are quite variable and overlap with other colonic pathology; however, it is important for radiologists to know the imaging features of primary colorectal lymphoma with their pathologic correlation.

This paper compares several methods for obtaining sparse and compact point distribution models suited for data sets containing many variables. These are evaluated on a database consisting of 3D surfaces of a section of the pelvic bone... more

This paper compares several methods for obtaining sparse and compact point distribution models suited for data sets containing many variables. These are evaluated on a database consisting of 3D surfaces of a section of the pelvic bone obtained from CT scans of 33 porcine carcasses. The superior model with respect to sparsity, reconstruction error and interpretability is found to be a varimax rotated model with a threshold applied to small loadings. The models describe the biological variation in the database and are used for developing robotic tools when automating labor-intensive procedures in abattoirs.

A method for automatic segmentation of pulmonary lobes from computed tomography (CT) scans is presented that is robust against incomplete fissures. The method is based on a multiatlas approach in which existing lobar segmentations are... more

A method for automatic segmentation of pulmonary lobes from computed tomography (CT) scans is presented that is robust against incomplete fissures. The method is based on a multiatlas approach in which existing lobar segmentations are deformed to test scans in which the fissures, the lungs, and the bronchial tree have been automatically segmented. The key element of our method is a cost function that exploits information from fissures, lung borders, and bronchial tree in an effective way, such that less reliable information (lungs, airways) is only used when the most reliable information (fissures) is missing. To cope with the anatomical variation in lobe shape, an atlas selection mechanism is introduced. The method is evaluated on two test sets of 120 scans in total. The results show that the lobe segmentation closely follows the fissures when they are present. In a simulated experiment in which parts of complete fissures are removed, the robustness of the method against different ...

Background: A subset of patients with schizophrenia, defined on the basis of longitudinal deficits in self-care, may show a classic (“Kraepelinian”) degenerative course. An independent validator of the phenomenologically defined... more

Background: A subset of patients with schizophrenia, defined on the basis of longitudinal deficits in self-care, may show a classic (“Kraepelinian”) degenerative course. An independent validator of the phenomenologically defined Kraepelinian subtype might be provided by a structural indicator of possible brain degeneration: ventricular size as measured by computed tomography (CT).Methods: To examine whether Kraepelinian patients would show a differential increase in ventricular size over time, two CT scans were conducted at intervals separated by >4 years, an average of 5 years. Fifty-three male patients with DSM-III-R diagnoses of chronic schizophrenia were subdivided into Kraepelinian (n = 22; mean age = 42 ± 8.6 years) and non-Kraepelinian (n = 31; mean age = 38 ± 12.2 years) subgroups. Kraepelinian patients were defined on the basis of longitudinal criteria: >5 years of complete dependence on others for life necessities and care, lack of employment, and sustained symptomatology. Thirteen normal elderly volunteers (mean age = 60 ± 17.8) were also scanned at 4-year intervals. CT measurements were made by raters without knowledge of subgroup membership. A semiautomated computer program was used to trace the anterior horn, lateral ventricles, and temporal horns for each slice level on which they were clearly seen.Results: The ventricles showed a bilateral increase in size over the 4-year interval in the Kraepelinian subgroup, more marked in the left hemisphere than the right. By contrast, neither the non-Kraepelinian subgroup nor the normal volunteers showed significant CT changes from scan 1 to scan 2.Conclusions: Thus, the longitudinal dysfunctions in self-care that characterize the Kraepelinian patients were associated with an independent indicator of brain abnormality.

This is a case report of an 85-year old patient who presented with abdominal pain, nausea and vomiting associated with altered liver function test. The plain X-rays and CT scan showed pneumobilia with an ectopic gallstone. The patient was... more

This is a case report of an 85-year old patient who presented with abdominal pain, nausea and vomiting associated with altered liver function test. The plain X-rays and CT scan showed pneumobilia with an ectopic gallstone. The patient was diagnosed with Bouveret syndrome and managed surgically. The report is followed by a discussion about Bouveret syndrome.

CT bronchus sign (BS) designates a bronchus leading directly to a peripheral pulmonary lesion. The objective of this investigation is to determine the contribution of BS-guided bronchoscopic multiple diagnostic procedures (BMDPs) to the... more

CT bronchus sign (BS) designates a bronchus leading directly to a peripheral pulmonary lesion. The objective of this investigation is to determine the contribution of BS-guided bronchoscopic multiple diagnostic procedures (BMDPs) to the diagnostic yield of solitary nodules or masses (SPNMs) suspected of pulmonary carcinoma (PC). A prospective study was carried out in 92 patients with a 2–5 cm diameter

The aim of the study was to define a simple system for the identification of unknown bodies by using CT images of frontal sinus and to discuss whether it was worth to add measurements to the system or not. The system was including simple... more

The aim of the study was to define a simple system for the identification of unknown bodies by using CT images of frontal sinus and to discuss whether it was worth to add measurements to the system or not. The system was including simple features as F (presence or absence of frontal sinus), S (intersinus and intrasinus septum) and S (scalloping), and named as FSS system. Measurements selected for the study were width, height, anteroposterior length, total width of two sinuses, the distance between the highest points of the two sinuses and the distance of each sinus to its maximum lateral limit.
The study was conducted retrospectively on the paranasal CT scans of 100 cases (38 male and 62 female) who had no apparent sinonasal pathology. All the features and measurements were coded according to the system defined by the authors for each case and coded formulas were compared. At least 93 % of the formulas could be eliminated for a case by using FSS system. The rate of success was increased to 98 % by adding measurements. Contrary to objective criteria of FSS system, measurements were prone to bias. Therefore, in practice success rate would be expected to be lower than calculated.
In the study population, instead of making 100 measurements, eliminating the most of the cases with FSS system and later discriminating the rest by pattern matching was seen logical.