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PubMed1986

Nuclear magnetic resonance proton imaging of bone pathology.

Thirty-two patients with diversified pathology were examined with a supraconductive NMR imager using spin echo with different TR and TE to obtain T1 and T2 weighted images. They included 20 tumors (12 primary, eight metastasis), six osteomyelitis, three fractures, two osteonecrosis, and one diffuse metabolic (Gaucher) disease. In all cases except for the stress fractures, the bone pathology was clearly visualized in spite of the normal lack of signal from the compact cortical bone. Nuclear magnetic resonance (NMR) imaging proved to be at least as sensitive as radionuclide scintigraphy but much more accurate than all other imaging procedures including computed tomography (CT) and angiography to assess the extension of the lesions, especially in tumors extended to soft tissue. This is due both to easy acquisition of sagittal and coronal sections and to different patterns of pathologic modifications of T1 and T2 which are beginning to be defined. It is hoped that more experience in clinical use of these patterns will help to discriminate between tumor extension and soft-tissue edema. We conclude that while radionuclide scintigraphy will probably remain the most sensitive and easy to perform screening test for bone pathology, NMR imaging, among noninvasive diagnostic procedures, appears to be at least as specific as CT. In addition, where the extension of the lesions is concerned, NMR imaging is much more informative than CT. In pathology of the spine, the easy visualization of the spinal cord should decrease the need for myelography.

Adolescent↗
PubMed2003

Segmentation of volumetric tissue images using constrained active contour models.

In this article we describe an application of active contour model for the segmentation of 3D histo-pathological images. The 3D images of a thick tissue specimen are obtained as a stack of optical sections using confocal laser beam scanning microscope (CLSM). We have applied noise reduction and feature enhancement methods so that a smooth and slowly varying potential surface is obtained for proper convergence. To increase the capture range of the potential surface, we use a combination of distance potential and the diffused gradient potential as external forces. It has been shown that the region-based information obtained from low-level segmentation can be applied to reduce the adverse influence of the neighbouring nucleus having a strong boundary feature. We have also shown that, by increasing the axial resolution of the image stack, we can automatically propagate the optimum active contour of one image slice to its neighbouring image slices as an appropriate initial model. Results on images of prostate tissue section are presented.

Models, Anatomic↗
PubMed1987

Multispectral magnetic resonance image analysis.

Multiecho magnetic resonance (MR) scanning produces tomographic images with approximately equal morphologic information but varying gray scales at the same anatomic level. Multispectral image classification techniques, originally developed for satellite imaging, have recently been applied to MR tissue characterization. Statistical assessment of multispectral tissue classification techniques has been used to select the most promising of several alternative methods. MR examinations of the head and body, obtained with a 0.35, 0.5, or 1.5T imager, comprised data sets with at least two pulse sequences yielding three images at each anatomical level: (1) TR = 0.3 sec, TE = 30 msec, (2) TR = 1.5, TE = 30, (3) TR = 1.5, TE = 120. Normal and pathological images have been analyzed using multispectral analysis and image classification. MR image data are first subjected to radiometric and geometric corrections to reduce error resulting from (1) instrumental variations in data acquisition, (2) image noise, and (3) misregistration. Training regions of interest (ROI) are outlined in areas of normal (gray and white matter, CSF) and pathological tissue. Statistics are extracted from these ROIs and classification maps generated using table lookup, minimum distance to means, maximum likelihood, and cluster analysis. These synthetic maps are then compared pixel by pixel with manually prepared classification maps of the same MR images. Using these methods, the authors have found that: (1) both supervised and unsupervised classification techniques yielded theme maps (class maps) which demonstrated tissue characteristic signatures and (2) tissue classification errors found in computer-generated theme maps were due to subtle gray scale changes present in the original MR data sets arising from radiometric inhomogeneity and spatial nonuniformity.

Brain↗
PubMed2005

Resuscitating the teaching of anatomical pathology in undergraduate medical education: Web-based innovative clinicopathological cases.

AIMS: Medical education has undergone substantial change in recent years, resulting in shorter, more compact courses that often contain much less pathology than previously. There has also been a concurrent decrease in the academic pathologist workforce in Australia, such that medical schools struggle to deliver even this reduced pathology curriculum. This paper reports the development and evaluation of an innovative approach in an undergraduate medical school to supporting pathology lectures, through integrating pathology with clinical medicine. METHODS: A series of 32 clinical pathological cases (CPCs) was developed to replicate clinicopathological conferences in a small group format. The CPCs were based on the pathology lectures, developed by a multidisciplinary clinical team and delivered to the students by clinical tutors. Students had access to learning support resources on the School's Intranet in both the main campus and rural teaching sites. Digitised pathology images, Web-based delivery and semi-guided learning issues are the main characteristics of the pathology module. The module was evaluated by a ranking system by the medical students for two consecutive years. RESULTS: In both years, the CPC module achieved a high score when compared with other components of the pathology curriculum. Positive feedback and frequent inquiries were also received about the module. CONCLUSION: The Web-based CPC modules provide an important resource that can facilitate teaching of pathology to medical students in the main campus and rural teaching sites. The module provides an opportunity to improve the profile of pathology in the medical school, in a manner that is sustainable with only one academic pathologist. It has the potential to be used nationally and internationally because of its multidisciplinary nature and the flexibility in its mode of delivery.

Curriculum↗
PubMed2001

[Key technologies in image analysis of comparative genomic hybridization].

Comparative genomic hybridization has become a new technique in molecular-cytogenetics, and it has found significant applications in tumor pathology. Image analysis is an important part of comparative genomic hybridization. It analyzes the fluorescent images by many steps and finally determines whether there is any abnormality in the copy number of the test tumor tissue. This paper expatiates on the key steps in the image analysis of comparative genomic hybridization, including background correction, chromosome segmentation, chromosome axis determination, karyotyping and determining ratio profile. The future trend is also discussed.

Cytogenetics↗
PubMed2006

Early bile duct carcinoma: comparison of imaging features with pathologic findings.

PURPOSE: To retrospectively evaluate the imaging features of early bile duct carcinoma and to compare these features with histopathologic findings. MATERIALS AND METHODS: The institutional review board did not require its approval or informed patient consent for this study. Twenty-one patients (13 men, eight women; mean age, 60 years; range, 48-75 years) with early bile duct carcinoma that was surgically resected and histopathologically confirmed were included. Ultrasonography (US) was performed in 15 patients, computed tomography (CT) in 21, cholangiography in 18, and magnetic resonance (MR) cholangiography in six. Two radiologists retrospectively reviewed imaging features by consensus; they compared growth pattern of tumors, integrity of the bile duct wall that harbored the tumor, and periductal infiltration with histopathologic findings. RESULTS: Pathologic specimens showed intraluminal tumor growth in all cases. Tumors were confined to the mucosa in 11 patients and involved the fibromuscular layer in 10 patients. In four of the 10 intrahepatic cholangiocarcinomas, four of the five hilar cholangiocarcinomas, and six of the six extrahepatic cholangiocarcinomas, there were intraductal tumor masses and the wall of the tumor-bearing bile ducts was preserved without periductal infiltration on US and CT images. On cholangiograms and MR cholangiograms, tumors were better delineated but the wall invasion could not be evaluated. No difference in image findings was found between carcinoma confined to the mucosa and carcinoma involving the fibromuscular layer. CONCLUSION: Imaging features of early bile duct carcinoma are a tumor mass in the bile duct lumen and integrity of the tumor-bearing bile duct wall without infiltration outside the wall.

Adenocarcinoma↗
PubMed2002

[Perthes disease].

The Legg-Calve-Perthes disease is an idiopathic avascular necrosis of the hip during early childhood. It is characterized by different stages with the main risk of persisting hip deformation, dysfunction of the joint movement, and the potential for early osteoarthritis. For the evaluation of prognosis and therapy planning patients age and extent of the necrotic area of the epiphysis are important factors. For an early diagnosis and sufficient therapy all radiological efforts have to be performed. MR imaging is an ideal method for the assessment of osteonecrotic changes of the Morbus Perthes. Compared to plain radiography by MR imaging pathologic alterations can be detected earlier and with higher specificity. However, conventional radiograms have to be still used as basic imaging modality. Nowadays x-rays and MR imaging should be the main methods for the evaluation of children suffering from Perthes disease.

Arthrography↗
PubMed1996

Radiology information and image management system: new approach to PACS with hypermedia capabilities of personal computers.

A system for archiving patient data and images was developed, installed, and evaluated in a radiology department. The system was developed with a relational database program for use with commercially available computers linked with an Ethernet network. The main options of the system are those of a conventional radiology information system: scheduling, registration, examination execution, reporting, archives and statistics, and system administration. However, the main feature of the system is the image archiving capability. Images are associated with patient records after capture by direct acquisition of the video signal or by scanning. Only relevant pathologic images are archived and a commonly employed compression algorithm is used, reducing the total memory requirement for each case to 200-600 kbytes. The diagnosis is still made by reading the original images. The low-resolution images stored in the system have an important role in teaching and consultation and as a first-line archive. Good results have been obtained with this system, which is used by medical and nonmedical staff without any special training.

Humans↗
PubMedDate not supplied

Electronically-scanned ophthalmic ultrasound.

A linear-array ultrasonic system has been developed for ophthalmic application. The clinical apparatus gives real-time digital imaging at higher speeds and sensitivity compared to contemporary mechanically-scanned single transducer equipment. The linear-array system is electronically scanned to produce 60 images s-1 with 64 gray-tone levels. The 256 X 580 pixel B-mode image is presented simultaneously with an A-mode display on a television monitor. Fast-frame imaging at high sensitivity has special advantages in ophthalmic differential diagnosis enabling a more comprehensive evaluation of retinal, vitreous and orbital pathology. Imaging of fine blood vessels has improved ultrasonic diagnosis of ocular neoplasms and inflammatory conditions. Clinical advantages of this apparatus and special technical specifications are discussed in this report.

Eye Diseases↗
PubMed1991

Aggressive papillary middle ear tumour.

A rare middle ear tumour is reported. The clinical presentation was similar to that of a glomus tumour but the pathology that of an aggressive papillary middle ear tumour. This is a recently recognized subgroup of middle ear glandular tumours. Clinical findings, imaging, pathology and treatment are presented.

Adult↗
PubMed1998

Neuroimaging in psychiatry.

The promise of neuroimaging as an aid to diagnosis is discussed, and findings from the most accessible imaging techniques are reviewed. In addition, some of the earliest findings from functional MR imaging and other technologies are presented with several illustrations. Strategies for interpretation, critique of imaging techniques, and review of major findings for brain injury, mood, anxiety, schizophrenia, and attention deficit disorders are offered. Examples of normal and pathologic images illustrate actual cases and examples of the newer imaging technologies.

Attention Deficit Disorder with Hyperactivity↗
PubMed2003

Imaging the ankle and foot and using magnetic resonance imaging.

Magnetic resonance (MR) imaging has improved the possibility of evaluating musculoskeletal structures thus gaining an important role in the diagnosis and treatment of foot and ankle pathologies. In this review, the normal and pathological images of the ankle and foot obtained using MR techniques are presented and discussed. The high soft-tissue contrast resolution and the multiplanar sections of MRI allow the imaging of contiguous tissues where small contrast differences exist, such as ligamentous and tendinous injuries or impingement syndromes. The spatial resolution with high sensitivity for bone signal changes offers an early detection of osseous abnormalities such as stress fractures or osteonecrosis. Here it is specified possibilities and limitations of MRI in the diabetic foot: this technique is superior to nuclear medicine and computed tomography (CT), however it is unable to distinguish between neuro arthropathy and infection.

Journal Article↗
PubMed2006

Multiple sclerosis: advances in understanding, diagnosing, and treating the underlying disease.

Recent advances in our understanding of the diagnosis, imaging, pathology, and clinical monitoring of multiple sclerosis (MS) have significantly increased our ability to successfully treat this often perplexing neurologic disorder. Magnetic resonance imaging (MRI) is now integral to the diagnostic process. Treatment of MS can be considered as three parallel pathways: treatment of relapses, symptom management, and long-term prevention of tissue injury.

Antibodies, Monoclonal↗
PubMed2007

Improvements in cancer staging with PET/CT: literature-based evidence as of September 2006.

PET/CT with 18F-FDG is increasingly being used for staging, restaging, and treatment monitoring for cancer patients. CT is still frequently used only for attenuation correction and lesion localization. However, increasing sales of high-end scanners that combine PET with 64-detector CT strongly suggest that the field is moving toward a comprehensive concept, whereby diagnostic CT studies during intravenous contrast material application are combined with the highest-quality PET studies. At many institutions, in-line PET/CT has replaced separately acquired PET and CT examinations for many oncologic indications. This replacement has occurred despite the fact that only a relatively small number of well-designed prospective studies have verified imaging findings against the gold standard of histopathologic tissue evaluation. However, a large number of studies have used acceptable reference standards, such as pathology, imaging, and other clinical follow-up findings, for validating PET/CT findings. From these data, we believe, has emerged reliable evidence in support of the notion that PET/CT offers diagnostic advantages over its individual components for the major cancers.

Clinical Trials as Topic↗
PubMed1989

MRI of the mandible.

Eighteen patients with abnormalities of the mandible and two normal volunteers were studied with MRI. Correlation was made with MR, CT, plain X-rays, clinical examination, and surgical findings when possible. In primary tumors of the mandible, MR was able to differentiate between solid and cystic lesions. In the cases of secondary invasion of the mandible by malignant tumors, MR was able to demonstrate replacement of the normal high signal bone marrow by low signal tumor. In some cases, the extent of marrow involvement shown on MR and confirmed at surgery was significantly underestimated by clinical examination, plain films, and CT. From this limited experience, it appears that MR may play an important role in imaging pathology of the mandible.

Humans↗
PubMed2000

Primary musculoskeletal tumors of fibrous origin.

Tumors of fibrous origin include fibrous dysplasia (FD), fibroxanthoma (nonossifying fibroma), cortical desmoid, desmoplastic fibroma, fibrosarcoma, and malignant fibrous histiocytosis (MFH). Benign fibrous lesions (FD, fibroxanthoma, and cortical desmoid) frequently demonstrate pathognomonic radiologic characteristics obviating the need for biopsy. Indeed, biopsy of these lesions can occasionally lead to confusion with more aggressive lesions. Desmoplastic fibroma and the malignant fibrous lesions (fibrosarcoma and MFH) often reveal nonspecific imaging features of a solitary nonmineralized lesion with aggressive characteristics. However, imaging is important as with other neoplasms in delineating the extent of involvement for staging purposes. This article reviews the spectrum of clinical characteristics, pathology, imaging appearances, treatment, and prognosis of lesions of fibrous origin in bone.

Bone Diseases↗
PubMed1991

[CT diagnosis in primary lung cancer (a correlative study of roentgenogram CT, surgical and pathological findings)].

A correlative study of roentgenogram, CT, surgical and pathological findings was investigated on 40 cases with primary lung cancer to evaluate differences between x-ray and CT of the chest in imaging pathological changes of lung cancer. The study revealed that CT was more sensitive than roentgenogram in showing lobulation, speculate and internal structure of SPN or masses, hilar and mediastinal adenopathy, invasion to neighbouring tissues and soft tissues of chest wall and abnormal pattern of the bronchus in cross section. Abnormal findings in CT was 67.4% higher than that in roentgenogram, CT provided more information in diagnosis of primary lung cancer. Some limitations of CT in diagnosis of primary lung cancer were also discussed.

Adenocarcinoma↗