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At least 415 records · Page 23Linked to original sources
PubMed2004

Contrast enhanced ultrasound in liver imaging.

Ultrasound contrast agents were originally introduced to enhance the Doppler signals when detecting vessels with low velocity flow or when imaging conditions were sub-optimal. Contrast agents showed additional properties, it was discovered that a parenchymal enhancement phase in the liver followed the enhancement of the blood pool. Contrast agents have made ultrasound scanning more accurate in detection and characterization of focal hepatic lesions and the sensitivity is now comparable with CT and MRI scanning. Further, analysis of the transit time of contrast agent through the liver seems to give information on possible hepatic involvement, not only from focal lesions but also from diffuse benign parenchymal disease. The first ultrasound contrast agents were easily destroyed by the energy from the sound waves but newer agents have proved to last for longer time and hereby enable real-time scanning and make contrast enhancement suitable for interventional procedures such as biopsies and tissue ablation. Also, in monitoring the effect of tumour treatment contrast agents have been useful. A brief overview is given on some possible applications and on different techniques using ultrasound contrast agents in liver imaging. At present, the use of an ultrasound contrast agent that allows real-time scanning with low mechanical index is to be preferred.

Contrast Media↗
PubMed2004

Necrosis of hippocampus and piriform lobe: clinical and neuropathological findings in two Italian cats.

The present paper reports the clinical and neuropathological findings in two cats with a neuropathologically confirmed diagnosis of necrosis of the hippocampus and piriform lobe. The cats were presented because of acute onset of behavioural changes and complex partial seizures. The neurological examination suggested a forebrain lesion. The results of blood examination were within the normal range, and the cerebrospinal fluid (CSF) analysis and computed tomography (CT) scan in one cat did not show any abnormality. Despite therapy with diazepam (Valium; Roche) there was deterioration of the clinical signs and the cats were euthanased. The neuropathological examination revealed hippocampal necrosis that included the piriform lobe.

Amygdala↗
PubMed2004

A single reformatted oblique sagittal view as an adjunct to coronal computed tomography for the evaluation of orbital floor fractures.

PURPOSE: We sought to determine whether it is beneficial to routinely include a single reformatted oblique sagittal view as an adjunct to coronal computed tomography (CT) for the evaluation and treatment of orbital floor fractures, when imaging is obtained on patients with orbital trauma. MATERIALS AND METHODS: A retrospective analysis of 12 midface CT scans was performed. All of the patients included in the study had been determined by a staff radiologist to have radiographic evidence of orbital fractures. Five surgeons who treat orbital floor fractures, but do not routinely order oblique sagittal views, were asked to evaluate the selected CT scans without being given a clinical history. The surgeons were allowed to evaluate the reformatted coronal CT and were asked to rate their ability to determine the location and the size of the fracture in a medial-lateral dimension and an anterior-posterior dimension, volume of orbital contents herniated into the maxillary sinus, and radiographic evidence of inferior rectus entrapment. The surgeons were then allowed to evaluate a single reformatted oblique sagittal view through each orbit. They were asked the same questions and these 2 additional questions, "Do you think the oblique view gave you additional information, and would it change your treatment plan?" RESULTS: Confidence in determining the size and location of the fracture in a medial-lateral dimension was not improved with the addition of the reformatted oblique sagittal view; however, location and size of the fracture in an anterior-posterior dimension and volume displaced from the orbit into the maxillary sinus and evidence of inferior rectus entrapment were improved with the addition to the oblique sagittal view. Seventy-eight percent of responders said that the oblique sagittal view provided additional information, and 18% of the responders said that the additional information changed the treatment plan. CONCLUSION: Routinely obtaining a single reformatted oblique sagittal view as an adjunct to coronal CT provides additional valuable information to the surgeon in treating orbital floor fractures. Reformatted views do not subject patients to additional radiation and the time to obtain these views is minimal.

Humans↗
PubMed2005

Video-thoracoscopic surgical pleurodesis in the management of malignant pleural effusion: the importance of an early intervention.

Thoracentesis plays an important role in cancer patients with symptomatic effusions, although its effect is short-lived and symptoms recur in almost all patients. Early video-thoracoscopic surgical pleurodesis may provide added benefit to a group of patients with advanced cancer presenting with symptomatic malignant pleural effusion. Seventy-six patients with advanced cancer and pleural effusion due to pulmonary-pleural metastases were recruited. In 51 cases (67.1%), at least one thoracentesis was performed before admission for surgery. Preoperative staging consisted of chest radiograph, CT scan, and blood gas analysis. The mean Karnofsky performance status was about 50. Pleurodesis with talc poudrage was completely successful in all patients, with a morbidity rate of 2.6%. There was no post-operative mortality. Three patients (3.9%) underwent further thoracenteses for recurrence of pleural effusion within two months after the procedure. Early use of talc insufflated by video-thoracoscopic surgery is an effective and relatively safe method for treating pleural effusion, and preventing recurrence, in advanced cancer patients.

Female↗
PubMed2005

Stereotactic computer assisted navigation: state of the art for sinus surgery, not standard of care.

There are circumstances in which image guidance is clearly useful to facilitate a more complete operation. By confirming the identity of known anatomic structures, a knowledgeable surgeon's understanding of the disease process can improve and only the necessary structures removed. CT guidance is a clear aid to understanding altered anatomy when combined with a thorough analysis of the preoperative CT scan and office nasal endoscopy. It is the combination of this preoperative planning with image guidance that allows a skilled surgeon to operate with confidence. This discussion intentionally did not refer to image guidance as the standard of care, because although this technology is clearly useful, valuable, and helpful in confirming anatomy and performing many procedures, it is not always necessary in achieving a complete operation. Therefore, it should not be considered the standard of care.

Decompression, Surgical↗
PubMed2006

Ecological and evolutionary implications of dinosaur feeding behaviour.

Dinosaurs had a wide variety of feeding mechanisms that strongly impacted on their ecology and evolution. Here, we show how novel application of technologies borrowed from medicine and engineering, such as CT scanning and Finite Element Analysis, have recently been combined with traditional approaches to result in significant advances in our understanding of dinosaur palaeobiology. Taxon-specific studies are providing quantitative data that can be used to generate and test functional hypotheses relating to jaw mechanics and feeding behaviour. In turn, these data form a basis for investigating larger scale patterns of ecological and macroevolutionary change, such as possible coevolutionary interactions and the influence of feeding adaptations on species richness, which are of more general interest to ecologists and evolutionary biologists.

Animals↗
PubMed1993

Computed tomography of vertebral tuberculosis: patterns of bone destruction.

A retrospective analysis was performed of CT scans of 30 consecutive patients with a clinical suspicion or diagnosis of spinal tuberculosis. Four patterns of bone destruction were noted, namely, fragmentary, osteolytic, subperiosteal and well-defined lytic with sclerotic margins. The fragmentary type was most common (47%). Intervertebral disc destruction was always associated with contiguous vertebral body destruction. Associated paravertebral soft-tissue masses were seen in all patients. Epidural extension of disease was seen in 66% and showed a very good correlation with neurological signs on clinical evaluation. Bone fragments were detected in the epidural soft-tissue mass in 65% of patients with epidural extension of disease. CT appearances of bone destruction are highly suggestive of tuberculous osteomyelitis in about half the patients.

Adult↗
PubMed1996

Air-trapping in extrinsic allergic alveolitis on computed tomography.

AIM: To document the phenomenon and distribution of air-trapping on computed tomography in patients with sub-acute extrinsic allergic alveolitis (EAA). PATIENTS AND METHODS: A retrospective analysis of high resolution CT scans was performed on 20 patients with proven EAA. All patients had inspiratory scans and 12 patients had expiratory scans. These were assessed for the presence and distribution of: air-trapping, ground-glass opacification and nodularity. RESULTS: Areas of decreased attenuation consistent with small airways disease was demonstrated in 15/20 patients on inspiratory scans, and confirmed to be areas of air-trapping in 11/12 patients on expiratory scans. Additional areas of air-trapping were identified in 5/11 patients on expiratory scans. 18/20 patients had found-glass opacification and 14/20 patients demonstrated a nodular patter. CONCLUSION: Air-trapping is a common finding in sub-acute extrinsic allergic alveolitis on CT and its detection is enhanced by performing expiratory scans.

Acute Disease↗
PubMed1994

Blunt renal trauma in the pediatric population: indications for radiographic evaluation.

OBJECTIVES: The purpose of this study was to define more clearly the clinical indications for radiographic evaluation of blunt renal injury in the pediatric population. METHODS: Children evaluated for blunt abdominal trauma at the Children's Hospital of Los Angeles and Los Angeles County/University of Southern California Medical Center undergo routine physical examination, laboratory analysis, and computed tomography (CT) scan of the abdomen and pelvis regardless of urinalysis results. We retrospectively evaluated the abdominal and pelvic CT scans of 412 children sustaining blunt abdominal trauma between June 1985 and June 1990. A total of 48 children, ages 6 months to 14 years (mean 5.6 years), with CT-documented renal injuries secondary to blunt trauma were identified. The radiographic findings were correlated with clinical presentation in this group of patients. RESULTS: Of the 48 children sustaining renal injuries (12% of the group), 23 (48%) had renal contusions and 25 children (52%) sustained more serious (significant) renal injuries. Of the children with significant renal injuries, 17 (68%) had minor renal lacerations and 8 (32%) had major renal lacerations. No child sustained a renal pedicle injury. All 25 children sustaining significant renal injuries presented with hematuria: 17 (68%) had microscopic (more than 3 red blood cells per high-power field) and 8 (32%) had gross hematuria. In the 23 children with renal contusions, 4 (17%) had no hematuria, 13 (57%) had microscopic hematuria, and 6 (26%) presented with gross hematuria. Hypotension occurred in 2 of the 25 children with significant renal injuries and in 2 of 23 children with renal contusions. Fifteen of the 25 patients (60%) with significant renal injuries had associated organ injuries, and 17 of the 23 children (74%) with renal contusions had associated organ injuries. CONCLUSIONS: In adults, gross hematuria and microscopic hematuria with hypertension following blunt trauma have been correlated with significant renal injuries requiring radiographic investigation. We conclude that these clinical criteria proposed to guide the radiographic evaluation of the adult population with blunt trauma do not apply to children. In our study, the degree of hematuria did not correlate with the degree of renal injury, and significant renal injury did occur with microhematuria in the absence of hypotension. We suggest that any child with a history of blunt abdominal trauma and any evidence of hematuria should undergo abdominal and pelvic CT scanning for the proper diagnosis and staging of renal and other associated intra-abdominal injuries.

Abdominal Injuries↗
PubMed1993

Orbital fat removal. Decompression for Graves orbitopathy.

BACKGROUND: Orbital decompression has been used to describe surgical procedures that remove some portion of the orbital walls to reduce pressure on the orbital contents. Substantial morbidity associated with these procedures includes infraorbital anesthesia, worsened extraocular motility, globe displacement, and blindness. The authors believe that orbital contents also may be decompressed by removing orbital fat. METHODS: Eighty-one patients with nonactive Graves orbitopathy were selected for orbital fat decompression based on the presence of proptosis and associated signs and symptoms to avoid bone removal. Soft-tissue analysis by computed tomography (CT) scan showed distended pockets of fat extending into the intraconal space, which were removed through medial-upper and lateral-lower anterior orbitotomies. Decompression with bone removal was reserved for those few patients with compressive optic neuropathy unresponsive to medical treatment and those patients with residual deforming exophthalmos after fat removal. RESULTS: One hundred fifty-eight fat decompressions were performed on 81 patients over 9 years. The authors measured an average reduction in proptosis of 1.8 mm (range, 0-6.0 mm). The greatest average reduction in proptosis (3.3 mm) was produced in patients with preoperative Hertel measurements of greater than 25.0 mm. Morbidity was limited to temporary motility impairment of the inferior oblique in two patients. CONCLUSION: The concept of orbital decompression can include removal of orbital fat to reduce proptosis, eliminate symptoms, and improve appearance with far less morbidity than when bone decompression is used as the primary decompressive procedure.

Adipose Tissue↗
PubMedDate not supplied

[Transverse fracture of the sacrum: value of imaging. A case report].

Transverse fractures of the sacrum with major displacement are rare and often misdiagnosed. A case of transverse fracture of the sacrum with cauda equina injury is reported. The diagnosis was not recognized initially. Conventional radiographs of the pelvis failed to demonstrate the fracture. True lateral sacral views and CT scan with reconstructions allowed analysis of the different sagittal fracture lines to facilitate surgical planning. These examinations should be considered in all patients with history of high energy trauma and clinical signs indicating lumbosacral injury.

Adolescent↗
PubMed1997

[Benzodiazepine withdrawal presenting as pseudo-surgical abdominal pain].

A 39-year-old patient was admitted to the emergency department for acute abdominal pain. Physical examination showed a peritoneal syndrome. However, CT-scan, Doppler and blood analysis were unremarkable. As the patient had a history of auto-medication with benzodiazepines at high doses, a withdrawal syndrome was considered. An intravenous administration of 3 mg of midazolam determined the relief of all symptoms in a few minutes.

Abdomen, Acute↗
PubMed2003

The reliability of "Analyze" software in measuring orbital volume utilizing CT-derived data.

INTRODUCTION: Craniomaxillofacial surgeons require to estimate the orbital volume in a variety of clinical situations. This paper evaluates a new method based on software analysis of computerized tomography (CT) scan data. MATERIAL AND METHODS: Five dried skulls with prosthetic globes and periorbita were non-helically scanned in an Elscint 2400 CT scanner. Images obtained were processed using the "Analyze" software package and results compared to the volume of the intraorbital prosthesis as determined by a volume displacement gravimetric method. RESULTS: Estimates of volume produced by the software varied from the gold standard by 0.06-50.44%, with a mean error of 8.8%. CONCLUSION: Despite the use of a variety of scan protocols it was not possible to obtain results with "Analyze" software which were sufficiently accurate for clinical use.

Eye, Artificial↗
PubMed1991

CT of the paranasal sinuses and functional endoscopic surgery: a critical analysis of 100 symptomatic patients.

CT scans of 100 patients from the Rhinology Clinic at the Royal National Throat, Nose and Ear Hospital were reviewed in order to test the precepts forming the basis of functional endoscopic sinus surgery, especially as they relate to the radiological investigation. These were: (a) the site of origin of sinus infection, (b) The relevance of certain anatomical variants in the middle meatus to sinus infection and (c) The use of CT as the radiological method of diagnosis in all cases. Obstruction in the middle meatus and ostiomeatal complex was associated with an increased incidence of opacity in the sinuses but the primary site of disease was not established: the concept that sinus disease takes origin in the middle meatus was not proven. Anatomical variants in the middle meatus were not associated with an increase in sinus opacity and there was no evidence that these anomalies have any effect on sinus disease by causing middle meatal stenosis. The radiological assessment of patients with inflammatory naso-sinus disease should start with plain X-ray. CT is unnecessary as a routine examination. It should be reserved for the pre-operative assessment of patients for endoscopic surgery, its main function being to show important anatomical landmarks.

Endoscopy↗
PubMed2005

Multiple gastrointestinal stromal tumors and synchronous ileal carcinoids.

BACKGROUND: A 74-year-old African-American male presented with a 3-day history of hematemesis and melena. The patient reported no abdominal pain, constitutional symptoms, bright red blood per rectum, constipation, or diarrhea. His physical examination and medical history were unremarkable except for benign prostatic hypertrophy. An esophagogastroduodenoscopy showed a 3 x 2 x 2 cm smooth round mass in the cardia, 2 cm distal to the gastroesophageal junction. Biopsy of the mass revealed an ulcerated tumor composed of spindle cells. Immunohistochemistry showed positive staining for a number of biochemical markers, including KIT, Ki-67 and smooth muscle actin, but was negative for the markers S100 and desmin. A gastric-wedge resection revealed an ulcerated 4.5 cm mass in the stomach, and exploration of the abdomen revealed two ileal carcinoid tumors, jejunal diverticula and reactive mesenteric lymphadenopathy. INVESTIGATIONS: Esophagogastroduodenoscopy, biopsy, CT scan, immunohistochemistry, DNA microarray analysis and quantitative reverse transcriptase-PCR. DIAGNOSIS: Multiple gastrointestinal stromal tumors occurring concomitantly with ileal carcinoids. MANAGEMENT: Gastric-wedge resection and segmental resection.

Aged↗
PubMedDate not supplied

[Computer-assisted periacetabular triple osteotomy for treatment of dysplasia of the hip].

AIM: Besides general risks, reorienting periacetabular osteotomies include the risks of over- or under-correction. Therefore, intraoperative computer-assisted control of the pelvic fragment may allow for precise reorientation of the acetabulum in all planes. METHODS: The advantages and problems of a computer assisted periacetabular osteotomy are demonstrated in a 19 year old female with spastic paresis and severe secondary dysplasia of the hip over a postoperative follow up period of 2 years. Because of progressive subluxation of the left femoral head with initial degenerative changes of the hip joint a pelvic triple osteotomy as described by Tönnis and an intertrochanteric derotation-varus osteotomy were performed. The intraoperative control of the acetabular position was optimized by CT based navigation. To compare and evaluate the pre- and postoperative clinical and functional outcome, X-rays, CT scans and a gait analysis were applied. RESULTS: The computer assisted orthopedic surgery (CAOS) technique allows for precise intraoperative control following reorientation of the acetabular fragment in all three planes. The pre- and postoperative clinical and radiological findings were compared and the result was classified as good. CONCLUSION: Although the costs and logistics for pelvic osteotomies are increased by CAOS technology, the authors favor this technique for corrective surgery of complex acetabular deformities, although individual parameters need to be considered in each patient.

Acetabulum↗
PubMed2002

Results of radiotherapy for orbital and adnexal lymphoma.

Twenty-five patients presenting with stage I primary orbital and/or ocular adnexal lymphoma from May 1990 through January 1997 were retrospectively reviewed at National Taiwan University Hospital. Staging workups included physical examination, chest radiography, blood analysis, whole-body CT scan, CSF examination and bone marrow biopsy. The histological types, based on the National Cancer Institute working formulation, were 17 cases of low-grade and 8 of intermediate lymphoma. Twenty patients received radiotherapy, while five cases refused. All patients except two received a radiation dose of 40 Gy, the other two received 30 Gy. The mean follow-up period was 4.7 +/- 1.6 years (2-8 years). Local control of disease was achieved in all 20 patients, but one patient with low-grade lymphoma developed disseminated disease with parotid gland, bone marrow and lung involvement 43 months after radiotherapy. Two out of five patients who refused treatment with radiotherapy developed systemic involvement 24 months and 18 months after diagnosis. Dry eye (45%) and cataract formation (35%) were among the most frequent complications in this study. One patient developed a recalcitrant trophic corneal ulcer and ultimately required corneal transplantation. In conclusion, radiotherapy is a safe and effective local treatment in the management of primary orbital or adnexal lymphoma.

Adult↗
PubMed1997

Factors influencing the tracheal fluctuation of inhaled nitric oxide in patients with acute lung injury.

BACKGROUND: Inhaled nitric oxide (NO) improves arterial oxygenation in patients with acute lung injury (ALI) by selectively dilating pulmonary vessels perfusing ventilated lung areas. It can be hypothesized that NO uptake from the lung decreases with increasing ventilation perfusion mismatch. This study was undertaken to determine the factors influencing the fluctuation of tracheal NO concentration over the respiratory cycle as an index of NO pulmonary uptake in patients with ALI. METHODS: By using a prototype system (Opti-NO) delivering a constant flow of NO only during the inspiratory phase, 3 and 6 ppm of NO were administered during controlled mechanical ventilation into a lung model and to 11 patients with ALI. All patients had a thoracic computed tomography (CT) scan. Based on an analysis of tomographic densities, lungs were divided into three zones: normally aerated (-1.000 to -500 Hounsfield units [HU]), poorly aerated (-500 to -100 HU), and nonaerated (-100 to +100 HU), and the volume of each zone was computed. Concentrations of NO in the inspiratory limb and trachea were continuously measured by a fast-response chemiluminescence apparatus. RESULTS: In the lung model, tracheal NO concentration was stable with minor fluctuation. In contrast, in patients, tracheal NO concentration fluctuated widely during the respiratory cycle (55 +/- 10%). Because uptake of NO from the lungs was absent in the lung model but present in the patients, this fluctuation was considered as an index of pulmonary uptake of NO. This was further substantiated by (1) the coincidence of the peak and minimum tracheal NO concentration with the end-inspiratory and end-expiratory phases, respectively, and (2) continued decrease of tracheal NO concentration during prolonged expiratory phase. In patients with ALI, the fluctuation of tracheal NO concentration expressed as the difference between inspiratory and expiratory NO concentrations divided by inspiratory NO concentration was greater at 6 ppm than at 3 ppm (P < 0.01), was linearly correlated with normally aerated lung volume, inversely correlated with alveolar dead space and with poorly aerated lung volume. CONCLUSION: In patients with ALI, fluctuation of tracheal NO concentration over the respiratory cycle can be considered as an index of NO uptake from the lungs that depends on aerated lung volume and perfusion of ventilated lung areas. At bedside, it may be used to follow the evolution of ventilation-perfusion mismatch.

Administration, Inhalation↗