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PubMed2000

Correlation of preoperative computed tomography and postoperative ocular motility in orbital blowout fractures.

PURPOSE: To determine a relationship between preoperative soft tissue disruption and postoperative ocular motility in orbital blowout fractures. METHODS: This retrospective cohort study reviewed 30 patients who met all criteria: retrievable coronal computed tomography (CT) scans; internal fractures of the orbital floor, with or without medial wall extension; preoperative diplopia; repair by a single surgeon; complete release of entrapped tissues; and postoperative binocular visual fields (BVFs). Motility outcomes were quantified by one group of the authors, who measured the vertical fusion within BVFs. Other authors analyzed CT scans, designating each fracture as either A or B, based on lesser or greater soft tissue distortion relative to the configuration of bone fragments. The interval between trauma and surgery was also determined. RESULTS: Among the 15 patients with a postoperative motility outcome poorer than the median (86 degrees or less), four (27%) had A fractures; 11 (73%) had B fractures. Among the 15 patients with an outcome better than the median (88 degrees or more), 10 (67%) had A fractures; five (33%) had B fractures. Differences were more defined away from the median. Among five patients with B fractures and better than the median result, three (60%) had surgical repair during the first week after injury. Among the 11 patients with B fractures and less than the median result, one (9%) had repair during the first week. CONCLUSIONS: Postoperative motility is influenced by soft tissue-bone fragment relationships. Whether the outcome can be altered by earlier surgery in selected cases will be determined by prospective studies.

Cohort Studies↗

PubMed2005

Selectivity descriptors for the Michael addition reaction as obtained from density functional based approaches.

Density functional (DF) based numerical approaches for computing orbital and atomic reactivity indices were employed in the study of selectivity descriptors for the 1,4 Michael addition reaction. To this aim, atomic and orbital Fukui indices and atomic softnesses for 2-arylmethylene-1,4-butanolides and N,N-disubstituted phenylacetamides were computed. Further on, these local selectivity descriptors have been rationalized in terms of the Pearson's hard-soft-acid-base principle to explain the observed regioselectivity. It is shown that the methods employed for local (atomic and orbital) reactivity index computations are useful and reliable for prediction of the regioselectivity upon conjugate addition of ambident nucleophiles to 2,3-unsaturated carboxylic esters. All the results reveal similar degree of localization/hardness of the 1,4-butanolides C4 and active alpha-carbon belonging to the N,N-dimethyl-phenylacetamide, while the soft alpha-carbon in LiCH2CN reacts with the soft C2 1,4-butanolide center.

Journal Article↗

PubMed2004

Inter-rater reliability of sleep cyclic alternating pattern (CAP) scoring and validation of a new computer-assisted CAP scoring method.

OBJECTIVE: To assess inter-rater reliability between different scorers, from different qualified sleep research groups, in scoring visually the Cyclic Alternating Pattern (CAP), to evaluate the performances of a new tool for the computer-assisted detection of CAP, and to compare its output with the data from the different scorers. METHODS: CAP was scored in 11 normal sleep recordings by four different raters, coming from three sleep laboratories. CAP was also scored in the same recordings by means of a new computer-assisted method, implemented in the Hypnolab 1.2 (SWS Soft, Italy) software. Data analysis was performed according to the following steps: (a) the inter-rater reliability of CAP parameters between the four different scorers was carried out by means of the Kendall W coefficient of concordance; (b) the analysis of the agreement between the results of the visual and computer-assisted analysis of CAP parameters was also carried out by means of the Kendall W coefficient; (c) a 'consensus' scoring was obtained, for each recording, from the four scorings provided by the different raters, based on the score of the majority of scorers; (d) the degree of agreement between each scorer and the consensus score and between the computer-assisted analysis and the consensus score was quantified by means of the Cohen's k coefficient; (e) the differences between the number of false positive and false negative detections obtained in the visual and in the computer-assisted analysis were also evaluated by means of the non-parametric Wilcoxon test. RESULTS: The inter-rater reliability of CAP parameters quantified by the Kendall W coefficient of concordance between the four different scorers was high for all the parameters considered and showed values above 0.9 for total CAP time, CAP time in sleep stage 2 and percentage of A phases in sequence; also CAP rate showed a high value (0.829). The most important global parameters of CAP, including total CAP rate and CAP time, scored by the computer-assisted analysis showed a significant concordance with those obtained by the raters. The agreement between the computer-assisted analysis and the consensus scoring for the assignment of the CAP A phase subtype was not distinguishable from that expected from a human scorer. However, the computer-assisted analysis provided a number of false positives and false negatives significantly higher than that of the visual scoring of CAP. CONCLUSIONS: CAP scoring shows good inter-rater reliability and might be compared in different laboratories the results of which might also be pooled together; however, caution should always be taken because of the variability which can be expected in the classical sleep staging. The computer-assisted detection of CAP can be used with some supervision and correction in large studies when only general parameters such as CAP rate are considered; more editing is necessary for the correct use of the other results. SIGNIFICANCE: This article describes the first attempt in the literature to evaluate in a detailed way the inter-rater reliability in scoring CAP parameters of normal sleep and the performances of a human-supervised computerized automatic detection system.

Adult↗

PubMed1987

Screen-film mammographic technique for breast cancer screening.

The values of dose and signal-to-noise ratio (SNR) for many techniques and breast thicknesses were computed and compared with a reference technique and breast thickness to provide a valid basis upon which to select a screening technique for screen-film mammography. The reference consisted of a Min-R/OM1 combination (or its equivalent) exposed through a 4.5-cm thick breast via 28 kV and a molybdenum target-beryllium window tube with a 0.03-mm Mo filter. Radiographs of an improved breast phantom were used to relate computed relative SNR values of techniques to diameters of the smallest calcific and soft-tissue objects demonstrated in mammograms. Without use of a grid, four Mo target/filtration combinations yielded similar computed dose and SNR levels, as did a tungsten target tube operated at 23 kV without a filter. Operation of the latter tube at 27.5 kV with a 0.051-mm rhodium filter should reduce dose by half but also SNR by 22%. However, such operation with a grid should greatly improve imaging moderate to large breasts without increasing dose over reference values.

Breast Neoplasms↗

PubMed1986

Chordomas.

Chordomas constitute between 1% and 4% of primary malignant bone tumors. Approximately 50% originate in the sacrum, 35% at the base of the skull, and 15% in the true vertebrae. The majority of tumors are encountered from the fifth through seventh decades, with a male preponderance. The clinical symptoms and signs are nonspecific and lead to frequent errors in clinical diagnosis. Radiographic findings include nonspecific destruction of the vertebral body, with reactive sclerosis; calcification is more often seen in sacral tumors. Computed tomography (CT) frequently reveals an anterolateral soft-tissue mass, which is often more extensive than the osseous involvement. The optimal treatment for sacral tumors should be en bloc resection of the tumor performed through intact bone a level above (wide local excision); for vertebral lesions, an anterior surgical approach with resection of the vertebral body should be performed. While conventional radiation has little efficacy in this tumor, a variety of innovative newer approaches may prove more effective in the future. Conventional chemotherapy has not proved effective in this tumor. With early diagnosis, and more effective surgical therapy, the current disease-free survival at five years should be between 30% and 50%.

Aged↗

PubMed2005

[Tuberculosis of the sternum].

Isolated involvement of the sternum is rare, representing less than 1% of tuberculosis osteomyelitis. Only a few cases of sternal tuberculosis have been reported in the pediatric literature. The authors report the case of a 10 year old boy presenting with a 6 month history of presternal swelling and pain. Computed tomography (CT) showed a ring-enhancing hypodense soft tissue mass surrounding the sternum, with marked cortical thickening. Treatment included both surgical intervention and medical therapy.

Antitubercular Agents↗

PubMed2006

A case of alveolar rhabdomyosarcoma of the ethmoid sinus invading the orbit in an adult.

PURPOSE: A case study and literature review of alveolar rhabdomyosarcoma (RMS) in an adult. METHODS: A 48-year-old male patient presented at our clinic complaining of proptosis that had persisted for 2 weeks in his left eye. A computed tomography (CT) scan revealed a destructive soft-tissue mass in the left ethmoid sinus with invasion of the left orbit and compression of the medial rectus muscle. Endoscopic intranasal biopsy revealed alveolar RMS. Conservative debulking and orbital wall decompression were performed. RESULTS: Immunohistochemical testing was positive for desmin, S-100, and smooth muscle actin (SMA), supporting the diagnosis of RMS. Since ipsilateral cervical and spinal metastasis was detected, systemic treatment was administered simultaneously. CONCLUSIONS: Although rarely found in adults, RMS should be considered in the differential diagnosis of orbital tumors. Immunohistochemical analysis plays an important role in the definitive diagnosis of RMS.

Biopsy↗

PubMed2006

Dissection of the internal carotid artery following trauma of the soft palate in children.

OBJECTIVES: We undertook this report to underline the risks of lesions of the internal carotid artery after lateral oropharyngeal trauma in children and to discuss the diagnosis and treatment of this complication. METHODS: We present 2 pediatric cases of carotid dissection following lateral soft palate trauma. RESULTS: In 1 case, transient symptomatic cerebral ischemia occurred 24 hours after the initial traumatic injury. In both patients, the carotid dissection was assessed by magnetic resonance imaging with vascular and diffusion sequences. Treatment with low-molecular weight heparin calcium was maintained for several months. At the end of follow-up, both children were asymptomatic. CONCLUSIONS: We suggest noninvasive imaging of the carotid artery by enhanced computed tomographic scanning after trauma to the lateral part of the soft palate in children. Magnetic resonance imaging with vascular and diffusion sequences is useful in assessing the extension of the dissection toward the cerebral circulation and in early detection of cerebral ischemia. Anticoagulation with heparin probably reduces the risks of cerebral infarction. Patients must regularly undergo physical examination and noninvasive imaging of the carotid artery for at least 1 year after the traumatic injury.

Accidental Falls↗

PubMed2006

First application of X-ray refraction-based computed tomography to a biomedical object.

We have developed X-ray refraction-based computed tomography (CT) that is able to visualize soft tissue in between hard tissue. The experimental system consists of Si(220) diffraction double-crystals and is called the DEI (diffraction-enhanced imaging) method, in which the object is located between the crystals and a CCD camera to acquire data as 360 X-ray images. The X-ray energy used was 17.5 keV. The algorithm used to reconstruct CT images was developed by A. Maksimenko and colleagues. We successfully visualized articular cartilage and the distribution of bone marrow, which are inner structures. Our method has much higher contrast compared to the conventional absorption-based CT system.

Algorithms↗

PubMed1999

Correlation of orbital computed tomographic findings with office probing and irrigation in 17 patients after successful and failed dacryocystorhinostomy.

PURPOSE: To investigate the role of orbital computed tomography (CT) in the evaluation of patients after dacryocystorhinostomy (DCR). METHODS: Computed tomography scans of patients who underwent both successful and failed DCR were examined to determine the relationship of the soft-tissue changes to the surgical ostium, and the findings were correlated with postoperative results of office probing and irrigation. RESULTS: After a successful DCR (n = 7), a patent fistulous tract was confirmed by office probing and irrigation. A characteristic "Y-on-its-side" configuration of the soft tissue was noted on a CT scan. Total occlusion of the osteotomy by soft tissue on probing and irrigation corresponded to a mucocelelike soft-tissue density with a central lucency and soft-tissue obstruction (n = 2). Total occlusion of the osteotomy by inadequate excision of bone and adjacent soft tissue, visualized by CT imaging, was confirmed by palpation of bone by office probing (n = 1). Partial obstruction on probing and irrigation was associated on a CT scan with an increased soft-tissue density (n = 4) and bone in the region of the osteotomy (n = 3). CONCLUSIONS: Computed tomography allows visualization of a patent fistula after successful DCR as well as soft-tissue or bone obstruction of the surgically created fistula after failed DCR. When combined with probing and irrigation, CT helps to formulate a surgical plan after failed DCR.

Anti-Bacterial Agents↗

PubMed2004

Head and neck hemangiopericytoma in a child: case report.

CONTEXT: Hemangiopericytoma is a relatively rare tumor, first described in 1942, with approximately 300 cases described in the literature to date. In most cases, it affects the trunk and lower extremities. The head and neck incidence is less than 20%, mostly in adults. We describe a case of malignant head and neck hemangiopericytoma in a child. TYPE OF STUDY: Case report. CASE REPORT: A twelve-year-old male patient noted the presence of a firm painless right-side retroauricular lymph node of 1 cm in diameter, which at first remained unchanged for six months, but subsequently enlarged progressively. He denied having had previous trauma at that site. In November 2000, he presented nasal obstruction and voluminous epistaxis that required hospitalization and blood transfusion. During dental treatment one month later, a cranial x-ray revealed bone alterations. A subsequent computed tomography scan showed an extensive lesion of soft tissue density that had invaded the maxillary fossa, eroding the skull base and middle and nasal fossa. The child was then referred to our service, where biopsy was performed, giving a diagnosis of hemangiopericytoma. Shortly afterwards, magnetic resonance imaging revealed that this lesion had undergone significant growth, while maintaining the same invasion pattern. The patient was submitted to conservative surgery in April 2001, with only partial resection of the tumor because of its extent. Histopathological examination of the specimen confirmed the presence of malignant hemangiopericytoma. Following the surgery, the patient presented fast regrowth of the lesion, with partial response to chemotherapy and radiotherapy.

Adult↗

PubMed1997

Periosteal chondrosarcoma: a case report and review of the literature.

Periosteal chondrosarcoma occurs predominantly in the long tubular bones. The long-term survival rate is better and there are fewer local recurrences than with central chondrosarcoma. A case of periosteal chondrosarcoma is reported with a review of the literature. A 13-year-old girl presented with swelling of the distal right thigh of 3 weeks' duration. Radiographs and computed tomographic scan of the lesion showed a soft tissue mass, measuring 6 x 6 cm, with matrix calcification arising from the surface of the bone. An open biopsy followed by en bloc resection of the tumor was performed. The histologic features were those of a chondrosarcoma. An 8-year follow-up period has shown no local recurrence or distant metastases. The differential diagnosis of periosteal chondrosarcoma includes periosteal (chondroblastic) osteosarcoma and periosteal chondroma. Controversy exists as to whether periosteal chondrosarcoma is an entity distinct from periosteal osteosarcoma. The clinicopathologic features in this case and in the cases reported in the literature support the contention that periosteal chondrosarcoma is indeed distinct.

Adolescent↗

PubMed1995

Advances in interactive craniofacial surgery planning by 3D simulation and visualization.

In craniofacial surgery careful preoperative planning is essential. Traditional preoperative work-up consists of cast model surgery, cephalometric prediction tracing and analysis of photographs. Recently, we introduced 3-dimensional (3D) computed tomography (CT) model surgery in our preoperative work-up and presurgical prediction of the postoperative result. However, only limited information can be extracted concerning soft tissue changes which are most important for the patients' postoperative appearance. We propose a new system which will allow a precise preoperative visualization of not only bony structures but also the soft tissue surfaces. 3D CT data of the skull are integrated with 3D surface data acquired by laser scanning. Based on the 3D CT data the bony structures are segmented automatically and processed interactively to simulate the planned surgical procedure. Afterwards, the 3D soft tissue changes resulting from the shifting of bony segments are computed. The postoperative appearance of the patient is visualized using computer animation techniques.

Algorithms↗

PubMed2000

Computed tomography of cryogenic biological specimens based on X-ray microscopic images.

Soft X-ray microscopy employs the photoelectric absorption contrast between water and protein in the 2.34-4.38 nm wavelength region to visualize protein structures down to 30 nm size without any staining methods. Due to the large depth of focus of the Fresnel zone plates used as X-ray objectives, computed tomography based on the X-ray microscopic images can be used to reconstruct the local linear absorption coefficient inside the three-dimensional specimen volume. High-resolution X-ray images require a high specimen radiation dose, and a series of images taken at different viewing angles is needed for computed tomography. Therefore, cryo microscopy is necessary to preserve the structural integrity of hydrated biological specimens during image acquisition. The cryo transmission X-ray microscope at the electron storage ring BESSY I (Berlin) was used to obtain a tilt series of images of the frozen-hydrated green alga Chlamydomonas reinhardtii. The living specimens were inserted into borosilicate glass capillaries and, in this first experiment, rapidly cooled by plunging into liquid nitrogen. The capillary specimen holders allow image acquisition over the full angular range of 180 degrees. The reconstruction shows for the first time details down to 60 nm size inside a frozen-hydrated biological specimen and conveys a clear impression of the internal structures. This technique is expected to be applicable to a wide range of biological specimens, such as the cell nucleus. It offers the possibility of imaging the three-dimensional structure of hydrated biological specimens close to their natural living state.

Algorithms↗

PubMed2001

Soft-tissue haemangioma and periosteal new bone formation on the neighbouring bone.

Deeply situated soft-tissue haemangioma sometimes causes periosteal new bone formation on the neighbouring bone. The purpose of this study was to elucidate the aetiological factors for this phenomenon. We studied 25 patients with soft-tissue haemangioma on whom plain radiographs and computed tomography (CT) and/or magnetic resonance imaging (MRI) examinations were performed. We examined the presence or absence of periosteal new bone formation, haemangioma-bone distance, size of haemangioma and pain. Periosteal new bone formation was seen in 12 of 25 patients. In these 12 patients, the haemangioma was adjacent to the bone in 11 patients, while the haemangioma-bone distance was 4 mm in the other patient. In the remaining 13 patients who had no periosteal new bone formation, the haemangioma-bone distance was 5-27 mm. Pain in the former group was stronger than that in the latter group, the difference being statistically significant. There was no statistically significant difference in size of haemangioma between the two groups. Therefore, the main factor that induces periosteal new bone formation on the neighbouring bone was not the size of haemangioma, but the distance between the haemangioma and the bone.

Adolescent↗

PubMed1983

Aneurysmal bone cyst of the spine: computed tomographic appearance.

Computerized tomography can depict most of the characteristic features of aneurysmal bone cyst of the spine even when the plain film findings are not diagnostic. The computed tomographic appearance is that of a benign expansile soft tissue mass surrounded by a shell of bone, an appearance which is analogous to the typical changes of aneurysmal bone cyst in the extremities. Extension into adjacent bones and soft tissues can be demonstrated and thereby facilitate both preoperative planning and later follow-up for recurrence.

Adolescent↗

PubMed1997

Assessment of intraaxial and extraaxial brain lesions with digitized computed tomographic images versus film: ROC analysis.

RATIONALE AND OBJECTIVES: The authors evaluated the diagnostic accuracy of viewing computed tomographic (CT) scans as film versus soft-copy images at a workstation. METHODS: Receiver operating characteristic analysis of the interpretation of 202 CT scans (103 were normal, 99 were abnormal) by five neuroradiologists was performed. Abnormal images contained high- or low-attenuation intraaxial lesions or extraaxial fluid (subdural, subarachnoid, or epidural hemorrhage). Hard copies were read on a standard light box, and digital images were examined at a 1,024 x 1,250 workstation. Lesion location and type and confidence ratings were recorded on a worksheet. RESULTS: There were no statistically significant differences in diagnostic accuracy between the two display modes. Reader performance was slightly better with the workstation in the assessment of low-attenuation lesions. CONCLUSION: Diagnostic accuracy is similar for CT scans displayed at a workstation and those displayed as hard copy in the assessment of subtle intra- and extraaxial brain lesions.

Brain↗

PubMed1994

Foreign-body abscesses presenting as soft-tissue tumours: two case reports.

Foreign bodies in the extremities often present as bony extensions of soft-tissue masses. Wooden foreign bodies can be detected by computed tomography and magnetic resonance imaging, but these studies are often nonspecific and cannot detect small bodies. As illustrated by two cases reported in this paper, these masses are difficult to distinguish from primary soft-tissue sarcomas when the history and imaging findings suggestive of a foreign-body reaction are absent.

Abscess↗