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1.
OBJECTIVE: To assess objectively the results of flashlamp-pumped dye laser treatment of port-wine stains (PWS). DESIGN: Pretreatment and posttreatment photographs were compared with the appearance of the lesion at follow-up examination. Clinical response was determined by assigning a percentage of lesional lightening score by 2 physicians and the patient, and by reflectance spectrophotometric measurements. SETTING: University and university-affiliated health center. PATIENTS: One hundred two patients (118 PWS) aged 1 month to 66 years (mean, 20 years; median, 16 years) treated from July 1, 1989, to June 30, 1994. RESULTS: Eighteen (15.3%) of the 118 PWS had more than 90% lesional lightening (complete or almost complete response), 77 (65.3%) had lightening from 50% to 90% (good response), 21 (17.8%) had lightening from 11% to 49% (poor response), and 2 (1.7%) had lightening less than 10% (no response). Clinical response did not vary among age groups, but showed statistically significant differences between anatomical locations. A return of PWS after initial response was observed in patients who were seen more than 1 year following completion of treatment. CONCLUSIONS: Treatment of PWS by flashlamp-pumped dye laser results in a good to complete response in most patients. Anatomical location of the lesion is a valuable prognostic indicator of response to treatment. The initially impressive results of flashlamp-pumped dye laser treatment of PWS may be tempered by the gradual return of the vascular lesion as time elapses after completion of therapy. Our experience indicates that PWS show a tendency to recur at a rate approaching 50% between 3 and 4 years after completion of treatment.  相似文献   

2.
We investigated whether an association exists between genetic variants of the human obesity (OB or leptin) gene and body mass index (BMI) or weight in subjects with Prader Willi syndrome (PWS) and in age- and gender-matched lean and obese subjects without PWS. The study included 51 subjects with PWS (mean age = 17.7 +/- 9.5 years, BMI = 29.7 +/- 8.3 kg/m2); 50 non-PWS obese subjects (mean age = 18.2 +/- 10.8 years, BMI = 33.3 +/- 9.5 kg/m2); and 53 non-PWS lean subjects (mean age = 17.8 +/- 9.5 years, BMI = 19.5 +/- 2.9 kg/m2). Allele sizes were determined via standard polymerase chain reaction of the D7S1875 locus, a dinucleotide repeat polymorphism close to the OB gene and classified as trichotomous (homozygous < 208 bp, heterozygous < 208/ > or = 208 bp, homozygous > or = 208 bp) or dichotomous (homozygous < 208 bp or not). Non-PWS males showed a marked decrease in weight with larger alleles while females did not (interaction effect, p < 0.05). Comparable effects were not observed among the PWS subjects. Associations between BMI and genotype were statistically significant (r = 0.22, one-tailed p < 0.05) and comparable to previous research among the non-PWS subjects < 18 years, but not the adults (r = 0.05, one-tailed p = 0.38). Correlations were not statistically significant among either the adult or non-adult PWS subjects.  相似文献   

3.
PURPOSE: Our goal was to determine the prevalence of intrathoracic lymphadenopathy on chest CT in patients with empyema. METHOD: We retrospectively identified 27 patients (14 men, 13 women, mean age 43 years) with nontuberculous empyema examined with chest CT. All scans were reviewed by two of three board-certified radiologists for the presence of intrathoracic lymphadenopathy (> or = 1 cm, short axis) in an American Thoracic Society (ATS) nodal station or the internal mammary region. Differences were resolved by consensus. RESULTS: Thirteen (48%) patients with empyema had lymphadenopathy on chest CT. The mean number of enlarged lymph nodes for the patients with lymphadenopathy was 3.2 (SD +/-2.3, range 1-8). The mean size of the largest lymph node was 1.4 cm (range 1.0-2.5 cm). The lymphadenopathy was unilateral and ipsilateral to the empyema in seven (54%), bilateral in five (38%), and unilateral contralateral to the empyema in one. The distribution of lymphadenopathy according to ATS nodal stations was 4R (n = 8), 7 (n = 6), 10R (n = 5); n = 2 each 2R, 10L, 11L; and n = 1 each 11R, 2L, 4L, and 6. Four patients had internal mammary lymphadenopathy. Pleural fluid and smooth pleural thickening were present in each case. Four patients had follow-up CT after treatment. There was a decrease or resolution of the lymphadenopathy in each case. CONCLUSION: Intrathoracic lymphadenopathy is a common CT finding in patients with empyema and occurred in 48% of this series. In patients with smooth pleural thickening and pleural effusion, intrathoracic lymphadenopathy should not be used as a criterion to differentiate empyema from malignant or tuberculous pleural effusion.  相似文献   

4.
OBJECTIVES: To describe the clinical presentations and discuss the guidelines for surgical management of pilomatrixoma involving the head and neck in children. DESIGN: Retrospective study. SETTING: A tertiary care center. PATIENTS: Thirty-three patients, with a mean age of 4.5 years, underwent surgical treatment for pilomatrixoma (n = 38) between 1989 and 1997. INTERVENTION: All patients were treated surgically. In 34 cases, a direct approach was used to achieve complete removal of the lesion with (n = 11) or without (n = 23) skin resection. In the remaining 4 cases, an indirect approach via a parotidectomylike incision was used. RESULTS: In 88% of cases, the presenting symptom was a hard, slow-growing, subcutaneous tumor. The lesion was associated with pain and inflammation in 7 cases (18%) and abscess or ulceration in 4 cases (11%). Twenty-nine patients presented with single nodules and 4 presented with multiple occurrences. The lesions were located on the face (cheek, eyelid, or forehead) in 20 cases (53%), on the neck in 8 cases (21%), in the parotid region in 8 cases (21%), and on the scalp in 2 cases (5%). CONCLUSIONS: Pilomatrixoma is a rare, benign skin tumor, but practitioners should be aware of its clinical features. Diagnosis is usually easy based on clinical findings, but computed tomographic scan is helpful, especially in cases involving tumors located in the parotid region. Spontaneous regression is never observed. Complete surgical excision, including the overlying skin, is the treatment of choice.  相似文献   

5.
The spontaneous growth of 315 patients (109 girls and 208 boys) with Prader-Willi syndrome (PWS) was analysed in a mixed longitudinal and cross-sectional manner. 33 patients were seen in the department between 1970 and 1994; height and weight of 76 patients from Germany were evaluated by means of a questionnaire with detailed measuring instructions, and 206 definite cases were added from the literature. Mean ( SD) length of newborn babies with PWS was 50.2+/-2.8 cm (145 boys) and 48.9 3.3 cm (79 girls). Mean weight at birth was 2945 570 g in boys and 2782+/-594 g in girls. During the 1st year, the children's growth was nearly normal, thereafter short stature was present in approximately 50% of PWS patients. Between 3 and 13 years of age, the 50th percentile for height in PWS is roughly identical with the 3rd percentile in healthy controls. Body weight was normal for all boys and girls during the first 2 years. Thereafter, a rapid weight gain occurred; after an age of 10 years weight-for-height index in nearly all patients exceeded the normal range. The extent of pubertal growth was reduced for the group. Mean adult height was 161.6+/-8.1 cm (23 males) and 150.2+/-5.5 cm (21 females). Head circumference for age was normal for boys and girls. CONCLUSION: Reference data on spontaneous development of growth and weight gain of children with Prader-Willi syndrome are described allowing a better counselling of patients and parents.  相似文献   

6.
The thalamus is believed to play an integrative role in the central nervous system. In the present study, thalamic rCBF was measured in 65 CVD patients and 15 normal volunteers by stable Xe/CT scanning. ROIs were chosen in the thalamic slice at a level 5cm over the OM line, and mean CBF was 7 cm over the OM line. The clinical factors focused on in multiple regression analysis were: age (A), sex (Se), stage from onset (St), lesion side (Sd); unilaterality or bilaterality, size (Sz) thalamic lesion (Tl). GCS (G), HDS-R (H); Hasegawa dementia score (revised), symptoms (Ss) such as anxiety, dizziness, head-headed feeling and headache, and neurological deficits (N). Each factor was graded and scored. Statistically, there was a significant correlation between thalamic rCBF (Y) and mean CBF (X) in the less affected hemisphere: Y = 1.82X + 2.2, r = 0.801, p < 0.001, n = 65. Multiple regression analysis of the thalamic rCBF revealed that the Sz factor was significant (p < 0.0001) on the lesion side: Y = 76.7-10.2Sz, r = 0.644, p < 0.001, n = 51, while the Se, Sd and St factors were significant (p < 0.005) on the less affected side: Y = 71.9 + 9.7Se-6.8Sd-5.0St, R = 0.585, p < 0.001, n = 65. The thalamic index (X), an indicator of thalamic atrophy, and thalamic rCBF were significantly correlated: Y = 28.7X + 10.2, r = 0.386, p < 0.001, n = 80. In conclusion, thalamic rCBF appeared to reflect the degree of organic changes and time course in the cerebral hemisphere, because factors such as size, sex and stage were statistically significant.  相似文献   

7.
Doppler echocardiographic characteristics of normally functioning Sorin Bicarbon prostheses were prospectively assessed in 226 consecutive patients (135 male and 91 female patients, mean age 61 +/- 10 years) with 233 valves in the mitral (n = 67) and aortic (n = 166) positions whose function was considered normal by clinical and echocardiographic evaluation. Patterns of "normal" transprosthetic leakage were assessed with transthoracic echocardiography in all valves and with transesophageal echocardiography in six selected mitral valve prostheses. For the mitral valve prostheses, we found that peak and mean gradient, as well as pressure half-time, were not significantly different in either the 25 or the 31 mm valves (median values from 15 to 10 mm Hg, from 4 to 4 mm Hg, and from 70 to 83 ms; p = Not significant for all). On transthoracic study, 12 patients (17%) with a Sorin Bicarbon valve in the mitral position showed minimal transprosthetic leakage. On transesophageal study, all patients showed a transprosthetic leakage whose spatial distribution had a complex pattern: in planes orthogonal to the leaflet axis, two to four jets arising from the hinge points and converging toward the center of the valve plane could be visualized; in planes parallel to the leaflet axis, there were three jets, the two lateral ones diverging and the central one perpendicular to the valve plane. For the aortic valve prostheses, there was a significant decrease in transprosthetic gradients and an increase in effective orifice areas as prosthesis size increased. Peak and mean gradients decreased from a median value of 25 and 13 mm Hg in the 19 mm valves to 9 and 5 mm Hg in the 29 mm valves, respectively. Effective prosthetic valve area calculated with the continuity equation increased from a median value of 0.97 cm2 for the 19 mm size valves to 3.45 cm2 for the 29 mm size. With analysis of variance, effective prosthetic aortic valve area differentiated various valve sizes (F = 40.9, p < 0.0001) better than peak (F = 10.3, p < 0.0001) or mean (F = 8.04, p < 0.0001) gradients alone did. Furthermore, effective prosthetic aortic valve area correlated better than peak and mean gradients with prosthetic size (r = 0.76, r = -0.45, and r = -0.39, respectively). On transthoracic study, 109 patients (66%) showed minimal transprosthetic leakage. These normal values, obtained in a large number of patients with normofunctioning mitral and aortic Sorin Bicarbon valves, may help to identify Sorin Bicarbon prosthesis dysfunction.  相似文献   

8.
PURPOSE: To compare the magnetic resonance (MR) imaging findings of primary hepatocellular carcinoma (HCC) in cirrhotic versus noncirrhotic livers. MATERIALS AND METHODS: MR images in 36 patients with HCC (30 men and she women aged 42-84 years [mean age, 65 years]) were retrospectively reviewed. The number and size of hepatic lesions were assessed. Lesion margins were categorized as well circumscribed or ill defined. The presence of a capsule, intratumoral high signal intensity on T1-weighted MR images, and a stellate scar were determined. RESULTS: Eleven (31%) patients had MR imaging evidence of cirrhosis, and 25 (69%) did not: Lesions in cirrhotic livers differed significantly from those in noncirrhotic livers in terms of size (22 cm2 vs 99 cm2, P < .05), frequency of a solitary lesion (27% vs 72%, P < .05), and frequency of a central scar (6% vs 50%, P < .05). There was no difference between the cirrhotic and noncirrhotic livers with regard to tumor margin, intratumoral high signal intensity on T1-weighted images, or tumor capsule. CONCLUSION: Differences exist in the MR imaging appearance of HCC between patients with and those without cirrhosis, although there is overlap of imaging findings.  相似文献   

9.
Hexarelin (Hex) is a synthetic hexapeptide with potent GH-releasing activity in both animals and men. Aim of this study was to evaluate the GH response to a maximal dose of Hex and GH-releasing hormone (GHRH) in a group of patients with Prader-Willi syndrome (PWS). Seven patients (4 boys and 3 girls, age 2.4-14.2 yr) with PWS, 10 prepubertal obese children (7 boys and 3 girls, age 7.5-12.0 yr), and 24 prepubertal short normal children (11 boys and 13 girls, age 5.9-13 yr) with body weight within +/- 10% of their ideal weight were studied. All subjects were tested on two occasions with GHRH 1-29 at the dose of 1 microgram/Kg i.v., and with Hex at the dose of 2 micrograms/Kg i.v. In the PWS patients the GH response to GHRH (peak = 6.4 +/- 2.0 micrograms/l, p < 0.0001; AUC = 248 +/- 70 micrograms min/l, p < 0.0001) was significantly lower than that observed in the short normal children and similar to that observed in the obese children. In the PWS children the GH response to Hex (peak = 7.5 +/- 1.6 micrograms/l; AUC = 309 +/- 53) was similar to that observed after GHRH and significantly lower than that observed in the obese children (p < 0.05). The results of this study show that PWS patients have a blunted GH response to the administration of a maximal dose of Hex. Whether these findings reflect a more severe pituitary GH deficiency in PWS than in obese children or a deranged hypothalamic regulation of GH secretion need further investigation.  相似文献   

10.
The prevalence of an incidentally discovered adrenal mass or "incidentaloma" by abdominal computerized tomography (CT) scan is 1% to 2%. The majority of patients with incidentalomas do not have clinical manifestations nor require further treatments of their incidentalomas. Thus the goal for their management is two-fold: 1) To identify and treat the hormonally hyperactive adrenal adenoma and the rare adrenal carcinoma, and 2) To avoid creating an iatrogenic disease of medical progress. An adrenal mass > or = 6 cm, excluding metastatic malignant disease, needs to be surgically resected due to the risk for carcinoma. The risk of primary adrenal cancer for a hormonally inactive lesion < or = 3 cm is extremely low and can be safely observed. Treatment for the hormonally inactive lesion between 3 and 6 cm must be individualized, based on age, specific scan characteristics (irregular border, local invasion, metastasis), and clinical status of the patient. All hormonally active adrenal adenomas should be surgically resected. In this article, we review the data to support the above recommendations.  相似文献   

11.
OBJECTIVE: To assess the role of surgery on survival of patients with grade II gliomas of the cerebral hemispheres. METHODS: One hundred and thirty one low grade hemispheric gliomas surgically treated (biopsied patients excluded) between 1978 and 1989 were retrospectively reviewed. Thalamic, basal ganglia, callosal, or ventricular location were not considered. All tumours were World Health Organisation (WHO) grade II gliomas: 42 fibrillary and 11 gemistocytic astrocytomas, 49 oligodendrogliomas, and 29 oligoastrocytomas. Patients' ages ranged from 14 to 63 (mean 32.9, median 34) years, Karnofsky performance from 0.50 to 0.90 (mean 80.7, median 80), and postsurgical follow up of the living patients from 24 to 190 (mean 97.02, median 93) months. Postoperative external radiotherapy was performed in 49 cases. RESULTS: The overall survival probability at five years was 97.1%, at eight years 76.1%, and at 10 years 62.7% (median survival time 144 months). The impact on survival of the following variables was analysed: age (< 20, 21-40, and > 40 years), Karnofsky score (80-100, 70 < or = 70), histology, tumour extension (T1 < 3 cm, T2 3-5 cm, T3 > 5 cm maximum diameter), extent of surgical resection (S1 radical, S2 subtotal < 10% residual tumour, S3 partial-10%-50% residual tumour), and radiotherapy (either performed or not). A significant positive association with survival at univariate analysis was found for the age group < 20 years (P = 0.003), for total and subtotal surgical resections (S1 and S2; P < 0.001) and for the non-irradiated patients (P = 0.0049), whereas a shorter survival probability was noticed for gemistocytic astrocytomas (P < 0.001) and for tumour extension > 5 cm (T3; P = 0.0193). Karnofsky performance did not show any significant association with survival. The most relevant factor affecting survival at the multivariate analysis was the extent of surgical resection, which resulted as the only variable retaining a significant value (P = 0.001, risk factor = 2.20). CONCLUSIONS: The data strongly support the role of a surgical removal as extensive as possible in the treatment of these tumours.  相似文献   

12.
We investigated the accuracy of spiral computed tomography angiography (CTA) in the detection and study of intracranial aneurysms by comparing CTA with selective angiograms and surgical findings. Twenty-six patients (9 men and 17 women; mean age 53.1 +/- 1.8 years) with suspected intracranial aneurysms were submitted to CTA (1- to 2-mm slices, pitch 1:1, 24 s, RI = 1) after a conventional CT examination showing subarachnoid hemorrhage (SAH) in 19 cases and during neuroradiological investigations performed for other reasons in 7 cases. One hundred twenty to 150 ml iodate contrast agent (0.3-0.4 gI/ml) were injected intravenously at 5 ml/s rate and with 12- to 25-s delay calculated with a preliminary test bolus. Three-dimensional shaded surface display (3D SSD) and maximum intensity projection (MIP) reconstructions were obtained from axial images. Then, within 48 h, all patients were submitted to digital subtraction angiography (DSA), with separate assessment of CTA and DSA findings. Twenty-two aneurysms shown by CTA were confirmed at DSA and surgery (true positives), whereas the vascular lesion was not confirmed at DSA in 2 cases (false positives). The presence of intracranial aneurysms was excluded at both CTA and subsequent DSA in 7 cases (true negatives) and there were no false negatives; sensitivity was 100 %, specificity 77.8 %, and diagnostic accuracy 93.5 %. Computed tomography angiography aneurysm location was confirmed at surgery in all cases, with very high accuracy in assessing the presence of an aneurysm neck (100 %). Computed tomography angiography accurately depicted the aneurysm shape in 20 of 22 cases, but failed to depict its multilobed nature in 2 cases. The mean aneurysm diameter calculated at CTA was 0.99 +/- 0.12 cm vs 1.09 +/- 0.11 cm at surgery (p < 0.01). The present results suggest that the high sensitivity of CTA, if confirmed by further studies, might help in avoiding having to resort to arteriography after negative CTA in SAH patients.  相似文献   

13.
We present our experience with 980 women who had subcutaneous forehead lifts using the anterior hairline incision, during the years 1989-1996. The dissection is easy and fast; the forehead wrinkles are smoothed by the separation of the septa between the frontalis and the skin. The access to the corrugator and the procerus muscles is easy, and the adjustment of the brows to the desired location can be accurate. We use this approach for 90% of women who are eligible for upper face rejuvenation. We have obtained a 96% satisfaction rate; only 1.8% of our patients had minor and reversible complications. The scar, which is supposed to be the main disadvantage of this procedure, is almost unnoticeable, and none of our patients has permanently changed her hairstyle due to this operation. Now, during the peak of interest in forehead lifts with limited scars using the endoscope, is the time to highlight this time-worn, safe, reproducible, and effective approach.  相似文献   

14.
We investigated the long-term outcome of percutaneous ethanol injection (PEI) in the treatment of hepatocellular carcinoma (HCC). A series of 184 HCC patients received PEI as the sole anticancer treatment over an 8-year period, December, 1987, to December, 1995. Ninety-four patients had a single tumor < or = 3 cm, 50 patients had a single lesion of 3.1-5 cm, and 40 patients had multiple nodules (up to four) < or = 3 cm each. All patients had liver cirrhosis, classified as Child-Pugh class A in 127 cases and as Child-Pugh class B in 57 cases. The treatment schedule included, for each lesion, 6-14 therapeutic sessions performed once or twice weekly. The total amount of alcohol administered ranged 10 to 110 ml (mean: 36 ml). All patients were followed after therapy with clinical examinations, laboratory tests, and imaging studies performed at regular time intervals. The follow-up period ranged 2 to 94 months (mean: 23.6 months). Overall survival rates by the Kaplan-Meier method were 67% at 3 years, 41% at 5 years, and 19% at 7 years. The survival rates of patients with single lesion < or = 3 cm (78% at 3 years, 54% at 5 years, and 28% at 7 years, respectively) were significantly higher (p < .01) than those of the patients with a single lesion of 3.1-5 cm (61% at 3 years, 32% at 5 years, and 16% at 7 years) or multiple lesions (51% at 3 years, 21% at 5 years, and 0% at 7 years). The survival of Child-Pugh A patients (79% at 3 years, 53% at 5 years, and 32% at 7 years) was significantly longer (p < .01) than that of Child-Pugh B patients (50% at 3 years, 28% at 5 years, and 8% at 7 years). A selected group of 70 patients with Child-Pugh A cirrhosis and a single lesion < or = 3 cm had a 3-, 5-, and 7-year survival of 89%, 63% and 42%, respectively. During the follow-up, new lesions appeared in 93 patients. The recurrence rates by the Kaplan-Meier method were 15% at 1 year, 34% at 2 years, 51% at 3 years, 67% at 4 years, 78% at 5 years, 88% at 6 years, and 94% at 7 years. The analysis of the survival curves of the treated patients confirms the effectiveness of PEI in the treatment of HCC. This therapeutic approach is particularly indicated for patients with a single lesion 3 cm or less in greatest diameter, as in these cases the long-term results of PEI are comparable to those reported in the best surgical series published in the literature.  相似文献   

15.
To determine what factors contribute to and change bone mineral density (BMD) in dialysis patients, serial lumbar spine dual x-ray absorptiometry studies were analyzed by stepwise regression analysis in 67 black dialysis patients. The patients were 50.5 +/- 2.0 years of age (mean +/- SE) and 49% were men; the patients had received dialytic therapy for 3.7 +/- 0.5 years. The mean initial BMD z-score was 0.147 +/- 0.182. By cross-sectional analysis, the BMD increased in the male and premenopausal female patients but decreased in the postmenopausal female patients by 2.5% g/cm2/decade of life, less than that observed in black patients with normal renal function. Univariate analysis and stepwise regression analysis demonstrated radiographic evidence of osteopenia (beta-coefficient = -0.180 +/- 0.050; P = 0.001) and prior parathyroidectomy (beta-coefficient = 0.133 +/- 0.070; P = 0.054) as the only variables significantly correlated to the BMD. The effects of biochemical variables and different treatments on the delta BMD, calculated as the difference between each patient's first and second BMDs divided by the interval in years, were evaluated by stepwise regression analysis in 41 patients. The mean interval between the two BMDs was 18.4 +/- 1.02 months (range, 5 to 34 months) and the delta BMD was 0.025 +/- 0.018 g/cm2/yr, increasing in 65% of the patients. By univariate and stepwise regression analysis, the mean monthly serum total alkaline phosphatase concentration was the only variable that correlated with the delta BMD (beta-coefficient = 0.0001; P = 0.030).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
We currently recommend excision of adrenal incidentalomas > or = 4 cm in size and all hormonally active tumors. The optimal management and follow-up of smaller nonfunctioning tumors are controversial. The aim of this study was to determine the clinical outcome of a well defined population of patients with incidentalomas followed without operative intervention. The study group comprised 231 patients, identified from the records of abdominal or thoracic computed tomographic (CT) scans performed between 1985 and 1989. The primary outcome variable analyzed was survival. Follow-up was obtained by office records, telephone contact, or letter. There were 101 male and 130 female patients with a mean age at diagnosis of 64 years (range 5-86 years). Most adrenal tumors were unilateral (right 113; left 98); 20 were bilateral. Mean tumor size was 2 cm (range 1-6 cm). In nine (4%) patients the tumor was > or = 4 cm. Follow-up [mean 7 years; range 1 month (patient died) to 11.7 years] was complete in 224 (97%) patients. Ninety-one (39%) patients had one or more additional CT scans performed during the follow-up period, with only four patients demonstrating a > 1 cm increase in the size of the adrenal mass. Surgical excision of these four lesions identified benign pathology. Eighty-one (35%) patients died of conditions unrelated to adrenal pathology. No patient developed subsequent adrenal hyperfunction or adrenal malignancy. Within the context of our guidelines, conservative management of adrenal incidentalomas considered benign or nonfunctioning at diagnosis is appropriate. Additional information provided by repeat CT scanning appears to confer limited benefit. This study does not support laparoscopic removal of small, nonfunctional adrenal tumors, as has been suggested.  相似文献   

17.
OBJECTIVE: To determine, in vivo, the effect of radiofrequency ablation (RFA) treatment time and tissue blood flow on the size and shape of the resulting necrotic lesion in porcine liver. SUMMARY BACKGROUND DATA: Radiofrequency ablation is an electrosurgical technique that uses a high frequency alternating current to heat tissues to the point of desiccation (thermal coagulation). Radiofrequency ablation is well established as the treatment of choice for many symptomatic cardiac arrhythmias because of its ability to create localized necrotic lesions in the cardiac conducting system. Until recently, a major limitation of RFA was the small lesion size created by this technique. Development of bipolar and multiple-electrode RFA probes has enabled the creation of larger lesions and therefore has expanded the potential clinical applications of RFA, which includes the treatment of liver tumors. A basic understanding of factors that influence RFA lesion size in vivo is critical to the success of this treatment modality. The optimal RFA technique, which maximizes liver lesion size, has yet to be determined. Theoretically, lesion size varies directly with time of application of the RF current, and inversely with blood flow, but these relationships have not been previously studied in the liver. METHODS: Six animals underwent hepatic RFA (460 kHz), for 5, 7.5, 10, 12.5, 15, and 20 minutes. Identical, predetermined anatomic areas of the liver were ablated in each animal. Two additional animals underwent 12 RFA treatments -- 6 with vascular inflow occlusion (Pringle maneuver) and 6 with uninterrupted hepatic blood flow. Animals were euthanized and the livers were removed for gross pathologic examination. All lesions were measured in three dimensions and photographed. Tissues were examined by routine histology and by histochemistry to determine viability. RESULTS: Increasing duration of RFA application from 5 through 20 minutes did not create lesions of larger diameter, but this time increase did predict deeper lesion production (beta = 0.34, p = 0.04). A range of lesion shapes were created from four separate ovals (corresponding to each electrode), to larger ovals intersecting to form a cross, to spheroid lesions. The number of blood vessels in close proximity to the probe tip (within a 1-cm radius from the center of the lesion) strongly predicted minimum lesion diameter (beta = -0.61, p = 0.0001) and lesion volume (beta = -0.56, p = 0.0004). This negative effect of blood flow on lesion size was confirmed experimentally. Radiofrequency ablation lesions created during a Pringle maneuver were significantly larger in all three dimensions than lesions created without a Pringle maneuver: minimum diameter was 3.0 cm (with Pringle) versus 1.2 cm (p = 0.002), maximum diameter was 4.5 cm (with Pringle) versus 3.1 cm (p = 0.002), depth was 4.8 cm (with Pringle) versus 3.1 cm (p < 0.001), and lesion volume was 35.0 cm3 (with Pringle) versus 6.5 cm3 (p < 0.001). CONCLUSIONS: Blood flow is a strong predictor of all RFA lesion dimensions in porcine liver in vivo, whereas a change of treatment time from 5 to 20 minutes is predictive only of lesion depth, but not diameter or volume.  相似文献   

18.
BACKGROUND: Focal nodular hyperplasia (FNH) is an unusual hepatic tumour in children and should be distinguished from other hepatic lesions. OBJECTIVE: To describe the imaging characteristics of FNH in children. MATERIALS AND METHODS: We examined five patients (three boys and two girls, mean age 9.4 years) with pathologically confirmed FNH. The diagnosis was obtained by tumour resection (n = 4) and percutaneous needle biopsy (n = 1). One patient with multiple FNHs showed recurrent lesions after tumour resection. All patients were studied with US (including colour and power Doppler US [n = 3]) and CT. Dynamic enhanced CT scans were available in three patients. MRI (n = 2) or coeliac angiography (n = 1) was performed in three patients. RESULTS: Seven of eight FNH lesions in five patients were demonstrated by imaging. The average size of the lesions was 6.5 cm. Six lesions detected on US showed variable echogenicity with a central hyperechoic scar (n = 2). On Doppler examination, central or peripheral hypervascular areas were seen (n = 3). Six lesions detected on contrast-enhanced CT showed high attenuation (n = 4) or iso-attenuation (n = 2). On early phase scans, all the lesions (n = 3) showed high attenuation. Irregular linear or ovoid central scars were detected in two patients on CT. MR demonstrated three lesions in two patients, one of which had not been detected by US or CT. A central low signal intensity scar (n = 1) was seen on T2-weighted MRI. Coeliac angiography performed in one patient showed a hypervascular mass with homogeneous staining. CONCLUSION: FNH in children shows a wide spectrum of imaging findings on various radiological examinations and the typical central scar was not always seen on imaging studies. Dynamic enhanced CT obtained in the early phase and colour Doppler studies may be helpful in the diagnosis of FNH by allowing characterisation of tumour vascularity. FNH should be included in the differential diagnosis of liver mass in children.  相似文献   

19.
OBJECTIVE: The purpose of this study was to analyze CT findings of active and inactive disease in patients with mediastinal tuberculous lymphadenitis. MATERIALS AND METHODS: Using biopsy and culture results, we categorized 49 consecutive patients with mediastinal tuberculous lymphadenitis studied with CT scans as patients with active disease (n = 37) or patients with inactive disease (n = 12). Follow-up CT scans were obtained after antituberculous therapy in 25 patients with active disease and three patients with inactive disease. In 10 patients (seven with active disease and three with inactive disease), CT findings were analyzed and correlated with pathologic findings. RESULTS: In all 37 patients with active disease, the nodes (n = 151) varied in size (1.5-6.7 cm; mean, 2.8 +/- 1.0 cm) and had central low attenuation and peripheral rim enhancement. Calcifications within the nodes were seen in seven patients (19%). In the 12 patients with inactive disease, the nodes (n = 34) varied in size (1.0-4.7 cm; mean, 2.1 +/- 1.0 cm) but were usually smaller than nodes in patients with active disease. In the patients with inactive disease, the diseased nodes were homogeneous and without low-attenuation areas. Calcifications within the nodes were seen in 10 (83%) of the 12 patients with inactive disease. Low-attenuation areas within the nodes corresponded pathologically to areas of caseation necrosis in seven patients with active disease and in no patients with inactive disease. After treatment, enlarged mediastinal nodes in patients with active disease shrunk and low-attenuation areas within the nodes disappeared in all 25 patients. However, the findings of calcified nodes in the three patients with inactive disease did not change after 6 months of follow-up. CONCLUSION: In these 49 patients with mediastinal tuberculous lymphadenitis, CT findings of nodes with central low attenuation and peripheral rim enhancement suggested active disease, and findings of homogeneous and calcified nodes suggested inactive disease. Low-attenuation areas within the nodes had pathologic correspondence to areas of caseation necrosis and may be a reliable indicator for disease activity.  相似文献   

20.
The distinguishing histopathologic features of focal cemento-osseous dysplasia (FCOD) (including lesions occurring in both anterior and posterior jaws) and cemento-ossifying fibroma (COF) (ossifying fibroma and cementifying fibroma) were demonstrated in our earlier work. The aim of the current study was to further refine their clinical and radiographic features. We have assessed 18 clinical and radiographic parameters by univariate comparisons (chi-squared and Student t tests), and a multivariate assessment (logistic regression) in 241 cases of FCOD and 75 of COF. These cases were diagnosed from a combination of clinical, radiographic, and histopathologic information. FCOD was seen predominantly in black women, with a peak incidence in the fourth and fifth decades, whereas COF showed no female predilection except in the fourth decade (p < 0.005). COF occurred in patients an average of 10 years younger than patients with FCOD (p < 0.0001). Most patients with FCOD were asymptomatic (62%); the average lesion size was 1.8 cm. More than half of patients with COF displayed jaw expansion and a considerably larger size lesion (mean 3.8 cm, p < 0.001). The mandible was the most frequent site for both FCOD (86%) and COF (70%). Radiographically, a well-defined border was observed in 53% of cases of FCOD and 85% of cases of COF (p < 0.01). Cases of FCOD mostly demonstrated an irregularly mixed radio-opacity (69%), whereas 53% of COFs presented as a radiolucency (p < 0.005). In FCOD, there was a close association with tooth apices (70.6%, p < 0.0001) or with previous extraction sites (21%, p < 0.05); however, the majority of COF cases (86%) showed no relationship with either. Combining the radiographic feature of a periapical location with the pathology of multiple curetted fragments and "ginger root" bony trabeculae, allowed 90% sensitivity and 89% specificity in a logistic regression model to predict the lesion to be an FCOD. These findings provide guidelines not only to distinguish these two entities clinically, but also aid in reaching an accurate diagnosis histopathologically.  相似文献   

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