Acute right ventricular dilatation: a new helical CT sign of massive pulmonary embolism

Acute right heart failure is a principal cause of circulatory collapse and death in patients with massive pulmonary embolism (PE). The purpose of this study was to investigate if helical computed tomography (CT) could contribute to the assessment of the right ventricle (RV) in those with massive PE. Over an 8-month period 79 helical CT pulmonary angiograms were performed to investigate suspected PE. Emboli were demonstrated in 28 (35%) patients and seven (9%) were considered to have had a major thromboembolic event. The CT scans of all patients were evaluated using parameters derived in the axial plane (maximum minor axis RV and LV dimensions, RV:LV minor axis ratio and RV wall thickness). Acute right ventricular dilatation with an RV:LV ratio> 1.5:1 (range 1.6:1-2.3:1, mean 2:1) was found in all seven patients who had sustained major PE. In the remaining group of 21 with lesser degrees of embolism no patient had an RV:LV ratio > 1.1:1 (range 0.8-1.1, mean 1.0). To our knowledge, this CT sign has not been described before. CONCLUSION: Helical CT can identify acute RV dilatation in addition to making the primary diagnosis in patients with massive PE. This observation may help identify those at greatest risk of a second fatal event and facilitate therapeutic strategy.     

Accuracy of helical CT for acute pulmonary embolism: ROC analysis of observer performance related to clinical experience

The aim of this study was to test the influence of observer experience on the accuracy for interpreting helical CT for acute pulmonary embolism (PE) and to identify sources of observer errors. Three observers of different expertise blindly assessed 147 helical CT scans for suspected PE (true status regarding absence or presence of PE known from independent reference studies). These observers were (a) an experienced CT radiologist, (b) a fellow in CT, and (c) a second-year resident without any formal training in CT. None of them had prior experience with CT for PE. Firstly, 70 CT scans were scored without revealing true PE status. Afterwards, feedback was provided and another 77 CT scans were evaluated. The CT scans were scored on a 5-point confidence scale and receiver-operator-characteristic analysis was performed. Different sources of interpretation errors were analyzed. The two observers with CT experience were significantly more accurate than the unexperienced observer. Their performance was not influenced by feedback training. Certain observer errors were identified, but there was no clear difference among the three observers considering the type of errors. There is significant influence of observer experience on accuracy of reading helical CT for PE: A basic working experience with whole-body CT seems to be a prerequisite. These results suggest that with this experience any radiologist should be able to achieve good accuracy; helical CT thus might become a suitable technique for acute PE in routine clinical practice.     

DNase activity in murine lenses: implications for cataractogenesis

Idiopathic pulmonary fibrosis (IPF) and pulmonary emphysema (PE) have distinct clinical and pathological characteristics, and have been considered to be separate disorders. However, recent animal experiments have suggested that, with regard to their pathogenesis, the diseases have some features in common. However, there are no clinical data supporting this hypothesis. We report here 9 patients (all male, 67 +/- 2 years, mean +/- SE) who had PE followed by IPF. They were found among 152 PE patients who came to Tohoku University Hospital during the past 15 years (1976-1991). All patients were male and heavy smokers and 2 patients also had prostate cancer and gastric cancer, respectively. Three patients were alive during this study and had been diagnosed as having IPF and PE by the combination of transbronchial biopsy, selective alveolobronchogram, CT examination and lung function tests. The diagnosis of IPF and PE in the other patients was based on the pathological findings of autopsied lungs in addition to clinical findings. All patients showed PE mainly in the upper lobes and IPF in the lower lobes. In all patients, in addition to all known causes of pulmonary fibrosis, the possibilities that chronic or recurrent infections in PE induced pulmonary fibrosis and that IPF produced emphysematous changes were carefully excluded by medical records and pathological findings. It is not clear whether the occurrence of emphysema and pulmonary fibrosis in these cases is coincidental, or whether the two diseases are linked by a common pathogenetic pathway.     

Clinical features and genetics of progressive myoclonus epilepsy of the Univerricht-Lundborg type

INTRODUCTION: We retrospectively reviewed the CT findings of the acute abdomen patients examined in the last two years to investigate the frequency of a new CT sign of intestinal infarction, the pneumoretroperitoneum, and its association with other CT findings highly suggestive of this condition. MATERIAL AND METHODS: The CT findings of 60 patients with diagnostic confirmation of intestinal infarction were retrospectively reviewed. CT was performed without (no. = 55) and with (no. = 5) oral administration of contrast material and without (no. = 3) and with (no. = 57) the i.v. injection of nonionic contrast agents in repeated 50 mL boluses. To assess the specificity of this sign, we selected a control group of 400 patients submitted to CT for acute abdomen, but not blunt trauma; 19 of these patients had pneumoretroperitoneum. RESULTS: Pneumoperitoneum was found in five patients with intestinal infarction; it was an isolated sign in two cases and it was associated with few small perihepatic air bubbles in one case. Finally, it was associated with highly suggestive findings of late intestinal infarction in the other two cases. All cases of pneumoretroperitoneum in the control group had been correctly referred to other diseases by previous plain film and/or CT findings and surgery and/or endoscopy confirmed this diagnosis. DISCUSSION AND CONCLUSIONS: Pneumoretroperitoneum has been described as a complication of different benign or severe disorders; prompt recognition of its origin is essential since surgical and/or septic conditions may be involved. However, if the patient's history is negative for abdominal trauma, gastroduodenal ulcer or sepsis, pneumoretroperitoneum is generally cured with conservative treatment. Intestinal infarction or severe ischemia, a usually surgical conditions, should be considered among the different causes of pneumoretroperitoneum alone or associated with pneumoperitoneum or with highly suggestive late findings of infarction such as portal venous gas or pneumatosis intestinalis. This sign had a non-negligible incidence in intestinal infarction in our review (8.5%), but it should be known of and sought with specific window setting to enhance gas depiction on CT images to avoid false negatives.     

The CT halo sign: a new finding in intestinal lymphangiectasia

A "halo sign" has been described in patients with Crohn disease, ulcerative colitis, radiation enteritis, ischemic colitis, and pseudomembranous colitis. This sign is characterized by an inner ring of low CT attenuation surrounded by a higher attenuation outer ring. We present a patient with primary intestinal lymphangiectasia in whom CT demonstrated a halo sign correlated with mucosal biopsy.     

Effects of a high NaCl diet on eating and drinking patterns in pygmy goats

PURPOSE: Our goal was to determine the spectrum of 2-[18F]fluoro-2-deoxy-D-glucose (FDG) PET findings in patients with round atelectasis (RA). METHOD: All patients from 1992 to 1997 with radiologic features of RA and FDG-PET scans were evaluated. There were nine men ranging in age from 52 to 75 years (mean 65 years). All had chest radiographs and CT scans that were correlated with FDG-PET. FDG-PET was considered positive if lesion activity was greater than mediastinal activity and negative if lesion activity was the same as or less than mediastinal activity. RESULTS: Nine patients had 10 lesions, ranging in size from 1.2 to 5.0 cm (mean 3.1 cm). Lesion locations were right lower lobe (n = 5), left lower lobe (n = 4), and lingula (n = 1). All lesions were homogeneous and of soft tissue attenuation on CT. None contained air bronchograms or calcification. All had in-curving vessels and bronchi (comet tail sign), adjacent pleural thickening, and volume loss on CT. All lesions were negative on FDG-PET. Four lesions were percutaneously biopsied and showed chronic inflammation consistent with RA. Two lesions were unchanged on 2 and 3 year follow-up CT and were presumed to be RA as were four other lesions with characteristic CT features and negative FDG-PET. CONCLUSION: Our experience suggest that RA in not metabolically active on FDG-PET imaging. Thus, FDG-PET scans can play a role in differentiating RA from malignancy when there are few or atypical features of RA on chest radiographs and CT.     

Unsuspected pulmonary embolism: prospective detection on routine helical CT scans

PURPOSE: To determine the prevalence of unsuspected pulmonary embolism (PE) on routine thoracic helical computed tomographic (CT) scans and to quantify the improvement in PE detection by using a cine-paging mode on a workstation instead of hard-copy review. MATERIALS AND METHODS: Seven hundred eighty-five patients referred for routine contrast medium-enhanced thoracic CT within 9 months were prospectively recruited. Helical CT was performed. Studies were prospectively interpreted by four radiologists. Two radiologists performed routine, undirected, hard-copy consensus review for official interpretation; two of three thoracic radiologists independently performed a dedicated workstation-based search for PE. The presence of PE involving the main, lobar, or segmental pulmonary arteries was assigned a score of 1-5 (1 = definitely negative, 5 = definitely positive) by each independent reviewer. Patients with a score of 4 or 5 underwent lower-extremity ultrasound, ventilation-perfusion scintigraphy, or both, followed by pulmonary CT angiography if the findings were still equivocal. RESULTS: Twelve (1.5%) of the 785 patients had unsuspected PE, with an inpatient prevalence of 5% (eight of 160) and an outpatient prevalence of 0.6% (four of 625). Of the 12 patients with unsuspected PE, 10 (83%) had cancer. Of the 81 inpatients with cancer, seven (9%) had unsuspected PE. A dedicated workstation-based search resulted in detection of PE in three more patients (25%) than did hard-copy interpretation. CONCLUSION: The prevalence of unsuspected PE was highest among inpatients with cancer. A directed, workstation-based search can improve the PE detection rate over that with hard-copy review.     

Clinical and instrumental diagnosis of pulmonary embolism

Pulmonary embolism shows a high mortality especially for the difficulty in establishing an early correct diagnosis. The pathophysiology and thus the clinical manifestations of pulmonary embolism (PE) are essentially conditioned by three factors: the size of the embolus, the pre-existing cardiorespiratory condition, the release caused by the embolus, of some substances or the activation of reflexes which tend to worsen the purely mechanical consequences of PE. The clinical manifestations resulting from the combination of these factors result in three clinical patterns: acute cor pulmonare, pulmonary infarction, acute dyspnea. PE symptoms may be absent in a moderate percentage of cases and if present, they are nonspecific. Some laboratory tests were shown to be of no diagnostic accuracy, as enzyme determination, a sign of necrosis, blood gas analysis, and determination of alveolar arterial oxygen gradient. Among blood coagulation tests, D-dimer determination was shown to be of some relevance. However, at present, it cannot be used to confirm the diagnostic suspicion of PE. Among the instrumental cardiologic procedures, while ECG has a poor diagnostic reliability, transesophageal echocardiography in central embolism may be able to visualize the embolus and to accurately assess the hemodynamic effects, supplying sufficient information for PE therapy. Even if imaging procedures as pulmonary angiography and more recently CT or MRI are the most reliable diagnostic tools, the diagnostic suspicion of PE in subjects at risk, the use of the examined methods and the search in these patients for the presence of lower limb deep vein thrombosis, often asymptomatic, may increase the number of treated patients thus decreasing the mortality of this disease.     

肺硬化性血管瘤的CT影像学特点

Objective: The aim of the study was to analyze the CT morphology features of pulmonary sclerosing hemangiomas (PSHs) and improve the diagnosis ability of this disease. Methods: The 18 cases of pulmonary sclerosing hemangioma (PSH) confirmed by operation and histopathology from August 2002 to May 2009 were collected, including 17 females and 2 males, aged from 19 to 60 years old, with an average age of 43 years. All the cases underwent plain CT scan, among them,16 cases received enhanced CT scan. Results: The 18 cases had isolated mass. Mean long-axis diameter of these lesions was (2.7 ± 1.3) cm (range, 1.9-4.2 cm). Of all cases, 5 cases (27.8%) were round in shape, 9 cases (50%) were oval, 4 cases (22.2%) were lobulated, and 14 cases (77.8%) were smooth margin. The air meniscus sign was in 2 cases (11.1%), and the halo sign in 3 cases (16.7%). Two cases (11.1%) contained small nodular calcification, the remaining 16 cases (70%) were homogeneous density, the CT density of the masses ranged from 24-47 HU, and the mean value was 35 HU. Sixteen cases received enhanced scan, the welt vessel sign was in 8 cases (44.4%),1 case showed less enhancement, 5 cases showed marked homogeneous enhancement and 10 cases showed intense and patchy heterogeneous enhanced. The CT density of the enhancing masses ranged from 60-110 HU, the mean value was 35 HU, and the net enhancement value was 14-80 HU, the mean value was 55 HU. Conclusion: PSH should be considered in middle-aged female whose CT found that single round or oval pulmonary nodules, with smooth margin, or associated with the air meniscus sign, the halo sign, or the marked enhancement.     

Unenhanced helical CT of ureterolithiasis: value of the tissue rim sign

OBJECTIVE: The tissue rim sign-a rim or halo of soft-tissue attenuation seen around the circumference of an intraureteral calculus on unenhanced axial CT-has been described as useful in differentiating ureteral calculi from extraurinary abdominal or pelvic calcifications. The purpose of this study was to determine the prevalence of the tissue rim sign in patients with ureterolithiasis and extraurinary calcifications and to determine the relationship between the tissue rim sign, the size of a calculus, and the degree of urinary obstruction. MATERIALS AND METHODS: Unenhanced helical CT studies followed by excretory urography were obtained in 59 patients with suspected acute ureterolithiasis. Each calcification along the expected course of the ureter seen on axial CT scans was categorized as a ureteral calculus or as an extraurinary calcification. Each categorization was based on CT, urographic, and clinical findings and the presence or absence of a tissue rim sign. When the outer wall of the ureter could not be seen because there was no clear fat plane at the level of the calcification on CT, the sign was categorized as "indeterminate." The size of the calculus was measured on CT, and the degree of urinary obstruction was estimated on the basis of the urograms. RESULTS: Thirty-two patients each had a single ureteral calculus. Of these patients, CT revealed a positive tissue rim sign in 16 patients (50%), was negative in five patients (16%), and was indeterminate in 11 patients (34%). In addition, we saw 57 extraurinary calcifications in 18 patients (11 patients with ureteral calculi and seven patients without ureteral calculi). None of the 57 extraurinary calcifications was associated with a positive tissue rim sign. The tissue rim sign was negative in 39 (68%) of the 57 extraurinary calcifications and indeterminate in the remaining 18 (32%). Ureteral calculi with a negative tissue rim sign were larger than ureteral calculi with a positive tissue rim sign (p < .01). A high degree of obstruction was present in four of five patients with ureteral calculi for which CT showed a negative tissue rim sign. Conversely, six of 16 patients in whom CT revealed a positive tissue rim sign also had a high degree of obstruction. Therefore, no clear relationship was found between the degree of obstruction and the presence of a positive tissue rim sign. CONCLUSION: A positive tissue rim sign is specific for the diagnosis of ureterolithiasis. However, a negative tissue rim sign does not preclude such a diagnosis. The presence or absence of this tissue rim sign correlates with the size of a calculus but not with the degree of urinary obstruction. When CT reveals an indeterminate tissue rim sign, careful inspection for other CT findings, such as ipsilateral ureteral dilatation, perinephric edema, dilatation of the intrarenal collecting system, and renal swelling, is necessary.     

Thrombolytic therapy for venous thromboembolism. Utilization by practicing pulmonologists

BACKGROUND: Pulmonary embolism (PE) is a potentially life-threatening condition for which thrombolytic therapy may be useful, although the appropriate setting, agent, and duration of therapy remain controversial. Deep venous thrombosis (DVT) can cause substantial morbidity and can be complicated by PE. METHODS: A questionnaire was submitted to 100 randomly selected practicing pulmonary physicians in 10 southeastern states. We sought to determine how physicians use thrombolytic therapy in PE and DVT. Characteristics of physicians, such as practice setting and the number of cases of PE and DVT treated in the last 2 years, were obtained. Physicians were asked if they would strongly consider the use of these agents in a variety of PE or DVT scenarios. RESULTS: Responses were tabulated from 56 practicing pulmonary physicians. Thirty-eight (70%) of responding physicians were in private practice. Fifty-four percent of physicians had used thrombolytic agents for acute PE, while only 28% had used them for DVT. All physicians who responded favored treating massive PE associated with hypotension with thrombolytic therapy, and 73% would strongly consider this treatment for acute PE associated with severe hypoxemia. Agreement on treatment in other scenarios was less uniform. CONCLUSIONS: Pulmonary physicians strongly favored thrombolytic therapy for massive PE associated with hypotension in the absence of absolute contraindications. A majority favored their use in PE associated with severe hypoxemia in the absence of hypotension or in massive proximal DVT present less than 7 days. Further prospective, multicenter, randomized trials appear indicated. Examining crucial end points, such as mortality, may help to unify therapeutic strategies and further refine the guidelines for the use of these agents in venous thromboembolism.     

Chemotaxis in a gliding bacterium

Myxococcus xanthus cells exhibit directed motility up phosphatidylethanolamine (PE) gradients, and we suggest that PE behaves as a chemoattractant. Computer-assisted stop-motion digital microscopy was used to record cell movements in slide culture. PE decreased cellular reversal frequency with molecular specificity that was correlated with the fatty acid composition. Synthetic dilauroyl (di C12:0) PE and dioleoyl (di C18:1 omega9c) PE suppressed direction reversals and stimulated movement up the gradient. Sensory adaptation occurred about 1 hr after the onset of stimulation. Null mutants in a methylated chemotaxis protein homolog (FrzCD) and a CheA/CheY homolog (FrzE) moved up a PE gradient at a reduced rate. The mutants displayed normal excitation but were defective in adaptation. A dominant, hyper-reversal mutant in the M. xanthus methyl accepting chemotaxis protein homolog, frzCD224, failed to respond to PE stimulation, which argued that PE was a transduced stimulus. Neither dilauroyl PE nor dioleoyl PE is present at high enough concentrations in vegetative or developmental PE to account for all of the chemotactic activity. It appears then that there are additional, as yet unknown, PE species that serve as autoattractants. We report on a discrete phospholipid chemoattractant in a gliding bacterium     

Subclinical hypothyroidism: deciding when to treat

While screening patients for thyroid disease, physicians often find increased thyrotropin-stimulating hormone (TSH) levels in patients whose free thyroxine (T4) levels are not below normal. This state, termed "subclinical hypothyroidism," is most commonly an early stage of hypothyroidism. Although the condition may resolve or remain unchanged, within a few years in some patients, overt hypothyroidism develops, with low free T4 levels as well as a raised TSH level. The likelihood that this will happen increases with greater TSH elevations and detectable antithyroid antibodies. Because patients with subclinical hypothyroidism sometimes have subtle hypothyroid symptoms and may have mild abnormalities of serum lipoproteins and cardiac function, patients with definite and persistent TSH elevation should be considered for thyroid treatment. Levothyroxine, in a dosage that maintains serum TSH levels within the normal range, is the preferred therapy in these patients.     

Environmental tobacco smoke exposure and health effects in children: results from the 1991 National Health Interview Survey

PURPOSE: There is no consensus in the literature regarding the role of lymphangiography in promoting hypothyroidism in individuals with Hodgkin's disease irradiated with a mantle field. We sought to analyze the onset and rate of developing clinical or chemical hypothyroidism as well as possible factors related to its development in patients who received irradiation to the thyroid gland during treatment of Hodgkin's disease. METHODS AND MATERIALS: One hundred and forty-two patients with Hodgkin's disease were treated at the Fox Chase Cancer Center between June 1967 and October 1993. All patients were treated with curative intent with radiation therapy using a mantle field. After exclusion of patients without available thyroid function tests, < 200 days of follow-up, or no radiation to the thyroid, 104 patients were eligible for analysis. Follow-up ranged from 7-170 months (median: 43 months). Sixty-seven patients had a lymphangiogram. Seventy-three patients were treated with radiation alone and 31 with radiation plus chemotherapy. RESULTS: The actuarial 2-, and 5-year rates of biochemical hypothyroidism for all 104 patients were 18 and 37%, respectively. Forty patients developed hypothyroidism: 9 (23%) at < or = 1 year, 18 (45%) at < or = 2 years, and 33 (83%) at < or = 5 years. The actuarial 2-, and 5-year rates of biochemical hypothyroidism for patients who underwent a lymphangiogram were 23 and 42%, respectively, compared to 9 and 28%, respectively, for patients who received mantle irradiation without a lymphangiogram (p = 0.05). The effects of lymphangiogram, total thyroid dose, stage, chemotherapy, dose per fraction, energy, and age were evaluated for all patients by Cox proportional hazards regression analysis. The use of a lymphangiogram (p = 0.05) was the only variable that significantly influenced hypothyroidism. CONCLUSIONS: This paper demonstrates in a multivariate analysis accounting for other potentially important variables the significant effect of lymphangiography and subsequent radiation therapy on the development of hypothyroidism. This information must be balanced with the fact that lymphangiograms remain a useful aid in assessing lymph node involvement, staging patients, and planning treatment fields.     

Prevalence of acute pulmonary embolism in central and subsegmental pulmonary arteries and relation to probability interpretation of ventilation/perfusion lung scans

PURPOSE: The purpose of this investigation is to determine the prevalence of acute pulmonary embolism (PE) limited to subsegmental pulmonary arteries. BACKGROUND: Contrast-enhanced helical (spiral) and electron-beam CT, in the hands of experienced radiologists who are skillful with this modality, are sensitive for the detection of acute PE in central pulmonary arteries, but have a low sensitivity for the detection of PE limited to subsegmental pulmonary arteries. The potential for CT to diagnose PE, therefore, is partially dependent on the prevalence of PE limited to subsegmental pulmonary arteries. METHODS: Data are from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED). The largest pulmonary arteries that showed PE, as interpreted by the PIOPED angiographic readers, were identified in 375 patients in PIOPED with angiographically diagnosed PE. RESULTS: Among all patients with PE, 6% (95% confidence interval [CI], 4 to 9%) had PE limited to subsegmental branches of the pulmonary artery. Patients with high-probability ventilation/ perfusion (V/Q) scans had PE limited to subsegmental branches in only 1% (95% CI, 0 to 4%). Among patients with low-probability V/Q lung scans, 17% (95% CI, 8 to 29%) had PE limited to the subsegmental branches. Patients with low-probability V/Q scans and no prior cardiopulmonary disease had PE limited to the subsegmental pulmonary arteries in 30% (95% CI, 13 to 53%), whereas patients with low-probability V/Q scans who had prior cardiopulmonary disease had PE limited to subsegmental pulmonary arteries in 8% (95% CI, 2 to 22%) (p < 0.05). CONCLUSION: Based on data from all patients with PE in PIOPED, the prevalence of PE limited to subsegmental pulmonary arteries is low, 6%. PE limited to subsegmental pulmonary arteries was most prevalent among patients with low-probability V/Q scans, particularly if they had no prior cardiopulmonary disease.     

Transitory neonatal hypothyroidism caused by transplacental transfer of anti-receptor antibodies of hypophyseal thyroid simulation. Case report and estimated incidence]

Transient neonatal hypothyroidism induced by transplacental transfer of thyrotropin receptor-blocking antibodies is rare, but should be diagnosed early because its course, treatment, and prognosis are different from the other forms of congenital hypothyroidism. Transient neonatal hypothyroidism should be suspected in infants with a history of maternal autoimmune thyroid disease. We describe two siblings whose mother has been treated for idiopathic primary nongoitrous hypothyroidism since adolescence. High levels of thyrotropin receptor-blocking antibodies were first detected in maternal serum at the time of the first child's birth. At the time of the second child's birth antithyroid peroxidase antibodies were found in addition to the thyrotropin receptor-blocking antibodies. Both children were clinically healthy newborns without evidence of congenital malformations. Thyroid suppression, reflected by high levels of TSH during neonatal screening, was transient in both infants. Hormonal substitution was only necessary in one child for a period of 4 months. When tested at the age of 6-7 months, maternal antibodies had completely disappeared from the infants' sera. At ages 7 and 4 years respectively the 2 children do not require treatment and show normal growth and neurodevelopmental skills. In the north-eastern part of Switzerland congenital hypothyroidism has an incidence of one in 3300 live-born infants, the most frequent form being permanent congenital hypothyroidism (1:4500). In this population, analyzed over a period of 16 years, the two cases reported represent the only observations of transient neonatal hypothyroidism due to thyrotropin receptor-blocking antibodies; the incidence can thus be estimated to be approximately 1:310,000 live newborns. In this rare condition, early recognition is pertinent in order to avoid unnecessary treatment and parental anxiety.     

Spiral CT angiography in the diagnosis of central pulmonary embolism: comparison with pulmonary angiography and scintigraphy

PURPOSE: To evaluate the accuracy of spiral CT angiography in the diagnosis of central pulmonary embolism (PE). MATERIAL AND METHODS: A retrospective study was undertaken in a population of 90 patients who were evaluated with spiral CT angiography (acquisition: 12 to 24 s with or without strict apnea; injection of 90 cm3 of 12, 20 or 30% contrast material at a rate of 4 to 7 cm3, selective pulmonary angiography of each lung (n = 55) and/or ventilation-perfusion (VP) scanning (n = 35). RESULTS: Among the 55 patients evaluated with both spiral CT and angiography, central pulmonary embolism was excluded in 19 patients (34%), assessed in 29 patients (53%) whereas CT examination was considered as inconclusive in 7 patients (13%) due to interpretive difficulties at the level of obliquely oriented arteries and/or presence of hilar lymph nodes (sensitivity: 90.5%; specificity: 82.6%). With spiral CT, the finding of 95 central emboli (3 main, 61 lobar and 31 segmental) corresponded exactly to the angiographic findings; spiral CT enabled direct visualization of intraluminal filling defects (n = 95) whereas the angiographic recognition of PE was based on direct (n = 57) and indirect (n = 38) signs. Spiral CT angiography was more sensitive and specific than VP scanning. CONCLUSION: Spiral CT angiography appears as a sensitive and specific noninvasive method for the diagnosis of central PE.     

Pulmonary embolism: the role of computed tomography and magnetic resonance imaging

The technological progress in Computed Tomography (CT) (spiral and electron beam) and Magnetic Resonance Imaging (MRI fast sequences) has stimulated their interest in the diagnosis of acute and chronic pulmonary embolism (PE). They are noninvasive procedures able to identify thrombi up to the level of segmental pulmonary branches. This result, albeit not ideal, is significant, in view of the lower clinical relevance of peripheral emboli as compared to more central locations, especially in the absence of peripheral venous thrombosis. Spiral CT allows satisfactory assessment of pulmonary branches with high sensitivity (65-100%), specificity (89-96%), positive predictive value (95%) and negative predictive value (80-100%) in the diagnosis of PE. MRI with spin-echo sequences has also a satisfactory sensitivity (75-90%), specificity (up to 100%), positive predictive value (86%) and negative predictive value (85%). Recently, MR angiography was shown to be able to depict smaller pulmonary branches (6th and 7th generation), even if its efficacy in the identification of emboli has not been demonstrated as yet. CT and MRI are bound to play an increasingly relevant role in the diagnosis of PE.     

Pulmonary thromboembolism

Pulmonary embolism (PE) is a serious complication of chronic obstructive pulmonary disease (COPD). Retrospective studies on patients with COPD treated in the intensive care unit (ICU) were performed to determine: 1) the frequency of PE; 2) the clinical course of PE in cases of COPD in the ICU; and 3) the frequency of PE as a cause of death in the studied group. The frequency of PE was 10.9% in COPD patients. In the group analysed, clinical presentation of PE was characterized by acute severe, life-threatening complications leading to death in 86.7% of cases. PE was the most frequent cause of death (40.6%) in COPD patients in the ICU. The results of treatment of pulmonary embolism in chronic obstructive pulmonary disease are poor and mortality in this group of patients is very high. We believe that improvement of management can be achieved by antithromboembolic prophylaxis, which should be instituted as soon as possible in all patients with chronic obstructive pulmonary disease in the intensive care unit.     

Clinical significance of thyrotropin measurement by immunoradiometric assay and thyrotropin-releasing hormone test

The levels of serum TSH were measured by a sensitive immunoradiometric assay (IRMA) method and the responses of TSH to TRH stimulation were observed in three groups of hyperthyroidism, primary hypothyroidism and secondary hypothyroidism. The levels of serum TSH were found to be undetected in 98% (1/51) of the patients with hyperthyroidism, very high in 100% (35/35) of the patients with primary hypothyroidism and normal in 91% (30/33) of the patients with secondary hypothyroidism. TRH test showed no responses of TSH in all patients with hyperthyroidism, high responses in all patients with primary hypothyroidism and blunt responses in 69% (11/16) of patients with secondary hypothyroidism. The results indicate that the measurement of serum TSH by IRMA is a sensitive index in the diagnosis of hyperthyroidism and primary hypothyroidism, but can not be differentiated the secondary hypothyroidism from normal conditions. TRH test may be helpful in the differential diagnosis between secondary hypothyroidism and normal conditions.