COMPARISON OF PULMONARY NODULE DETECTION, READING TIMES AND PATIENT DOSES OF ULTRA-LOW DOSE CT, STANDARD DOSE CT AND DIGITAL RADIOGRAPHY.

The purpose of the present work was to evaluate performance in pulmonary nodule detection, reading times and patient doses for ultra-low dose computed tomography (ULD-CT), standard dose chest CT (SD-CT), and digital radiography (DR). Pulmonary nodules were simulated in an anthropomorphic lung phantom. Thirty cases, 18 with lesions (45 total lesions of 3-12 mm) and 12 without lesions were acquired for each imaging modality. Three radiologists interpreted the cases in a free-response study. Performance was assessed using the JAFROC figure-of-merit (FOM). Performance was not significantly different between ULD-CT and SD-CT (FOMs: 0.787 vs 0.814; ΔFOM: 0.03), but both CT techniques were superior to DR (FOM: 0.541; ΔFOM: 0.31 and 0.28). Overall, the CT modalities took longer time to interpret than DR. ULD chest CT may serve as an alternative to both SD-CT and conventional radiography, considerably reducing dose in the first case and improving diagnostic accuracy in the second.

COMPARISON OF PHOTON-COUNTING AND FLAT-PANEL DIGITAL MAMMMOGRAPHY FOR THE PURPOSE OF 3D IMAGING USING A NOVEL IMAGE PROCESSING METHOD.

The purpose of the present work was to compare the quality of low-dose projections from a photon-counting with a flat-panel system, and to evaluate a novel image processing method. Images were acquired of phantoms in both systems at average glandular doses ranging from ~ 0.15 to 1.4 mGy. Automated detection of low-contrast features and modulation transfer functions were evaluated in phantom images. The novel image processing method was compared with standard processing in a series of clinical cases. At low-doses (~0.15) the photon-counting system out-performed the flat-panel system with a much higher detectability of low-contrast features. The novel algorithm was superior to both manufacturers' processing in terms of conspicuity of soft-tissue lesions (p > 0.05), whereas it was not significantly different in calcification conspicuity. Photon-counting should allow more low-dose projections to be acquired at the same total dose. The novel image enhancer can help to further increase the image quality.

Evaluation of time-efficient reconstruction methods in digital breast tomosynthesis.

Three reconstruction algorithms for digital breast tomosynthesis were compared in this article: filtered back-projection (FBP), iterative adapted FBP and maximum likelihood-convex iterative algorithms. Quality metrics such as signal-difference-to-noise ratio, normalised line-profiles and artefact-spread function were used for evaluation of reconstructed tomosynthesis images. The iterative-based methods offered increased image quality in terms of higher detectability and reduced artefacts, which will be further examined in clinical images.

Digital breast tomosynthesis in one or two views as a replacement or adjunct technique to full-field digital mammography.

Clinical studies using different imaging protocols to perform digital breast tomosynthesis (DBT) were reviewed (2008-14) to assess interpretive accuracy. Descriptive pooled statistics were used to estimate and summarise accuracy measures for each type of imaging protocol in relation to that of two-view full-field digital mammography (FFDM). In studies comparing multiple DBT imaging protocols, a trend of increased performance was often seen when including both the mediolateral oblique and craniocaudal views for DBT alone and even more so for DBT adjunct to FFDM. Overall, the average ΔAUC (%; sd) across studies for stand-alone DBT (relative to FFDM), in one and in two views, were 2.2 (± 3.7) and 5.9 (± 4.6), and when used together with FFDM, 3.9 (± 2.0) and 6.7 (± 0.9). With respect to individual studies, improvements in accuracy using DBT were present for different types of imaging protocols although the magnitude of the impact varied between studies, and some studies did not show significant improvements in comparison with FFDM. The most consistent effect of improvement in breast cancer detection was seen across studies for two-view DBT with FFDM. These summary findings may depend on the sampling constraints present in tomosynthesis imaging and on other factors discussed in this paper. In order to investigate these effects more thoroughly and how they might impact outcomes, comparative or randomized-controlled trials are warranted.

Review of radiation dose estimates in digital breast tomosynthesis relative to those in two-view full-field digital mammography.

We examined how radiation dose levels in digital breast tomosynthesis (DBT) differ from those used in 2-view full-field digital mammography (FFDM). Acquisition parameter settings and information on the average absorbed dose to the glandular tissues within the breasts were reviewed based on clinical studies that evaluated DBT and FFDM. Dose ratios (DDBT/DFFDM) were derived from imaging protocols, which included tomosynthesis in 1- or 2-views alone, and as an adjunct technique to FFDM. Stand-alone DBT was associated with a much lower to a slightly higher radiation dose compared to that of comparable FFDM units, as summarized in dose ratio ranges of 0.34-1.0 for 1-view DBT, and 0.68-1.17 for 2-view DBT. One of the lowest reported dose estimates was obtained using a photon-counting DBT unit (avg. 0.70 mGy/scan; range: 0.28-1.26 mGy). Breast doses for DBT combined with FFDM are summarized in dose ratio ranges of 1.03-1.5 for 1-view DBT plus FFDM, and 2.0-2.23 for 2-view DBT plus FFDM. In the latter of these settings, the dose was reduced by ∼45% when 2D-views, reconstructed from the DBT images ("synthetic 2D images"), were used as a substitute for FFDM. Stand-alone DBT operated at lower to slightly higher radiation doses in comparison to FFDM. For DBT combined with FFDM, radiation doses were elevated, at maximum by a factor ∼2 1/4 of that of FFDM alone. In this setting, a replacement of FFDM with synthetic 2D-views reduced the breast dose approximately by half, which has substantial implications for population screening programs.

Breast tomosynthesis and digital mammography: a comparison of diagnostic accuracy.

OBJECTIVE: Our aim was to compare the ability of radiologists to detect breast cancers using one-view breast tomosynthesis (BT) and two-view digital mammography (DM) in an enriched population of diseased patients and benign and/or healthy patients. METHODS: All participants gave informed consent. The BT and DM examinations were performed with about the same average glandular dose to the breast. The study population comprised patients with subtle signs of malignancy seen on DM and/or ultrasonography. Ground truth was established by pathology, needle biopsy and/or by 1-year follow-up by mammography, which retrospectively resulted in 89 diseased breasts (1 breast per patient) with 95 malignant lesions and 96 healthy or benign breasts. Two experienced radiologists, who were not participants in the study, determined the locations of the malignant lesions. Five radiologists, experienced in mammography, interpreted the cases independently in a free-response study. The data were analysed by the receiver operating characteristic (ROC) and jackknife alternative free-response ROC (JAFROC) methods, regarding both readers and cases as random effects. RESULTS: The diagnostic accuracy of BT was significantly better than that of DM (JAFROC: p=0.0031, ROC: p=0.0415). The average sensitivity of BT was higher than that of DM (∼90% vs ∼79%; 95% confidence interval of difference: 0.036, 0.108) while the average false-positive fraction was not significantly different (95% confidence interval of difference: -0.117, 0.010). CONCLUSION: The diagnostic accuracy of BT was superior to DM in an enriched population.

Breast cancer screening with tomosynthesis--initial experiences.

Experiences gained so far using tomosynthesis for breast cancer screening will be reported. A short summary of results from preparatory studies will also be presented. The sensitivity and specificity of breast tomosynthesis (BT) will be compared with conventional two-dimensional digital mammography (DM) for breast cancer screening in a population-based study. Over 2000 women have been examined so far with BT and DM. The BT reading is significantly more time-consuming than the DM reading. Preparatory studies have shown that BT has a higher diagnostic precision and higher accuracy of size measurements and stage determination than DM. There is potential to use lower compression force with BT compared with DM, without decreasing the diagnostic accuracy. BT might play an important role in clinical as well as screening mammography. A large-scale population-based study to investigate BT as a screening modality is underway.

The diagnostic accuracy of dual-view digital mammography, single-view breast tomosynthesis and a dual-view combination of breast tomosynthesis and digital mammography in a free-response observer performance study.

The purpose of the present study was to compare the diagnostic accuracy of dual-view digital mammography (DM), single-view breast tomosynthesis (BT) and BT combined with the opposite DM view. Patients with subtle lesions were selected to undergo BT examinations. Two radiologists who are non-participants in the study and have experience in using DM and BT determined the locations and extents of lesions in the images. Five expert mammographers interpreted the cases using the free-response paradigm. The task was to mark and rate clinically reportable findings suspicious for malignancy and clinically relevant benign findings. The marks were scored with reference to the outlined regions into lesion localization or non-lesion localization, and analysed by the jackknife alternative free-response receiver operating characteristic method. The analysis yielded statistically significant differences between the combined modality and dual-view DM (p < 0.05). No differences were found between single-view BT and dual-view DM or between single-view BT and the combined modality.

The effect of reduced breast compression in breast tomosynthesis: human observer study using clinical cases.

The aim of this study was to investigate whether the compression force used with conventional mammography can be reduced with breast tomosynthesis (BT), without adversely affecting the visualisation of normal and pathological structures. Forty-five women were examined with BT using full (same as for 2D mammography) and half compression force. Both examinations were performed with the same acquisition parameters. A total of 103 paired structure images were evaluated according to specified image quality criteria. Three experienced radiologists participated in the study. They had to make a forced choice, i.e. choose the image they felt best fulfilled the image quality criteria. The results showed no evident difference in the image quality, indicating that BT may be performed with substantially less compression force compared with 2D mammography. A majority of the examined women felt that half compression was more comfortable than full compression.

Dose reduction and its influence on diagnostic accuracy and radiation risk in digital mammography: an observer performance study using an anthropomorphic breast phantom.

This study aimed to investigate the effect of dose reduction on diagnostic accuracy and radiation risk in digital mammography. Simulated masses and microcalcifications were positioned in an anthropomorphic breast phantom. Thirty digital images, 14 with lesions, 16 without, were acquired of the phantom using a Mammomat Novation (Siemens, Erlangen, Germany) at each of three dose levels. These corresponded to 100%, 50% and 30% of the normally used average glandular dose (AGD; 1.3 mGy for a standard breast). Eight observers interpreted the 90 unprocessed images in a free response study, and the data were analysed with the jackknife free response receiver operating characteristic (JAFROC) method. Observer performance was assessed using the JAFROC figure of merit (FOM). The benefit of radiation risk reduction was estimated based on several risk models. There was no statistically significant difference in performance, as described by the FOM, between the 100% and the 50% dose levels. However, the FOMs for both the 100% and the 50% dose were significantly different from the corresponding quantity for the 30% dose level (F-statistic = 4.95, p-value = 0.01). A dose reduction of 50% would result in three to nine fewer breast cancer fatalities per 100,000 women undergoing annual screening from the age of 40 to 49 years. The results of the study indicate a possibility of reducing the dose to the breast to half the dose level currently used. This has to be confirmed in clinical studies, and possible differences depending on lesion type should be examined further.

Formoterol as needed with or without budesonide in patients with intermittent asthma and raised NO levels in exhaled air: A SOMA study.

Patients with mild intermittent asthma sometimes show signs of inflammation, and guidelines suggesting bronchodilator therapy alone as needed may be questioned. The current study compared as-needed use of a rapid-acting beta2-agonist with as-needed use of a beta2-agonist and corticosteroid combination as the only medication in asthma patients with intermittent symptoms. A total of 92 nonsmoking asthma patients (of 187 screened) using only an inhaled beta2-agonist as needed (28 males, 64 females; mean age 37 yrs; mean forced expiratory volume in one second (FEV1) 101% predicted, mean reversibility 6.5% pred and fractional exhaled nitric oxide (FeNO) > or =20 parts per billion (ppb)) were randomised to treatment with formoterol (Oxis Turbuhaler) 4.5 microg as needed (n = 47) or budesonide/formoterol (Symbicort Turbuhaler) 160/4.5 microg as needed (n = 45) in a double-blind, parallel-group 24-week study. The primary variable of efficacy was change in FeNO. Baseline FeNO was 60 ppb and 59 ppb in the budesonide/formoterol and formoterol groups, respectively. Mean reductions in FeNO in the budesonide/formoterol and formoterol groups were 18.2 ppb and 2.8 ppb, respectively (95% confidence interval (CI) 7.5-23.5 ppb). The reduction in the budesonide/formoterol group occurred during the first 4 weeks of treatment and remained at this low level. Mean FEV1 increased by 1.8% pred normal value in the budesonide/formoterol group and decreased by 0.9% pred normal value in the formoterol group (95% CI -4.7- -0.7). In the budesonide/formoterol group, use of > or =4 inhalations x day(-1) of study medication was seen on 21 treatment days compared with 74 in the formoterol group. In conclusion, as-needed use of an inhaled corticosteroid together with a rapid-acting bronchodilator may be more beneficial than a beta2-agonist alone in patients with intermittent asthma and signs of airway inflammation. The long-term benefits are unknown.

Comparison of high and low dose of the inhaled steroid, budesonide, as an initial treatment in newly detected asthma.

The importance of early initiation of inhaled steroids even in mild asthma has been documented in several studies. It is not, however, clear whether the treatment should be started with a high or a low dose of the inhaled steroid. We have compared the effects of high and low dose inhaled steroid, budesonide, in patients with newly detected asthma. We studied 101 adult patients with newly detected bronchial asthma who were without inhaled steroid or any regular pharmacological treatment for their asthma. The patients were randomly allocated to two treatment groups: one to receive 800 microg inhaled budesonide per day and the other to receive 200 microg inhaled budesonide per day. The drugs were given with a Turbuhaler dry powder inhaler. During the 3-month treatment period, no significant differences between the treatment groups were noted in morning or evening PEF values, in spirometric parameters, in asthmatic symptoms or in the use of rescue beta2-agonists. The decrease in bronchial hyperresponsiveness was, however, more marked in the high dose budesonide group, reaching a borderline significance (P=0.10 high vs. low dose budesonide). In addition, in serum markers of asthmatic inflammation significant differences were shown between the treatment groups. The decrease in the number of blood eosinophils during the treatment was more marked in the high dose budesonide group (P=0.02; high vs. low dose budesonide). In serum ECP no change was observed in the low dose budesonide group, but a marked decrease in the high-dose budesonide group (P=0.008; high vs. low dose budesonide). The change was even more marked with regard to serum EPX (P=0.005; high vs. low dose budesonide). Our results support the view that the treatment of newly detected asthma should be started with a high dose of inhaled steroid. The low dose may not be enough to suppress asthmatic inflammation despite good clinical primary response.

Randomised comparison of guided self management and traditional treatment of asthma over one year.

OBJECTIVE: To compare the efficacy of self management of asthma with traditional treatment. DESIGN: 12 month prospective randomised trial. SETTING: Outpatient clinics in Finland. SUBJECTS: 115 patients with mild to moderately severe asthma. INTERVENTIONS: Patient education and adjustment of anti-inflammatory therapy guided by peak flow measurements. MAIN OUTCOME MEASURES: Unscheduled admissions to hospital and outpatient visits, days off work, courses of antibiotics and prednisolone, lung function, and quality of life. RESULTS: The mean number of unscheduled visits to ambulatory care facilities (0.5 v 1.0), days off work (2.8 v 4.8), and courses of antibiotics (0.4 v 0.9) and prednisolone (0.4 v 1.0) per patient were lower and the quality of life score (16.6 v 8.4 at 12 months) higher in the self management group than in the traditionally treated group. In both groups admissions for asthma were rare. CONCLUSIONS: Self management reduces incidents caused by asthma and improves quality of life.

Comparison of terbutaline Turbuhaler and albuterol chlorofluorocarbon (CFC) inhaler in middle-aged and elderly patients with obstructive lung disease.

The aim of the present study was to compare the effect of terbutaline Turbuhaler (0.5 mg qid) with that of albuterol chlorofluorocarbon (CFC) inhaler (0.2 mg qid) in middle-aged and elderly patients with obstructive lung disease. The study was performed as an open cross-over (2 x 2 weeks) and randomized study in 85 patients. A significant increase in PEF was seen after inhalation from both devices (P less than .001). Baseline PEF values before inhalation were higher with Turbuhaler than with the CFC inhaler both in the mornings and in the evenings. Fifty-six percent of the patients preferred terbutaline Turbuhaler and 26% albuterol CFC inhaler (P = .004).

Prospective evaluation of chronic cardiotoxicity due to high-dose epirubicin or combination chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil.

In a prospective study the left ventricular ejection fraction (LVEF), right ventricular ejection fraction (RVEF), systolic blood pressure, ECG, and heart rate were recorded at rest and during submaximal work to compare the cardiotoxic effect of epirubicin with a combination chemotherapy without known cardiotoxicity. A total of 14 females with advanced breast cancer were treated with epirubicin at a median cumulative dose of 827 mg/m2 (range, 550-1244). These patients had previously received cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) or cyclophosphamide alone as adjuvant treatment, or CMF for advanced disease. The control group consisted of 11 females with advanced breast cancer given CMF only. The systolic blood pressure at rest as well as during submaximal work was significantly lower (P less than 0.05) after treatment in the epirubicin group than in the CMF controls. With regard to LVEF, the median value of 54% at rest was significantly lower after treatment in the epirubicin group than in the controls (59%). There was a significant fall in LVEF at rest and during exercise in the epirubicin group, whereas no such changes were found in the CMF controls after treatment. The RVEF was unaffected. In the epirubicin-treated group one patient developed fatal congestive heart failure, and in the remaining 13 patients treatment was discontinued due to progression of the cancer and not to cardiotoxicity. Thus, the cardiotoxicity of epirubicin changed the clinical outcome in only 1 of 14 patients with advanced breast cancer.

Twice-a-day regimen of erythromycin base is effective in the treatment of acute streptococcal tonsillitis.

A multicenter clinical trial on the efficacy and safety of a twice-a-day administration of erythromycin base was performed on 261 adolescent or adult patients with acute tonsillitis. The patients were randomized for each doctor separately into q.i.d. (4 x 250 mg) and b.i.d. (2 x 500 mg) groups. Throat swabs were cultured for group A beta-haemolytic streptococci before the treatment and, in positive cases (100 patients), 2-3 days after completing the treatment of at least 7 days. No significant difference in the efficacy between the two regimens was observed as judged by clinical evaluation or bacteriological examination. About 90% of patients were completely healed by both criteria in both treatment groups. Side-effects were reported in 40 and 44% respectively, in the treatment groups. However, only 9/244 (3.7%) had to stop the treatment because of side-effects. Six of these belonged to the b.i.d. group and 3 to the q.i.d. group. This difference is not statistically significant (p greater than or equal to 0.05). Our results suggest that twice-a-day regimen of erythromycin base is an effective and well-tolerated treatment of streptococcal tonsillitis.

Skeletal complications following renal transplantation.

The occurrence of skeletal complications was examined in a series of 204 renal graft recipients who had maintained graft function for more than 12 months. Osteonecrosis was observed in 22 of the patient (11 per cent) from 5 to 46 months after the transplant operation. The lesions were often multifocal, with as many as 40 joints affected. The most common site was the femoral head, necrosis of which was recorded in 24 instances. The lesions here present a major clinical problem, and total hip replacement was deemed necessary in 4 cases, in all of which an excellent result was achieved. Fractures had occurred after the transplantation in 53 patients (26 per cent), against only 6 before the operation. A total of 109 fractures had been sustained after periods ranging from 1 to 58 months, the most common site being the pelvic bones. The fractures were treated according to standard principles; no complications were encountered. The skeletal complications were equally common among the males and females; they tended to occur at advanced ages. They occurred to roughly the same extent whether the graft was from a related or a cadaveric donor and whether the patient had received one or more grafts.

Angiography and scintigraphy of human pancreatic allografts.

Serial graft angiographies and scintigraphies were obtained in 4 human pancreatic allograft recipients. Important information was obtained both of graft morphology and function. Graft rejection was accompanied by characteristic abnormalities, including arterial irregularities and prolonged contrast medium passage time. On scintigraphy, rejection was associated with reduced isotope uptake.