Texture-based quantification of pulmonary emphysema on high-resolution computed tomography: comparison with density-based quantification and correlation with pulmonary function test

PURPOSE: To develop a system for texture-based quantification of emphysema on high-resolution computed tomography (HRCT) and to compare it with density-based quantification in correlation with pulmonary function test (PFT). MATERIALS AND METHODS: Two hundred sixty-one circular regions of interest (ROI) with 16-pixel diameter [66 ROIs representing typical area of normal lung; 69 representing bronchiolitis obliterans (BO); 64, mild emphysema (ME); and 62, severe emphysema (SE)] were used to train the automated classification system based on the Support Vector Machine classifier and on variable texture and shape features. An automated quantification system was developed with a moving ROI in the lung area, which classified each pixel into 4 categories. To validate the system, the HRCT and standard-kernel-reconstructed volumetric CT data of 39 consecutive patients with emphysema were included. Using this system, the whole lung area was evaluated, and the area fractions of each class were calculated (normal lung%, BO%, ME%, SE%, respectively). The emphysema index (EI) of texture-based quantification was defined as follows: (0.3 x ME% + SE%) (TEI). EIs from density-based quantification with a threshold of -950 Hounsfield Units, were measured on both HRCT (DEI_HR_2D) and on volumetric CT (DEI_standard_3D). The agreement between TEI, DEI_HR_2D, and DEI_standard_3D was assessed using interclass correlation coefficients (ICC). Correlation of the results on the TEI with the PFT results was compared with the results of the DEI_standard_3D and the DEI_HR_2D with Spearman's correlation test. To evaluate the contribution of each texture-based quantification lesion (BO%, ME%, SE%) on PFT, multiple linear regression analysis was performed. RESULTS: The calculated TEI (19.71% +/- 17.98%) was well correlated with the DEI_standard_3D (19.42% +/- 14.30%) (ICC = 0.95), whereas the ICC with DEI_HR_2D (37.22% +/- 9.42%) was 0.43. TEI showed better correlation with PFT than DEI_standard_3D or DEI_HR_2D did [R = 0.71 vs. 0.67 vs. 0.61 for forced expiratory volume in 1 second (FEV(1))/forced vital capacity (FVC); 0.54 vs. 0.50 vs. 0.43 for diffusing capacity (DLco), respectively]. Multiple linear regression analysis revealed that the BO% and SE% areas were independent determinants of FEV(1)/FVC, whereas the ME% and the SE% were determinants of DLco. CONCLUSION: Texture-based quantification of emphysema using an automated system showed better correlation with the PFT results than density-based quantification. Separate quantification of the BO, ME, and SE areas showed a different contribution of each component to the FEV(1)/FVC and the DLco. The proposed system can be successfully used for detailed regional and global evaluation of lung lesions on HRCT scanning for emphysema.     

Technological development and advances in single-photon emission computed tomography/computed tomography

Single-photon emission computed tomography/computed tomography (SPECT/CT) has emerged during the past decade as a means of correlating anatomical information from CT with functional information from SPECT. The integration of SPECT and CT in a single imaging device facilitates anatomical localization of the radiopharmaceutical to differentiate physiological uptake from that associated with disease and patient-specific attenuation correction to improve the visual quality and quantitative accuracy of the SPECT image. The first clinically available SPECT/CT systems performed emission-transmission imaging using a dual-headed SPECT camera and a low-power x-ray CT subsystem. Newer SPECT/CT systems are available with high-power CT subsystems suitable for detailed anatomical diagnosis, including CT coronary angiography and coronary calcification that can be correlated with myocardial perfusion measurements. The high-performance CT capabilities also offer the potential to improve compensation of partial volume errors for more accurate quantitation of radionuclide measurement of myocardial blood flow and other physiological processes and for radiation dosimetry for radionuclide therapy. In addition, new SPECT technologies are being developed that significantly improve the detection efficiency and spatial resolution for radionuclide imaging of small organs including the heart, brain, and breast, and therefore may provide new capabilities for SPECT/CT imaging in these important clinical applications.     

Use of the airway scope for difficult airway

The Airway Scope (AWS) is a new videolaryngoscope which consists of an optical system and a single-use blade. The blade of the device is designed according with the pharyngeal anatomy, and thus the AWS is expected to have a role in the management of difficult airway. We here report 15 patients with difficult airway in whom the AWS provided in successful intubation. The AWS provides a view of the glottis with Cormack-Lehane grade 1 and resulted in successful intubation in the 15 patients. The AWS is useful for the management of difficult airway.     

Older age at diagnosis of Hirschsprung disease decreases risk of postoperative enterocolitis, but resection of additional ganglionated bowel does not

Purpose

This study was conducted to determine the effect of age at diagnosis and length of ganglionated bowel resected on postoperative Hirschsprung-associated enterocolitis (HAEC).

Methods

Children who underwent endorectal pull-through (ERPT) between January 1993 and December 2004 were retrospectively reviewed. t Test, analysis of variance, Kaplan-Meier, and Cox's proportional hazards analyses were performed.

Results

Fifty-two children with Hirschsprung disease (median age, 25 days; range, 2 days-16 years) were included. Nineteen (37%) had admissions for HAEC. Proportional hazards regression showed that HAEC admissions decreased by 30% with each doubling of age at diagnosis (P = .03) and increased 9-fold when postoperative stricture was present (P < .01), after controlling for type of ERPT, trisomy 21, transition zone level, and preoperative enterocolitis. Thirty-six children, with age at initial operation less than 6 months, were grouped based on length of ganglionated bowel excised (A [5 cm] and B [>5 cm]). No significant difference in the number of HAEC admissions during initial 2 years post-ERPT was seen between groups A (n = 18) and B (n = 18). The study had a power of 0.8 to detect a difference of 1 admission over 2 years.

Conclusions

Children diagnosed with Hirschsprung disease at younger ages are at a greater risk for postoperative enterocolitis. Excising a longer margin of ganglionated bowel (>5 cm) does not seem to be beneficial in decreasing HAEC admissions.     

Nasotracheal intubation using the Airtraq versus Macintosh laryngoscope: a manikin study

The Airtraq laryngoscope is a new intubation device that provides a non-line-of-sight view of the glottis. We evaluated this device by comparing the ease of nasotracheal intubation on a manikin with the use of Airtraq versus the Macintosh laryngoscope with and without Magill forceps. Nasotracheal intubation on a manikin was performed by 20 anesthesiologists and 20 residents with the Airtraq or Macintosh laryngoscope. The mean (+/- SD) time required for nasotracheal intubation by the residents was significantly shorter with the Airtraq laryngoscope than with the Macintosh laryngoscope (16 +/- 7 sec vs 22 +/- 10 sec; P < .001), but no difference in intubation time was observed between Airtraq (15 +/- 11 sec) and Macintosh (13 +/- 6 sec) laryngoscopy by the anesthesiologists. The Magill forceps was used more frequently to facilitate intubation with the Macintosh laryngoscope than with the Airtraq laryngoscope in both groups of operators 7(P < .001). The Airtraq laryngoscope scored better on the visual analog scale than did the Macintosh laryngoscope in both groups of operators (P < .05). The Airtraq laryngoscope offers potential advantages over standard direct laryngoscopy for nasotracheal intubation.     

The Sigma-trial protocol: a prospective double-blind multi-centre comparison of laparoscopic versus open elective sigmoid resection in patients with symptomatic diverticulitis

Backround  

Diverticulosis is a common disease in the western society with an incidence of 33–66%. 10–25% of these patients will develop diverticulitis. In order to prevent a high-risk acute operation it is advised to perform elective sigmoid resection after two episodes of diverticulitis in the elderly patient or after one episode in the younger (< 50 years) patient. Open sigmoid resection is still the gold standard, but laparoscopic colon resections seem to have certain advantages over open procedures. On the other hand, a double blind investigation has never been performed. The Sigma-trial is designed to evaluate the presumed advantages of laparoscopic over open sigmoid resections in patients with symptomatic diverticulitis.     

Spontaneous resolution of tetraparesis because of postoperative cervical epidural hematoma

Background contextSymptomatic postoperative spinal epidural hematoma (PSEH) is a rare but potentially devastating postoperative complication, accounting for 0.1% to 0.2% of cases.PurposeTo describe a patient with a PSEH that completely resolved, clinically and radiographically, without surgical treatment.Study designCase report and review of the literature.MethodsA 47-year-old man with no history of a bleeding disorder underwent anterior cervical interbody fusion for C5–C6 disc herniation. The dura was exposed through removal of the posterior longitudinal ligament, and extensive decompression of posterior osteophytes of C5 and C6 vertebral bodies was performed. The patient developed tetraparesis and respiratory distress rapidly in the postanesthesia care unit and was reintubated for assisted ventilation. The computed tomography (CT) scan revealed a very large ventral epidural hematoma compressing the dural sac from C1 to C6.ResultsThe patient was prepared for hematoma evacuation. However, the neurological symptoms and respiration problems began to resolve spontaneously before the surgery was started. The hematoma was markedly improved on the follow-up CT scan, and the patient was discharged 2 weeks after surgery without neurological deficit.ConclusionsThis case illustrates that an unpredictable extensive hematoma can occur after uneventful surgery of the cervical spine in low-risk patients. In case of the dural exposure with a creation of hidden and large epidural space, the spine surgeon must pay particular attention to the possibility of a PSEH during the early postoperative period.     

Urinary urgency outcomes after propiverine treatment for an overactive bladder: the ‘Propiverine study on overactive bladder including urgency data’

Study Type – Therapy (RCT)
Level of Evidence 1b

OBJECTIVE

To investigate the effects of a daily regimen of propiverine 20 mg in patients with an overactive bladder (OAB), focused on improving urgency, as the clinical efficacy of treatment for OAB should be measured in terms of urgency, the cornerstone symptom of OAB.

PATIENTS AND METHODS

Eligible patients aged ≥18 years with symptoms of OAB were enrolled in this multicentre, prospective, parallel, double‐blind, placebo‐controlled trial. Of 264 patients (mean age 52.2 years), 221 who had efficacy data available from baseline and at least one on‐treatment visit with >75% compliance with medication were analysed (142 in the propiverine group and 79 in the placebo group). All patients were randomized to receive a placebo or 20 mg propiverine once daily in a 12‐week study. They completed a 3‐day voiding diary before visits during the study period, including the severity of urgency associated with every voiding, using the Indevus Urgency Severity Scale and the Urgency Perception Score. The patients’ overall self‐evaluation of treatment benefits at the end of the study, and safety data, were also collected.

RESULTS

The daily urgency episodes reduced significantly from baseline to 12 weeks on propiverine treatment, compared with placebo (?46.0% vs ?31.3%, P = 0.005). Secondary endpoints, including sum of urgency severity per 24 h, urgency severity per void, and daytime voiding frequency, were also improved significantly in the propiverine group. Overall, of those patients treated with propiverine, 38.7% rated their treatment as providing ‘much benefit’, compared with 15.2% of the placebo group (P = 0.025). Adverse events reported by 32 (22.5%) and 10 (12.7%) patients in the propiverine and placebo group were all tolerable. However, this is a short‐term study using only one fixed regimen.

CONCLUSIONS

Propiverine 20 mg once‐daily could be an effective treatment for patients with OAB, by improving urgency.     

Annual report of perioperative mortality and morbidity for the year 1999 with a special reference to anesthetic methods at Certificated Training Hospitals of Japanese Society of Anesthesiologists

The Committee on Operating Room Safety of Japanese Society of Anesthesiologists (JSA) sends annually confidential questionnaires of perioperative mortality and morbidity to Certificated Training Hospitals of JSA. This report is on perioperative mortality and morbidity in 1999 with a special reference to anesthetic methods. Four hundred and sixty-seven hospitals reported the number of cases referred to anesthetic methods and total numbers of cases were 727,723. The incidences of cardiac arrest per 10,000 cases due to all etiology are estimated to be 6.77 cases in average, 5.33 cases in inhalation anesthesia, 34.26 cases in total intravenous anesthesia (TIVA), 5.26 cases in inhalation anesthesia plus epidural or spinal or conduction block, 5.29 cases in TIVA plus epidural or spinal or conduction block, 0.73 cases in spinal with continuous epidural block (CSEA), 2.85 cases in epidural anesthesia, 1.63 cases in spinal anesthesia, 2.53 cases in conduction block and 46.51 cases in other methods. However, the incidences of cardiac arrest per 10,000 cases totally attributable to anesthesia are estimated to be 0.78 case in average, 0.51 case in inhalation anesthesia, 1.35 cases in TIVA, 0.97 case in inhalation anesthesia plus epidural or spinal or conduction block, 1.51 cases in TIVA plus epidural or spinal or conduction block, 0.73 case in CSEA, 1.71 cases in epidural anesthesia, 0.54 case in spinal anesthesia, 2.52 cases in conduction block and 1.08 cases in other methods. The incidences of severe hypotension per 10,000 cases due to all etiology are estimated to be 16.64 cases in average, 13.61 cases in inhalation anesthesia, 100.36 cases in TIVA, 13.32 cases in inhalation anesthesia plus epidural or spinal or conduction block, 9.07 cases in TIVA plus epidural or spinal or conduction block, 3.65 cases in CSEA, 6.26 cases in epidural anesthesia, 7.31 cases in spinal anesthesia, 2.52 cases in conduction block and 28.12 cases in other methods. On the other hand, the incidences of cardiac arrest per 10,000 cases totally attributable to anesthesia are estimated to be 2.40 cases in average, 1.65 cases in inhalation anesthesia, 0.81 cases in TIVA, 3.92 cases in inhalation anesthesia plus epidural or spinal or conduction block, 2.77 cases in TIVA plus epidural or spinal or conduction block, 2.56 cases in CSEA, 3.42 cases in epidural anesthesia, 2.71 cases in spinal anesthesia, zero case in conduction block and zero case in other methods. The incidences of severe hypoxia per 10,000 cases due to all etiology are estimated to be 5.32 cases in average, 6.7 cases in inhalation anesthesia, 9.17 cases in TIVA, 5.16 cases in inhalation anesthesia plus epidural or spinal or conduction block, 4.53 cases in TIVA plus epidural or spinal or conduction block, 2.56 cases in CSEA, zero case in epidural anesthesia, 1.08 cases in spinal anesthesia, zero case in conduction block and 1.08 cases in other methods. On the other hand, the incidences of severe hypoxia per 10,000 cases totally attributable to anesthesia are estimated to be 2.39 cases in average, 3.22 cases in inhalation anesthesia, 2.43 cases in TIVA, 2.26 cases in inhalation anesthesia plus epidural or spinal or conduction block, 2.77 cases in TIVA plus epidural or spinal or conduction block, zero case in CSEA, zero case in epidural anesthesia, 0.54 cases in spinal anesthesia, zero case in conduction block and 1.08 cases in other methods. The mortality rates of cardiac arrest per 10,000 cases due to all etiology are estimated to be 3.56 cases in average, 2.82 cases in inhalation anesthesia, 24.55 cases in TIVA, 1.4 cases in inhalation anesthesia plus epidural or spinal or conduction block, 1.51 cases in TIVA plus epidural or spinal or conduction block, zero cases in CSEA, 0.57 cases in epidural anesthesia, 0.27 cases in spinal anesthesia, zero case in conduction block and 42.18 cases in other methods. On the other hand, the mortality rates of cardiac arrest per 10,000 cases totally attributable to anesthesia are estimated to be 0.08 case in average, 0.09 case in inhalation anesthesia, 0.27 case in TIVA, 0.05 case in inhalation anesthesia plus epidural or spinal or conduction block, zero case in TIVA plus epidural or spinal or conduction block, zero case in CSEA, 0.57 case in epidural anesthesia, zero case in spinal anesthesia, conduction block and other methods. The outcomes of cardiac arrest totally attributable to anesthesia are 70.2% of full recovery without any sequelae, 10.5% of death within 7 days, 1.8% of vegetative state and 17.5% of unknown results while the outcome of critical events including severe hypotension and severe hypoxia totally attributable to anesthesia is 94.9% of full recovery without any sequelae, 0.4% of death within 7 days, 0.2% of vegetative state and 4.5% of unknown results. These results indicate that there are no differences in mortality and morbidity totally attributable to anesthesia among anesthetic methods in 1999 at Certificated Training Hospitals of Japan Society of Anesthesiologists.     

Synergistic effects of sildenafil on relaxation of rabbit and rat cavernosal smooth muscles when combined with various vasoactive agents.

OBJECTIVE: To evaluate which vasoactive agents have synergistic effects on the cavernosal smooth muscles of rabbits and rats when the agents are combined with sildenafil. MATERIALS AND METHODS: Relaxation responses of cavernosal smooth muscle to single agents (phentolamine, moxisylyte, sodium nitroprusside, forskolin, vasoactive intestinal peptide, VIP, papaverine and sildenafil) in the rabbit, and prostaglandin-E1 and sildenafil in the rat, and to combinations of each agent plus sildenafil, were assessed in vitro. The response to sildenafil of the rabbit strips with and without incubation with l-arginine (1 mmol/L) for 20 min was also evaluated. The effective concentrations for a half-maximal response of single agents and combination solutions were compared. RESULTS: All single agents induced concentration-dependent relaxation of the rabbit and rat cavernosal smooth muscles. There was significant synergism on rabbit cavernosal smooth muscle when the sildenafil was combined with forskolin, sodium nitroprusside, VIP or phentolamine. There was also significant synergism with sildenafil plus prostaglandin-E1 in rat cavernosal muscles. There were no synergistic effects of combinations of sildenafil plus moxisylyte, papaverine or l-arginine. CONCLUSIONS: These results suggest potentially effective combined therapies of sildenafil and intraurethral or intracavernosal prostaglandin-E1, intracavernosal forskolin or VIP, or oral phentolamine for patients with erectile dysfunction who have no success after monotherapy with these agents.