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.     

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.     

Renal damage caused by warm ischaemia during laparoscopic and robot-assisted partial nephrectomy: an assessment using Tc 99m-DTPA glomerular filtration rate

Background

Few studies assessing the functional change of each kidney following warm ischaemia after partial nephrectomy are available.

Objectives

Our aim was to identify the effects of the warm ischaemic time (WIT) on renal function after partial nephrectomy under the pneumoperitoneum.

Design, setting, and participants

Forty-four consecutive patients who underwent laparoscopic partial nephrectomy (LPN) or robot-assisted partial nephrectomy (RAPN) from June 2008 to May 2009 for a single cT1 renal tumour were included in this prospective protocol.

Measurements

Technetium Tc 99m-diethylenetriaminepentaacetic acid (Tc 99m-DTPA) renal scintigraphy was used to determine the glomerular filtration rate (GFR) of both kidneys and each kidney individually. Tc 99m-DTPA GFR was performed preoperatively and 3 mo postoperatively. In addition, we analysed Tc 99m-DTPA scintigraphy GFR regionally in the healthy areas of the affected kidney.

Results and limitations

Patients with WIT >28 min had a significantly greater decrease in the GFR of the affected kidney (p = 0.031). The GFR of the affected kidney showed a significant decrease perioperatively (46.4 ± 14.3 to 37.9 ± 11.9 ml/min per 1.73 m²; p = 0.003). The functional change of the nonaffected kidney showed an increasing trend (47.5 ± 13.8 to 51.4 ± 14.3 ml/min per 1.73 m²), although it was not statistically significant (p = 0.103). Regional Tc 99m-DTPA GFR of both affected kidney and nonaffected kidney showed no significant differences perioperatively (6.3 ± 1.8 to 6.1 ± 1.9 ml/min per 1.73 m²; p = 0.641; 6.6 ± 1.9 to 7.1 ± 2.0 ml/min per 1.73 m²; p = 0.200). On multivariate analysis, preoperative GFR, resected volume of marginal healthy tissue, and WIT were independent predictors for functional reduction of the affected kidney (p < 0.05). The study was limited by small numbers and short follow-up periods.

Conclusions

Stationary overall renal function after LPN or RAPN is masked possibly by functional compensation of the contralateral healthy kidney. The damage of the affected kidney estimated by scintigraphy occurs when WIT exceeds 28 min during partial nephrectomy under the pneumoperitoneum.     

Case report of endotracheal intubation using AirWay Scope (Pentax-AWS) in a Forestier's disease patient

A Forestier's disease patient was scheduled for endoscopic mucosal resection under general anesthesia, because of his hypoxic episode during gastric endoscopy. Endotracheal intubation was planned while awake, because he was suspected as a case of difficult airway. By using AWS, we could easily confirm his larynx and aditus of trachea in spite of his narrow pharynx caused by Forestier's disease. The procedure was successful with no complications. AWS seems to be a useful device for endotracheal intubation in Forestier's disease.     

Hybrid repair of thoracoabdominal aortic aneurysm in high-risk patients using a quadrifurcated graft

Surgical treatment for thoracoabdominal aortic aneurysm is still challenging and is associated with a high risk of paraplegia. Hybrid repair with stent graft insertion for the thoracoabdominal aorta excluding the branches of the lumbar and visceral arteries and bypass grafting to the visceral branches has been introduced as a less invasive treatment that reduces the risk of paraplegia. For hybrid repair, it is important to have appropriate management of the revascularized grafts to the 4 visceral arteries with sufficient inflow. We have recently adopted a knitted quadrifurcated graft applied inversely from the abdominal aorta or the iliac artery to the 4 visceral arteries; the celiac, superior mesenteric, and bilateral renal arteries. To date, we have used the graft in hybrid repair of thoracoabdominal aortic aneurysm in 2 high-risk elder patients who had disseminated intravascular coagulopathy and severe renal failure, respectively. We found that a knitted quadrifurcated graft was easy to handle and useful for reducing the number of anastomoses, which were expected to shorten the operation time. Postoperative courses were uneventful without paraplegia in either patient. Postoperative computed tomography showed excellent patency of the inversely applied quadrifurcated graft without any endoleak or migration in the thoracoabdominal stent. In conclusion, revascularization of 4 visceral arteries using a quadrifurcated graft should be considered a preferable option in hybrid treatment for thoracoabdominal aortic aneurysm.     

Endoscopic removal of impacted magnetic foreign bodies in the gastroesophageal junction

Ingestion of foreign bodies is common in gastroenterology practice. Most of them are spontaneously passed through gastrointestinal tract. However, ingestion of multiple magnets can cause serious complications, because magnets attract each other and they hold the gastrointestinal wall. Here, we describe a patient who ingested multiple magnets that attracted each other between distal esophagus, and a part of them was impacted into the esophageal wall. In general, impacted magnetic foreign bodies should be removed by surgical intervention because of a high perforation risk. But, in this case, we used an insulated-tip knife for endoscopic submucosal dissection technique to make an incision to expose the impacted magnetic foreign bodies, and removed them successfully without surgery. With this report, we hope to encourage gastroenterologists to consider this new technique as one of procedures for difficult cases, including impacted foreign bodies.     

Characteristics and Trends of Orthopedic Publications between 2000 and 2009

Background

This study was undertaken to investigate the trends of orthopedic publications during the last decade, and to document the country of origin, journal, funding source, and language of contribution using PubMed.

Methods

Orthopedic articles published between 2000 and 2009 were retrieved from PubMed using the following search terms: "orthopaedic[Affiliation] AND ("2000/1/1"[PDAT]: "2009/12/31"[PDAT])" and "orthopedic[Affiliation] AND ("2000/1/1"[PDAT]: "2009/12/31"[PDAT])." The articles were downloaded in XML file format, which contained the following information: article title, author names, journal names, publication dates, article types, languages, authors'' affiliations and funding sources. These information was extracted, sorted, and rearranged using the database''s management software. We investigated the annual number of published orthopedic articles worldwide and the annual rate of increase. Furthermore, the country of publication origin, journal, funding source, and language of contribution were also investigated.

Results

A total of 46,322 orthopedic articles were published and registered in PubMed in the last 10 years. The worldwide number of published orthopedic articles increased from 2,889 in 2000 to 6,909 in 2009, showing an annual increase of 384.6 articles, or an annualized compound rate of 10.2%. The United States ranked highest in the number of published orthopedic articles, followed by Japan, the United Kingdom, Germany, and the Republic of Korea. Among the orthopedic articles published worldwide during the last 10 years, 37.9% pertained studies performed in the United States. Fifty-seven point three percent (57.3%) of articles were published in journals established in the United States. Among the published orthopaedic articles, 4,747 articles (10.2%) disclosed financial support by research funds, of which 4,688 (98.8%) articles utilized research funds from the United States. Most articles were published in English (97.2%, 45,030 articles).

Conclusions

The number of published orthopedic articles has been increasing over the last decade. The number of orthopedic articles, journals publication, and funding sources were dominated by research conducted in the United States, while share and growth of Asian countries including Japan, the Republic of Korea, and China were notable.     

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.     

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.