Initial application of respiratory-gated 201Tl SPECT in pulmonary malignant tumours

AIM: Respiratory-gated thallium-201 chloride (201Tl) single photon emission computed tomography (SPECT) was used in preliminary investigations to reduce the adverse respiratory motion effects observed on standard ungated SPECT images and to obtain reliable fusion images with computed tomography (CT) in patients with malignant lung tumours. METHODS: Fifteen patients with primary lung cancer (n=10) or metastatic lung tumours (n=5) underwent gated SPECT 20 min after intravenous injection of 148 MBq 201Tl, using triple-headed SPECT and laser light respiratory tracking units. Projection data were acquired by a step and shoot mode, with 20 stops over 120 degrees for each detector and a preset time of 30 s for each 6 degrees stop. Gated end-inspiratory and ungated images were obtained from 1/8 data centred at peak inspiration for each regular respiratory cycle and for the full respiratory cycle data, respectively. The degree and size of tumour 201Tl uptake were compared between these images by regions of interest (ROI) analysis. Gated SPECT images were registered with rest inspiratory CT images using an automated three-dimensional (3D) image registration tool. Registration mismatch was assessed by measuring the 3D distance of the centroid of 14 201Tl-avid peripheral tumours. Attenuation correction of gated SPECT images was performed using CT attenuation values of these fusion images. RESULTS: Gated SPECT images improved image clarity and contrast of tumour 201Tl uptakes compared with ungated images, regardless of the decreased count density due to the use of gated images. The lesion-to-normal (L/N) lung count ratios and ROI size in 18 well-circumscribed 201Tl-avid tumours were significantly higher and smaller on gated images (both P<0.0001). Gated images showed positive 201Tl uptakes in two small peripheral tumours, although negative on ungated images, and demarcated 201Tl-avid tumours from adjacent 201Tl-avid lymph node or surrounding focal 201Tl uptakes caused by other pathology, although these were not clearly demarcated on ungated images. On fusion images, gated images yielded a significantly better SPECT-CT matching compared with ungated images (P<0.0001). Fusion images accurately localized 201Tl uptakes of tumour/lymph node and other focal pathological/physiological conditions. Attenuation-corrected gated SPECT images further facilitated the detection of 201Tl uptake in small or deeply located lesions, with significantly increased L/N ratios. CONCLUSION: Gated SPECT images facilitate the detection of tumour 201Tl uptake and provide reliable SPECT-CT fusion images, which contribute to accurate interpretation and attenuation correction of Tl SPECT images.     

A case of hepatocellular carcinoma initially treated by carbon ions, followed by protons for marginal recurrence with portal thrombus

We report a case of hepatocellular carcinoma (HCC), initially treated by carbon ions, then subsequently by protons for marginal recurrence. A 52-year-old man with stage II HCC was enrolled in the clinical study for carbon ion therapy. A total dose of 52.5 GyE in 8 fractions was delivered through a right lateral port for 13 days. Dynamic CT performed 7 months after the initiation of carbon ion therapy showed a decrease in the size of the tumor. Dynamic CT performed 12 months after the therapy revealed marginal recurrence of HCC accompanied with portal vein tumor thrombus (PVTT). Proton therapy of 66 GyE in 22 fractions was delivered through posterior and right lateral ports for 33 days. Dynamic CT performed 3 months after the initiation of proton therapy showed a regression of the recurrent tumor and disappearance of the PVTT. No serious adverse effects were observed during or after these two treatments. He was free from further recurrence 27 months after the initiation of the first carbon ion therapy. Both carbon ions and protons were effective with minimal side effects.     

Arthroscopic findings in chronic lateral ankle instability: do focal chondral lesions influence the results of ligament reconstruction?

BACKGROUND: There are few studies that have assessed the influence of focal chondral lesions on the results of ligament reconstruction for chronic lateral ankle instability. HYPOTHESIS: Focal chondral lesions do not influence the results of ligament reconstruction. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Arthroscopic examination of the ankle was performed on 30 consecutive patients immediately before ligament reconstruction using the palmaris longus tendon. Clinical assessment was performed using the Karlsson scoring scale. A radiologic assessment was performed on stress radiographs of the ankle. Preoperative anteroposterior and lateral weightbearing radiographs of the ankle did not show any joint space narrowing in any ankle. The mean duration of follow-up was 38 months. RESULTS: On arthroscopy, focal chondral lesions were found in 19 ankles (63%). Chondral lesions were located on the medial side of the tibial plafond in 13 ankles (43%), on the lateral side in 2 ankles (7%), on the lateral side of the talar dome in 3 ankles (10%), and on the medial side in 9 ankles (30%). Postoperative mean Karlsson scores in patients without chondral lesions and in those with chondral lesions were 99.1 and 98.4 points, respectively. Postoperative mean talar tilt angles in patients without chondral lesions and in those with chondral lesions were 5.9 degrees and 4.7 degrees , respectively. There were no significant differences in the clinical and radiologic results between patients with chondral lesions and those without chondral lesions. CONCLUSIONS: Reconstruction of the lateral ligament can be successful regardless of the presence of focal chondral lesions in patients with chronic lateral ankle instability when preoperative weightbearing radiographs of the ankle do not show any joint space narrowing.     

Contact area, contact pressure, and pressure patterns of the tendon-bone interface after rotator cuff repair

BACKGROUND: The contact pressure and contact area at the tendon-bone interface after the most commonly used rotator cuff repair methods have not been investigated. HYPOTHESIS: There are no significant differences among the transosseous, the single-row suture anchor, and the double-row suture anchor techniques in terms of contact pressure, contact area, and pressure patterns at the tendon-bone interface. STUDY DESIGN: Controlled laboratory study. METHODS: After creating a full-thickness supraspinatus tendon tear in 10 cadaveric shoulder specimens, we inserted pressure-sensitive film between the tendon stump and the bone, and we repaired the tear by (1) transosseous, (2) single-row suture anchor, and (3) double-row suture anchor techniques. RESULTS: The contact area of the double-row technique was 42% greater than that of the transosseous technique (P < .0001) and 60% greater than that of the single-row technique. The contact area of the transosseous technique was 31% greater than that of the single-row technique (P = .0015). The average pressures of the single-row and double-row techniques were 18% (P = .014) and 16% (P = .03) greater, respectively, than that of the transosseous technique, but there was no significant difference between the single-row and double-row techniques (P = .915). CONCLUSIONS: The double-row technique produced the greatest contact area and the second-highest contact pressure, whereas the single-row technique created the highest contact pressure and the least contact area. The transosseous technique produced the second-greatest contact area and the least contact pressure. CLINICAL RELEVANCE: The double-row suture anchor technique and the transosseous technique may provide a better environment for tendon healing.     

HBL-3 Cell Line,Derived from Precursor B-cell lymphoblastic Leukemia,Lacks Somatic Hypermutation of Immunoglobulin Heavy Chain Variable Region Genes

Somatic mutation (SM) analysis provides a useful tool for understanding the stages at which neoplastic differentiate from normal B-cells. B-cell precursor neoplasms are considered to be somatically premutational. However, the variable frequency of SM of the variable region (VH) genes has been described in cases of precursor B-cell acute lymphoblastic leukemia (PB-ALL). To better characterize PB-ALL based on the differentiation stage, we investigated the SM of the VH genes expressed by tumor cells of the surface immunoglobulin (sIg)^– HBL-3 cell line derived from childhood PB-ALL. In the HBL-3 cell line, the rearranged Ig heavy chain VH gene sequence showed no SM in the complementarity-determining regions of 1, 2, and 3, or in the framework regions of 1, 2, and 3 relative to the putative germline VH gene sequences. In addition, the VH segment of HBL-3 cells showed no intraclonal sequence heterogeneity, indicating ongoing SM. Our data demonstrated that HBL-3 cells express unmutated and developmentally regulated rearrangement of VH genes at the stage of B-cell precursor cells. HBL-3 cells, which are derived only from the sIg^– PB-ALL, showed that SM cannot be recognized in VH genes of tumor cells before the expression of sIg.     

Endoscopic treatment or surgery for undifferentiated early gastric cancer?

BACKGROUND: Although almost all (96%) the surgical cases of undifferentiated intramucosal early gastric cancer (EGC) have been found not to have lymph node metastasis (LNM), local treatment by endoscopic mucosal resection (EMR) is not accepted as an alternative treatment to surgery for this type of EGC. If a subgroup of patients with undifferentiated EGC with negligible risk of LNM can be defined, unnecessary surgery can be avoided. This study was conducted to determine this subgroup among undifferentiated EGC patients in whom the risk of LNM can be highly ruled out in an attempt to identify candidates who can be treated by EMR. METHODS: Data from 175 patients surgically resected for undifferentiated EGC were retrospectively collected, and clinicopathological factors were multivariately analyzed to identify predictive factors for LNM. RESULTS: Multivariate logistic regression analysis identified two independent risk factors for LNM, namely, a large tumor (>/=20 mm, P = 0.011) and presence of lymphatic involvement (P = 0.0005). Using these two risk factors as the predictive factors, LNM was observed in 5.8% of patients who had neither of the two predictive factors, whereas 23.1% or 13.1% of patients with one or two predictive factors had LNM, respectively. In contrast, the LNM rate was calculated to be 60% in patients who had both factors. Lymph node metastasis was not found in any of 6 patients with small intramucosal lesions (<10 mm) without lymphatic involvement. CONCLUSIONS: An intramucosal undifferentiated EGC that is smaller than 10 mm without lymphatic involvement can safely be treated by EMR alone, given the negligible possibility of LNM. When histological examination of endoscopically resected specimens shows lymphatic involvement or unexpectedly larger tumor size than that determined at pre-EMR endoscopic diagnosis, an additional surgical procedure should be considered.     

Automated computerized scheme for detection of unruptured intracranial aneurysms in three-dimensional magnetic resonance angiography

RATIONALE AND OBJECTIVES: A computerized scheme for automated detection of unruptured intracranial aneurysms in magnetic resonance angiography was developed based on the use of a three-dimensional selective enhancement filter for dots (aneurysms). MATERIALS AND METHODS: Twenty-nine cases with 36 unruptured aneurysms (diameter, 3 to 26 mm; mean, 6.6 mm) and 31 non-aneurysm cases were used in this study. The isotropic 3-dimensional magnetic resonance angiography images with 400 x 400 x 128 voxels (voxel size, 0.5 mm) were processed by use of the selective enhancement filter. The initial candidates were identified by use of a multiple gray-level thresholding technique on the dot-enhanced images and a region-growing technique with monitoring some image features. All candidates were classified into four types of candidates according to the size and local structures based on the effective diameter and skeleton image of each candidate (ie, large candidates and three types of small candidates including short-branch type, single-vessel type, and bifurcation type). In each group, a number of false-positives were removed by use of different rules on localized image features related to gray levels and morphology. Linear discriminant analysis was used for further removal of false-positives. RESULTS: With this computer-aided diagnostic scheme, all of 36 aneurysms were correctly detected with 2.4 false-positives per patient based on a leave-one-out-by-patient test method. CONCLUSION: This computer-aided diagnostic system would be useful in assisting radiologists for the detection of intracranial aneurysms in magnetic resonance angiography.     

Assessment of regional lung functional impairment with co-registered respiratory-gated ventilation/perfusion SPET-CT images: initial experiences

In this study, respiratory-gated ventilation and perfusion single-photon emission tomography (SPET) were used to define regional functional impairment and to obtain reliable co-registration with computed tomography (CT) images in various lung diseases. Using a triple-headed SPET unit and a physiological synchroniser, gated perfusion SPET was performed in a total of 78 patients with different pulmonary diseases, including metastatic nodules (n=15); in 34 of these patients, it was performed in combination with gated technetium-99m Technegas SPET. Projection data were acquired using 60 stops over 120° for each detector. Gated end-inspiration and ungated images were reconstructed from 1/8 data centered at peak inspiration for each regular respiratory cycle and full respiratory cycle data, respectively. Gated images were registered with tidal inspiration CT images using automated three-dimensional (3D) registration software. Registration mismatch was assessed by measuring 3D distance of the centroid of the nine selected round perfusion-defective nodules. Gated SPET images were completed within 29 min, and increased the number of visible ventilation and perfusion defects by 9.7% and 17.2%, respectively, as compared with ungated images; furthermore, lesion-to-normal lung contrast was significantly higher on gated SPET images. In the nine round perfusion-defective nodules, gated images yielded a significantly better SPET-CT match compared with ungated images (4.9±3.1 mm vs 19.0±9.1 mm, P<0.001). The co-registered SPET-CT images allowed accurate perception of the location and extent of each ventilation/perfusion defect on the underlying CT anatomy, and characterised the pathophysiology of the various diseases. By reducing respiratory motion effects and enhancing perfusion/ventilation defect clarity, gated SPET can provide reliable co-registered images with CT images to accurately characterise regional functional impairment in various lung diseases.     

Sedation in Japanese dental schools

There is very little information about the practice of sedation in Japan. Despite the remarkable advances in dentistry, fear and anxiety continue to be significant deterrents for seeking dental services. Most dental procedures can fortunately be undertaken with the aid of sedation. A comprehensive survey of all the dental schools in Japan was carried out to determine what sedation practices were used in Japan. All 29 dental schools in Japan possessed a dedicated department of anesthesiology at the time of this survey. The survey attempted to determine the specific sedation methods (techniques, routes of administration, and agents used in sedation) as well as practices (monitoring, fasting, location, education, and fees involved in sedation). The results indicate that there was a broad range in sedation practices. The Japanese Dental Society of Anesthesiology may wish to examine the findings of this study and may wish to formulate guidelines appropriate for the practice of sedation in Japan. Others may also wish to compare their own practices with those of Japan.     

Magnetic resonance angiographic localization of the artery of Adamkiewicz for spinal cord blood supply

Background

The purpose of this study was to determine whether the artery of Adamkiewicz (ARM) can be detected by magnetic resonance angiography and to determine the usefulness of preoperative magnetic resonance angiography evaluation of the ARM.

Methods

Between April 2000 and December 2003, 120 patients underwent magnetic resonance angiography for detection of the ARM. The morphology of the anterior spinal artery at the ARM junction, as revealed by magnetic resonance angiography, in 99 patients in whom ARM was preoperatively detected was classified into the following three types: noncontinuation of the anterior spinal artery above the ARM junction (type A), continuation of the anterior spinal artery above and below the ARM junction (type B), and noncontinuation of the anterior spinal artery below the ARM junction (type C).

Results

The ARMs were detected in 99 (83%) of 120 patients, and from a total of 110 ARMs 105 (95%) originated from intercostal arteries branching from the left side and 94 (86%) originated between Th9 and Th11. Two ARMs were found in 11 (11%) of 99 patients in whom ARMs were detected. In 107 patients, who underwent magnetic resonance angiography to reveal the morphology of the anterior spinal artery at the ARM junction, the patterns of the anterior spinal artery were type A in 59 patients (55%), type B in 21 patients (20%), type C in 3 patients (3%) and not classified in 24 patients (22%). No spinal cord injury occurred in patients in whom the ARM had been preoperatively detected.

Conclusions

Preoperative detection of the ARM is possible by magnetic resonance angiography and is very useful for reducing the incidence of ischemic injury of the spinal cord.