Comparison of 2-dimensional and 3-dimensional acquisition for 18F-FDG PET oncology studies performed on an LSO-based scanner.

Three-dimensional (3D) PET acquisition has the potential to reduce image noise but the advantage of 3D PET for studies outside the brain has not been well established. To compare the performance of 2-dimensional (2D) and 3D acquisition for whole-body (18)F-FDG applications, a series of patient studies were performed using a lutetium oxyorthosilicate (LSO)-based tomograph. METHODS: Comparative 2D and 3D images were acquired for 27 oncology patients using an LSO-based tomograph. Data acquisition (350-650 keV, 6 ns) started 99 +/- 12 min (mean +/- SD) after injection of 624 +/- 76 MBq (18)F-FDG. Bias caused by tracer redistribution and decay was eliminated by acquiring dynamic data over a single-bed position using a protocol that alternated between septa-in and septa-out modes (2D, 3D, 2D, 3D, 2D, 3D). Frames were combined to form 8 statistically independent sinograms: four 2D replicates (105 s) and four 3D replicates (90 s). The different frame durations in 2D and 3D compensated for the different number of overlapping bed positions required for an 85-cm whole-body study. Images were reconstructed with either 2D or fully 3D ordered-subsets expectation maximization (2 iterations and 8 subsets; 2D 6-mm gaussian, 3D 5- and 6-mm gaussian). Image target-to-background ratio was assessed by dividing the lesion maximum by the mean within a neighboring background region. Image noise was assessed by applying background regions of interest to the replicate images and calculating the within-patient coefficient of variation. RESULTS: The difference in target-to-background ratio between the 2D and 3D images, when they were filtered with 6-mm and 5-mm gaussian filters, respectively, was not highly statistically significant (P = 0.16). The mean ratio of 3D to 2D image values was 0.94 with 95% limits of agreement of 0.63-1.41. The within-patient coefficients of variation for the 2D and 3D images were 13% +/- 15% and 9% +/- 10%, respectively (P = 0.0005). CONCLUSION: Under conditions of matched target to-to-background ratios, the 3D mode was found to produce images with significantly less variability than the 2D mode. These data provide support for the use of 3D acquisition with LSO detectors to reduce scan times in whole-body (18)F-FDG applications.     

Instillation of bacillus Calmette-Guerin into the renal pelvis of a solitary kidney for the treatment of transitional cell carcinoma

Intravesical bacillus Calmette-Guerin is effective in the treatment and prophylaxis of superficial urothelial cancer of the bladder. There have been few reports of its efficacy and toxicity when instilled into the upper urinary tract. We elected to use intracavitary bacillus Calmette-Guerin in a patient with recurrent high grade transitional cell carcinoma in the renal pelvis of a solitary autotransplanted kidney. The patient required hospitalization and triple-drug therapy after 5 instillations. She was free of tumor 1 year after bacillus Calmette-Guerin instillations.     

Down's syndrome and the acquisition of phonology by Cantonese-speaking children

ABSTRACT. The phonological abilities of two groups of 4–9-year-old intellectually impaired Cantonese-speaking children are described. Children with Down's syndrome did not differ from matched non-Down's syndrome controls in terms of a lexical comprehension measure, the size of their phoneme repertoires, the range of sounds affected by articulatory imprecision, or the number of consonants, vowels or tones produced in error. However, the types of errors made by the Down's syndrome children were different from those made by the control subjects. Cantonese-speaking children with Downs syndrome, as compared with controls, made a greater number of inconsistent errors, were more likely to produce non-developmental errors and were better in imitation than in spontaneous production. Despite extensive differences between the phonological structures of Cantonese and English, children with Downs syndrome acquiring these languages show the same characteristic pattern of speech errors. One unexpected finding was that the control group of non-Down's syndrome children failed to present with delayed phonological development typically reported for their English-speaking counterparts. The argument made is that cross-linguistic studies of intellectually impaired children's language acquisition provide evidence concerning language-specific characteristics of impairment, as opposed to those characteristics that, remaining constant across languages, are an integral part of the disorder. The results reported here support the hypothesis that the speech disorder typically associated with Down's syndrome arises from impaired phonological planning, i.e. a cognitive linguistic deficit.     

Predictive validity of certification by the American Board of Internal Medicine

STUDY OBJECTIVE: To determine the predictive validity of the American Board of Internal Medicine (ABIM) certification process. DESIGN: Prospective measurement of the knowledge, skills, and attitudes of 185 ABIM-certified and 74 noncertified internists by a written examination; evaluation by professional associates; a patient questionnaire assessing satisfaction with care, physician's counseling role, and preventive care; and review of records of patients with common illnesses. SUBJECTS: Practicing internists who completed training or received ABIM certification 5 to 10 years previously. SETTING: Office-based practices in six western states. RESULTS OF DATA ANALYSIS: Physicians certified by the ABIM had significantly higher scores on the written examination than the noncertified physicians, and scores on our examination correlated highly with the ABIM certification examination (r = 0.73). Ratings of clinical skills by professional associates were significantly higher for certified internists and also correlated highly with ABIM examination scores (r = 0.53 to 0.59). Regression analysis showed that ABIM certification status was the major variable affecting performance on these measures of clinical competence. Results from other measures did not show many differences between certified and noncertified physicians in the care of patients with common illnesses, but modest differences in preventive care and a few differences in outcome favored the certified physicians. CONCLUSIONS: Comparison of findings from the written examination and the professional associate ratings with certification status and original ABIM certification examination scores shows predictive validity of ABIM certification. Further studies are needed to determine if certification status predicts important differences in the care of patients with complex illnesses.     

Extradural lymphoma presenting as an acute surgical emergency

Extradural lymphoma can present as an acute neurosurgical emergency. The clinical presentation and radiological appearance may suggest epidural hematoma or meningioma. Lymphoma should be considered as a rare but possible diagnosis before operation. High resolution computed tomography using direct coronal imaging with and without contrast enhancement may aid in suggesting the correct preoperative diagnosis.     

'What do you notice?' Using posters containing questions and general instructions to guide preschoolers' science and mathematics learning

To increase preschoolers' science and mathematics learning experiences both within and outside the classroom, we developed age-appropriate materials containing general questions and instructions that teachers and parents could use when interacting with their students and children. The questions and instructions were related to a specific science or mathematics skill (e.g., classifying), but were general enough so that they could be applied to a variety of situations. Observations of three classrooms and interviews with the classroom teachers and aides, and the parents of the children in the classrooms suggested that use of these materials was beneficial to the children, teachers, and parents, and resulted in increasing the amount of science and mathematics activities and discussions in two of the classrooms as well as outside the classrooms.     

Minimal Acute Rejection after Lung Transplantation: A Risk for Bronchiolitis Obliterans Syndrome

Bronchiolitis obliterans syndrome (BOS) is a major cause of lung allograft dysfunction. Although previous studies have identified mild to severe rejection (grade>or=A2) as a risk factor for BOS, the role of minimal rejection (grade A1) remains unclear. To determine if A1 rejection by itself is a risk factor for BOS, we performed a retrospective cohort study on 228 adult lung transplant recipients over a 7-year period. Cohorts were defined by their most severe rejection episode (none, A1 only, and >or=A2) and analyzed for the subsequent development and progression of BOS using univariate and multivariate time-dependent Cox regression analysis. In the univariate model, the occurrence of isolated minimal rejection was a risk factor for all stages of BOS. Similarly, multivariate models that included HLA mismatch, cytomegalovirus pneumonitis, community acquired viral infection, underlying disease and type of transplant demonstrated that A1 rejection was a distinct risk factor for BOS. Furthermore, the associated risk with A1 rejection was slightly greater than the risk from >or=A2 and treatment of A1 rejection decreased the risk for subsequent BOS stage 1. We conclude that minimal rejection is associated with an increased risk for BOS development and progression that is comparable to A2 rejection.