Adaptive histogram equalization in digital radiography of destructive skeletal lesions

Adaptive histogram equalization, an image-processing technique that distributes pixel values of an image uniformly throughout the gray scale, was applied to 28 plain radiographs of bone lesions, after they had been digitized. The non-equalized and equalized digital images were compared by two skeletal radiologists with respect to lesion margins, internal matrix, soft-tissue mass, cortical breakthrough, and periosteal reaction. Receiver operating characteristic (ROC) curves were constructed on the basis of the responses. Equalized images were superior to nonequalized images in determination of cortical breakthrough and presence or absence of periosteal reaction. ROC analysis showed no significant difference in determination of margins, matrix, or soft-tissue masses.     

US-guided biopsy of neck masses in postoperative management of patients with thyroid cancer

High-frequency (10-MHz) sonography demonstrated a cervical mass or lymphadenopathy, or both, during postoperative follow-up of 52 patients who had undergone surgery for thyroid cancer. Percutaneous biopsy with ultrasonographic (US) guidance was performed in all 52 masses, 44 of which were nonpalpable. Malignant cells were obtained in 29 biopsies, and the results of 20 biopsies were negative, yielding benign lymphocytes only. Results in three biopsies were nondiagnostic due to hypocellular specimens. Therefore, 94% of biopsy results (49) of 52) were confidently assigned as either positive (56%) or negative (38%) for malignancy. There were no complications. High-frequency sonography can demonstrate clinically occult thyroid bed tumor recurrence and lymph node metastases. US-guided biopsy is an accurate and safe technique to confirm or exclude malignancy in patients at high risk of recurrence of thyroid cancer.     

Comparison of micro-CT and cone beam CT-based assessments for relative difference of grey level distribution in a human mandible

Objectives:

The purpose of this study was to examine the ability of CT to assess the relative difference of degree of bone mineralization (grey level) parameters in a human mandible.

Methods:

Ten mandibular sections from cadavers (81.5 ± 12.1 years) were scanned using micro-CT with 27.2 μm voxel size and cone beam CT (CBCT) with 200 μm, 300 μm, and 400 μm voxel sizes. In addition, 15 clinical CBCT images from young patients (mean age 18.9 ± 3.3 years) were identified. After segmentation of bone voxels, alveolar bone and basal cortical bone regions were digitally isolated. A histogram of grey level, which is equivalent to degree of bone mineralization, was obtained from each region of the CT images. Mean, standard deviation (SD), coefficient of variation (COV), fifth percentile low (Low₅) and high (High₅) of alveolar bone and basal cortical bone regions were obtained. Percentage differences of grey level parameters between alveolar and basal cortical bones were computed.

Results:

The alveolar bone region had significantly lower Mean, Low₅ and High₅ values but significantly higher SD and COV than the basal cortical bone region for all CT images (p < 0.05). All parameters were significantly lower for the old cadaver group than for the young patient group (p < 0.05).

Conclusions:

CBCT and micro-CT provide comparable results in the assessment of relative difference in grey level distribution between alveolar and basal cortical bone regions in the human mandible. The percentage difference relative to an internal reference (basal cortical bone) can be a reliable method when assessing the degree of bone mineralization using CBCT images for both cross-sectional and longitudinal comparisons.     

Orthotopic liver transplantation in a patient with carbamyl phosphate synthetase deficiency and cystic fibrosis

A 15-year-old female with carbamyl phosphate synthetase deficiency, cystic fibrosis, and cystic fibrosis-related diabetes underwent orthotopic cadaveric liver transplantation. Metabolic control was maintained during the procedure with nutritional support and the use of intravenous sodium phenylacetate and benzoate. Her postoperative course was complicated by seizures and a transient decline in her pulmonary function tests, which returned to preoperative levels within one year of the transplant. Now, four years post-transplant, her quality of life has dramatically improved. There are only four Canadian centres with paediatric liver transplantation programs. However, expert medical care for adults with inborn error of metabolism is even more limited, suggesting that access to adult medical care is one of the many factors to be considered when liver transplantation is contemplated for patients with metabolically unstable conditions.     

Estimation of the age at onset in spinocerebellar ataxia type 2 Cuban patients by survival analysis

Almaguer‐Mederosa LE, Falcón NS, Almira YR, Zaldivar YG, Almarales DC, Góngora EM, Herrera MP, Batallán KE, Armiñán RR, Manresa MV, Cruz GS, Laffita‐Mesa J, Cyuz TM, Chang V, Auburger G, Gispert S, Pérez LV. Estimation of the age at onset in spinocerebellar ataxia type 2 Cuban patients by survival analysis. Previous studies have investigated the close association that exists between CAG repeat number and the age at onset in SCA2 = spinocerebellar ataxia type 2. These studies have focused on affected individuals. To further characterize this association and estimate the risk of a carrier developing SCA2 at a particular age as a function of a specific CAG repeat size, we have analyzed a large group of 924 individuals, including 394 presymptomatic and 530 affected individuals with a CAG repeat length of 32–79 units. Using a Kaplan–Meier survival analysis, we obtained cumulative probability curves for disease manifestation at a particular age for each CAG repeat length in the 34–45 range. These curves were significantly different (p < 0.001) and showed small overlap. All these information may be very valuable in predictive‐testing programs, in the planning of studies for the identification of other genetic and environmental factors as modifiers of age at onset, and in the design of clinical trials for people at enlarged risk for SCA2.     

Fetal electrocardiography: feasibility of long-term fetal heart rate recordings

The feasibility and accuracy of long-term transabdominal fetal electrocardiogram (fECG) recordings throughout pregnancy were studied using a portable fECG monitor. Fifteen-hour recordings of fetal heart rate (FHR) were performed in 150 pregnant women at 20–40 weeks of gestation and 1-hour recordings were performed in 22 women in labour and compared with simultaneous scalp electrode recordings. When ≥60% of fECG signals was present, the recording was defined as good. Eighty-two percent (123/150) of antenatal recordings were of good quality. This percentage increased to 90.7 (136/150 recordings) when only the night part (11 p.m.–7 a.m.) was considered. Transabdominal measurement of FHR and its variability correlated well with scalp electrode recordings ( r = 0.99, P < 0.01; r = 0.79, P < 0.01, respectively). We demonstrated the feasibility and accuracy of long-term transabdominal fECG monitoring.     

Persistence of the immune response induced by BCG vaccination

Background  

Although BCG vaccination is recommended in most countries of the world, little is known of the persistence of BCG-induced immune responses. As novel TB vaccines may be given to boost the immunity induced by neonatal BCG vaccination, evidence concerning the persistence of the BCG vaccine-induced response would help inform decisions about when such boosting would be most effective.     

Routine microbiological testing in sudden and unexpected infant death

Objective : To evaluate the significance of microbiological test results in a series of infants who had died suddenly and unexpectedly.
Methodology : Following a review of all cases of sudden natural death in infants presenting to the Adelaide Children's Hospital (ACH) division of the Women's and Children's Hospital (WCH) over the 10 year period between 1983 and 1992, specific evaluation of microbiological test results was undertaken.
Results : There were 329 cases of sudden infant death syndrome (SIDS) and 23 cases in which sudden infant death was either attributed to other conditions or was unclassifiable. Positive microbiological results were recorded in the majority of cases, most being considered to be due to postmortem overgrowth or to contamination at autopsy. Of the remaining cases, microbiological results were essential to the establishment of the diagnosis in three cases, and were a useful adjunct to the diagnosis in a further six cases.
Conclusions : Routine microbiological testing in cases presenting as SIDS did not reveal occult sepsis in most instances. Such testing did, however, add support to the diagnosis of SIDS where no pathogens were isolated and, if not undertaken, would have resulted in a small percentage of cases of sudden infant death due to infections remaining undiagnosed.     

Survival from acute non-lymphocytic leukaemia, 1971-88: a population based study

Survival rates were studied among 1258 children with acute non-lymphocytic leukaemia diagnosed in 1971-88 and included in the population based National Registry of Childhood Tumours. Of the total, 147 (12%) died without receiving treatment. Among the remaining treated children, actuarial five year survival rates were 6% in 1971-4, 15% in 1975-9, 23% in 1980-3, and 40% in 1984-8. Infants aged less than 1 year had a significantly worse prognosis and there was a significant trend towards lower survival rates with increasing white cell count. No independent significant effects on survival were found with sex, French-American-British (FAB) subtype, or the presence or absence of Down's syndrome. Children entered in national trials had a higher survival rate than those who were not entered, and children treated at teaching hospitals had a higher survival rate than those who were treated elsewhere. Among the 535 (43%) children who survived at least one year from diagnosis no factor studied had a significant effect on survival, emphasising the importance of achieving first remission as a determinant of long term survival.