PubMed Health⌕ Search

Biomedical subjects

N J Cozens

Publications and source records attributed to N J Cozens.

11 recordsLinked to original sources
PubMed2002

Good practice in head and neck fine needle aspiration cytology as assessed by CUSUM.

Providing data as evidence of good practice is becoming imperative to meet the demands of professional revalidation and clinical governance. Sensitivity and specificity are common performance measures in fine needle aspiration (FNA) but are vulnerable to discordant analytical methods. We introduce a CUSUM technique and show how it may be used to show attainment and maintenance of proficiency in head and neck (H&N) FNA. In addition, we show how it can be used to compare practices and demonstrate different performance for FNAs from different tissues; a fact that must be recognized by anyone devising minimum performance values.

Biopsy, Needle↗
PubMed2000

Sestamibi scan-directed unilateral neck exploration for primary hyperparathyroidism due to a solitary adenoma.

AIM: To evaluate the accuracy of Tc-99m sestamibi scintography in pre-operative localization of a single parathyroid adenoma and to determine if neck exploration can be limited to the side of the adenoma. METHODS: Over a period of 4 years, 30 patients with primary hyperparathyroid disease underwent surgical treatment in the form of unilateral neck exploration after localization by Tc-99m sestamibi scintigraphy. The scan findings were interpreted by one radiologist with a special interest in parathyroid imaging and the operative findings were correlated with scan findings. RESULTS: Tc-99 sestamibi scan localized a single parathyroid adenoma in 29 patients. There was doubtful uptake of isotope in one patient. Unilateral cervical exploration confirmed isotope scan findings in 29 patients with a positive scan, and these were subsequently proven by histology. In the patient with doubtful sestamibi scan, bilateral neck exploration was undertaken and three enlarged glands were excised. All the three glands were reported to be abnormal, consistent with either adenomas or hyperplasia. All the patients were normocalcaemic after 6 months follow-up. CONCLUSIONS: Our results demonstrate that Tc-99m sestamibi scintigraphy is highly accurate in pre-operative localization of a single parathyroid adenoma when performed by an experienced radiologist. Unilateral cervical exploration, as directed by a positive Tc-99m sestamibi scintigram, seems to be a logical approach for the patients with primary hyperparathyroid disease due to solitary adenoma.

Adenoma↗
PubMed1999

Does a joint ultrasound guided cytology clinic optimize the cytological evaluation of head and neck masses?

AIM: To compare the results of fine-needle aspiration (FNA) of head and neck masses performed in an ultrasound-guided cytology clinic (USGCC) staffed by a radiologist and pathologist to those obtained with specimens sent from other sources. METHODS: Comparison of broad-category FNA diagnoses (malignant, uncertain, benign or inadequate) with the patient's ultimate clinical or pathological outcome. Because FNA outcomes are semi-quantitative, accuracy of the procedure (the proportion of all tests resulting in a true- positive or negative fine-needle aspirate) is a better measure than sensitivity or specificity. Specimens (n = 292) from the first 2 years of the USGCC are compared with 600 specimens received from other sources over the previous 4 years. RESULTS: Accuracy was 23.4% better for specimens from the USGCC compared with those obtained by clinician guided aspiration (83.9%, 95% CI 79.7-88.1%, vs 60.5%, 95% CI 56.6-64.4%). There was an 84% reduction in inadequate specimens (from 21.5% to 3.4%). The proportion resulting in an uncertain result did not alter; 12.0% for USGCC and 11.9% for clinician-derived specimens. Improvement in accurate identification of salivary gland, lymph node, soft tissue and thyroid pathology was 27.0%, 21.2%, 18.3% and 15.8% respectively. CONCLUSIONS: The common practice of FNA performed by clinicians produces sub-optimal results in head and neck masses. A combined approach of ultrasound-guided fine-needle aspiration of head and neck masses, with immediate assessment of the material by a pathologist, is more accurate than with specimens obtained in other ways. If the results of FNA are to be incorporated into clinical decision making, the samples are best obtained using the USGCC model.

Biopsy, Needle↗
PubMed1996

Atypically located submandibular gland diagnosed by Doppler ultrasound.

The anatomical location and relationships of the submandibular gland are well-known to most otolaryngologists and gross variations from the norm are rare. We report a case of an atypical submandibular gland located 2 cm below the mandible which presented as a painful neck swelling with non-diagnostic fine needle aspiration cytology. Using Doppler ultrasound the mass was noted to be closely located to the facial artery and vein and following the administration of oral lemon juice, the peak systolic velocity of a small artery within the mass rose from 8.5 cm/s to 16.4 cm/s, confirming the tissue's salivary nature. We review the literature on using Doppler ultrasound in this area of the neck and discuss realistic practical applications of the technique.

Arteries↗
PubMed1994

Should we have confidence in radiology papers?

This study aims to assess whether Confidence Intervals are used appropriately in papers published in Clinical Radiology, and compares 50 consecutive papers in this journal with similar samples in Radiology and the British Medical Journal (BMJ). The utilization or omission of Confidence Intervals and statistical hypothesis testing is analysed. The results are discussed using chi 2 tests and 95% Confidence Intervals for the difference between proportions. This illustrates the important additional quantitative information that Confidence Intervals can convey, particularly when evaluating the degree of uncertainty related to a result from a small sample or subgroup in a study.

Confidence Intervals↗
PubMed1992

Conventional 15 G needle technique for renal biopsy compared with ultrasound-guided spring-loaded 18 G needle biopsy.

Two techniques for percutaneous renal biopsy were retrospectively reviewed to assess their relative safety and efficacy. Ultrasound localization of the kidney by a radiologists, with subsequent biopsy performed by a renal physician using a hand-held 15 G cutting needle (Tru-Cut), was compared with biopsy performed by a radiologist using an 18 G cutting needle with a spring-loaded biopsy device (Biopty) and real-time ultrasound guidance. The smaller needle with real-time ultrasound is more reliable at retrieving an adequate specimen for histological examination (93%) than the "conventional" technique (79%). Fewer complications occurred in the Biopty group although the difference did not reach statistical significance. The average length of stay in hospital was significantly shorter for elective biopsies with the Biopty device (1.80 compared with 2.93 nights, p less than 0.01). We recommend the use of the Biopty device with an 18 G needle and real-time ultrasound guidance as the method of choice for percutaneous renal biopsy.

Adolescent↗
PubMed1987

Are we taught how to use a radiology department as medical students?

Thirty-six final year medical students and 28 senior house officers answered a questionnaire designed to evaluate their efficacy in requesting common radiological procedures and their knowledge of what the patient experiences during the investigation. Both groups revealed a significant degree of ignorance, though the house officers were better informed than the students. The need for undergraduate teaching in radiology, particularly in the role of diagnostic radiology in clinical management is discussed.

Education, Medical↗