PubMed Health⌕ Search

Biomedical subjects

W Janowitz

Publications and source records attributed to W Janowitz.

8 recordsLinked to original sources
PubMed2000

Sensitivity of two electron beam tomography protocols for the detection and quantification of coronary artery calcium.

OBJECTIVE: The purpose of this study was to compare the sensitivity of two electron beam tomography protocols for detection and quantification of coronary artery calcium. SUBJECTS AND METHODS: We selected 101 patients (57% men, mean age 53 +/- 10 years) to undergo two consecutive electron beam tomography and acquired imaging with both a 6-mm and a 3-mm slicing protocol. Three pixels (area, 1.03 mm(2)) and a minimal density of 130 H were used for definition of calcified plaque. RESULTS: We found coronary artery calcifications in 46 patients when we used a 6-mm protocol and in 61 patients when we used a 3-mm protocol (p < 0.001). The average total calcium score was 77 (+/-140) with a 6-mm protocol and 251 (+/-395) with a 3-mm protocol (p < 0.005). The average number of calcified lesions per patient was 1.7 for a 6-mm protocol and 3.7 for a 3-mm protocol (p < 0.01). Of 179 individual lesions seen using a 3-mm protocol, 103 (58%) were missed using a 6-mm protocol, and only 27% of the lesions with a calcium score less than or equal to 40 seen with a 3-mm protocol were detected with 6-mm slicing (p < 0.001). The mean lesion attenuation with a 6-mm protocol was 160 (+/-42) H, compared with 218 (+/-44) H with a 3-mm protocol (p < 0.001), indicating a significantly greater partial volume averaging with the former protocol. CONCLUSION: A 6-mm slicing protocol is significantly less sensitive than a 3-mm protocol for the detection and quantification of coronary artery calcium. Since one third of coronary events occur in patients with low calcium scores, a 6-mm protocol might be unreliable for risk assessment because of substantial loss of information in this calcium score range.

Calcinosis↗
PubMed1990

Iatrogenic aorto-sinus of valsalva fistula: angiographic and cine computerized tomography delineation.

A patient is reported who underwent cardiac catheterization 4 years following coronary artery bypass grafting. Cardiac catheterization revealed the presence of a fistulous tract in the wall of the ascending aorta, originating at the site of aortic anastomosis of a saphenous vein bypass graft and ending in the superior aspect of the right sinus of Valsalva. This complication was felt to have resulted from a inadvertent localized dissection of the aorta during bypass surgery. The fistula was also imaged by ultrafast cine computerized tomography which proved a useful non-invasive method for follow-up examination.

Aortic Diseases↗
PubMed1989

Endovaginal and transabdominal sonography of ovarian follicles.

Endovaginal and transabdominal sonography (EVS and TAS, respectively) are effective methods for monitoring ovarian follicular development. Our study evaluates both modalities by subjective comparisons and objective correlations with serum estradiol levels. In 21 of 41 studies, TVS showed more follicles over 1 cm than did TAS. The same number was seen by both in 17 studies and more by TAS in only 3 studies. Margins of the follicles were sharply defined in 37 of 41 EVS studies (90%) but only in 18 of 41 TAS studies (41%). In each of the 4 cases in which follicles were not sharply defined by EVS the ovaries were located high in the pelvis. In 29 sonographic studies, there were corresponding estradiol levels. The number and size of dominant follicles correlated well with estradiol levels (r = .9074) for EVS but less so (r = .3816) for TAS. EVS has several advantages when monitoring follicular development.

Abdomen↗
PubMed1986

Bedside radionuclide scanning in the postoperative management of intraperitoneal sump drains.

The volume of the peritoneal cavity opacificable by the instillation of 99mTechnetium labeled albumin through a sump drain was studied over successive postoperative days in 19 patients (21 drains) using a portable gamma camera. After operation, a constant gravity drip of saline solution was delivered through the sump "in" port. The "out" port was connected to low constant suction. Encapsulation (opacification of only the catheter) was demonstrated in eight of the catheters on either the initial study (six) or on successive (two) studies. This encapsulation was demonstrated sometime between the first and sixth postoperative day. The volume of the peritoneal cavity which was perfuseable did decrease measurably over several successive days in three of the patients. In nine of 21 drains, a significant volume of the peritoneal cavity was still perfuseable on the third and up to the sixth postoperative day. The classic teaching that a drain placed in the peritoneal cavity promptly encapsulates may apply to static gravity drains but does not apply to perfused sump drains used in this study. The manner in which fluid is instilled may modify the volume of peritoneal cavity perfused. The 99mTechnetium labelled albumin technique is suitable for bedside use because of its simplicity and lack of adverse reactions. Its accuracy facilitates the decision as to when a sump drain should be removed.

Catheters, Indwelling↗
PubMed1984

Intravenous DSA of extracranial carotid lesions: comparison with other techniques and specimens.

Intravenous digital subtraction arteriography (DSA) was performed in 306 patients with suspected ischemic cerebrovascular disease. Forty-eight carotid endarterectomies were performed in 43 of these patients. The percentage stenosis as determined on the intravenous DSA examination concurred (+/- 10%) with the surgical findings in 83.3%. There were 12.5% undercalls (false-negatives) and 4.3% overcalls (false-positives). Of the false-negative and false-positive examinations only three would have affected the clinical management of the patient, yielding an overall sensitivity of 93.7%. Nine surgical lesions had both intravenous DSA and conventional arteriography. Intravenous DSA was correct in six and arteriography in seven of these lesions. There were four surgically confirmed ulcerations. Two were evaluated by intravenous DSA alone. Two had intravenous DSA and arteriography. The latter showed both ulcers; the former, only one. Thirty-seven surgical lesions had both intravenous DSA and high-resolution real-time sonographic imaging. Sonography agreed in 67.5% and intravenous DSA in 83.7% of these lesions. When an abnormal supraorbital Doppler or an abnormal oculopneumoplethysmography/Gee examination is added to the sonographic examination, an overall sensitivity of 93% was obtained in detecting a surgical lesion (stenosis greater than 50%).

Adult↗
PubMed1980

New observations in scintigraphy of subdural and extradural hematomas.

Static radionuclide images of subacute subdural hematomas demonstrate significant variations in findings over a 3-hr period in the same patient. The lesion can appear, disappear, and reconstitute in an entirely different pattern. This transformation has not appeared in extradural hematomas, and may provide a differential diagnostic sign. In patients with a clinical history or physical findings suspicious for these intracranial hematomas, immediate and sequential delayed static imaging is recommended.

Aged↗