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J W Oestmann

Publications and source records attributed to J W Oestmann.

At least 19 recordsLinked to original sources
PubMed1996

Infrarenal abdominal aortic aneurysms: implications of CT evaluation of size and configuration for placement of endovascular aortic grafts.

PURPOSE: To measure infrarenal abdominal aortic aneurysms and assess the implications and potential obstacles for placement of an endovascular aortic graft undergoing clinical testing in Europe. MATERIALS AND METHODS: Helical computed tomography was used to measure 77 infrarenal aortic aneurysms (77 patients) and the distances between the aneurysms and the renal arteries and the aortic bifurcation. RESULTS: Mean length of the aneurysms was 8.2 cm; mean distance to the renal arteries, 2.7 cm; mean aortic diameter 1.5 cm distal to the renal arteries, 1.9 cm; and mean minimal diameter of perfused lumen, 2.5 cm. Thirteen aneurysms extended into the common iliac artery; 40 reached the bifurcation. The mean minimal luminal diameter of the iliac artery was 1.1 cm. CONCLUSION: Sufficient nonaneurysmal segments below the renal arteries and distal to the aneurysms are necessary for stent fixation. The large diameter of the delivery introducer in relation to the iliac arteries may be a major obstacle to graft delivery. At best, 33 patients could have benefited from use of the graft evaluated.

Aged↗
PubMed1996

Microcalcifications in breast core biopsy specimens: disappearance at radiography after storage in formaldehyde.

PURPOSE: To determine whether radiographically proved calcifications in core biopsy specimens are better preserved in a nonaqueous fixative than in aqueous solutions. MATERIALS AND METHODS: One hundred fifty core biopsy specimens were taken from two female breast specimens that had been preserved in ethanol. Forty-one of the specimens with radiographically proved microcalcifications were divided into four groups and deposited in four different solutions: 10% formaldehyde, 0.9% sodium chloride, electrolyte solution, and 74.1% ethanol with 10% 2-propanol. The core specimens were radiographed again after 1 and 3 days. Five ethanol-preserved specimens were also reexamined radiographically after 2 weeks. RESULTS: Within 3 days, total radiographic disappearance of microcalcifications was observed in all core biopsy specimens that were immersed in solutions with high water content. In those core specimens preserved in ethanol, microcalcifications showed no change. CONCLUSION: A nonaqueous fixative, such as ethanol, is a better preservative of microcalcifications in breast core biopsy specimens than various aqueous solutions, possibly because calcium compounds are water-soluble.

Biopsy↗
PubMed1996

Dual-phase helical CT of the liver: effects of bolus tracking and different volumes of contrast material.

PURPOSE: To evaluate the effects of tracking and volume of contrast material on dual-phase helical computed tomography (CT) of the liver. MATERIALS AND METHODS: CT was performed in 120 consecutive patients. Either 100 mL (groups 1 and 2) or 120 mL (groups 3 and 4) of contrast material was injected at a rate of 4 mL/sec. In groups 1 and 3, the scanning delay was fixed, whereas in groups 2 and 4, scanning delays were determined individually by means of a semiautomatic bolus tracking device. The arterial phase began when splenic enhancement was greater than 10 HU and ended when hepatic enhancement was greater than 20 HU, which characterized the start of the portal venous phase. RESULTS: The mean duration of the arterial phase was 11.6 (100 mL) and 12.2 seconds (120 mL). The arterial phase of the liver within the defined limits was sufficiently timed in only 16 (54%) patients in group 1, 25 (83%) in group 2, and 20 (67%) in groups 3, whereas it was significantly (P < .05) better in 28 (93%) patients in group 4. A significantly (P < .05) higher mean parenchymal enhancement in the portal venous phase (63.6 HU +/- 8.5) was obtained in group 4. CONCLUSION: Bolus tracking of a volume of 120 mL provided the most accurate results in dual-phase liver CT.

Adult↗
PubMed1996

MR arthrography in the diagnosis of rotator cuff tears. Standard spin-echo alone or with fat suppression?

PURPOSE: To examine the value of fat-suppressed images in MR arthrography of the shoulder in patients with rotator cuff tears. MATERIAL AND METHODS: MR arthrography was performed in 25 patients (9 women, 16 men) ranging from 19 to 64 years. Standard T1-weighted spin-echo images (sSE) and fat-suppressed images (FS) were obtained after intraarticular injection of contrast material. The MR studies were analyzed according to contrast, image quality and conspicuity of pathology. A diagnosis was established without knowledge of the conventional arthrographic findings on the basis of sSE versus FS techniques. RESULTS: The contrast between the intraarticular fluid and the adjacent structures in FS images was increased compared to sSE images in all patients. The conspicuity of anatomical structures was improved in 8 patients. Without fat suppression, 2 false-negative and one false-positive full-thickness tears were diagnosed. With the FS technique, 14 full-thickness tears and 4 partial-thickness tears of the cuff were correctly classified. CONCLUSION: The results suggest that, if MR arthrography is chosen for a diagnosis of rotator cuff disorders, a fat suppression sequence should be included.

Adult↗
PubMed1996

Must radiation dose for CT of the maxilla and mandible be higher than that for conventional panoramic radiography?

We evaluated the feasibility of performing preoperative spiral CT of the maxilla and mandible with a radiation dose similar to that used for conventional panoramic radiography. The skin entrance doses of radiation used for spiral CT (collimation, 1 mm; pitch, 2; tube voltage, 80 kV; tube current, 40 mA) and for panoramic radiography (75 kV, 8 mA, 15 seconds) were measured in one patient by using thermoluminescent dosimeter chips. Results were 0.56 +/- 0.06 mGy for CT and 0.59 +/- 0.04 mGy for radiography. Image quality was adequate for preoperative implant planning. Spiral CT of the mandible and maxilla may therefore be feasible with a radiation dose of similar magnitude as that used for conventional panoramic radiography.

Dental Implants↗
PubMed1995

True aneurysm of the superior gluteal artery: case report and review of the literature.

Aneurysms of the gluteal arteries are rare and mostly are caused by pelvic fractures or penetrating injuries. As such these aneurysms are pseudoaneurysms. As an absolute rarity we report the case of a 43-year-old man with a histologically verified 5 cm-diameter, true saccular aneurysm of the left superior gluteal artery. The patient was admitted with 6-weeks ongoing sciatic pain without previous trauma. He was scheduled for surgery because an initial attempt of transcatheter embolization failed. By dividing the origin of the gluteus maximus muscle from the iliac crest, the aneurysm was exposed at the pelvic outlet by an extrapelvic approach and was excluded by endoaneurysmorrhaphy. Uncontrolled bleeding was prevented by temporary occlusion of the left iliac artery by a percutaneously inserted balloon catheter, thus avoiding an additional retroperitoneal approach. The postoperative course was uneventful, and sciatic pain had resolved completely. The chosen strategy provides safe and successful surgical management of gluteal artery aneurysms.

Adult↗
PubMed1995

Broadband ultrasound attenuation in the diagnosis of osteoporosis: correlation with osteodensitometry and fracture.

PURPOSE: To evaluate the usefulness of broadband ultrasound attenuation in the prediction of osteoporosis. MATERIALS AND METHODS: Broadband ultrasound attenuation measurements of the calcaneus and dual x-ray absorptiometry (DXA) measurements of the lumbar spine and the femoral neck were obtained in 400 patients (295 female and 105 male), 135 of whom were classified as having osteoporosis. Correlation coefficients between broadband ultrasound attenuation and DXA were calculated. RESULTS: Patients with osteoporosis showed a statistically significant decrease in broadband ultrasound attenuation compared with healthy patients (59.7 dB/MHz +/- 1.3 [standard deviation] vs 75.1 dB/MHz +/- 0.8). Broadband ultrasound attenuation correlated statistically significantly with vertebral bone density (r = .49) and femoral neck density (r = .52). At a broadband ultrasound attenuation index of 64 dB/MHz, the sensitivity and specificity were both 85% for patients with osteoporotic fractures. CONCLUSION: Broadband ultrasound attenuation can be used to help differentiate between patients with osteoporosis and healthy patients and seems to be useful in the prediction of fracture risk.

Absorptiometry, Photon↗
PubMed1995

Parenchymal liver enhancement with bolus-triggered helical CT: preliminary clinical results.

A software-driven device for bolus-triggered start of helical computed tomography (CT) was evaluated in liver studies of 30 patients with suspected metastatic liver disease. Compared with results in a control group of 30 patients who underwent conventional contrast material-enhanced helical CT, the study group had significantly higher and more constant parenchymal enhancement (P < .05, Mann-Whitney U test). This technique helps optimize findings at contrast-enhanced helical CT.

Contrast Media↗
PubMed1995

MR imaging-guided breast intervention: experience with two systems.

PURPOSE: To evaluate two different systems for magnetic resonance (MR) imaging-guided breast intervention. MATERIALS AND METHODS: Thirty-four patients with 34 lesions detected exclusively with contrast material-enhanced MR imaging underwent 51 interventional procedures (23 needle biopsies and 28 preoperative wire localizations) with two different systems. An add-on device for surface coils was used in 25 cases, and a dedicated single breast biopsy coil was used in 26. For needle biopsies, material was aspirated with nonmagnetic 19.5-gauge needles. For preoperative localizations, nonmagnetic hook wires were used. RESULTS: Surgical excision or follow-up verified the cytologic findings in 19 of the 23 cases sampled for biopsy. Cytologic diagnosis was impossible in three of the 23 cases. One technical failure occurred with the biopsy coil. Open biopsy performed after MR imaging-guided localization successfully removed 26 of the 28 lesions. One missed carcinoma was found at repeat localization and removed. One technical failure occurred with the biopsy coil. In that case, the lesion was close to the chest wall. CONCLUSION: Both systems are suitable for fine-needle biopsy and preoperative localization of lesions seen exclusively on MR images.

Adult↗
PubMed1994

[Inflammatory lesions of the breast: indication for MR-mammography?].

In a retrospective study the value of MR imaging of the breast in inflammatory changes was evaluated. The signal enhancement of 8 patients with histopathologically verified inflammatory carcinomas and 9 patients with global mastitis as well as local inflamed lesions was analysed. Neither signal behaviour nor signal/time relation were suitable to differentiate between malignant and benign changes. In conclusion inflammatory changes of the female breast are not indicated to be examined with MR imaging.

Adenocarcinoma↗
PubMed1994

Superimposed peripheral pulmonary vasculature in anthropomorphic chest phantoms.

RATIONALE AND OBJECTIVES: Comparative radiologic studies often involve the use of phantoms. However, in most chest phantoms, the lack of sufficient peripheral vessels results in unrealistic images. This can impair the reliability of conclusions drawn from the studies performed. The authors present a method of improving the simulation of the peripheral pulmonary vasculature in anthropomorphic chest phantoms. METHODS: The appearance of peripheral vessels was simulated using red lead painted on transparent foils. Several of the foils were taped to the back of the phantom to give the impression of superimposed blood vessels. RESULTS: Subjectively, a more realistic appearance of peripheral vasculature was obtained in the radiograph. CONCLUSIONS: Our method improves the quality of widely available anthropomorphic chest phantoms, and the modification is easily implemented. However, the use of lead limits the modified phantom to comparative studies with constant exposure voltage.

Humans↗
PubMed1994

Optimization of chest films of equalization radiography (advanced multiple beam equalization radiography). Comparison by means of a receiver operating characteristic study of simulated nodular interstitial disease.

RATIONALE AND OBJECTIVE: To optimize screen-film combinations for equalization radiography (advanced multiple beam equalization radiography [AMBER]), five different film-screen-technique combinations were compared by receiver operating characteristics study of simulated interstitial disease. MATERIALS AND METHODS: The Ortho C-Lanex Regular and the Insight Thoracic Imaging HC system were compared in conventional nonequalized technique; T-Mat G-Lanex Regular and T-Max L-Lanex Regular were compared in conventional, nonequalized, and AMBER technique; and an experimental high-contrast, low-noise, near-zero crossover film-screen combination was compared in AMBER technique. Interstitial disease was simulated by superimposing birdseed on the back of a humanoid phantom. Twenty-five posterior-anterior radiographs were made with each technique. Seven observers scored the presence of interstitial disease in each of the quadrants on a 5-point scale following receiver operating characteristic methodology. RESULTS: The highest performance was found with the experimental film-screen-AMBER combination (Az = 0.92) and the lowest with the T-Mat L-Lanex Regular-AMBER combination (Az = 0.83) and the Insight Thoracic Imaging HC system-conventional combination (Az = 0.85). T-Mat L-Lanex Regular-conventional ranked second (Az = 0.90) while T-Mat G-Lanex Regular-conventional (Az = 0.89), T-Mat L-Lanex Regular-AMBER (Az = 0.88) and Ortho-C-Lanex Regular-conventional (Az = 0.87) scored lower. CONCLUSION: Higher contrast films in AMBER improve diagnostic performance, whereas a loss of information is found if the AMBER system is combined with lower contrast films.

Humans↗
PubMed1994

Scanning equalization mammography: preliminary evaluation.

The authors show preliminary work with an experimental scanning equalization mammography system intended to increase contrast and achieve adequate dose throughout the breast. The unit uses a modulated, segmented fan beam. Tests with and without scanning equalization were performed with contrast-latitude phantoms and a breast specimen with superimposed microcalcifications. Films of varying contrast were evaluated. Contrast at low and very high object densities was greatly improved with the equalization technique. Microcalcifications were better appreciated, especially in those regions of the specimen that were outside the optimal optical density range of the conventional technique.

Female↗
PubMed1994

Application of AMBER in single- and dual-energy digital imaging: improvement in noise level and display dynamic range.

The combination of computed radiography (CR) and advanced multiple beam equalization radiography (AMBER) was evaluated for both single- and dual-energy chest radiography. The improved signal-to-noise ratio found with CR and AMBER resulted in a better visualization of structures in the mediastinum and basal lung than that found with CR alone. For the central lung, no improvement was seen. Because of the compressed dynamic range with CR and AMBER, contrast on hard copies and video monitors could be high without a sacrifice in image latitude. Dual-energy images showed a considerably lower noise level. The combined use of AMBER and CR promises to overcome the dynamic range limitations of digital displays while improving signal-to-noise ratio.

Artifacts↗
PubMed1994

MR-guided biopsy of suspect breast lesions with a simple stereotaxic add-on-device for surface coils.

A guiding attachment is described that transforms a conventional magnetic resonance (MR) imaging surface coil into a stereotaxic biopsy unit. Eight patients, aged 38-66 years (mean, 54 years), with suspect breast lesions detected exclusively at contrast material-enhanced MR imaging underwent MR-guided needle biopsy with this unit. Diagnostic material was successfully aspirated in all patients (four carcinomas, three fibroadenomas, and one intraductal hyperplasia), and the diagnosis was subsequently confirmed at surgical biopsy. This technique promises to increase the diagnostic specificity for lesions seen solely at MR imaging.

Adult↗
PubMed1994

Dissection of the thoracic aorta: pre- and postoperative findings on turbo-FLASH MR images obtained in the plane of the aortic arch.

This pictorial essay illustrates the pre- and postoperative findings seen in patients with aortic dissections on contrast-enhanced turbo-fast low-angle shot (FLASH) MR images obtained in the plane of the aortic arch. Contrast-enhanced images provide morphologic and functional information not normally available with conventional spin-echo (SE) MR imaging or dynamic CT. Preoperative examination of the acute dissection is often troubled by cardiovascular insufficiency and motion artifacts. Therefore most of our patients were examined postoperatively. The main reason for postsurgical imaging is the evaluation of the flow in the different lumina and the detection of complications (i.e., aneurysms or progress of dissection).

Aortic Dissection↗
PubMed1993

Visualization of basal pleural space and lung with advanced multiple beam equalization radiography (AMBER).

During clinical use of AMBER (Advanced Multiple Beam Equalization Radiography) it was frequently felt that the basal lung and pleural space were better appreciated than with standard chest radiography. We aimed to quantify the amount of additional relevant anatomy seen in this part region and to review the normal radiographic anatomy. Four hundred patients without known chest disease were evaluated. Two groups of 200 patients (50% female) were studied with either AMBER or standard chest radiography (140 kVp, 180 cm FFD, Kodak Tmat G film, Lanex regular screen; for both techniques). Visualization of the pleural sinuses (in percent of the transverse thoracic diameter) and the basal pulmonary vessels (4-point scale) was evaluated by a panel of 3 radiologists. The shape of the sinus was traced if sufficiently visible and subjectively evaluated. A significantly (P < 0.05) larger segment of the dorsal (41 +/- 34%) and ventral (14 +/- 15%) sinuses was seen with the AMBER technique than with the standard technique (16 +/- 21% and 9 +/- 11%, respectively). Vessel visibility was also significantly (P < 0.001) better with AMBER (3.2 +/- 0.6) than with the standard technique (1.9 +/- 0.6). The dorsal sinus showed alternatively a curved or pointed configuration.

Adult↗