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R L Birdwell

Publications and source records attributed to R L Birdwell.

18 recordsLinked to original sources
PubMed2000

Characterization of breast lesion morphology with delayed 3DSSMT: an adjunct to dynamic breast MRI.

The purpose of the study was to determine the sensitivity and specificity of various morphologic criteria in distinguishing malignant from benign breast lesions using a new sequence (3DSSMT) performed immediately after dynamic breast MRI. 3DSSMT combines a water-selective spectral-spatial excitation and an on-resonance magnetization transfer pulse with three-dimensional spoiled gradient-echo imaging. Morphologic features of 87 pathologically confirmed lesions were analyzed. The presence of either skin thickening, or a combination of a spiculated or microlobulated border, with a rim, ductal, linear, or clumped enhancement pattern was 94% specific and 54% sensitive for malignancy. Conversely, the presence of either a perfectly smooth border, a well-defined margin, non-enhancing internal septations, or a macrolobulated border was 97% specific and 35% sensitive for a benign diagnosis. In conclusion, delayed 3DSSMT discriminates a significant number of benign and malignant breast lesions; it has the potential to improve the diagnostic accuracy of dynamic breast MRI.

Breast↗
PubMed2000

Dynamic breast MRI with spiral trajectories: 3D versus 2D.

A three-dimensional (3)D spiral sequence was developed for dynamic breast magnetic resonance (MR) imaging with much improved image quality. Partial Z phase encoding was applied to obtain thinner slices for a coverage of the whole breast. Comparison between the 3D and a previously developed multi-slice 2D spiral sequences was performed on ten healthy volunteers without contrast and five breast patients with gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA). The 3D spiral images had significantly less off-resonance blurring and spiral artifacts. With a small compromise on temporal resolution (7.7 seconds in 2D and 10.6 seconds in 3D), we obtained 32 interpolated 3-5 mm slices (with 20 Z phase encodes) for a full coverage of 10-16 cm breast with the same 1 x 1 mm2 in-plane resolution as the 2D sequence, which had 12 8-13 mm slices. Contrast between glandular and soft tissue in normal breasts was increased by about 25%. The reduced repetition time in the 3D spiral acquisition led to an increased Gd-enhanced signal. The difference between the enhancement of malignant and benign lesions increased by sevenfold. We expect that this new development could lead to improved specificity in characterizing breast lesions using MR imaging.

Adult↗
PubMed1999

Radiofrequency ablation of breast cancer: first report of an emerging technology.

HYPOTHESIS: Radiofrequency (RF) energy applied to breast cancers will result in cancer cell death. DESIGN: Prospective nonrandomized interventional trial. SETTING: A university hospital tertiary care center. PATIENTS: Five women with locally advanced invasive breast cancer, aged 38 to 66 years, who were undergoing surgical resection of their tumor. One patient underwent preoperative chemotherapy and radiation therapy, 3 patients received preoperative chemotherapy, and 1 had no preoperative therapy. All patients completed the study. INTERVENTIONS: While patients were under general anesthesia and just before surgical resection, a 15-gauge insulated multiple-needle electrode was inserted into the tumor under sonographic guidance. Radiofrequency energy was applied at a low power by a preset protocol for a period of up to 30 minutes. Only a portion of the tumor was treated to evaluate the zone of RF ablation and the margin between ablated and nonablated tissue. Immediately after RF ablation, the tumor was surgically resected (4 mastectomies, 1 lumpectomy). Pathologic analysis included hematoxylin-eosin staining and enzyme histochemical analysis of cell viability with nicotinamide adenine dinucleotide-diaphorase (NADH-diaphorase) staining of snap-frozen tissue to assess immediate cell death. MAIN OUTCOME MEASURE: Cancer cell death as visualized on hematoxylin-eosin-stained paraffin section and NADH-diaphorase cell viability stains. RESULTS: There was evidence of cell death in all patients. Hematoxylin-eosin staining showed complete cell death in 2 patients. In 3 patients there was a heterogeneous pattern of necrotic and normal-appearing cells within the ablated tissue. The ablated zone extended around the RF electrode for a diameter of 0.8 to 1.8 cm. NADH-diaphorase cell viability stains of the ablated tissue showed complete cell death in 4 patients. The fifth patient had a single focus of viable cells (<1 mm) partially lining a cyst. There were no perioperative complications related to RF ablation. CONCLUSIONS: Intraoperative RF ablation results in invasive breast cancer cell death. Based on this initial report of the use of RF ablation in breast cancer, this technique merits further investigation as a percutaneous minimally invasive modality for the local treatment of breast cancer.

Adult↗
PubMed1999

Silicone breast implant rupture: pitfalls of magnetic resonance imaging and relative efficacies of magnetic resonance, mammography, and ultrasound.

The objective of this study was to evaluate the relative efficacies of magnetic resonance (MR) imaging, ultrasonography, and mammography in implant rupture detection and to illustrate pitfalls in MR image interpretation. Thirty patients referred by plastic surgeons with suspected breast implant rupture were prospectively evaluated using MR, ultrasonography, and mammography. Imaging examinations were interpreted independently and blindly for implant rupture and correlated to operative findings. Surgical correlation in 16 patients (53 percent) with 31 implants showed 13 (42 percent) were intact, 5 (16 percent) had severe gel bleed, and 13 (42 percent) were ruptured. MR sensitivity was 100 percent and specificity was 63 percent. Accuracy for rupture was 81 percent with MR, higher than with ultrasonography and mammography (77 and 59 percent, respectively). We describe a specific pitfall in MR interpretation, the "rat-tail" sign, composed of a medial linear extension of silicone along the chest wall. Seen in eight cases (four intact, three ruptures, one gel bleed), the rat-tail sign may lead to misdiagnosis of implant rupture if seen in isolation. Magnetic resonance imaging is more accurate and sensitive than ultrasonography and mammography in detecting breast implant rupture. We describe a new sign (rat-tail sign) composed of medial compression of the implant simulating silicone extrusion as a potential false-positive MR finding for rupture. This article presents clinical experience with magnetic resonance, mammography, and ultrasound in the diagnosis of implant rupture and defines and illustrates potential pitfalls of MR interpretation, including the new rat-tail sign.

Adult↗
PubMed1999

Methods of compliance with Mammography Quality Standards Act regulations for tracking positive mammograms: survey results.

OBJECTIVE: We sent a questionnaire to fellows of the Society of Breast Imaging to determine how breast imaging facilities comply with regulations mandated by the Mammography Quality Standards Act for tracking patients whose mammograms show positive findings. SUBJECTS AND METHODS: We surveyed the Society of Breast Imaging fellows to determine practice types, follow-up methodology, additional time and personnel required, and end points of radiologists' responsibility for follow-up of mammograms with positive findings. RESULTS: Forty-six (68%) of 68 surveyed practices responded, including 21 academic, 16 private, and nine mixed practices that averaged 15,761 mammograms a year (range, 300-50,000). The 46 practices used computers (n = 30) or handwritten paper (n = 16) audits. Radiologists (n = 8), technologists (n = 6), other personnel (n = 10), or a combination (n = 22) tracked procedures and patients with abnormal mammographic results. Average time spent tracking was given as a few hours a week (n = 28), 2-4 hr a day (n = 11), and 40 hr a week (n = 5). The remaining two practices indicated that less than 1 hr per month was required (n = 1) or that they used two full-time data managers (n = 1). Accepted tracking end points included surgical biopsy (n = 30), referring physician recommended other management (n = 16), patient refused recommendation (n = 27), medical care transfer (n = 27), patient moved (n = 22), or patient lost to referring physician follow-up (n = 16). CONCLUSION: Among dedicated mammographers, the methodology in the task of tracking patients with positive findings on mammography varies. All methodologies described in responses to our survey involved considerable time and effort.

Breast Neoplasms↗
PubMed1999

Virtual endoscopy using perspective volume-rendered three-dimensional sonographic data: technique and clinical applications.

OBJECTIVE: We present a technique for obtaining three-dimensional external and virtual endoscopy views of organs using perspective volume-rendered gray-scale and Doppler sonographic data, and we explore potential clinical applications in the carotid artery, the female pelvis, and the bladder. CONCLUSION: Using the proposed methods, radiologists will find it possible to create virtual endoscopy and external perspective views using sonographic data. The technique works well for revealing the interior of fluid-filled structures and cavities. However, expected improvements in computer performance and integration with existing sonographic equipment will be necessary for the technique to become practical in the clinical environment.

Carotid Arteries↗
PubMed1998

Breast lesion localization: a freehand, interactive MR imaging-guided technique.

PURPOSE: To evaluate interactive magnetic resonance (MR) imaging-guided preoperative needle localization and hookwire placement in the noncompressed breast in patients in the prone position. MATERIALS AND METHODS: Nineteen MR imaging-guided breast lesion localization procedures were performed in 17 patients aged 38-70 years (mean age, 48 years) by using an open-platform breast coil in either a 1.5-T, closed-bore imager (n = 14) or a 0.5-T, open-bore imager (n = 5). Rapid imaging (fast spin-echo, water-selective fast spin-echo, or water-specific three-point Dixon gradient-echo) was alternated with freehand manipulation of an MR-compatible needle to achieve accurate needle placement. RESULTS: Up to three manipulations of the needle were required during an average of 9 minutes to reach the target lesion. MR imaging findings confirmed the final needle position within 9 mm of the target in all cases. The accuracy of 10 localizations was independently corroborated either at mammography or at ultrasonography. Nine lesions were visible on MR images only. CONCLUSION: Interactive MR imaging-guided, freehand needle localization is simple, accurate, and requires no special stereotactic equipment. Lesions throughout the breast, including those in the anterior part of the breast and those near the chest wall, which can be inaccessible with standard grid or compression-plate techniques, can be localized. A variety of needle trajectories in addition to the horizontal path are possible, including circumareolar approaches and tangential needle paths designed to avoid puncture of implants.

Adult↗
PubMed1998

Breast disease: dynamic spiral MR imaging.

PURPOSE: To compare various subjective, empiric, and pharmacokinetic methods for interpreting findings at dynamic magnetic resonance (MR) imaging of the breast. MATERIALS AND METHODS: Dynamic spiral breast MR imaging was performed in 52 women suspected of having or with known breast disease. Gadolinium-enhanced images were obtained at 12 locations through the whole breast every 7.8 seconds for 8.5 minutes after bolus injection of contrast material. Time-signal intensity curves from regions of interest corresponding to 57 pathologically proved lesions were analyzed by means of a two-compartment pharmacokinetic model, and the diagnostic performance of various parameters was analyzed. RESULTS: Findings included invasive carcinoma in 17 patients, isolated ductal carcinoma in situ (DCIS) in six, and benign lesions in 34. Although some overlap between carcinomas and benign diagnoses was noted for all parameters, receiver operating characteristic analysis indicated that the exchange rate constant had the greatest overall ability to discriminate benign and malignant disease. The elimination rate constant and washout were the most specific parameters. The exchange rate constant, wash-in, and extrapolation point were the most sensitive parameters. DCIS was not consistently distinguished from benign disease with any method. CONCLUSION: Dynamic spiral breast MR imaging proved an excellent method with which to collect contrast enhancement data rapidly enough that accurate comparisons can be made between many analytic methods.

Breast↗
PubMed1998

Compliance with recommended follow-up after percutaneous breast core biopsy.

OBJECTIVE: The purpose of this study was to use information from an established patient tracking system to evaluate patient outcome and assess patient compliance with recommended follow-up after percutaneous breast core biopsy. MATERIALS AND METHODS: All breast core biopsies performed from January 1994 through February 14, 1996, that used stereotaxic or sonographic guidance were reviewed. Clinical, imaging, and pathologic findings were correlated with patient outcomes established by recommended surgical and nonsurgical follow-up. RESULTS: Of 160 core biopsies in 153 women, 30 biopsies were performed on the basis of clinical complaints. One hundred thirty lesions were detected by mammography or sonography or both. Of the 70 lesions recommended for surgical excision, 52 (74%) had documented surgical outcomes. Mammographic surveillance was recommended for 90 lesions, of which 10 (11%) had resolved at the time of this study, 49 (54%) were on track toward 3-year lesion stability, 21 (23%) were being followed up elsewhere, four (4%) were lost to physicians, and six (7%) were lost to follow-up for other reasons. CONCLUSION: Known compliance with follow-up recommendations among these 153 patients who underwent breast core biopsy was higher for patients receiving surgical recommendation (74%) than for patients receiving imaging surveillance recommendation (54%). Problems tracking patients were caused both by loss of patients to follow-up and by incomplete reporting from referring physicians.

Biopsy, Needle↗
PubMed1997

Interactive MR-guided, 14-gauge core-needle biopsy of enhancing lesions in a breast phantom mode.

RATIONALE AND OBJECTIVES: The authors attempted to determine the accuracy of magnetic resonance (MR) imaging-guided core-needle biopsy performed with a titanium biopsy needle in a breast phantom. MATERIALS AND METHODS: Eight 6-7-mm lesions were created at random positions in a lard breast phantom. Each 0.2-mL lesion contained 0.118 mg of gadopentetate dimeglumine, 0.0025 mL of methylene blue dye, and 23.8 mg of gelatin. Rapid fast spin-echo MR imaging was used to guide placement of a 14-gauge titanium core-biopsy needle. A 1.5-T MR imager was used with an open-platform phased-array breast coil. RESULTS: Visualization of blue dye in core specimens confirmed successful biopsy in 16 of 16 attempts. One (n = 13) or two (n = 3) passes through the "skin" of the phantom were necessary for biopsy. The needle trajectory was adjusted less than three times for each pass through the "skin" in 15 of 16 biopsies. Cores that contained lesion material were obtained in the first sample in 15 of 16 biopsies. On T1-weighted images, needles cast 7-mm-diameter artifacts. CONCLUSION: MR imaging can be used accurately to guide core-needle biopsy of 6-7-mm lesions in a breast phantom.

Biopsy, Needle↗
PubMed1997

Preliminary experience with power Doppler imaging of solid breast masses.

OBJECTIVE: The purpose of our study was to assess the potential of power Doppler imaging (PDI) to differentiate benign from malignant solid breast masses. MATERIALS AND METHODS: Sixty-nine biopsy-proven solid breast masses were evaluated with PDI using 7- to 10-MHz transducers optimized for low-volume flow sensitivity. The extent of flow on PDI was estimated as a percentage of the lesion area on multiple longitudinal and transverse static sonographic images. Flow was categorized as avascular; less than 10%; 10-25%; 25.1-50%; and greater than 50%. RESULTS: Of the 69 lesions evaluated, 33 were malignant and 36 were benign. Of the avascular lesions, nine were malignant and eight were benign. Significant overlap was seen in the vascularity of the other 52 lesions: both malignant and benign lesions revealed a similar range of vascular patterns. CONCLUSION: Preliminary experience with PDI suggests that both malignant and benign lesions can be avascular and that the presence of color within a solid breast mass is a nonspecific finding. Assessing the extent of vascularity with PDI appears to be of limited value in the diagnostic evaluation of solid breast masses.

Adult↗
PubMed1996

Compliance with recommended follow-up after fine-needle aspiration biopsy of nonpalpable breast lesions: a retrospective study.

PURPOSE: To determine compliance with recommendations for mammographic or surgical follow-up after fine-needle aspiration biopsy of non-palpable breast lesions. MATERIALS AND METHODS: The authors reviewed the medical records of 419 patients in whom surgical or mammographic follow-up had been recommended after fine-needle aspiration biopsy. Mammographic, clinical, and follow-up findings were correlated with patient outcome. Of 466 lesions, 395 lesions in 359 patients (age range, 24-89 years; average age, 55 years) were nonpalpable and composed the study. RESULTS: Excisional biopsy was recommended in 141 cases (35.7%) and close-interval mammographic surveillance in 165 (41.8%). Biopsy was performed in 122 (86.5%) of the 141 cases in which it was recommended. Of 165 cases in which follow-up mammography was recommended, 84 (50.9%) were resolved at the close of the study. In the remaining cases, women either did not return (n = 24), were followed up elsewhere or moved (n = 35), were lost to follow-up by their physicians (n = 17), or were lost to follow-up for other reasons (n = 5). CONCLUSION: Noncompliance with follow-up recommendations is an important issue undermining the benefits of fine-needle aspiration biopsy. Difficulty in tracking patients hinders assessment of patient compliance.

Biopsy, Needle↗
PubMed1995

Axillary lymphadenectomy for breast cancer without axillary drainage.

OBJECTIVE: To evaluate axillary lymph node dissection done without closed drainage in conjunction with breast conservation cancer surgery. DESIGN: Prospective clinical study. SETTING: Two university hospitals. PATIENTS: Eighty-one women undergoing wide local excision of breast cancer with simultaneous or subsequent axillary lymph node dissection. INTERVENTIONS: No axillary drain was placed following axillary lymphadenectomy. MAIN OUTCOME MEASURES: The development and resorption of axillary seroma fluid as measured by clinical aspiration and serial sonographic examination. RESULTS: Thirty-four (42%) of the 81 women required axillary seroma aspiration even though axillary fluid was present in 92% (22/24) of those studied sonographically. The seromas accumulated over the first 2 weeks following axillary dissection and resorbed over the next 2 weeks, as assessed by both clinical and sonographic examination. The complication rate was 2% (2/81). The surgery was performed safely on an outpatient or short-stay basis in 99% (80/81) of patients. All patients except one were discharged within 23 hours of surgery, and 56 patients were discharged directly after anesthesia. CONCLUSION: Axillary lymph node dissection done in conjunction with breast conservation surgery can be performed in an ambulatory or short-stay setting without axillary drainage. Postoperative seromas will resolve within 1 month, and fewer than half will require aspiration. Lymphadenectomy without drainage reduces morbidity and allows the patient greater personal comfort.

Adult↗
PubMed1986

Ovarian leukemia detected by pelvic sonography. A case report.

Asymmetric enlargement of the right adnexa in a prepubertal, asymptomatic, 7-year-old girl with acute lymphocytic leukemia (ALL) was detected by pelvic sonography as part of examinations after the discontinuation of therapy. The case is the first where asymptomatic ovarian relapse has been detected prospectively by sonography. The technique should be considered for the follow-up female patients with ALL in remission, although more extensive studies are needed to establish its effectiveness.

Child↗
PubMed1979

Augmentation of pulmonary surfactant secretion by lung expansion at birth.

To study the effect of lung expansion at birth on surfactant secretion, we delivered by hysterotomy 11 litters of rabbit pups at 30 days of gestation and divided them into three groups that were killed: 1) after 30 min air-breathing, 2) after 30 min nitrogen-breathing, and 3) after 30 min tracheal occlusion. Each group was compared to a littermate group killed at birth. Groups 2) and 3) continued respiratory efforts for 30 min despite progressive asphyxia. Six additional litters were pretreated with atropine; at delivery one-half of each litter was killed, the remaining pups were subjected to 30 min of hypoxic gas breathing. After sacrifice, alveolar surfactant was recovered by saline lavage and estimated quantitatively on a surface-tension balance. Surfactant concentration at birth was 1.40 +/- 0.22 mg/g dry lung and increased to 1.86 +/- 0.19 (+/- SEM) after 30 min air-breathing (P less than 0.01). Also, surfactant was increased in the nitrogen-breathing pups (from 1.61 +/- 0.35 in littermate controls to 2.41 +/- 0.58; P less than 0.03), but not to a significant degree in the occluded group (1.34 +/- 0.33 vs. 1.41 +/- 0.28), or the atropine pretreated breathing pups (1.77 +/- 0.29 vs. 1.89 +/- 0.25).

Animals↗
PubMedDate not supplied

Three-dimensional shaded-surface rendering of MR images of the breast: technique, applications, and impact on surgical management of breast disease.

Contrast material-enhanced magnetic resonance (MR) imaging is reported to be the most accurate modality for determining the extent of breast cancer before surgery. Three-dimensionally rendered MR images can be used as an adjunct in planning breast surgery. Semiautomated methods are used to isolate the breast tissue within high-resolution MR images and to render the skin with a shaded-surface method. Cut-away views reveal lesions in the interior of the breast. Cut-plane shaded-surface display provides the surgeon with information on the size, extent, and spatial relationships of a breast lesion in a simple, intuitive format. This technique can help the surgeon plan a breast biopsy, lumpectomy, or mastectomy that will maximize local control of breast cancer while minimizing cosmetic damage to the unaffected portions of the breast. In a review of 15 clinical cases, cut-plane shaded-surface rendering aided surgical planning in 10 cases.

Adult↗
PubMedDate not supplied

Intensity-modulated parametric mapping for simultaneous display of rapid dynamic and high-spatial-resolution breast MR imaging data.

Contrast material-enhanced magnetic resonance (MR) imaging of the breast has variable specificity for differentiation of breast cancer from other enhancing conditions. Two principal strategies to improve its specificity are rapid dynamic MR imaging and high-spatial-resolution MR imaging. A method was developed of combining contemporaneously acquired dynamic and high-spatial-resolution MR imaging data into a single integrated display. Whole-breast rapid dynamic data were condensed into a color map by using pharmacokinetic analysis. The pharmacokinetic results were combined with the high-spatial-resolution images with a new technique that preserves underlying morphologic details. This new method was evaluated by five radiologists for eight breast lesions, and the results were compared with those of the standard method of overlaying parametric map data. The radiologists' ratings showed a statistically significant preference for the intensity-modulated parametric map display method over the overlaid parametric display method for 10 of the 12 evaluation criteria. The new method enabled simultaneous visualization of pharmacokinetic and morphologic information, facilitated assessment of lesion extent, and improved the suppression of noise in the pharmacokinetic data. The ability to simultaneously assess both dynamic and high-spatial-resolution features may ultimately improve the specificity of breast MR imaging.

Breast Neoplasms↗