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D M Ikeda

Publications and source records attributed to D M Ikeda.

At least 37 records · Page 2Linked to original sources
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

Diagnosis of silicone gel breast implant rupture by ultrasonography.

To prospectively evaluate the efficacy of ultrasonography in the diagnosis of ruptured silicone gel breast implants, 98 patients (192 implants) underwent preoperative breast ultrasonography prior to silicone gel breast implant removal. The prevalence of implant rupture confirmed at surgery in this group of patients was 62 of the 192 implants (32 percent). Of the 60 implants diagnosed as ruptured by ultrasonography, 46 were confirmed as having visible defects at surgery (true positive) for a positive predictive value of 77 percent. Of the 132 implants diagnosed as intact by ultrasonography, 116 were confirmed as intact at surgery (true negative) for a negative predictive value of 88 percent. Overall, the sensitivity of ultrasonography for implant rupture was 74 percent, and the specificity was 89 percent. These findings demonstrate that ultrasonography is an effective imaging modality for the diagnosis of silicone gel breast implant rupture. Compared with mammography, ultrasonography appears to offer superior sensitivity and specificity without radiation exposure or discomfort. Although magnetic resonance imaging has shown considerable promise in the diagnosis of implant rupture, ultrasonography provides comparable sensitivity at a fraction of MRI's cost.

Breast↗
PubMed1996

Primary squamous cell carcinoma of the breast.

Primary squamous cell carcinoma of the breast is a rare cancer. Published reports of prognosis are variable, and most studies are case reports of one or a few patients. We report an additional case of squamous cell carcinoma of the breast occurring in a 53-year-old black woman. In reviewing the reported cases of this tumor over the past 20 years, we compared features of this cancer with those of the more common breast adenocarcinoma with squamous metaplasia. When squamous cell carcinoma of the breast is encountered, a skin primary lesion and metastasis from a distant site should be excluded. Prognosis is determined largely by stage and does not differ significantly from the prognosis in breast adenocarcinoma with squamous metaplasia.

Adenocarcinoma↗
PubMed1996

Image compression in digital mammography: effects on computerized detection of subtle microcalcifications.

Our previous receiver operating characteristic (ROC) study indicated that the detection accuracy of microcalcifications by radiologists is significantly reduced if mammograms are digitized at 0.1 mm x 0.1 mm. Our recent study also showed that detection accuracy by computer decreases as the pixel size increases from 0.035 mm x 0.035 mm. It is evident that very large matrix sizes have to be used for digitizing mammograms in order to preserve the information in the image. Efficient compression techniques will be needed to facilitate communication and archiving of digital mammograms. In this study, we evaluated two compression techniques: full frame discrete cosine transform (DCT) with entropy coding and Laplacian pyramid hierarchical coding (LPHC). The dependence of their efficiency on the compression parameters was investigated. The techniques were compared in terms of the trade-off between the bit rate and the detection accuracy of subtle microcalcifications by an automated detection algorithm. The mean-square errors in the reconstructed images were determined and the visual quality of the error images was examined. It was found that with the LPHC method, the highest compression ratio achieved without a significant degradation in the detectability was 3.6:1. The full frame DCT method with entropy coding provided a higher compression efficiency of 9.6:1 at comparable detection accuracy. The mean-square errors did not correlate with the detection accuracy of the microcalcifications. This study demonstrated the importance of determining the quality of the decompressed images by the specific requirements of the task for which the decompressed images are to be used. Further investigation is needed for selection of optimal compression technique for digital mammograms.

Breast Diseases↗
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↗
PubMed1994

Digitization requirements in mammography: effects on computer-aided detection of microcalcifications.

We have developed a computerized method for detection of microcalcifications on digitized mammograms. The program has achieved an accuracy that can detect subtle microcalcifications which may potentially be missed by radiologists. In this study, we evaluated the dependence of the detection accuracy on the pixel size and pixel depth of the digitized mammograms. The mammograms were digitized with a laser film scanner at a pixel size of 0.035 mm x0.035 mm and 12-bit gray levels. Digitization with larger pixel sizes or fewer number of bits was simulated by averaging adjacent pixels or by eliminating the least significant bits, respectively. The SNR enhancement filter and the signal-extraction criteria in the computer program were adjusted to maximize the accuracy of signal detection for each pixel size. The overall detection accuracy was compared using the free response receiver operating characteristic curves. The results indicate that the detection accuracy decreases significantly as the pixel size increases from 0.035 mm x 0.035 mm to 0.07 mm x 0.07 mm (P < 0.007) and from 0.07 mm x 0.07 mm to 0.105 mm x 0.105 mm (P < 0.002). The detection accuracy is essentially independent of pixel depth from 12 to 9 bits and decreases significantly (P < 0.003) from 9 to 8 bits; a rapid decrease is observed as the pixel depth decreases further from 8 to 7 bits (P < 0.03) or from 7 to 6 bits (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Biophysical Phenomena↗
PubMed1994

Breast imaging.

Explore the source record for details and available documents.

Breast Neoplasms↗
PubMed1993

Heterozygous familial hypercholesterolemia: detection of xanthomas in the Achilles tendon with US.

Prospective sonographic evaluation of 44 Achilles tendons in 22 patients with heterozygous familial hypercholesterolemia (FH) was performed with linear-array transducers with high frequency and high resolution. Intratendinous hypoechoic regions believed to represent xanthomas, ranging from single hypoechoic nodules to diffusely enlarged tendons that were heterogeneously hypoechoic, were seen in 40 of the 44 tendons (91%) and 21 of the 22 patients (95%). In addition, focal xanthomas were seen in two of three patients whose Achilles tendons were either normal or questionably abnormal at palpation. The direct visualization of xanthomas in most of these patients contrasts with findings from previously published studies, in which sonographically detected involvement was based on secondary tendon enlargement alone. The improved sonographic visualization of tendon xanthomas in FH, rather than the secondary tendon enlargement caused by them, therefore, suggests a new role for ultrasound in the early diagnosis and follow-up of these cases.

Achilles Tendon↗
PubMed1993

Paget disease of the nipple: radiologic-pathologic correlation.

PURPOSE: To correlate the range of clinical presentations with mammographic and histologic findings in patients with Paget disease of the nipple. MATERIALS AND METHODS: The clinical, pathologic, and mammographic records of 58 patients who had biopsy-proved Paget disease of the nipple were retrospectively reviewed. The results of two previous studies were also included. RESULTS: Among 34 patients who had typical findings of Paget disease, the mammograms of 17 (50%) showed normal findings, those of 10 (29%) showed nipple, areolar, or subareolar abnormalities, and those of seven (21%) showed evidence of masses or calcifications. Of the mammograms of 24 women with Paget disease but without clinical findings, 19 (79%) showed evidence of suspicious masses or calcifications, four (17%) showed nipple or areolar abnormalities, and one was negative. CONCLUSION: Nonspecific findings of nipple-areolar complex thickening should be correlated with findings at breast physical examination to confirm or exclude Paget disease.

Adult↗
PubMed1992

Fibrosarcoma of the breast: mammographic findings in five cases.

The mammographic features of fibrosarcoma of the breast, a rare malignant tumor, have not been described. Accordingly, we reviewed the mammograms, pathology reports, and medical records of five women with this tumor. All cases had surgical biopsies and a diagnosis made by histologic evaluation. The age of the patients ranged from 48 to 79 years. Histologically, three of the five fibrosarcomas were thought to have arisen from phyllodes tumor, and four were palpable. On mammograms, the tumors were dense masses with largely indistinct margins, ranging from 1.5 to 7.0 cm in diameter. One contained calcified osseous elements suggesting osseous trabeculae. Although the osseous trabeculae in that tumor strongly suggested sarcoma, most of the tumors had a nonspecific appearance on mammograms. Fibrosarcomas of the breast have a nonspecific mammographic appearance. Surgical biopsy and histologic evaluation are necessary for definitive diagnosis.

Breast Neoplasms↗
PubMed1992

The role of fine-needle aspiration and pneumocystography in the treatment of impalpable breast cysts.

Prior studies have suggested that the recurrence rate is lower in breast cysts treated by pneumocystography (injection of air into cyst cavities after cyst aspiration) than in cysts treated by fine-needle aspiration alone. To determine if this is the case for impalpable breast cysts, we reviewed the hospital records and mammograms of 38 women with 41 impalpable cysts. Mammograms obtained immediately after aspiration show that pneumocystography was successful in 18 and unsuccessful in 20 of the 41 cysts. Four cysts were excluded from the study: one cyst that recurred after aspiration and was sampled by biopsy and three cysts for which immediate post-aspiration mammograms were unavailable but which had recurred or persisted 3 years after aspiration. Review of follow-up mammograms made 4 months to 3 years after the aspiration showed that three (17%) of 18 cysts in the group with successful pneumocystography recurred and 11 (58%) of 19 cysts in the unsuccessful group recurred (p = .02). No difference was found in the number of recurrent cysts in relation to estrogen therapy or menopausal status. Our results indicate that impalpable breast cysts treated by pneumocystography are less likely to recur than are cysts treated by aspiration alone.

Adult↗