Eisuke Fukuma

1H MR spectroscopy and diffusion-weighted imaging of the breast: are they useful tools for characterizing breast lesions before biopsy?

OBJECTIVE The objective of our study was to determine whether proton ((1)H) MR spectroscopy (MRS) and diffusion-weighted imaging might be useful tools for characterizing breast lesions before biopsy. MATERIALS AND METHODS Single-voxel (1)H MRS and diffusion-weighted imaging were performed in 171 suspicious or highly suspicious lesions. Using the residual water signal as a reference (4.7 ppm), a choline peak at 3.22-3.23 ppm was defined as malignant. If a high-signal-intensity lesion was detected in high-b-value (b = 1,500 s/mm(2)) images, that lesion was defined as positive for malignancy. Among the patients with positive results on diffusion-weighted imaging, the apparent diffusion coefficient (ADC) values of the mass or focus were calculated from two different gradient factors (b(1) = 500 s/mm(2) and b(2) = 1,500 s/mm(2)). RESULTS The diagnostic sensitivity and specificity of (1)H MRS were 44% (40/91) and 85% (68/80), respectively (p < 0.001). If (1)H MRS was applied for mass lesions larger than 15 mm, the diagnostic sensitivity and specificity were 82% (28/34) and 69% (11/16), respectively. Of the high-b-value images, 24 benign lesions and eight nonmass ductal carcinoma in situ were visually negative. With the use of a cutoff ADC value of 1.13 x 10(-3) mm(2)/s, a specificity of 67% (43/64) and sensitivity of 97% (61/63) was obtained on diffusion-weighted imaging. CONCLUSION (1)H MRS was useful for characterizing breast lesions measuring 15 mm or larger, and diffusion-weighted imaging was useful for characterizing lesions of any size. However, these two techniques still have potential pitfalls in relation to the diagnosis of nonmass breast lesions.

Preliminary study of ultrasonographic tissue quantification of the breast using the acoustic radiation force impulse (ARFI) technology

PURPOSE To investigate the shear wave velocity of normal breast tissue and breast lesion using acoustic radiation force impulse (ARFI) technology. MATERIALS AND METHODS This retrospective study was conducted with the approval of the institutional review board. Shear wave velocity was measured using a linear array transducer with a bandwidth of 4-9 MHz and Virtual Touch tissue quantification (Siemens Medical Solutions, Mountain View, CA, USA) in 50 patients. First, the values of the shear wave velocity were determined in the normal tissues. Then, the changes in the shear wave velocity while applying external compression on the breast were determined. For the differential diagnosis of breast lesions, the shear wave velocities of 30 mass lesions (13 benign and 17 malignant lesions) classified as BI-RADS category 4 were measured. RESULTS The mean shear wave velocities in the subcutaneous fat and the mammary gland parenchyma were 2.66 m/s and 3.03 m/s, respectively (p=0.0006). The mean shear wave velocity measured while applying external compression was 3.33 m/s for subcutaneous fat (p<0.0001), and 3.84 m/s for the mammary gland parenchyma (p<0.0001). In 4 of malignant cases, the shear wave velocity was not indicated (displayed as X.XX; unmeasurable state). The mean shear wave velocity of the 13 malignant lesions (4.49 m/s) was higher than that of benign lesions (2.68 m/s) (p<0.01). CONCLUSIONS ARFI tissue quantification is thought to be a potentially promising ultrasound technique for the diagnosis of breast lesions, but further investigation is required to identify the most appropriate method of measurement.

Pattern classification of ShearWaveTM Elastography images for differential diagnosis between benign and malignant solid breast masses

Background ShearWaveTM Elastography (SWE) provides a quantitative measurement of tissue stiffness and may improve characterization of breast masses. However, the significance of Youngs modulus measurements and appropriate SWE evaluation criteria has not been established yet. Purpose To assess the usefulness of the pattern classification and Youngs modulus measurements in the differential diagnosis between benign and malignant solid breast masses. Material and Methods Ninety-six patients (age range 18–84 years, mean 54 years) with 100 solid breast masses who underwent tissue sampling after a US examination were analyzed. We tried to create a visual pattern classification based on the SWE images. After classifying the visual patterns, the Youngs modulus of the lesions was measured in every case. Results It was possible to classify the images into four patterns by the visual evaluation: no findings (coded blue homogeneously; Pattern 1), vertical stripe pattern artifacts (Pattern 2), a localized colored area at the margin of the lesion (Pattern 3), and heterogeneously colored areas in the interior of the lesion (Pattern 4). There were 17 Pattern 1 lesions, 14 Pattern 2 lesions, 20 Pattern 3 lesions, and 49 Pattern 4 lesions. When Patterns 1 and 2 were assumed to be benign, and Patterns 3 and 4 were assumed to be malignant, the sensitivity and specificity were 91.3% (63/69) and 80.6% (25/31), respectively. The mean Youngs modulus measurements of the benign and the malignant lesions were 42 kPa and 146 kPa, respectively (P < 0.0001). No significant differences were found between benign and malignant lesions in Pattern 3. In Pattern 4, however, the Youngs modulus of the benign lesions (50 kPa) was lower than the smallest Youngs modulus of malignant lesions (61 kPa). Conclusion The visual pattern classification and adding Youngs modulus measurements may improve characterization of solid breast masses.

Predicting pathological response to neoadjuvant chemotherapy in breast cancer with quantitative 1H MR spectroscopy using the external standard method.

To assess the efficacy of quantitative 1H MR spectroscopy (MRS) using the external standard method to predict the pathological response to neoadjuvant chemotherapy with an anthracycline‐based regimen in breast cancer patients.

Optimal scanning technique to cover the whole breast using an automated breast volume scanner

PurposeThe aim of this study was to assess the scanning technique for covering the whole breast using a commercially available automated breast ultrasonography (US) system.Materials and methodsA total of 40 patients in the supine position underwent automated breast US (ABVS: Siemens Medical Solutions, Mountain View, CA, USA) and hand-held US. The scanning included sequential scans in the upper-outer, lower-outer, lower-inner, and upper-inner regions. After scanning all four segments of each breast using ABVS, hand-held US was performed in all the patients. The detectability of the lesions using the ABVS technique compared with that using the handheld US was evaluated. The average scanning time was compared between any two of the three examiners with various lengths of experience in breast US.ResultsIn all, 61 lesions were detected by hand-held US. The average size of the lesions was 7.7 mm (range 2.5–26.0 mm). The number of detected lesions by ABVS was consistent with those found by hand-held US in each patient. The average total scanning time for each examiner using ABVS was 10.9, 11.1, and 11.5 min, respectively. No significant difference was found in the total scanning time between any two of the three examiners.ConclusionThe four-scans technique for the major segments of the breast is thought to be an operator-independent, feasible method for performing automated breast US.

Monitoring of early response to neoadjuvant chemotherapy in breast cancer with 1H MR spectroscopy: Comparison to sequential 2-[18F]-fluorodeoxyglucose positron emission tomography

To assess the efficacy of 1H MR spectroscopy (MRS) to evaluate early responses to neoadjuvant chemotherapy in breast cancer patients, as compared to that of the standardized uptake value (SUV) in 18F‐fluorodeoxyglucose (FDG) positron emission tomography (PET).

Preliminary study of early response to neoadjuvant chemotherapy after the first cycle in breast cancer: comparison of 1H magnetic resonance spectroscopy with diffusion magnetic resonance imaging

PurposeThe aim of this study was to assess the efficacy of single-voxel 1H magnetic resonance spectroscopy (MRS) at 1.5 T to evaluate early responses to neoadjuvant chemotherapy after the first treatment in breast cancer patients and to compare it to measurements of apparent diffusion coefficient (ADC) values derived from diffusion-weighted magnetic resonance imaging (MRI).Materials and methodsNine patients with breast cancer who were scheduled to receive neoadjuvant chemotherapy were recruited. MR examination after the first cycle was scheduled for a few days before the administration of the second dose.ResultsTwo patients were excluded from the study because their regimen was changed after the first cycle. MRS before chemotherapy demonstrated the presence of choline (Cho) at 3.22–3.23 ppm in six cases and at 3.27 ppm in one case. Diffusion-weighted MRI before chemotherapy demonstrated a localized high-signal lesion in all cases. The change of the integral value of Cho after the first cycle of chemotherapy showed a positive correlation with the change in lesion size (r = 0.91, P = 0.01), whereas no correlation was observed between the change of ADC values after the first cycle and the change in lesion size (r = 0.45, P = 0.32).ConclusionMRS after the first cycle may be more sensitive to diffusion-weighted MRI to predict the pathological response.

Ultrasonographic tissue quantification of the breast using acoustic radiation force impulse technology: phantom study and clinical application

PurposeThe aim of this study was to perform the phantom experiment and demonstrate the clinical usefulness of tissue quantification using a linear array transducer and acoustic radiation force impulse (ARFI) technology.Materials and methodsFor the phantom study, the commercially available Elasticity QA Phantom Model 049 was used. First, we measured the shear wave velocity (m/s) for the four spheres and the background of the phantom. Then, the shear wave velocity at nine sites was measured, with the region of interest being moved gradually from a shallow region (3 mm) to a deeper region (38 mm). For the clinical study, the shear wave velocities of 15 solid breast mass lesions were measured.ResultsThe phantom study confirmed the feasibility of quantitative determination of the degree of tissue hardness. Dispersion of the measured values tended to be somewhat increased for the depths of 3 mm and 38 mm. The mean shear wave velocity was 2.07–2.93 m/s for five benign lesions, whereas higher shear wave velocities (n = 2) (7.15, 7.44 m/s) or “X.XX” (unmeasurable state) (n = 7) were found for malignant lesions other than mucinous carcinoma (2.44 m/s).ConclusionARFI tissue quantification is a potentially promising ultrasonographic technique for diagnosing breast lesions.

Ultrasonographic elastography of the breast using acoustic radiation force impulse technology: preliminary study

PurposeThe aim of this study was to investigate the clinical usefulness of acoustic radiation force impulse (ARFI) imaging for the differential diagnosis of breast lesions.Materials and methodsWe studied 40 solid mass lesions from a total of 40 patients (age range 29–67 years, mean 50 years). There were 18 benign lesions and 22 malignant tumors. ARFI imaging was performed using Virtual Touch tissue imaging. We examined the possibility of lesions seen on B-mode images being visually confirmed on ARFI images. When the lesion was visually confirmed, the lesions that were bright or dark inside were classified into patterns 1 and patterns 3, respectively. The lesions that failed to be visually confirmed were classified as pattern 2.ResultsThere were 3 pattern 1 lesions and 7 pattern 2 lesions; all of these lesions were benign. The remaining 8 benign lesions and 22 malignant lesions were determined to be pattern 3. The negative predictive value was 100%.ConclusionARFI imaging is a potentially promising ultrasonographic technique for the differential diagnosis of breast lesions, particularly complicated cysts without a cystic component on B-mode images.

Volume replacement with polyglycolic acid mesh for correcting breast deformity after endoscopic conservative surgery.

From April 2002 to August 2003, 60 patients (41 patients undergoing quadrantectomy and 19 patients undergoing wide excision) with early-stage breast cancer underwent endoscopic breast-conserving surgery and volume replacement with absorbable materials. The average volume of resected tissue was 75 mL (range, 15-145 mL). The absorbable materials consisted of polyglycolic acid mesh (Dexon Mesh DMS#4 10 × 12) folded and wrapped in oxidized regenerated cellulose, which just fit into the dead space. We expected that the polyglycolic acid mesh would help induce granulation and fibrous tissue with reactive tissue fluid and that oxidized regenerated cellulose would prevent adhesion between the skin and the polyglycolic acid mesh (Figure 1). The absorbable materials were gently inserted into the dead space, and the wound was closed in 3 layers. We used 1 sheet of polyglycolic acid mesh and 1 sheet of oxidized regenerated cellulose if the volume loss was 70 mL. The cosmetic outcome was evaluated with a 4-point scoring system of breast cosmesis judged by breast surgeons.1 The scores of breast cosmesis were evaluated every 1 or 2 months at a clinic. The average evaluation time was 6.1 months after surgery (range, 2-12 months). A favorable cosmetic outcome (excellent) was obtained in 83% of patients (77% of patients undergoing quadrantectomy and 91% of patients undergoing wide excision). Dynamic contrast-enhanced magnetic resonance mammography and ultrasonography were performed routinely 3 months after the operation. The images showed that the dead space was lined by granulated scar tissue and filled with fluid. Deformity was almost completely prevented, and the symmetric images helped us to detect local recurrence. In 1 patient, multiple cancers were detected by pathologic examination after conservative breast surgery. Total mastectomy was performed 1 month after the previous operation, and the resected tissue in which polyglycolic acid mesh had been inserted was examined pathologically. Pathologic examination showed that the peripheral part of the dead space was encapsulated by granulation and fibrous tissue, and the mesh was decomposed and phagocytosed by macrophages. Complications of the film-screen mammography (FSM) method were inflammation and overproduction of fluid induced by the polyglycolic acid mesh. These findings were observed in 3 cases that had been diagnosed by open biopsy before surgery. We believe that the open biopsy procedure induced inflammation and overproduction of fluid in these patients. We now regard a history of open biopsy to be a contraindication for the FSM method. It is likely that polyglycolic acid mesh helps to promote granulation and to fill the reactive fluid space in the encapsulating scar. The FSM method is a simple and useful procedure for preventing breast deformity after conservative surgery.