Speed of sound and shear wave speed for calf soft tissue composition and nonlinearity assessment.

BACKGROUND: The purpose of this study was threefold: (I) to study the correlation of speed-of-sound (SoS) and shear-wave-speed (SWS) ultrasound (US) in the gastrocnemius muscle, (II) to use reproducible tissue compression to characterize tissue nonlinearity effects, and (III) to compare the potential of SoS and SWS for tissue composition assessment. METHODS: Twenty gastrocnemius muscles of 10 healthy young subjects (age range, 23-34 years, two females and eight males) were prospectively examined with both clinical SWS (GE Logiq E9, in m/s) and a prototype system that measures SoS (in m/s). A reflector was positioned opposite the US probe as a timing reference for SoS, with the muscle in between. Reproducible tissue compression was applied by reducing probe-reflector distance in 5 mm steps. The Ogden hyperelastic model and the acoustoelastic theory were used to characterize SoS and SWS variations with tissue compression and extract novel metrics related to tissue nonlinearity. The body fat percentage (BF%) of the subjects was estimated using bioelectrical impedance analysis. RESULTS: A weak negative correlation was observed between SWS and SoS (r=-0.28, P=0.002). SWS showed an increasing trend with increasing tissue compression (P=0.10) while SoS values decayed nonlinearly (P<0.001). The acoustoelastic modeling showed a weak correlation for SWS (r=-0.36, P<0.001) but a very strong correlation for SoS (r=0.86, P<0.001), which was used to extract the SoS acoustoelastic parameter. SWS showed higher variability between both calves [intraclass correlation coefficient (ICC) =0.62, P=0.08] than SoS (ICC =0.91, P<0.001). Correlations with BF% were strong and positive for SWS (r=0.60, P<0.001), moderate and negative for SoS (r=-0.43, P=0.05), and moderate positive for SoS acoustoelastic parameter (r=0.48, P=0.03). CONCLUSIONS: SWS and SoS provide independent information about tissue elastic properties. SWS correlated stronger with BF% than SoS, but measurements were less reliable. SoS enabled the extraction of novel metrics related to tissue nonlinearity with potential complementary information.

Ultrasound Imaging of Injections in Masseter Muscle without Contrast Agent Using Strain Elastography and a Novel B-Mode Spatiotemporal Filter.

Botulinum toxin type A (BTX-A) injections in masseter muscle can alleviate muscle tightness and aching pain caused by idiopathic masticatory myalgia, a subform of the myofascial pain syndrome. Yet the injection procedure (number, amount) is currently empirical. In this ex vivo study, we determined the feasibility of using contrast-free ultrasound imaging to visualize the short-term injectate propagation. Ultrasound annotations of BTX-A injectate spread in N = 12 porcine masseter muscles were compared with the histopathology of the excised masseter. BTX-A presence was automatically detected in the ultrasound cine by: compensating tissue motion and deformation during injection with a novel spatiotemporal filtering (SF) algorithm, and by imaging tissue swelling strains with strain elastography (SE). BTX-A injectate introduced 6.5% (standard deviation = 5.0%) echogenicity contrast and 13.9% (standard deviation = 3.7%) tissue swelling strain. Muscle fasciae were a border for BTX-A distribution. The SF algorithm achieved significantly higher noise rejection (contrast-to-noise ratio = 4.63) than SE (2.56, p = 0.01), and state-of-the-art 2-D digital image correlation (1.81, p < 0.001) and direct image subtraction (1.29, p < 0.001) methods. Histopathology agreed well with ultrasound (Dice coefficient = 0.48), with deviations mainly explained by the three-dimensional inhomogeneous distribution of BTX-A. Preliminary in vivo patient results indicated that SF and SE discard artifactual BTX-A detection outside the injection region. The proposed methods contribute to objectivize ultrasound-guided injections, with additional applications, for instance, to monitor injectate spread of local anesthetics.

Breast Cancer Assessment With Pulse-Echo Speed of Sound Ultrasound From Intrinsic Tissue Reflections: Proof-of-Concept.

PURPOSE: The aim of this study was to differentiate malignant and benign solid breast lesions with a novel ultrasound (US) technique, which measures speed of sound (SoS) using standard US transducers and intrinsic tissue reflections and scattering (speckles) as internal reference. MATERIALS AND METHODS: This prospective, institutional review board-approved, Health Insurance Portability and Accountability Act-compliant prospective comparison study was performed with prior written informed consent from 20 women. Ten women with histological proven breast cancer and 10 with fibroadenoma were measured. A conventional US system with a linear probe was used for SoS-US (SonixTouch; Ultrasonix, Richmond, British Columbia, Canada). Tissue speckle reflections served as a timing reference for the US signals transmitted through the breasts. Relative phase inconsistencies were detected using plane wave measurements from different angular directions, and SoS images with 0.5-mm resolution were generated using a spatial domain reconstruction algorithm. The SoS of tumors were compared with the breast density of a larger cohort of 106 healthy women. RESULTS: Breast lesions show focal increments ΔSoS (meters per second) with respect to the tissue background. Peak ΔSoS values were evaluated. Breast carcinoma showed significantly higher ΔSoS than fibroadenomas ([INCREMENT]SoS > 41.64 m/s: sensitivity, 90%; specificity, 80%; area under curve, 0.910) and healthy breast tissue of different densities (area under curve, 0.938; sensitivity, 90%; specificity, 96.5%). The lesion localization in SoS-US images was consistent with B-mode imaging and repeated SoS-US measurements were reproducible. CONCLUSIONS: Using SoS-US, based on conventional US and tissue speckles as timing reference, breast carcinoma showed significantly higher SoS values than fibroadenoma and healthy breast tissue of different densities. The SoS presents a promising technique for differentiating solid breast lesions.

Speed-of-Sound Imaging Based on Reflector Delineation.

OBJECTIVE: Speed-of-sound (SoS) has large potential for tissue and pathology differentiation. We aim to develop a novel Ultrasound Computed Tomography (USCT) technique that can reconstruct local SoS in tissue on conventional ultrasound machines with hand-held linear arrays. METHODS: A passive reflector is placed opposite the tissue sample as an echogenic reference to measure the time-of-flight (ToF) of ultrasound wave- fronts. A Dynamic Programming algorithm provides a robust ToF measurements based on global optimization of all transmit- receive echo data. An Anisotropically-Weighted Total Variation (AWTV) algorithm allows sharp delineation of focal lesions based on limited-angle USCT data. RESULTS: Inclusions, which are not visible in conventional ultrasound, could be delineated in SoS images. AWTV allows to reconstruct focal lesions with a contrast-ratio of 93.7% of their nominal value, compared to that of 31.5% with conventional least-squares based algebraic tomographic reconstruction. In full-wave simulations of realistic heterogeneous breast models, a high CR of 84.3% is observed, with the reconstruction filtering out background heterogeneity. In experiments, our proposed method quantifies SoS in a homogeneous background with an accuracy of 0.93ms, allowing to differentiate several tissue types. CONCLUSION: We validate our method using numerical simulations with ray-tracing and full- wave models, and phantom and ex-vivo data. Preliminary in- vivo results show the potential of this new technique to detect and differentiate malignant and benign lesions in the breast. SIGNIFICANCE: Breast cancer is the most common cancer in women. Ultrasound B-mode only provides qualitative information about breast lesions, whereas USCT can provide quantitative tissue imaging biomarkers, such as SoS. The proposed method can potentially be implemented as a complementary modality to ultrasound for tissue and disease differentiation.

Breast-density assessment with hand-held ultrasound: A novel biomarker to assess breast cancer risk and to tailor screening?

OBJECTIVES: To assess feasibility and diagnostic accuracy of a novel hand-held ultrasound (US) method for breast density assessment that measures the speed of sound (SoS), in comparison to the ACR mammographic (MG) categories. METHODS: ACR-MG density (a=fatty to d=extremely dense) and SoS-US were assessed in the retromamillary, inner and outer segments of 106 women by two radiographers. A conventional US system was used for SoS-US. A reflector served as timing reference for US signals transmitted through the breasts. Four blinded readers assessed average SoS (m/s), ΔSoS (segment-variation SoS; m/s) and the ACR-MG density. The highest SoS and ΔSoS values of the three segments were used for MG-ACR whole breast comparison. RESULTS: SoS-US breasts were examined in <2 min. Mean SoS values of densities a-d were 1,421 m/s (SD 14), 1,432 m/s (SD 17), 1,448 m/s (SD 20) and 1,500 m/s (SD 31), with significant differences between all groups (p<0.001). The SoS-US comfort scores and inter-reader agreement were significantly better than those for MG (1.05 vs. 2.05 and 0.982 vs. 0.774; respectively). A strong segment correlation between SoS and ACR-MG breast density was evident (rs=0.622, p=<0.001) and increased for full breast classification (rs=0.746, p=<0.001). SoS-US allowed diagnosis of dense breasts (ACR c and d) with sensitivity 86.2 %, specificity 85.2 % and AUC 0.887. CONCLUSIONS: Using hand-held SoS-US, radiographers measured breast density without discomfort, readers evaluated measurements with high inter-reader agreement, and SoS-US correlated significantly with ACR-MG breast-density categories. KEY POINTS: • The novel speed-of-sound ultrasound correlated significantly with mammographic ACR breast density categories. • Radiographers measured breast density without women discomfort or radiation. • SoS-US can be implemented on a standard US machine. • SoS-US shows potential for a quantifiable, cost-effective assessment of breast density.

Ultrasound Needle Visibility in Contrast Mode Imaging: An In Vitro and Ex Vivo Study.

PURPOSE: To evaluate needle visibility in ultrasound under contrast mode conditions. MATERIALS AND METHODS: Needle visibility was evaluated for bevel, EchoTip ® and shaft of 18G Chiba biopsy needle with a 9 MHz linear probe (GE Logiq E9). Insertion angles varied between 30°(steep) and 90°(parallel to the probe surface). The acoustic output varied from 5-28%. 2 different contrast mode presets with either 'Amplitude Modulation' (Penetration) or 'Phase Inversion Harmonics' (High Resolution) were assessed. All other imaging parameters were kept constant. The visibility of bevel, EchoTip ® and shaft was assessed for grayscale and color-coded images with a 3-point Likert-like scale (not, poorly, well visible) by 2 independent readers. The echogenicity of the needle bevel, EchoTip ® and shaft was assessed in deciBel (dB) on the color-coded images. RESULTS: With the parallel insertion angle, all needle areas were well visible. With steep insertion the EchoTip ® was the only visible area. High Resolution was superior to Penetration (p<0.001). The visibility and echogenicity of the needle bevel ( rgrayscale =0.109, p grayscale =0.178; rcolor-coded =0.236, p color-coded =0.266; rdB =0.956, p dB =0.001), EchoTip ® ( rgrayscale += 0.477, p grayscale += 0.018; rcolor-coded =0.540, p color-coded += 0.006; rdB =0.911, p dB =0.001) and shaft ( rgrayscale =0.124, p grayscale =0.563; rcolor-coded =0.061, p color-coded += 0.775; rdB += 0.926, p dB =0.001) increased with increasing acoustic output. Grayscale images were superior to color-coded images for needle visibility (p=0.004). CONCLUSION: Parallel needle insertion, use of an echogenic tip, adequate choice of presets, increased acoustic output, and dual view of grayscale and color-coded images improve needle visibility in ultrasound under contrast mode conditions.

Microcalcification-Associated Breast Cancer: Presentation, Successful First Excision, Long-Term Recurrence and Survival Rate.

INTRODUCTION: In this study we evaluated mammographic, histological and immunohistochemical findings for microcalcification-associated breast cancer with regards to breast-conserving therapy, recurrence and survival rate. PATIENTS AND METHODS: We retrospectively analyzed 99 consecutive, non-palpable and microcalcification-associated breast cancers (94 women) that were treated surgically between January 2002 and December 2003 at a national academic breast cancer center. Calcifications were classified according to the Breast Imaging Reporting and Data System (BI-RADS). Descriptors, surgical outcome and histological findings were assessed. Recurrences and survival rates were evaluated based on medical records, standardized patient questionnaires and/or contacting the physician. RESULTS: 42 of the 99 lesions (42.4%) were invasive carcinomas, 57 (57.6%) were pure ductal carcinoma in situ (DCIS). 6 out of 99 (6.1%) lesions were triple negative, and 29 (29.3%) were HER2/neu positive. Successful first excision rate was 76/99 lesions (76.8%). Breast conservation was achieved in 73.7% (73/99). 10 women showed local recurrences without negatively impacting survival. The recurrences included round/punctate, amorphous, fine pleomorphic, and fine linear or fine-linear branching descriptors. The breast cancer-specific long-term survival rate was 91/94 (96.8%) for a mean follow-up of 81.4 months. The 3 patients who died due to breast carcinoma showed fine pleomorphic calcifications, and had nodal-positive invasive carcinoma at diagnosis. CONCLUSION: Microcalcification-associated breast cancers are frequently treated with breast-conserving therapy. Continuous clinical and mammographic follow-up is recommended for all descriptors.

Improvement in outcomes after implantation of a novel polyurethane meniscal scaffold for the treatment of medial meniscus deficiency.

PURPOSE: Meniscal injury resulting in segmental loss of meniscal tissue is a major risk factor for the development of osteoarthritis. Tissue engineering strategies have provided scaffolds for meniscal regeneration in order to establish a treatment option for patients with limited opportunities for meniscal reconstruction. The purpose of this study was to assess the clinical and magnetic resonance imaging (MRI) results 2 years after implantation of a polyurethane scaffold for chronic segmental medial meniscus deficiency following partial medial meniscectomy. METHODS: Eighteen patients were treated with arthroscopic implantation of an ActiFit(®) (Orteq Sports Medicine) polyurethane meniscal scaffold for meniscus deficiency of the medial meniscus. Patients were followed up at 6, 12, and 24 months. Clinical outcome was assessed using patient-reported outcome scores (KOOS, KSS, UCLA activity scale, VAS for pain). Radiological outcome was assessed using MRI at 6, 12, and 24 months by evaluating scaffold morphology, scaffold integration, and additional joint injury, as well as joint inflammation. RESULTS: Eighteen patients with a median age of 32.5 years (range 17-49) were enrolled. Statistically significant improvements were present in all patients, but one at 2 years compared to baseline in all categories. Complete resorption of the scaffold occurred in one patient representing a failure to treatment. MRI showed abnormal signal intensity of the scaffold when compared to residual meniscal tissue but without synovitis or joint inflammation. Extrusion of the scaffold was present in four patients. No correlation between scaffold extrusion and clinical outcome was observed. CONCLUSION: Arthroscopic implantation of a polyurethane meniscal scaffold in patients with chronic segmental medial meniscus deficiency is not only a safe procedure but leads to good clinical results at a 2-year follow-up. Scaffold extrusion did not appear to affect clinical outcome. LEVEL OF EVIDENCE: IV.

Patellofemoral osteoarthritis after Insall's proximal realignment for recurrent patellar dislocation.

PURPOSE: The aim of the present study was to retrospectively investigate the development of patellofemoral osteoarthritis after the historical Insall's proximal realignment for patellar stabilisation in patients with recurrent patellar dislocation. Furthermore, risk factors for recurrent patellar dislocation and for patellofemoral osteoarthritis development were evaluated. METHODS: Forty-two patients underwent patellofemoral stabilising surgery by the historic Insall's proximal realignment; they were evaluated with a mean follow-up period of 52 months. Plain radiography was used to document osteoarthritic changes by using the Iwano classification. MRIs obtained at the latest follow-up were evaluated for patellofemoral cartilage lesions. Univariate and multivariate logistic regression analyses were performed to evaluate the influence of trochlear dysplasia, tibial tubercle-trochlear groove distance and patellar height on redislocation. Pearson's χ (2) and the Spearman's correlation tests were used to assess a possible correlation between trochlear dysplasia and patellar dislocation, as well as between instability and development of patellofemoral osteoarthritis. RESULTS: At the latest follow-up, plain radiographs showed a significant increase in patellofemoral osteoarthritis (grades II-IV according to the Iwano classification) in 18 patients (43%) compared with 4 patients (10%) at the time of surgery (P = 0.001). Patellofemoral cartilage lesions (grades II-IV) were detected in 18 patients (43 %) on MRI. Nine patients (21%) had at least one incidence of redislocation at follow-up. Estimated redislocation-associated risk factors could not be determined. Trochlear dysplasia had a significant impact on patellofemoral osteoarthritis development (P = 0.001), whereas recurrent patellar instability had none (n.s.). CONCLUSION: Insall's proximal realignment technique leads to a significant progression of patellofemoral osteoarthritis. No risk factors for redislocation could be found; however, the presence of trochlear dysplasia did correlate with patellofemoral osteoarthritis. LEVEL OF EVIDENCE: IV.

Use of cell-free collagen type I matrix implants for the treatment of small cartilage defects in the knee: clinical and magnetic resonance imaging evaluation.

PURPOSE: Articular cartilage defects of the knee are a common condition for which several repair techniques have been described. The aim of the present study was to assess medium-term results of a one-step procedure using a cell-free collagen type I matrix. METHODS: Fifteen patients with articular cartilage defects of the knee were treated with an 11-mm-diameter cell-free collagen type 1 matrix implant. The matrices were implanted in a press-fit manner into the defect after careful debridement down to the subchondral bone but without penetration of this margin. Follow-up examinations were carried out at 6 weeks, 6 months, and at 12, 24, 36, and 48 months after implantation. Clinical assessment included the visual analogue scale (VAS), the Tegner activity scale, and the International Knee Documentation Committee (IKDC) score. Radiological assessment for graft attachment and tissue regeneration was performed using the magnetic observation of cartilage repair tissue (MOCART) score. RESULTS: A total of 15 patients (males: n = 6 and females: n = 9) with a mean age of 26.4 years (range 19-40) were treated. The mean VAS improved significantly when compared to the preoperative values (P < 0.05). Six weeks after implantation, IKDC values were slightly lower than the preoperative values (n.s.), but increased significantly at final follow-up (P < 0.05). At 24 months, there were no significant differences in the median Tegner score between the post-operative values and the preoperative values (n.s.). However, after 36 months, a significant improvement was noted that lasted at least up to 48 months (P < 0.05). The MOCART score improved consistently up to 4 years after implantation, with significant improvements already observed after 12 months (P < 0.05). No correlation between the clinical scores and the MOCART score could be perceived. CONCLUSION: The present study showed that the use of cell-free collagen type I matrix implants led to a significant and durable improvement in all the clinical and imaging scores investigated 4 years after implantation. LEVEL OF EVIDENCE: IV.

Repair of a chondral defect using a cell free scaffold in a young patient--a case report of successful scaffold transformation and colonisation.

BACKGROUND: Chondral defects of the articular surface are a common condition that can lead to osteoarthritis if not treated. Therapy of this condition is a topic of constant debate and a variety of chondral repair strategies are currently used. One strategy involves implantation of a cell-free matrix of type I collagen (COL1), to provide a scaffold for chondrocyte migration and proliferation and extracellular matrix production. Although several studies have suggested that chondrocytes can move, to the best of our knowledge there is still no proof of chondrocyte occurrence in a former cell-free scaffold for articular cartilage repair in humans. CASE PRESENTATION: An 18-year-old male patient underwent arthroscopic surgery of the knee for patellar instability and a chondral defect of the femoral condyle. Clinical outcome scores were recorded pre-operatively, after 6 weeks and after 6, 12, 24 and 36 months. MRI was recorded after 6 weeks and after 6, 12, 24 and 36 months postoperatively. At 42 months after implantation of a cell-free type I collagen matrix and reconstruction of the medial patellofemoral ligament, the patient was again treated arthroscopically for a tear of the medial meniscus of the same knee. A biopsy of the previous chondral defect was taken during arthroscopy for histological examination. CONCLUSION: In addition to good clinical and radiological results reported for cell-free scaffolds for cartilage repair in several other studies, transformation of the scaffold could be observed during re-arthroscopy for the meniscal tear. Histological examination of the specimen revealed articular cartilage with vital chondrocytes and a strong staining reaction for type II collagen (COL II), but no reaction for type I collagen staining. This might indicate a complete transformation of the scaffold and supports the theory that cell free scaffolds could support cell migration. Although the cell source remains unclear, migrating chondrocytes from the periphery remain a possibility.

Occurrence and positive predictive value of additional nonmass findings for risk stratification of breast microcalcifications in mammography.

PURPOSE: To assess the occurrence and positive predictive value of additional nonmass findings to stratify the risk of breast microcalcifications. METHODS: This retrospective evaluation included 278 lesions with vacuum- or image-guided hook-wire biopsy for suspicious microcalcifications. The lesions were categorized into exclusive microcalcifications and microcalcifications with focal asymmetry, tubular density or architectural distortion (ie, nonmass findings). To evaluate the utility of additional nonmass findings for risk stratification, outcome variables were positive predictive values and odds ratios for malignancy and invasive carcinoma. RESULTS: Forty-five of 278 microcalcification lesions (16%) were associated with nonmass findings: 28 focal asymmetries, 2 tubular densities, and 15 focal asymmetries in conjunction with tubular densities. Architectural distortion was observed in 28 of these cases. The odds ratio for additional nonmass findings relative to exclusive microcalcifications was 5.9 and was statistically significant (P < .00001). Architectural distortion was the most specific indicator for malignancy and invasiveness, with odds ratios of 6.5 (P = .0072) and 5.6 (P = .0214), respectively. CONCLUSIONS: Microcalcifications with nonmass findings were less frequent than exclusive microcalcifications but were more predictive for malignancy. Architectural distortion demonstrated the highest risk of malignancy and invasiveness. Assessment of additional nonmass findings might be useful for further risk stratification of microcalcifications, indications for additional imaging, and pretreatment considerations.

MR, CT, and PET imaging in pericardial disease.

Although echocardiography remains the standard diagnostic tool for identifying pericardial diseases, procedures with better delineation of morphology and heart function are often required. The pericardium consists of an inner visceral (epicardium) and outer parietal layer (pericardium), which constitute for the pericardial cavity. Pericardial effusion can occur as transudate, exudate, pyopneumopericardium, or hemopericardium. Potential causes are inflammatory processes, that is, pericarditis due to autoimmune or infective reasons, neoplasms, irradiation, or systemic disorders, chronic renal failure, endocrine, or metabolic diseases. Pericardial fat can mimic pericardial effusion. Using various image-acquisition sequences, MRI allows identifying and separating fluid and solid structures. Fast spin-echo T1-weighted sequences with black-blood preparation are favourably used for morphological evaluation. Fast spin-echo T2-weighted sequences, particularly with fat saturation, and short-tau inversion-recovery sequences are useful to visualize oedema and inflammation. For further tissue characterization, delayed inversion-recovery imaging is used. Therefore, image acquisition is performed at 5-20 min subsequent to contrast agent administration, the so-called technique of late gadolinium enhancement. Ventricular volumes and myocardial mass can be assessed accurately by steady-state free-precession sequences, which is required to measure cardiac function and ventricular wall stress. Constrictive pericarditis usually results from chronic inflammatory processes leading to increased stiffness, which impedes the slippage of both pericardial layers and thereby the normal cardiac filling. CT imaging can favourably assess pericardial calcification. Thus, MR and CT imaging allow a comprehensive delineation of the pericardium. Superior to echocardiography, both methods provide a larger field of view and depiction of the complete chest including abnormalities of the surrounding mediastinum and lungs. PET provides unique information on the in vivo metabolism of 18-fluorodeoxyglucose that can be superimposed on CT findings and is useful for identifying inflammatory processes or masses, for example neoplasms. These imaging techniques provide advanced information of anatomy and cardiac function to optimize the pericardial access, for example by the AttachLifter system, for diagnosis and treatment.

Cell-free collagen type I matrix for repair of cartilage defects-clinical and magnetic resonance imaging results.

PURPOSE: Several well-described techniques are available for the treatment of chondral and osteochondral defects. The aim of the study was to assess the efficacy of a single-stage procedure incorporating a new cell-free collagen type I gel for the treatment of small chondral and osteochondral defects in the knee evaluated at 2-year follow-up. METHODS: Fifteen patients were treated with a cell-free collagen type I gel matrix of 11 mm diameter. The grafts were implanted in the debrided cartilage defect and fixed by press-fit only. The clinical outcome was assessed preoperatively and at 6 weeks, and 6, 12 and 24 months after surgery using the International Knee Documentation Committee (IKDC) score, Tegner activity scale and visual analogue scale (VAS). Graft attachment rate was assessed 6 weeks postoperatively using magnetic resonance imaging (MRI). Cartilage regeneration was evaluated using the Magnetic Observation of Cartilage Repair Tissue (MOCART) score at 6, 12 and 24 months after implantation. Clinical results were correlated with MRI findings. RESULTS: Six male and nine female patients were included in this study, with a mean age of 26 (range: 19-40). No complications were reported. The mean VAS values after 6 weeks and the mean IKDC patient values after 6 months were significantly improved from the preoperative values (P = 0.005 and P = 0.009, respectively). This improvement remained up to the latest follow-up. There were no significant differences between the median preoperative and postoperative Tegner values (n.s.). Significant improvement of the mean MOCART score was observed after 12 months and remained by 24 months (P < 0.001). MR images showed that in 14 of the 15 patients, the graft was completely attached by 6 weeks postoperatively. At 24 months after implantation, MRI demonstrated complete filling in all cases with a mainly smooth surface, complete integration of the border zone, homogenous structure of the repaired tissue and nearly normal signal intensity. No correlation between any variables of the MOCART score and the clinical scores was observed. CONCLUSIONS: The present study reveals that the new method produces both good clinical and magnetic resonance imaging results. Use of press-fit only implanted grafts of a smaller diameter leads to a high attachment rate at 24-month follow-up. LEVEL OF EVIDENCE: IV.

Accuracy of MRI volume measurements of breast lesions: comparison between automated, semiautomated and manual assessment.

The aim of this study was to investigate the efficacy of a dedicated software tool for automated and semiautomated volume measurement in contrast-enhanced (CE) magnetic resonance mammography (MRM). Ninety-six breast lesions with histopathological workup (27 benign, 69 malignant) were re-evaluated by different volume measurement techniques. Volumes of all lesions were extracted automatically (AVM) and semiautomatically (SAVM) from CE 3D MRM and compared with manual 3D contour segmentation (manual volume measurement, MVM, reference measurement technique) and volume estimates based on maximum diameter measurement (MDM). Compared with MVM as reference method MDM, AVM and SAVM underestimated lesion volumes by 63.8%, 30.9% and 21.5%, respectively, with significantly different accuracy for benign (102.4%, 18.4% and 11.4%) and malignant (54.9%, 33.0% and 23.1%) lesions (p < 0.05). Inter- and intraobserver reproducibility was best for AVM (mean difference +/- 2SD, 1.0 +/- 9.7% and 1.8 +/- 12.1%) followed by SAVM (4.3 +/- 25.7% and 4.3 +/- 7.9%), MVM (2.3 +/- 38.2% and 8.6 +/- 31.8%) and MDM (33.9 +/- 128.4% and 9.3 +/- 55.9%). SAVM is more accurate for volume assessment of breast lesions than MDM and AVM. Volume measurement is less accurate for malignant than benign lesions.

Right ventricular cardiac myxoma. Diagnostic usefulness of cardiac magnetic resonance imaging.

BACKGROUND: Cardiac myxomas are the most common type of cardiac tumors. About 75-85% of cardiac myxomas originate in the left atrium, 15-20% in the right atrium. Most myxomas arise from the interatrial septum adjacent to the fossa ovalis. Only 3-4% are found in the left and right ventricle each. Although myxomas are histologically benign, they may be fatal because of their strategic position. CASE STUDY: The authors report on a 24-year-old patient with stabbing thoracic pain and dyspnea due to pulmonary thromboembolism that was caused by an atypically localized myxoma at the right ventricular apex originating from the interventricular septum. The diagnosis was based on cardiac magnetic resonance (CMR) imaging. Superior to echocardiography, CMR could strengthen the diagnostic accuracy by additional information on tissue characterization using different imaging sequences. Typically for cardiac myxomas, contrast enhancement was moderate and delayed enhancement was found in the outer circumferential tumor margins only. CONCLUSION: High spatial resolution and multiplane imaging combined with different acquisition patterns of CMR achieve a global view of the heart that seems to be useful for diagnosing cardiac tumorous masses.