Clinical optoacoustic imaging combined with ultrasound for coregistered functional and anatomical mapping of breast tumors.

Optoacoustic imaging, based on the differences in optical contrast of blood hemoglobin and oxyhemoglobin, is uniquely suited for the detection of breast vasculature and tumor microvasculature with the inherent capability to differentiate hypoxic from the normally oxygenated tissue. We describe technological details of the clinical ultrasound (US) system with optoacoustic (OA) imaging capabilities developed specifically for diagnostic imaging of breast cancer. The combined OA/US system provides co-registered and fused images of breast morphology based upon gray scale US with the functional parameters of total hemoglobin and blood oxygen saturation in the tumor angiogenesis related microvasculature based upon OA images. The system component that enabled clinical utility of functional OA imaging is the hand-held probe that utilizes a linear array of ultrasonic transducers sensitive within an ultrawide-band of acoustic frequencies from 0.1 MHz to 12 MHz when loaded to the high-impedance input of the low-noise analog preamplifier. The fiberoptic light delivery system integrated into a dual modality probe through a patented design allowed acquisition of OA images while minimizing typical artefacts associated with pulsed laser illumination of skin and the probe components in the US detection path. We report technical advances of the OA/US imaging system that enabled its demonstrated clinical viability. The prototype system performance was validated in well-defined tissue phantoms. Then a commercial prototype system named Imagio™ was produced and tested in a multicenter clinical trial termed PIONEER. We present examples of clinical images which demonstrate that the spatio-temporal co-registration of functional and anatomical images permit radiological assessment of the vascular pattern around tumors, microvascular density of tumors as well as the relative values of the total hemoglobin [tHb] and blood oxygen saturation [sO2] in tumors relative to adjacent normal breast tissues. The co-registration technology enables increased accuracy of radiologist assessment of malignancy by confirming, upgrading and/or downgrading US categorization of breast tumors according to Breast Imaging Reporting And Data System (BI-RADS). Microscopic histologic examinations on the biopsied tissue of the imaged tumors served as a gold standard in verifying the functional and anatomic interpretations of the OA/US image feature analysis.

Breast biopsy avoidance: the value of normal mammograms and normal sonograms in the setting of a palpable lump.

PURPOSE: To review the authors' experience with patients who presented with breast lumps and had normal mammograms and normal sonograms. MATERIALS AND METHODS: The findings from 600 lumps in 486 women with no focal ultrasonographic (US) mass or mammographic finding in the area of clinical concern were retrospectively studied. Evaluated parameters included the individual reporting the lump, qualitative descriptors for the physical finding, mammographic density, US characteristics in the area of concern, whether there was a change in imaging and/or physical examination results, and whether there were diagnostic biopsy findings at follow-up. The study group included 540 lumps in 435 women who had a minimum mammographic and clinical follow-up of 2 years, as well as 60 additional lumps in 51 patients who underwent biopsy. RESULTS: No patient in the nonbiopsy group developed carcinoma at the initial site of concern during a mean mammographic and clinical follow-up period of 43 months, and all biopsy specimens were benign (negative predictive value, 100%). CONCLUSION: Results of this retrospective study suggest that breast biopsy may be avoided in women with palpable abnormalities when both US and mammography depict normal tissue at the lump site.

Comparative value of 99mTc-sestamibi scintimammography and sonography in the diagnostic workup of breast masses.

OBJECTIVE: This study was conducted to assess the relative roles of 99mTc-sestamibi scintimammography and sonography in the evaluation of breast lesions that are indeterminate or suspicious on mammography or clinical examination. SUBJECTS AND METHODS: Twenty-five patients with 33 biopsy-proven breast lesions underwent both scintimammography and sonography. Lesions were categorized as benign or requiring biopsy on the basis of the absence or presence of a focus of increased activity on scintimammography and the shape, orientation, and echogenicity of the lesion on sonography. RESULTS: Sensitivity and specificity in detecting breast cancer were 92% and 95%, respectively, for scintimammography and 100% and 48%, respectively, for sonography. The higher specificity of scintimammography was statistically significant (p < 0.01). CONCLUSION: Although the overall accuracy of 99mTc-sestamibi scintimammography in the diagnosis of breast cancer was high, it has several disadvantages in comparison with sonography. Scintimammography has a slightly higher false-negative rate for breast cancer, is unable to reveal cysts, is more expensive, takes longer to perform, and involves ionizing radiation. For these reasons, scintimammography with 99mTc-sestamibi is unlikely to either replace sonography or be frequently used in addition to sonography.

Incidental treatment of nipple discharge caused by benign intraductal papilloma through diagnostic Mammotome biopsy.

OBJECTIVE: The purpose of this study was to evaluate imaging-guided vacuum-assisted mammotome biopsy as a minimally invasive method of obtaining a satisfactory diagnosis and eliminating the bothersome symptoms in patients presenting with nipple discharge. MATERIALS AND METHODS: Forty-nine women who presented with nipple discharge and who had final pathologic diagnoses of papillary lesions were retrospectively identified. Fifty-six lesions were biopsied in this group. The examinations included mammography, ductography, sonography, and, if possible, percutaneous biopsy. All lesions were centrally located and most were superficial. Of this study group, four patients with five lesions proceeded to sonographically guided automated core biopsy, and 38 patients with 44 intraductal lesions identified by sonography advanced to sonographically guided biopsy with an 11-gauge mammotome probe. One patient underwent stereotactic 11-gauge mammotome biopsy. Patients not advancing to sonographically guided biopsy were those with masses either in the nipple or nipple-areolar complex (five patients), one patient with no identifiable lesion at sonography, and one directly referred for open surgical biopsy. RESULTS: In all biopsied patients, satisfactory tissue for diagnosis was obtained. In patients biopsied with the mammotome probe, follow-up at a mean time of 13 months revealed resolution of the presenting problematic discharge in 97.2% of patients. Complications were mild and infrequent. Only one of 50 percutaneously biopsied lesions was not benign and required subsequent surgery. CONCLUSION: Papilloma excision with percutaneous biopsy allows safe and accurate tissue analysis and a high probability of terminating the symptomatic nipple discharge.

Surgical treatment of posttraumatic cystic and tethered spinal cords.

Posttraumatic syringomyelia as a cause of progressive neurologic deterioration has been well described. More recently, the noncystic posttraumatic tethered cord has been associated with identical progressive neurologic deterioration. A retrospective analysis of patients treated surgically with spinal cord untethering and/or cyst shunting to arrest a progressive myelopathy from a posttraumatic tethered and/or cystic cord was performed. Emphasis was on outcome using the American Spinal Injury Association (ASIA) sensory and motor scoring systems. During an 18-month period from May 1993 to December 1994, 70 patients with spinal cord injury were operated upon for tethered and/or cystic spinal cords because of a progressive myelopathy and deteriorating ASIA sensory/motor scores. Fifty-nine patients had follow-up data 1 year postoperatively. At the 1 year follow-up, there was small improvement in light touch sensory scores (0.67 points), pinprick scores (1.3 points), and motor scores (0.41 points) demonstrating that the progression of the myelopathic process was arrested. Thirty-four of these 59 patients had no previous surgery to their spinal cords. At 1 year follow-up, light touch scores improved on average 2.38 points, pinprick scores 3.88 points (p < 0.05), and motor scores 1.47 points, suggesting better outcome with first-time surgery. Of this latter group, 64.3% regained a lost function, 62.5% saw improvement in spasticity, 55.6% had substantial improvement in neurogenic pain, and 95.8% felt that surgery prevented further neurologic deterioration.

Needle biopsy techniques.

With the ability to perform good diagnostic mammography, breast ultrasound, ductography, cyst aspiration, abscess drainage, and stereotactic or ultrasound-guided percutaneous biopsy, the modern breast radiologist should play the central role in breast diagnosis. The definitive diagnoses afforded by percutaneous breast biopsy that obviate surgery entirely in benign lesions and streamline the therapeutic surgery for malignant lesions now can be obtained routinely. The future holds even more exciting challenges for the radiologist as percutaneous lumpectomy becomes a reality. Thus the breast radiologist, armed with the technology and techniques of the twenty-first century, truly stands on the threshold of a new era.

Solid breast nodules: use of sonography to distinguish between benign and malignant lesions.

PURPOSE: To determine whether sonography could help accurately distinguish benign solid breast nodules from indeterminate or malignant nodules and whether this distinction could be definite enough to obviate biopsy. MATERIALS AND METHODS: Seven hundred fifty sonographically solid breast nodules were prospectively classified as benign, indeterminate, or malignant. Benign nodules had no malignant characteristics and had either intense homogeneous hyperechogenicity or a thin echogenic pseudocapsule with an ellipsoid shape or fewer than four gentle lobulations. Sonographic classifications were compared with biopsy results. The sensitivity, specificity, and negative and positive predictive values of the classifications were calculated. RESULTS: Benign histologic features were found in 625 (83%) lesions; malignant histologic features, in 125 (17%). Of benign lesions, 424 had been prospectively classified as benign. Two lesions classified as benign were found to be malignant at biopsy. Thus, the classification scheme had a negative predictive value of 99.5%. Of 125 malignant lesions, 123 were correctly classified as indeterminate or malignant (98.4% sensitivity). CONCLUSION: Sonography can be used to accurately classify some solid lesions as benign, allowing imaging follow-up rather than biopsy.

US-guided automated large-core breast biopsy.

To evaluate the efficacy of ultrasound (US)-guided automated large-core percutaneous needle breast biopsy, biopsy of 181 ultrasonographically suspicious breast lesions was performed by using a long-throw biopsy gun and 14-gauge needles with continuous US guidance. A "freehand" technique with either 5.0- or 7.5-MHz linear-array transducers was used. Needle core diagnoses were compared with surgical diagnoses in the 49 lesions subsequently surgically excised. The remaining 132 cases were followed for 12-36 months. Agreement between needle-core and surgical diagnoses in the 49 lesions was 100%. This group included 34 cancers (28 infiltrating ductal, two mucinous, one mixed infiltrating ductal and lobular, and one each of intraductal, infiltrating lobular, and tubular carcinoma). To date, no cancers have been found in the other 132 cases. The procedure time averaged 20 minutes, and no complications occurred. With an accuracy approaching that of excisional biopsy, US-guided needle core biopsy provides an alternative to surgery.

Segmental stenosis of the renal artery: pattern recognition of tardus and parvus abnormalities with duplex sonography.

Segmental renal artery branches within the renal sinus were prospectively evaluated with color Doppler imaging and pulsed-Doppler spectral analysis in 56 patients before angiography. Waveforms were evaluated for the tardus and parvus abnormalities of prolonged acceleration time, diminished acceleration index, and loss of the normal early systolic compliance peak/reflective-wave complex (ESP). Findings obtained with these parameters were compared with the subsequent findings on angiograms to ascertain their efficacy in detection of hemodynamically significant (greater than or equal to 60%) renal arterial stenosis (RAS), which was present in 32 kidneys in 26 patients. Simple pattern-recognition analysis of ESP proved to be the best of the three parameters. Loss of ESP enabled identification of RAS with 95% sensitivity, 97% specificity, a 92% positive predictive value, a 98% negative predictive value, a 96% overall accuracy. On the basis of the high technical success rate, high sensitivity and specificity, and short examination time, waveform analysis for detection of tardus-parvus abnormalities, especially loss of ESP, of the segmental artery is recommended as an alternative to direct examination of the main renal arteries for evaluation of RAS.

MR imaging of symptomatic peripheral vascular malformations.

We performed a retrospective study of symptomatic peripheral vascular malformations to determine if MR imaging can be used to distinguish slow-flow venous malformations from high-flow arteriovenous malformations and arteriovenous fistulas. Twenty-seven MR examinations in 25 patients with malformations outside the CNS were reviewed. Sixteen venous malformations, nine arteriovenous malformations, and two arteriovenous fistulas were included. In all cases, the MR findings were correlated with the results of angiography. The distinction between slow-flow venous malformations and high-flow arteriovenous malformations and arteriovenous fistulas was made primarily on T2-weighted MR images, which showed high signal intensity in venous malformations and flow voids in high-flow lesions. In addition to the previously described MR features of venous malformations (serpentine pattern with septations, associated muscle atrophy, and typical T1 and T2 signal intensities), several new MR features were apparent. Venous malformations had a propensity for multifocal involvement (37%), orientation along the long axis of extremities or affected muscles (78%), and adherence to neurovascular distributions (64%). Prominent subcutaneous fat was commonly seen adjacent to the malformation. MR images of arteriovenous malformations and arteriovenous fistulas also commonly showed muscle atrophy and subcutaneous fatty prominence. Our results show that slow-flow venous malformations can be distinguished from high-flow arteriovenous malformations and fistulas on the basis of spin-echo MR signal characteristics. The associated imaging characteristics help in the differential diagnosis in problematic cases.

Ethanol embolization of vascular malformations.

Absolute ethanol was used to treat 20 patients with symptomatic vascular malformations (SVMs) (ie, venous malformations, arteriovenous malformations, and congenital and posttraumatic arteriovenous fistulas) in whom previous surgery or standard embolotherapy had failed or who were not candidates for surgery. All large complex lesions required multiple embolizations as staged procedures. Immediate thrombosis was achieved in all patients; complications (13% of cases) were generally minor and were treated conservatively. Follow-up studies, performed in 19 of 20 patients, showed persistent occlusion of the SVM in all cases. Ethanol embolization of SVMs, performed according to strict techniques, has proved efficacious in SVM management and is emerging as a definitive form of therapy.

Carotid duplex sonography: a multicenter recommendation for standardized imaging and Doppler criteria.

A complex duplex carotid evaluation involves high resolution imaging and characterization of the carotid plaque as well as quantitative Doppler spectral analysis to determine the presence and degree of flow restriction. Each of the components of the examination is essential to evaluate the carotid arteries adequately for the presence of disease. Both of these components should be assimilated into a final report that can be used to determine who is at risk for embolic as well as flow restrictive disease. By carefully following the reporting system described in this paper, an accurate and reproducible means of evaluating the carotid arteries can be achieved that permits comparison of studies. In addition, this will allow accurate communications among institutions and help to insure a better understanding of the etiology and pathogenesis of atherosclerotic carotid artery disease.

Duplex sonography in the evaluation of carotid artery disease.

High-resolution duplex sonography was compared with biplane magnified carotid angiography in a prospective evaluation of 161 carotid arteries in 86 patients. The duplex scanner combined real-time B-mode imaging (7.5 MHz) with simultaneous range-gated pulsed Doppler frequency analysis (3 MHz). The degree of stenosis was usually determined by the true and residual lumen of the carotid artery at the atherosclerotic plaque on the transverse image. The Doppler frequency signals were automatically converted to velocity data by a minicomputer. The accuracy of the duplex system in detecting and assessing stenoses graded in 20% increments is demonstrated according to specificity, sensitivity, and positive and negative predictive value by both cumulative and subgroup analyses. A 93.7% sensitivity was shown for minimal (0-20%) stenosis and 100% sensitivity for severe (greater than 60%) stenosis. An apparent limitation of duplex sonography is the differentiation of a high-grade stenosis from occlusion (sensitivity, 82.6%; positive predictive value, 90.4%).