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Women with high mammographic breast density have a four- to fivefold increased risk of developing breast cancer compared to women with fatty breasts. Many preventative strategies have attempted to correlate changes in breast density with response to interventions including drugs and diet. The purpose of this work is to investigate the feasibility of assessing breast density with acoustic velocity measurements with ultrasound tomography, and to compare the results with existing measures of mammographic breast density. An anthropomorphic breast tissue phantom was first imaged with our computed ultrasound tomography clinical prototype. Strong positive correlations were observed between sound speed and material density, and sound speed and computed tomography number (Pearson correlation coefficients= 0.87 and 0.91, respectively). A cohort of 48 women was then imaged. Whole breast acoustic velocity was determined by creating image stacks and evaluating the sound speed frequency distribution. The acoustic measures of breast density were evaluated by comparing these results to two mammographic density measures: (1) qualitative estimates determined by a certified radiologist using the BI-RADS Categorical Assessment based on a 1 (fatty) to 4 (dense) scale, and (2) quantitative measurements via digitization and computerized analysis of archival mammograms. A one-way analysis of variance showed that a significant difference existed between the mean values of sound speed according to BI-RADS category, while post hoc analyses using the Scheffé criterion for significance indicated that BI-RADS 4 (dense) patients had a significantly higher sound speed than BI-RADS 1, 2, and 3 at an alpha level of 0.05. Using quantitative measures of breast density, a direct correlation between the mean acoustic velocity and calculated mammographic percent breast density was demonstrated with correlation coefficients ranging from 0.75 to 0.89. The results presented here support the hypothesis that sound speed can be used as an indicator of breast tissue density. Noninvasive, nonionizing monitoring of dietary and chemoprevention interventions that affect breast density are now possible.

A screening study with transrectal ultrasound (US) and digital rectal examination to diagnose early prostate cancer was performed to calculate diagnostic costs. The total costs of screening 784 men were $130,400 with transrectal US and $41,080 with digital rectal examination. Per diagnosed cancer, the costs were $6,520 for transrectal US and $4,108 for digital rectal examination, a difference of 37%. The costs per early diagnosed cancer (stage A or B) were $7,671 and $5,869 for transrectal US and digital rectal examination, respectively--a difference of 23%. The costs per early cancer that would have been advanced if diagnosed without screening were $22,177 for transrectal US and $28,528 for digital rectal examination--a difference of 22% in favor of transrectal US. Equations for these relative costs were generated for transrectal US and digital rectal examination. Costs are related to changes in prevalences and to changes in the stages of prostate cancer when diagnosed without screening.

A study was undertaken to assess the ability of transrectal ultrasound (TR/US), digital rectal examination (DRE), and Prostate Specific Antigen (PSA), to diagnose persistent prostate cancer following an I125 seed implant (SI). Twenty-six patients formed the study group. The median follow-up time was 38 months, and the range was 20 to 60 months. Eighty-eight percent (23/26) had suspicious lesions on TR/US, followed by ultrasound-guided biopsies. Biopsies were performed only on those patients having suspicious lesions on TR/US. Histologically proven adenocarcinoma was found in 81% (21/26) of the patients. Statistical evaluation was done using tissue obtained at biopsy as the "gold standard." The sensitivities for the DRE and PSA were 33% and 76%, respectively. The specificities for DRE and PSA were 50% and 0%, respectively. The positive predictive values for cancer were 91% by TR/US, 100% by DRE, and 89% by PSA. The negative predictive values were 13% for DRE and 0% for PSA. Overall detection rates (N = 26) were 81% for TR/US, 27% for DRE, and 62% for PSA. We conclude that ultrasound criteria for the presence of cancer are the same for both the post-irradiated prostate and the untreated prostate, and that TR/US is the most sensitive test for the diagnosis of persistent local cancer following I125 seed implantation.

Percutaneous absolute ethanol injections and Nd:YAG laser ablations were performed bilaterally in canine prostates (N = 13) using transrectal ultrasound guidance. Seventy-one percent (10/14) of the ethanol injections produced an intraglandular focus of hemorrhagic necrosis. Associated morbidity of ethanol injections included necrosis of the external prostatic sphincter and mucosa of the urethra and bladder. Ninety-two percent (11/12) of the laser ablations produced intraglandular foci of thermal tissue damage, which had distinct margins of transition between necrotic and viable cells. The areas of ablation were well visualized by ultrasound and had minimal associated morbidity. The results of this study demonstrate the technical feasibility and low potential morbidity of transrectal ultrasound guided Nd:YAG laser ablations in the canine prostate.

The authors examined 784 self-referred men over age 60 years to compare clinical usefulness of transrectal ultrasound (US) and digital rectal examination in a screening program for prostate cancer. Biopsy was performed in 77 cases, 83% (64 of 77) for abnormalities detected with transrectal US and 38% (29 of 77) because of findings at digital examination. Twenty-two cancers were detected, 20 with transrectal US and ten at digital examination. Overall detection rate for prostate cancer with transrectal US was two times higher than that with digital examination (2.6% vs 1.3%). Sensitivity, specificity, and negative predictive value for transrectal US and digital examination were calculated for a range of prevalences (0.028-0.1543). Sensitivity was two times higher for transrectal US than for digital examination. Transrectal US demonstrated 100% (17 of 17) of tumors with the most favorable prognosis (less than or equal to 1.5 cm in diameter) compared with 41% (seven of 17) for digital examination. The authors conclude that transrectal US is more sensitive than digital examination in the detection of prostate cancer, and they advocate broader implementation and evaluation of transrectal US as a tool for early detection.

Biplanar, transrectal ultrasound (US) guidance of needles was used in the transperineal biopsy of possibly malignant prostatic lesions in 80 patients (83 biopsies). A 22-gauge cytologic needle was used to locate and fixate the lesion, and aspiration specimens for cytologic and histologic evaluation were obtained (with 22- and 14-gauge needles, respectively). Twenty-one 19-gauge needle core biopsies were also performed. Forty-nine patients (61%) had histologically prove adenocarcinoma. The rate of cancer diagnosis was 53% with cytologic evaluation and 54% with histologic evaluation (combined yield, 61%). This included 34% of cancers less than 1.0 cm in diameter and 56% of those 1.0-1.5 cm. Thirteen of 23 (57%) of these lesions were nonpalpable or equivocal on digital rectal examination. These results suggest that transrectal US guidance of thin-needle biopsies is useful in diagnosing early prostate cancer.

In the authors' experience, transrectal sonography has the ability not only to stage prostatic cancer accurately, but also to detect such lesions before they become palpable.

Transrectal ultrasonography (US) provides excellent anatomic detail of pathologic changes in the seminal vesicles and ejaculatory ducts. Fifty-two patients with US findings of seminal vesicle dilatation or cysts, ejaculatory duct cysts, or seminal vesicle or ejaculatory duct calculi were given questionnaires concerning a broad spectrum of genito-urinary symptoms. Compared with age-matched controls with normal US findings, patients with calculi in the seminal vesicles or ejaculatory ducts had a significantly increased prevalence of hematospermia and ejaculatory pain (P less than .01), and patients with cystic dilatation of the seminal vesicles were more likely to have perineal pain. Large midline cysts containing calculi or debris were symptomatic and probably represent müllerian duct remnants. Small cysts of the ejaculatory ducts were asymptomatic. Transrectal US may provide clinical insight into the causes of significant genitourinary symptoms that may previously have been ascribed to chronic nonbacterial prostatitis or have been considered to be idiopathic.

One hundred forty-nine ultrasound (US)-guided transrectal biopsies of the prostate were performed with an 18-gauge needle mounted in a spring-loaded firing device. Two probes were used, one with its sector transducer placed at the tip of the probe and the other with its sector transducer placed at an angle of 45 degrees. All biopsies provided a diagnostic tissue core. Histologic examination of biopsy specimens showed that 78 lesions were cancerous, 17 were dysplastic, and 54 were benign. Two patients developed fever; one of these received oral antibiotics after onset of the fever. Hospitalization was not required for either patient. The authors conclude that US-guided transrectal biopsy is a safe and valuable diagnostic tool.

Two hundred fifty-six patients with hypoechoic lesions of the prostate found at transrectal ultrasound (US) were evaluated with prostate-specific antigen (PSA) study, digital rectal examination (DRE), and US-guided transrectal biopsy. Positive predictive values for cancer were calculated for transrectal US alone and in combination with DRE, PSA study, or both. Results were correlated with lesion size. The positive predictive value for transrectal US alone was 41%; this value increased to 61% if the patient had positive results from DRE, 52% if the PSA level was elevated, and 71% if both the DRE results and PSA level were abnormal. The positive predictive value for transrectal US fell to 24% if results of the DRE were normal, 12% if the PSA level was normal, and 5% if both DRE results and PSA level were normal. No cancers were detected in lesions 1.0 cm or smaller if DRE results and PSA level were normal. DRE and PSA study are valuable complements to abnormal transrectal US examinations. Biopsy of small suspicious lesions may not be indicated if results of both of the studies are normal.

Indications for TRUS are: (a) for diagnosis of nonpalpable cancer, or detection of cancer with greater accuracy than is possible at present; (b) for guidance of transrectal biopsies of hypoechoic lesions for histologic confirmation of cancer; (c) for guidance of staging biopsies to ensure diagnoses of extraprostatic extension; and (d) for staging previously diagnosed prostate cancer.

Background: Cryosurgery of liver lesions is becoming increasingly accepted for the ablation of liver tumors. Attempts at laparoscopic cryosurgery have been very limited and often need to be converted to open laparotomy due to the complexity of the procedure.Methods: Seven domestic pigs were anesthetized, and 17 small (0.7 cm mean diameter) tumor mimicking agar "lesions" were percutaneously placed in the liver. Two small subcostal incisions ( approximately 2.0 cm) were placed, and an endocavitary ultrasound transducer (with a 2. 4-mm cryoprobe mounted on it) was placed on the liver surface. Lesions were localized and directly punctured with one or two cryoprobes under ultrasound guidance, and a single 15-min freeze was undertaken. The animals were then killed, and their livers were removed and serially sectioned.Results: Total time for probe placement was approximately 10 min after incisions had been made. Animals tolerated the procedure well and all survived until they were killed. No intraabdominal complications were detected at exploration. Mean cryolesion dimensions were 3.0 cm (single probe) and 3.3 cm (dual probe) (p > 0.05). Positive margins were detected in one lesion treated with a single probe, and in none of the lesions treated with dual probes. Mean margins were 0.9 cm: 1.2 cm for the single probe and dual probe techniques, respectively. Liver surrounding control agar lesions demonstrated a thin rim of necrosis, approximately 0.5 mm wide.Conclusions: We conclude that minilaparotomy is an effective, safe, and simple method for performing hepatic cryosurgery in this animal model. This minimally invasive technique may benefit a subset of patients with lesions in accessible locations. Lesions in posterior locations may not be as amenable to this technique due to deterioration of ultrasound image quality in the far field. [ABSTRACT FROM AUTHOR]