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Biomedical subjects

S H Parker

Publications and source records attributed to S H Parker.

At least 19 recordsLinked to original sources
PubMed1992

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.

Angiography↗
PubMed1992

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.

Adolescent↗
PubMed1992

The school nurse's role: early detection of growth disorders.

Many school-age children with short stature or apparent growth excess are growing normally; however, for the minority of children experiencing growth problems, treatment may be indicated. The school nurse is in an ideal position to perform a preliminary growth-screening program. For accurate identification of potential growth problems, children must be properly weighed and measured, and the numbers plotted on a growth chart. Growth disorders can be caused by numerous underlying pathologies and diseases. Knowledge of these conditions can raise the index of suspicion so that appropriate referral can be made.

Child↗
PubMed1991

Nonpalpable breast lesions: stereotactic automated large-core biopsies.

One hundred two patients with mammographically suspicious, nonpalpable lesions underwent stereotactic breast biopsy with a biopsy gun and an automated 14-gauge cutting needle. After biopsy, a localization wire was placed and surgical biopsy performed. There was agreement of the histologic results from the gun biopsy and the surgical biopsy specimens in 98 cases (96%), including 22 of 23 carcinomas (96%) (kappa = 0.936). The gun biopsy yielded findings that led to the correct diagnosis in two cases involving lesions that were missed at surgical biopsy; two lesions found at surgery were missed at gun biopsy. The results of this study suggest that the use of 14-gauge needles improves agreement between surgical and needle core biopsy findings and that stereotactic biopsy with an automated needle and gun can be an acceptable alternative to surgical biopsy in women with mammographically suspicious breast lesions.

Adenofibroma↗
PubMed1990

Ethanol embolization of arteriovenous fistulas: a primary mode of therapy.

Arteriovenous fistulas (AVFs) can be posttraumatic or congenital vascular malformations. In the initial arteriographic evaluation, chronic AVFs potentially can be confused with arteriovenous malformations (AVMs). The authors studied five patients with a single AVF and one patient with numerous AVFs. Three patients had undergone surgery for treatment of their AVFs, one patient had undergone isobutyl-2-cyanoacrylate (IBCA) embolization, and two patients had undergone no prior therapy. The AVFs recurred in the three patients who had undergone surgery and in the patient who had undergone IBCA embolization. All patients underwent ethanol embolization of their AVFs. Angiograms obtained immediately after embolization documented closure of all AVFs. At follow-up, none of the embolized lesions have recurred. The authors conclude that ethanol embolotherapy can cure these problematic lesions. Extreme caution, however, must be employed with the use of intravascular ethanol because nontarget embolization can potentially result in tissue devitalization. In this study, two patients developed a small focal area of skin necrosis that did not require skin grafting and healed with conservative management.

Adult↗
PubMed1990

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.

Adolescent↗
PubMed1990

Stereotactic breast biopsy with a biopsy gun.

One hundred three patients underwent stereotactic breast biopsy with an 18-, 16-, or 14-gauge cutting needle and a biopsy gun. After biopsy, a localization wire was placed and surgical biopsy performed. There was agreement of the histologic results in 89 cases (87%) including 14 of 16 cancers (87%) (kappa = 0.806). The gun biopsy yielded the correct diagnosis in four cases involving a lesion (including one cancer) that was missed at the surgical biopsy. Nine cases in which the lesion was missed at gun biopsy can be related to insufficient needle size, the greater difficulty in using one of the two stereotactic devices, and early inexperience with the technique. A 14-gauge needle was used in the last 29 biopsies, the results of which agreed with the surgical pathologic findings in 28 cases (97%). With greater experience, stereotactic-guided large-gauge automated percutaneous biopsy may prove to be an acceptable alternative to surgical biopsy in women with breast masses suspected at mammography.

Biopsy, Needle↗
PubMed1990

Efficacy of automated biopsy guns versus conventional biopsy needles in the pygmy pig.

Debate over which biopsy needle is the best has intensified recently with the introduction of automated biopsy guns including the 18-gauge long-throw and short-throw Biopty, the 18-gauge Cook, and the 14- and 18-gauge Klear Kut. To evaluate the efficacy of these mechanized biopsy guns versus that of conventional manual biopsy needles in the acquisition of adequate tissue for histopathologic evaluation, open hepatic and renal biopsies were performed in 15 pygmy pigs. The specimens were evaluated separately in a double-blind fashion by two histopathologists using graded criteria. Overall, the best results were obtained with the manual 14-gauge Tru-Cut needle, the long-throw 18-gauge Biopty gun, and the 18-gauge Cook biopsy gun. By comparison, the aspiration-type needles did not perform as well when considered as a group. Several other needles scored well in the biopsy of either the liver or kidney, but not in both. Disappointing results were obtained with the Klear Kut guns (both 14- and 18-gauge) and the Vacu Cut and PercuCut needles.

Animals↗
PubMed1990

Malacoplakia of the prostate sonographically mimicking carcinoma.

Malacoplakia is an uncommon granulomatous inflammatory disorder that usually affects the urinary bladder and only rarely affects the prostate. Prostatic malacoplakia was detected in five patients by means of transrectal sonography and confirmed by means of ultrasound-directed transrectal biopsy. Hypoechoic peripheral zone lesions, which are suggestive of carcinoma, were found in all five patients, including two with capsular irregularity and one with a lobular prostatic contour suggesting stage C disease. The results of this study suggest that, with the increased use of sonographically directed transrectal biopsy, prostatic malacoplakia may be found to be more common than previously suspected.

Aged↗
PubMed1989

Percutaneous transluminal aortic angioplasty: techniques and results.

Percutaneous transluminal angioplasty of the infrarenal abdominal aorta has been reported by a few authors. In the present series, aortic stenoses in 32 patients were treated with various percutaneous angioplasty techniques. Isolated aortic stenoses and primary aortic stenoses extending into the iliac arteries were successfully dilated. The initial success rate was 100%, without evidence of rupture, thrombosis, dissection, or distal embolization. In only three of the 28 patients who returned for follow-up did symptoms recur or noninvasive vascular laboratory indexes deteriorate (mean follow-up, 25 months). Percutaneous transluminal aortic angioplasty has proved safe and efficacious in the treatment of atherosclerotic aortic stenoses.

Adult↗
PubMed1989

Symptomatic vascular malformations: ethanol embolotherapy.

Absolute ethanol was used to perform nine transcatheter embolizations and 21 direct percutaneous puncture embolizations in eight patients with unresectable vascular malformations. Six patients had arteriovenous malformations and two patients had hemangiomas. Four of these patients had undergone unsuccessful surgery, and the other four were not considered candidates for operation. All large complex symptomatic vascular malformations (SVMs) required multiple embolizations that were staged procedures. Ethanol embolotherapy, performed according to strict techniques, has proved efficacious in the management of SVMs.

Adult↗
PubMed1989

Image-directed percutaneous biopsies with a biopsy gun.

Core tissue for histologic study is believed by many pathologists to be more diagnostic than material from needle aspiration. Recently, a biopsy "gun" has been introduced, which simplifies core biopsies. With this device, 182 biopsies of multiple anatomic sites were performed with ultrasonic, computed tomographic, and fluoroscopic guidance and 18-gauge needles. High-quality histopathologic specimens were obtained in 177 of the biopsies, and diagnostic target tissue was obtained in 167. Only three significant complications occurred: one bleeding complication that required transfusion and two cases of pneumothorax that necessitated placement of chest tubes. The biopsy gun eliminated the disjointed movements of conventional "skinny" needle biopsies, and none of the samples demonstrated significant "crush" artifact or obscuring blood, problems that are commonly associated with manual biopsy techniques. Patient discomfort was decreased with this system compared with that of manual biopsies, and the total procedure time was reduced. Because of these distinct advantages, the authors now use the biopsy gun exclusively for all percutaneous biopsies and recommend that other institutions consider the use of this biopsy method.

Adult↗
PubMed1988

Abdominal hemangiopericytoma scintigraphically simulating an accessory spleen.

Hemangiopericytoma is a soft tissue tumor composed histologically of pericytes of Zimmerman, which line capillaries. These neoplasms have been observed throughout the body in soft tissue and bone. Presented here is a case of abdominal hemangiopericytoma proven histologically that simulated an accessory spleen on a number of studies including Tc-99m sulfur colloid imaging.

Abdomen↗