Biomedical subjects

W D Middleton

Publications and source records attributed to W D Middleton.

At least 19 recordsLinked to original sources

PubMed2001

Musculoskeletal ultrasound: an update.

In summary, musculoskeletal sonography is a rapidly growing field of interest around the world. Outside of America, it is often the first and definitive imaging modality fordisorders of the musculoskeletal system. Musculoskeletal ultrasound offers rapid, inexpensive, real-time examination of the structures of interest with easy comparison to the contralateral side. Principles of one area of musculoskeletal sonography easily generalize to other areas.

Humans↗

PubMed2001

Hand and wrist sonography.

Although the anatomy of the hand and wrist is complex and the pathologic conditions encountered are diverse, many of the disease processes are localized, and in many situations, the clinical question is specific and limited. Because of this, ultrasound has always been an attractive imaging modality for evaluation of hand and wrist problems. Unfortunately, intrinsic difficulties in ultrasound image acquisition and interpretation have slowed the acceptance of hand and wrist sonography. Recently, however, new developments in high-resolution transducers and signal processing have dramatically improved image quality and scanning flexibility. For this reason, hand and wrist sonography is now more widely accepted and is taking its place along side other traditional modalities such as radiography, computed tomography, magnetic resonance imaging, and arthrography. Specific situations in which ultrasound offers definite benefits include evaluation of tendon inflammation and rupture, evaluation of palpable masses or suspected occult masses, and evaluation of suspected foreign bodies. Analysis of the median nerve is also possible and in the future, may have a role in patients with carpal tunnel syndrome.

Journal Article↗

PubMed2001

Testicular microlithiasis: US follow-up.

PURPOSE: To determine in patients with testicular microlithiasis (TM) the short-term natural history of classic TM (CTM) and limited TM (LTM). MATERIALS AND METHODS: In 104 patients, testicular microliths were identified on ultrasonographic (US) images; 39 patients had five or more microliths on at least one US image (criterion for CTM), and 65 patients had fewer than five microliths (criterion for LTM). Attempts were made to have all patients return for follow-up US to assess for change in TM or development of tumor. RESULTS: Seven (18%) of the 39 patients with CTM and one (2%) of the 65 patients with LTM had tumor at presentation (P =.004). Among all 104 patients, follow-up US was performed in 72 patients (31 with CTM, 41 with LTM), with mean follow-up of 45 months (range, 12-90 months). None of these patients had interval development of testicular neoplasm. LTM did not progress to CTM in any patient. Progression in number of microliths was seen in two patients with CTM. CONCLUSION: Patients with LTM have a lower prevalence of associated malignancy than do patients with CTM. The risk of developing malignancy in patients with isolated TM (LTM or CTM) is low at short-term follow-up. These results raise the question of the need for routine US in this patient population.

Adult↗

PubMed2000

Sonography of the hand and wrist.

Not only is the anatomy of the hand and wrist complex, but also its pathologic conditions are quite diverse. Although plain radiographs, CT, arthrography, and MRI have traditionally been used to evaluate the hand and wrist, ultrasound is beginning to take its place alongside these more traditional imaging modalities and is being ordered with increasing frequency by orthopedic surgeons. This article reviews the pertinent gross anatomy and sonographic technique used to scan the hand and wrist and also describes the sonographic findings associated with the most common hand and wrist pathologic conditions. These include soft tissue tumors, tenosynovitis, tendinous and ligamentous injuries of the hand, Dupuytren's contracture, foreign bodies, and carpal tunnel syndrome (CTS).

Carpal Tunnel Syndrome↗

PubMed2000

Follow-up of patients at low risk for hepatic malignancy with a characteristic hemangioma at US.

PURPOSE: To determine the need for follow-up imaging in patients with a low risk of malignancy and with ultrasonographic (US) findings typical of hepatic hemangioma. MATERIALS AND METHODS: A computer search of US reports completed between 1991 and 1994 helped identify 383 patients whose reports contained the word "hemangioma." One hundred eleven patients were excluded because the lesion's appearance was atypical (n = 16) or because the patients had a high risk of malignancy (prior history or current evidence of extrahepatic malignancy or chronic hepatic disease [n = 95]). Fifty-nine patients were excluded because they were lost to follow-up (n = 41) or had clinical follow-up of less than 2 years (n = 18). The conditions of the remaining 213 patients with typical-appearing hemangiomas and a low risk of malignancy were analyzed. One hundred twenty-one patients underwent imaging follow-up or histopathologic confirmation. Ninety-two had clinical follow-up of more than 2 years (mean, 46 months). RESULTS: Of the 213 patients, four had benign lesions other than hemangiomas. One patient who subsequently developed a malignancy (neuroendocrine metastases from primary colonic carcinoma diagnosed 22 months after initial US) potentially had an early metastasis that was misdiagnosed as a hemangioma. CONCLUSION: On the basis of these results, the authors no longer recommend follow-up studies in their patients with a low risk of malignancy and a typical-appearing hemangioma at US.

Adult↗

PubMed2000

Sonographic differences in the appearance of acute and chronic full-thickness rotator cuff tears.

This study was undertaken to identify differences in the sonographic appearance of acute and chronic full-thickness rotator cuff tears. The ultrasonograms of 24 patients with an acute rotator cuff tear and 20 with a chronic tear were reviewed for tear size (width), location, and the presence and distribution of fluid. Among these 24 patients, 75% with a midsubstance tear location had an acute tear; 64% of patients with joint or bursal fluid had an acute tear; 80% of patients with a nonvisualized rotator cuff due to a massive tear had a chronic tear; and 73% of patients with no sonographic evidence of bursal or joint fluid had a chronic tear. In conclusion, a midsubstance location and the presence of joint or bursal fluid were more commonly associated with an acute tear. A nonvisualized cuff and the absence of joint and bursal fluid were more commonly observed with a chronic tear.

Acute Disease↗

PubMed2000

Ultrasonography of the rotator cuff. A comparison of ultrasonographic and arthroscopic findings in one hundred consecutive cases.

BACKGROUND: There has been limited acceptance of shoulder ultrasonography by orthopaedic surgeons in the United States. The purpose of this retrospective study was to determine the diagnostic performance of high-resolution ultrasonography compared with arthroscopic examination for the detection and characterization of rotator cuff tears. METHODS: One hundred consecutive shoulders in ninety-eight patients with shoulder pain who had undergone preoperative ultrasonography and subsequent arthroscopy were identified. The arthroscopic diagnosis was a full-thickness rotator cuff tear in sixty-five shoulders, a partial-thickness tear in fifteen, rotator cuff tendinitis in twelve, frozen shoulder in four, arthrosis of the acromioclavicular joint in two, and a superior labral tear and calcific bursitis in one shoulder each. All ultrasonographic reports were reviewed for the presence or absence of a rotator cuff tear and a biceps tendon rupture or dislocation. All arthroscopic examinations were performed according to a standardized operative procedure. The size and extent of the tear and the status of the biceps tendon were recorded for all shoulders. The findings on ultrasonography and arthroscopy then were compared for each parameter. RESULTS: Ultrasonography correctly identified all sixty-five full-thickness rotator cuff tears (a sensitivity of 100 percent). There were seventeen true-negative and three false-positive ultrasonograms (a specificity of 85 percent). The overall accuracy was 96 percent. The size of the tear on transverse measurement was correctly predicted in 86 percent of the shoulders with a full-thickness tear. Ultrasonography detected a tear in ten of fifteen shoulders with a partial-thickness tear that was diagnosed on arthroscopy. Five of six dislocations and seven of eleven ruptures of the biceps tendon were identified correctly. CONCLUSIONS: Ultrasonography was highly accurate for detecting full-thickness rotator cuff tears, characterizing their extent, and visualizing dislocations of the biceps tendon. It was less sensitive for detecting partial-thickness rotator cuff tears and ruptures of the biceps tendon.

Arthroscopy↗

PubMed1999

Laparoscopic ultrasound imaging of adrenal tumors during laparoscopic adrenalectomy.

BACKGROUND: The purpose of this study was to determine the usefulness of laparoscopic ultrasound (LUS) during laparoscopic adrenalectomy (LA) and to define the ultrasound imaging characteristics of various adrenal tumors. METHODS: LUS was utilized in 27 patients who underwent LA (including one bilateral adrenalectomy) from May 1994 to October 1998. Tumor size ranged from 1.0 to 5.5 cm (mean 3.3 cm), and a transabdominal lateral approach to LA was used. RESULTS: LUS localized the adrenal gland and tumor in all 28 adrenalectomies and demonstrated the relationship of the tumor to the kidney and adjacent vascular structures (renal artery/vein and inferior vena cava). The adrenal vein was visualized sonographically in only six cases (21 %). Pheochromocytomas were mild to markedly heterogenous, whereas most aldosteronomas and cortical adenomas were homogenous. LUS provided useful information to the surgeon in 11 of 28 cases (39%) by: 1) localizing the adrenal gland and tumor and/or guiding the dissection; 2) demonstrating that tumors > or =4 cm were confined to the adrenal gland; and 3) investigating suspected pathology in other organs. Mean operating time for LUS was 10.9 min (range 5 to 24 min) and calculated hospital charges were $602. CONCLUSIONS: LUS accurately localizes adrenal tumors, helps define their relationship to adjacent structures, and provides confirmation that larger tumors are amenable to laparoscopic resection. LUS is a useful adjunct to laparoscopic adrenalectomy in selected patients.

Adrenal Cortex Neoplasms↗

PubMed1999

Shoulder sonography. State of the art.

Since the mid 1980s, sonography has been used to evaluate the rotator cuff. It is inexpensive, well tolerated, rapidly performed, and accurate. With the recent improvements in imaging equipment and refinements in scanning technique, an increasing number of radiologists are performing shoulder sonography. This article emphasizes the pertinent musculoskeletal anatomy, sonographic technique, normal sonographic anatomy, pathophysiology of rotator cuff and biceps tendon disease, sonographic findings of rotator cuff tears, and biceps tendon pathology. The accuracy of ultrasound in diagnosing rotator cuff tears and miscellaneous abnormalities that can be detected with ultrasound also are discussed.

Humans↗

PubMed1999

Hemodynamics revealed by Doppler sonography in patients who have undergone creation of transjugular intrahepatic portosystemic shunts: comparison of 10- and 12-mm metallic stents.

OBJECTIVE: The purpose of this study was to determine whether differences exist in baseline flow velocities in the main portal vein and the stent after the creation of transjugular intrahepatic portosystemic shunts with 10- and 12-mm Wallstents. SUBJECTS AND METHODS: We used Doppler sonography to determine baseline flow velocities in the stent and the main portal vein in 80 patients (38 patients with 10-mm Wallstents dilated to 10 mm and 42 patients with 12-mm Wallstents dilated to 12 mm) who had undergone creation of trans jugular intrahepatic portosystemic shunts without complications. RESULTS: We found no significant difference in the maximum flow velocity in the stent between the patients with 10-mm stents (160.3+/-34.3 cm/sec) and those with 12-mm stents (164.4+/-33.8 cm/sec). We also found no significant difference in the minimum flow velocity in the stent between the 10-mm group (132.4+/-28.9 cm/sec) and the 12-mm group (126.7+/-28.3 cm/sec). However, flow velocity through the main portal vein was significantly higher in the patients with 12-mm stents (53.6+/-18.4 cm/sec) than in those with 10-mm stents (45.1+/-13.8 cm/sec) (p < .03). CONCLUSION: After creation of transjugular intrahepatic portosystemic shunts, baseline flow velocities in the main portal vein in patients with 12-mm stents exceeded those in patients with 10-mm stents, although neither maximum nor minimum flow velocities in the stent differed between these two groups of patients. These findings suggest that criteria for shunt malfunction that use flow velocity in the main portal vein may need modification when 12-mm stents are being evaluated.

Blood Flow Velocity↗

PubMed1999

Extended field of view sonography in musculoskeletal imaging.

The usage patterns and benefits of extended field of view sonography were analyzed prospectively in 100 consecutive musculoskeletal ultrasonographic examinations. Extended field of view sonography was used in 23 of 58 abnormal cases (10 of 41 shoulders, five of eight other joints, seven of seven extra-articular extremities, one of two interventional procedures) and two of 42 normal cases. Of 23 abnormal cases using extended field of view sonography (12 of 46 tendon tears and 11 of 12 fluid collections or masses), this modality helped in measuring abnormalities in 13, displaying abnormalities in 19, showing spatial relationships in 17, communicating findings in 13, and making diagnoses in 0. Extended field of view is a useful technique for musculoskeletal ultrasonography. The primary benefits are measuring and displaying abnormalities (most often fluid collections or masses and extra-articular extremity abnormalities).

Adolescent↗

PubMed1999

Management of diagnostic dilemmas of the pancreas by ultrasonographically guided laparoscopic biopsy.

INTRODUCTION: Pancreatic lesions may be difficult to diagnose because of small size or inaccessibility. Such lesions are being seen with increasing frequency because of advances in pancreatic imaging techniques. In the past 18 months we have evaluated 14 patients whose pancreatic lesions could not be diagnosed by traditional means, including percutaneous biopsy. METHODS: With the patient under general anesthesia, the anterior surface of the pancreas was exposed by a three-trocar laparoscopic technique. The lesion was located by laparoscopic ultrasonography. A core biopsy needle was inserted into the lesion under simultaneous visual and ultrasonographic guidance using picture-in-picture techniques. RESULTS: The main diagnostic dilemma encountered was the differentiation of pancreatic cancer from pancreatitis. Other conditions were lymphoma and renal cell carcinoma. Excellent tissue samples were obtained, allowing diagnosis and planning of treatment in all cases. Operative time ranged from 1 to 4 hours, and length of stay ranged from 1 to 3 days. Blood transfusions were not required, and there were no complications. Alcohol nerve block was performed laparoscopically in one patient in this group after the diagnosis was made by frozen section. CONCLUSIONS: Direct ultrasonographically guided laparoscopic biopsy provides rapid, safe diagnosis of pancreatic lesions.

Adult↗

PubMed1998

Sonography of the female urethra.

OBJECTIVE: The purpose of this study was to explore the role of sonography for women with urethral symptoms and a suspected urethral diverticulum. SUBJECTS AND METHODS: Nineteen women with urethral symptoms underwent voiding cystourethrography (VCUG) and transvaginal, transperineal, and urethral sonography (using a catheter-based transducer). VCUGs and sonograms were evaluated for diverticula, defined on sonography by direct visualization of the neck connecting the periurethral sac with the urethral lumen. The diverticular neck, size, location, and shape were noted. Lesions revealed by sonography as not connected to the urethra were also noted. RESULTS: Of 19 women, 14 had urethral diverticula and one had two diverticula, for a total of 15 diverticula. On sonography the diverticula ranged in diameter from 2 mm to 5 cm. Both sonography and VCUG showed 13 of the 15 diverticula. In addition, sonography revealed two infected periurethral cysts, a periurethral leiomyoma, a diffuse urethritis, and scarring or deformity of one patient's urethra from a prior diverticulectomy. On sonography, eight of the 13 diverticula wrapped around more than 50% of the urethral circumference. The neck was precisely seen (by definition) in 13 of 15 diverticula on sonography and in two of 13 diverticula on VCUG. CONCLUSION: Sonography is useful in this group of women with urethral symptoms and suspected urethral diverticula. It provides information on the extent and location of the diverticular neck, both of which are important in surgical excision. Also, sonography provides information on lesions not connected to the urethra. Sonography may prove useful in a broader group of women with urethral symptomatology.

Adult↗

PubMed1997

Small (1.5 cm or less) liver metastases: US-guided biopsy.

PURPOSE: To determine the techniques used for and the success of ultrasound (US)-guided biopsy of hepatic metastases 1.5 cm in diameter or smaller. MATERIALS AND METHODS: A computer search of radiology reports identified 29 patients who underwent US-guided biopsy of 30 hepatic masses 1.5 cm in diameter or smaller suspected to be metastases. All 30 lesions were sampled for biopsy with the free-hand technique. Parameters assessed were lesion size and location, needle size, transducer type, number of passes made, cytologic or histologic analysis, and final histologic diagnosis. Biopsies were considered successful if a positive histologic diagnosis of metastasis was made. RESULTS: The mean lesion diameter was 1.3 cm (range, 0.9-1.5 cm). Lesion depth was 3-9 cm (mean, 5 cm). Twenty biopsies were performed with a 22-gauge aspirating needle and analyzed cytologically. An average of 2.7 passes were made per lesion. Phased-array sector transducers were used in 23 lesions. In 28 (93%) lesions and 28 (96%) patients, an adequate specimen was obtained to establish the histologic diagnosis of metastatic disease. CONCLUSION: US appears to be an effective guidance technique for biopsy of small liver metastases.

Biopsy, Needle↗

PubMed1997

Doppler sonography findings associated with transjugular intrahepatic portosystemic shunt malfunction.

OBJECTIVE: Our purpose was to determine the overall accuracy of Doppler sonography and the accuracy of specific Doppler parameters associated with a compromised transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: For 43 patients who had undergone TIPS, 64 correlated sonogram-venogram paired examinations were analyzed. Sonographic parameters assessed included absolute velocities plus absolute and percentage changes in velocities measured in the main portal vein (MPV) and in several intrashunt locations (including peak and minimum velocity). Direction of flow and change in direction of flow in the left and right portal veins were also examined. TIPS malfunction was defined as any shunt with greater than or equal to 50% stenosis or any stenosis with a portosystemic gradient greater than 15 mm Hg. RESULTS: The prospective interpretation of the sonograms using all available parameters resulted in a sensitivity of 92% and a specificity of 72% for detecting TIPS malfunction. Peak shunt velocity (absolute velocity and velocity change), distal shunt velocity, MPV velocity (absolute velocity and percentage change in velocity), change in minimum shunt velocity, and direction of flow in branch portal veins were found to have statistically significant differences between normal and abnormal shunts. Sensitivities for these individual parameters ranged from 64% to 84%, and specificities ranged from 70% to 100%. When either the MPV velocity or the distal shunt velocity was abnormal, the sensitivity was 94%. When both parameters were abnormal, the specificity for detecting TIPS malfunction was 100%. CONCLUSION: Doppler sonography is a sensitive and relatively specific means of revealing TIPS malfunction. Accuracy depends on analysis of multiple sonographic parameters.

Blood Flow Velocity↗

PubMed1997

Preoperative assessment of ureteropelvic junction obstruction with endoluminal sonography and helical CT.

OBJECTIVE: Our objective was to compare the value of endoluminal sonography with the value of helical CT in the preoperative assessment of crossing vessels in patients with ureteropelvic junction (UPJ) obstruction. SUBJECTS AND METHODS: Thirteen patients with UPJ obstruction underwent contrast-enhanced helical CT with multiplanar reformations and endoluminal sonography. Imaging preceded surgery for UPJ repair. On imaging, vessels were considered significant if greater than or equal to 2 mm in diameter and within 1 cm of the UPJ. RESULTS: Three patients had no crossing vessels revealed by either study. On sonography, another patient had a vessel revealed with a diameter that varied between 1.3 and 2.2 mm; on CT no correlate was detected. The remaining nine patients had vessels revealed by both techniques. On CT, four patients had two vessels revealed and five patients had single vessels revealed for a total of 13 vessels revealed by CT. On sonography, five patients had two vessels revealed and five patients had single vessels revealed. Thus, 15 vessels were revealed by sonography. Both arteries and veins were revealed anterior, posterior, and medial to the UPJ; no lateral vessels were seen. Four patients underwent laparoscopy, during which the absence, presence, and location of vessels were found to correlate with sonography and helical CT. CONCLUSION: Endoluminal sonography and helical CT were similar in revealing crossing vessels in patients with UPJ obstruction.

Adolescent↗

PubMed1997

Sonographic prediction of viability in testicular torsion: preliminary observations.

This study was performed to determine if sonography can assist in predicting testicular viability in the setting of testicular torsion. Sixteen patients with sonographically diagnosed and surgically proved testicular torsion were studied. The preoperative sonograms were reviewed retrospectively to determine testicular echogenicity and homogeneity, testicular size and vascularity, scrotal skin thickness and vascularity, and the presence or absence of a hydrocele. These findings were correlated with the viability of the testis at surgery. All nine patients with normal homogeneous testicular echogenicity had viable testes at surgery. All seven patients with hypoechoic or inhomogeneous testes had nonviable testes at surgery and pathologic evidence of necrosis. The other findings were less helpful in predicting viability. In the setting of testicular torsion, normal testicular echogenicity is a strong predictor of viability. Immediate surgical detorsion in these patients carries a very high likelihood of salvaging the affected testis.

Adolescent↗

PubMed1997

Doppler sonographic evaluation of the portal vein: effects of intravenous dodecafluoropentane.

The aim of this study was to determine if the intravascular contrast agent dodecafluoropentane (Phase III Clinical Trial) produces enhancement and facilitates visualization of portal vein and collateral blood flow. Twenty patients with advanced liver disease or an orthotopic liver transplant underwent gray scale, duplex, and color Doppler sonography. Sonograms were obtained prior to and after the randomized administration of a placebo and dodecafluoropentane in a double-blind fashion. Blinded readers independently reviewed all videotapes. Separate comparisons were made between the baseline study and placebo or dodecafluoropentane study for portal vein enhancement, increase in portal vein length or branching, and patency of the portal vein and collaterals. Flow enhancement was seen with dodecafluoropentane in 17 of 20 (85%) cases and with saline solution in zero cases. Improved visualization of the portal vein or collateral length or branching was observed with dodecafluoropentane in 11 of 20 (55%) cases and with saline solution in zero cases. Portal vein or collateral flow was not detected in six baseline studies. In two of six (33%) cases, flow was detected with dodecafluoropentane. Our results show that dodecafluoropentane is capable of enhancing portal vein and collateral flow, can improve visualization of portal vein length and its branches, and may be useful in cases in which portal vein flow cannot be demonstrated by noncontrast sonography.

Adult↗