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E M Remer

Publications and source records attributed to E M Remer.

15 recordsLinked to original sources
PubMed2000

Laparoscopic renal cryoablation in 32 patients.

OBJECTIVES: Laparoscopic renal cryoablation is a developmental minimally invasive nephron-sparing treatment alternative for highly select patients with small renal tumors. We present our evolving experience with this procedure. METHODS: Thirty-two patients (34 tumors) with a mean tumor size of 2.3 cm on preoperative computed tomography underwent laparoscopic renal cryoablation. As dictated by the tumor location, cryoablation was performed by either the retroperitoneal (n = 22) or the transperitoneal (n = 10) laparoscopic approach using real-time ultrasound monitoring. A double freeze-thaw cycle was routinely performed. RESULTS: The mean surgical time was 2.9 hours, cryoablation time 15.1 minutes, and blood loss 66.8 mL. For a mean intraoperative ultrasonographic tumor size of 2 cm, the mean cryolesion size was 3.2 cm. The hospital stay was less than 23 hours in 22 (69%) of 32 patients. Sequential magnetic resonance imaging scans demonstrated a gradual contraction in the mean diameter of the cryolesions. Of the 20 patients who underwent a 1-year follow-up magnetic resonance imaging scan, the cryoablated tumor was no longer visible in 5. Of note, 23 patients have now undergone a 3 to 6-month follow-up computed tomography-directed biopsy of the cryoablated tumor site; the biopsy was negative for cancer in all 23 patients. No evidence of local or port-site recurrence was found during a mean follow-up of 16.2 months. CONCLUSIONS: Critical long-term data regarding laparoscopic renal cryoablation, a developmental technique, are awaited. However, our initial experience is cautiously optimistic. Despite its significant potential for false-negative results, it is encouraging that the follow-up computed tomography-directed needle biopsies at 3 to 6 months were negative for cancer in 23 of 23 patients.

Adenoma, Oxyphilic↗
PubMed2000

MR imaging of the kidneys after laparoscopic cryoablation.

OBJECTIVE: We describe the MR imaging findings of patients who underwent laparoscopic renal lesion cryoablation. MATERIALS AND METHODS: Twenty-one patients (men, 11; women, 10; age range, 36-84 years; average age, 65.5 years; SD, 11.9) with 23 small renal masses (< or =4 cm) underwent laparoscopic renal lesion cryoablation. Twenty patients (22 masses) underwent follow-up MR imaging on the first day after surgery, 12 (13 masses) at 1 month, 16 (18 masses) at 3 months, 14 (15 masses) at 6 months, and 12 (12 masses) at 12 months. Three radiologists retrospectively reviewed MR images for the signal intensity, characteristics, and size of cryolesions. CT-guided needle biopsy was performed 6 months after cryoablation (18 patients) and no evidence of malignancy was discovered. RESULTS: Including all lesions at all times on T1-weighted images, cryolesion signal intensity was isointense to renal parenchyma (47/76, 61.8%) or isointense with hyper- or hypointense foci (7/76, 9.2%). On T2-weighted images, almost all lesions (72/76, 94.7%) were isointense or hypointense, and there was a hypointense rim between the cryolesion and renal parenchyma in 38.2% of lesions (29/76). A thin peripheral rim of enhancement was noted in 19.7% (14/74) of lesions. Cryolesions decreased in size an average of 61.5% (SD, 22.82; n = 12) at 1 month, 78.7% (SD, 13.5; n = 17) at 3 months, 83.5% (SD, 24.3; n = 15) at 6 months, and 94.2% (SD, 8.1; n = 11) at 1 year after cryoablation (one patient was not scanned 1 day after cryoablation and was not included in our calculations). CONCLUSION: After renal cryoablation, MR imaging revealed common signal characteristics such as low-signal-intensity rims on T2-weighted images, enhancement patterns such as thin peripheral rims, and interval size changes.

Adenoma, Oxyphilic↗
PubMed2000

Adrenal mass evaluation in patients with lung carcinoma: a cost-effectiveness analysis.

OBJECTIVE: This study evaluates the cost-effectiveness of various imaging and biopsy strategies for characterizing adrenal masses in patients with newly diagnosed non-small cell carcinoma of the lung. MATERIALS AND METHODS: A decision-analysis model was used to compare the cost-effectiveness of nine strategies. Initial imaging included unenhanced CT using an adenoma or nonadenoma threshold of 0 or 10 H or in- and opposed-phase MR imaging. When initial imaging did not confirm an adenoma, CT-guided biopsy or subsequent imaging was performed. Medicare reimbursement was used as a surrogate of cost. Net costs were calculated as the difference in costs between two limbs of the decision tree. Net benefits were calculated as the difference between strategies and were calculated for life expectancy in years. MR imaging, CT, and biopsy accuracy, average life expectancy, and surgical mortality rates were based on the literature. RESULTS: The base case analysis determined that the most cost-effective strategy was CT with an adenoma or nonadenoma threshold of 10 H followed by MR imaging, if necessary. CT with a threshold of 0 H followed by biopsy, if necessary, was the least costly. The incremental cost-effectiveness ratio between these two strategies was $16,370 per year of life gained. CONCLUSION: Unenhanced CT using a 10 H threshold followed by MR imaging, if needed, was the most cost-effective strategy for evaluating an adrenal mass in a patient with newly diagnosed non-small cell lung cancer.

Adrenal Gland Neoplasms↗
PubMed2000

Feasibility of instructing radiology technologists in the performance of gastrointestinal fluoroscopy.

OBJECTIVE: We sought to determine if dedicated gastrointestinal technologists could be trained to properly perform esophagography and double-contrast barium enema examinations. SUBJECTS AND METHODS: Ninety-four patients undergoing double-contrast barium enema examinations and 123 patients undergoing esophagographic examinations were included in the study. The study was conducted over a 4-month period, with examinations performed by eight gastrointestinal technologists, 10 radiology residents, and four staff radiologists. Four random lists were generated for each set of examinations. Each staff gastrointestinal radiologist, who was unaware of who had performed the examination, independently scored the representative radiographs. RESULTS: For the double-contrast barium enema examinations, no statistically significant differences were found between the technologists and residents for amount of barium used, degree of distention, cecal opacification, and quality of spot radiographs. The technologist-performed examinations had a statistically significant lower mean fluoroscopy time (3.2 min, compared with 4.0 min for staff radiologists and 5.7 min for residents). For the esophagrams, no statistically significant differences between technologists and residents were found for single-contrast esophagrams; radiographs of the gastric cardia; assessment of motility, reflux, and transit of a solid bolus; and fluoroscopy time. Double-contrast esophagrams obtained by technologists received a better mean score than did those of the residents. CONCLUSION: Radiology technologists can be trained to perform high-quality esophagography and double-contrast barium enema examinations without an unacceptably high radiation dose.

Adult↗
PubMed1999

MR characteristics of oxidized cellulose (Surgicel).

OBJECTIVE: Oxidized regenerated cellulose (Surgicel) is one of the most commonly used bioabsorbable topical hemostatic agents. Surgicel may mimic an abscess on both CT and sonography when a patient undergoes imaging early in the postoperative period. The objective of our study was to describe the appearance of Surgicel on postoperative MR imaging. CONCLUSION: Surgicel has a short relaxation time on T2-weighted images, resulting in low signal intensity in the early postoperative period. MR imaging may be helpful in differentiating Surgicel from an abscess and therefore in preventing unnecessary attempts at aspiration.

Abscess↗
PubMed1998

Laparoscopic renal cryoablation: initial clinical series.

OBJECTIVES: To present the technique and short-term results of retroperitoneal laparoscopic renal cryoablation. METHODS: Ten patients underwent laparoscopic renal cryoablation of 11 exophytic renal tumors ranging in size from 1.5 to 3 cm identified on computed tomography. Tumors were located at the upper (3), middle (5), or lower (3) pole of the kidney. Three patients had a solitary kidney. A 3-port retroperitoneal laparoscopic approach was used to create renal cryolesions. Puncture cryoablation was performed with a 4.8-mm cryoprobe. Real-time, endoscopic, steerable, color Doppler ultrasound was used to monitor the evolving cryolesion. All patients have completed a minimum follow-up of 3 months (mean 5.5, range 3 to 9). RESULTS: Cryoablation was technically successful in all 10 patients (11 tumors). Under ultrasound guidance, the ice ball was intentionally created up to 1 cm beyond the tumor edge with the aim of achieving negative margins. Mean surgical time was 2.4 hours, cryoablation (double freeze-thaw) time 12.9 minutes, cryoprobe tip temperature -186 degrees C, and blood loss 75 mL. Systemic temperature remained unaltered. Hospital stay was less than 23 hours in 9 of 10 patients. Follow-up magnetic resonance imaging at 1 day and 1, 2, and 3 months identified the punched-out, nonenhancing, spontaneously resorbing, renal cryolesion. Follow-up biopsies of the cryoablated tumor site were negative for cancer in the 3 patients who have undergone the biopsy. CONCLUSIONS: The initial series of laparoscopic renal cryoablation is presented. The retroperitoneoscopic approach, by avoiding the peritoneal cavity, minimizes the chances of the bowel coming in contact with the evolving cryolesion, and the potential sequelae thereof. Laparoscopic renal cryoablation is currently developmental and long-term data are awaited. Nevertheless, it is potentially an attractive addition to available nephron-sparing surgical techniques.

Aged↗
PubMed1998

Hepatocellular carcinoma in North America: a multiinstitutional study of appearance on T1-weighted, T2-weighted, and serial gadolinium-enhanced gradient-echo images.

OBJECTIVE: The purpose of this study was to define the common appearances of hepatocellular carcinoma (HCC) in patients in North America by analyzing T1-weighted, T2-weighted, and serial gadolinium-enhanced gradient-echo images interpreted by radiologists at multiple institutions in North America. MATERIALS AND METHODS: One hundred thirteen consecutive patients with HCC from eight institutions were included in this retrospective case series. Inclusion criteria included MR imaging examinations performed on 1.5-T MR imagers using T1-weighted breath-hold spoiled gradient-echo images, T2-weighted images, and serial gadolinium-enhanced spoiled gradient-echo images. Diagnosis was established by histology in all patients. Images were analyzed retrospectively for lesion count, lesion diameter as less than or equal to 1.5 cm and greater than 1.5 cm, and signal intensity, by individual experienced radiologists at each institution. RESULTS: We found 354 HCC lesions in the 113 patients. Tumors were solitary in 63 patients, multifocal in 45 patients, and diffuse in five patients. Lesion appearance on combined T1-weighted, T2-weighted, and immediate gadolinium-enhanced spoiled gradient-echo images was as follows: 102 lesions (29%) were hypointense on T1-weighted images, were hyperintense on T2-weighted images, and exhibited diffuse heterogeneous enhancement; 52 lesions (15%) were isointense on both T1- and T2-weighted images and exhibited diffuse homogeneous enhancement (all of these lesions measured < or = 1.5 cm in diameter); 50 lesions (14%) were hypointense on T1-weighted images, were hyperintense on T2-weighted images, and exhibited diffuse homogeneous enhancement; 33 lesions (9%) were hypointense on T1-weighted images, were hyperintense on T2-weighted images, and exhibited predominantly peripheral rim enhancement; and 27 lesions (8%) were hypointense on T1-weighted images, were isointense on T2-weighted images, and exhibited diffuse homogeneous enhancement. The remaining 90 lesions showed less common patterns. The appearance of HCCs greater than 1.5 cm and of HCCs less than or equal to 1.5 cm was significantly different (p = .001). The appearance of histologically proven HCCs is separately described. CONCLUSION: The combination of hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and diffuse heterogeneous enhancement was the most common appearance of HCC on MR images in a multiinstitutional patient population in North America. Small HCCs measuring less than or equal to 1.5 cm were frequently isointense on both T1-weighted and T2-weighted images and may be detected on immediate gadolinium-enhanced images only as diffuse homogeneously enhancing lesions.

Adolescent↗
PubMed1997

Spiral noncontrast CT versus combined plain radiography and renal US after extracorporeal shock wave lithotripsy: cost-identification analysis.

PURPOSE: To investigate the costs of spiral computed tomography (CT) versus those of combined plain radiography and renal ultrasound (US) in screening for postprocedural complications after extracorporeal shock wave lithotripsy (ESWL). MATERIALS AND METHODS: Twenty-five adult patients who had undergone ESWL were prospectively examined with spiral CT, renal US, and plain abdominal radiography. Each examination was timed, and direct technical costs were calculated by using a procedural-based cost-accounting system. The combined cost of US and plain radiography was compared with the cost of spiral CT. RESULTS: The average time for spiral CT was 15.3 minutes compared with 37.2 minutes for combined US and plain radiography. The direct technical cost of spiral CT was $36.86 compared with $57.60 for combined US and plain radiography. Average examination times were varied to assess the effect on overall costs. Within reasonable time ranges, combined US and plain radiography cannot be cost equivalent to spiral CT. CONCLUSION: Spiral CT is faster and is associated with less direct technical cost than combined US and plain radiography when used to examine patients after ESWL, given the dependence of this model on time of examination. Further studies are needed to assess the relative accuracy of these alternative approaches.

Adult↗
PubMed1993

MR evaluation of the anterior cruciate ligament: value of supplementing sagittal images with coronal and axial images.

OBJECTIVE: Most studies evaluating the anterior cruciate ligament have focused on sagittal MR images for the diagnosis of injury. Limitations of sagittal images have been reported, however, including nonvisualization and incomplete visualization of the ligament. This study was undertaken to assess the value of adding coronal and axial MR images to sagittal images in the evaluation of the anterior cruciate ligament. MATERIALS AND METHODS: We reviewed oblique sagittal T1-weighted, coronal T2-weighted, and axial T2-weighted images to determine the status of the anterior cruciate ligament in 325 patients. All patients had arthroscopy. Sagittal images were initially interpreted alone and then in combination with coronal and axial images. RESULTS: Sagittal T1-weighted images alone had a 94% sensitivity and an 84% specificity for determining the status of the anterior cruciate ligament. A multiplanar evaluation of the anterior cruciate ligament resulted in a change in MR interpretation in 21 patients (6%), which led to an improved sensitivity of 98% and a specificity of 93%. Diagnostic confidence was improved in an additional 14 patients (4%). CONCLUSION: Our results show that the efficacy of MR imaging for the detection of anterior cruciate ligament tears is greater when axial and coronal images are used in combination with sagittal images than when sagittal images are used alone.

Adult↗
PubMed1992

Anterior cruciate ligament injury: MR imaging diagnosis and patterns of injury.

The anterior cruciate ligament (ACL) is an important stabilizer of knee motion. Injury of the ACL can lead to substantial disability; an accurate diagnosis of ACL injury is vital in both short-term and long-term patient care. Magnetic resonance (MR) imaging has emerged as the study of choice to evaluate the status of the ACL and other associated structures in the knee. Sagittal MR images have been commonly used in the evaluation of the ACL. However, the authors believe that coronal and axial imaging planes can add useful information about ACL injury and, thus, lead to improved accuracy and confidence regarding diagnosis. Multiplanar imaging can readily demonstrate meniscal, ligamentous, and bone marrow injuries that commonly occur with the most frequent mechanisms of ACL injury. These mechanisms, in order of frequency, include internal rotation and valgus stress, hyperextension, and varus stress with external rotation. An understanding of these mechanisms is helpful in the MR diagnosis of ACL injury.

Anterior Cruciate Ligament Injuries↗
PubMed1992

Congenital and acquired orthopedic abnormalities in patients with myelomeningocele.

This article presents a radiologic review of the spectrum of acquired and congenital orthopedic abnormalities found in patients with myelomeningocele. These abnormalities are caused predominantly by muscle imbalance, paralysis, and decreased sensation in the lower extremity. Iatrogenic injury, such as a postoperative tethered cord, may also cause bone abnormalities. Selected images were obtained from more than 800 children. Important entities presented include spinal curvatures such as kyphosis, scoliosis, and lordosis; subluxation and dislocation of the hip, coxa valga, contractures of the hip, and femoral torsion; knee deformities; rotational abnormalities of the lower extremity and external and internal torsion; ankle and foot abnormalities such as ankle valgus, calcaneus foot, congenital vertical talus (rocker-bottom deformity), and talipes equinovarus; and metaphyseal, diaphyseal, and physeal fractures. Familiarity with congenital abnormalities and an understanding of the pathogenesis of acquired disorders in patients with myelomeningocele are essential for proper radiologic interpretation and timely therapy.

Child↗
PubMed1989

Hyperfunctioning and nonhyperfunctioning benign adrenal cortical lesions: characterization and comparison with MR imaging.

The authors evaluated the potential of magnetic resonance (MR) imaging at 0.35 T to permit differentiation of nine hyperfunctioning adrenal cortical lesions from 21 nonhyperfunctioning adrenal cortical adenomas. Both qualitative data (visual assessment) and quantitative data (signal intensity ratios, T1, and T2) were used for tissue characterization. With a 2,000/56-100 sequence (repetition time msec/echo time msec), the majority of lesions were visually isointense to liver. Of 34 quantitative measures, only lesion-liver and lesion-kidney intensity ratios at 2,000/150 showed statistically significant differences among nonhyperfunctioning adenomas, aldosterone-producing lesions, and corticosteroid-producing lesions; however, the authors question the significance of these differences because of the abundant noise associated with the 2,000/150 sequence. The results suggest that nonhyperfunctioning adrenal cortical adenomas cannot be distinguished from benign hyperfunctioning cortical lesions with use of MR imaging at 0.35 T.

Adenoma↗