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Eric vanSonnenberg

Publications and source records attributed to Eric vanSonnenberg.

At least 19 recordsLinked to original sources
PubMed2006

Augmented reality visualization for CT-guided interventions: system description, feasibility, and initial evaluation in an abdominal phantom.

UNLABELLED: The purpose of this study was to evaluate the feasibility and performance of an augmented reality (AR) visualization prototype for virtual computed tomography (CT)-guided interventional procedures in a multimodality abdominal phantom. With the aid of AR guidance, three radiologists performed 30 attempts at targeting simulated liver lesions of different sizes (range, 5-15 mm) with a biopsy needle. The position of the needle tip relative to the lesion was verified by using ultrasonography and CT. With AR guidance, lesions were successfully targeted with the first needle pass in all cases. On the basis of these results, AR visualization for CT-guided intervention appears feasible and allows intuitive and accurate lesion targeting in a phantom. SUPPLEMENTAL MATERIAL: radiology.rsnajnls.org/cgi/content/full/2401040018/DC1

Abdomen↗
PubMed2005

Gastrointestinal stromal tumor: new nodule-within-a-mass pattern of recurrence after partial response to imatinib mesylate.

PURPOSE: To investigate a new pattern of tumor recurrence observed at imaging in patients with metastatic gastrointestinal stromal tumor (GIST) after initial partial response to imatinib mesylate. MATERIALS AND METHODS: Ninety-two patients with metastatic GIST who underwent treatment in a clinical trial with oral imatinib mesylate were followed up for 29 months. An institutional review board-approved protocol was used. The study complied with the Health Insurance Portability and Accountability Act, and written informed consent was obtained from all patients. Images of the chest, abdomen, and pelvis, acquired with computed tomography (CT), positron emission tomography (PET), and, in some cases, magnetic resonance imaging, were evaluated for treatment response and disease recurrence. Thirty-nine patients (29 men, 10 women; age range, 18-84 years; mean, 49.2 years) had recurrent disease after an initial variable period of response (range, 2-24 months; median, 14.4 months). Initial response was determined with findings of decreased uptake of fluorine 18 fluorodeoxyglucose at PET, shrinkage of tumor, and decreased attenuation at CT. Images were evaluated for disease recurrence by two experienced radiologists who were blinded to each other's interpretation but not to clinical details. Final reading was performed by consensus. RESULTS: A nodule within a mass was seen in 21 of 39 patients (in intrahepatic tumor [n = 8], extrahepatic tumor [n = 10], or both intra- and extrahepatic tumors [n = 3]) and was the first sign of disease progression in 17 of 21 patients. Other patterns of recurrence included new site of disease (n = 7), regrowth of preexistent lesion (n = 20), and mixed (more than one) pattern (n = 9). Disease progression was verified at needle biopsy (n = 16), follow-up imaging (n = 14), and/or surgical resection (n = 9). CONCLUSION: A nodule within a mass is an important sign of recurrent GIST, but measurements of overall tumor size may not enable detection of such nodules.

Adolescent↗
PubMed2005

Practice patterns of nonvascular interventional radiology procedures at academic centers in the United States?

RATIONALE AND OBJECTIVES: To determine and analyze the patterns of practice of nonvascular interventional procedures in academic centers in the United States. MATERIALS AND METHODS: A survey was administered via e-mail to the chief residents of 112 academic radiology departments in the United States. Recipients of the survey were asked to identify which sections within their respective radiology departments performed each of 43 types of nonvascular interventional procedures. An additional entry for performance of procedures by non-radiologists was provided. A total of 66 (59%) recipients responded. The statistical method used was the analysis of contingency tables. RESULTS: Percutaneous abdominal biopsies are performed mainly by abdominal and body imaging sections (43/66, 65%), followed by vascular/interventional sections (21/66, 32%). Percutaneous abdominal drainages are performed mostly by abdominal, body imaging, and computed tomography sections (40/66, 61%), followed by vascular/interventional sections. Fluoroscopically guided procedures were performed most commonly by vascular/interventional sections, including percutaneous gastrostomy (40/66, 61%), percutaneous nephrostomy (42/66, 64%), and biliary interventions such as percutaneous transhepatic cholangiography (47/66, 71%). Breast and musculoskeletal procedures are performed by their respective sections most frequently. Non-radiologists perform a significant portion of certain types of procedures: paracenteses, thoracenteses, biliary interventions (particularly stone extractions), enterostomies (particularly percutaneous jejunostomies and cecostomies), and certain biopsies (kidney and prostate). CONCLUSIONS: Academic US radiology sections perform nonvascular interventional radiology procedures in a complex and nonuniform manner. The vascular/interventional sections and organ system and modality (especially CT) sections perform the bulk of the procedures included in the survey. Breast imaging sections predominate in procedures in their disciplines. A substantial number and amount of interventional radiology procedures are performed by non-radiologists.

Academic Medical Centers↗
PubMed2005

Renal tumors: MR imaging-guided percutaneous cryotherapy--initial experience in 23 patients.

PURPOSE: To evaluate the initial clinical experience of magnetic resonance (MR) imaging-guided percutaneous cryotherapy of renal tumors. MATERIALS AND METHODS: Twenty-six renal tumors (diameter range, 1.0-4.6 cm; mean, 2.6 cm) in 23 patients were treated with 27 cryoablation procedures by using a protocol approved by the human subjects committee at the authors' institution. The study complied with the Health Insurance Portability and Accountability Act. Written informed consent was obtained from each patient. There were 17 men and six women with an average age of 66 years (range, 43-86 years). Of 26 masses, 24 were renal cell carcinoma, one was a transitional cell carcinoma, and one was an angiomyolipoma. By using a 0.5-T open MR imaging system and general anesthesia in patients, one to five (mean, 2.4) needlelike cryoprobes were placed and lesions were ablated by using real-time MR imaging for intraprocedural monitoring of ice balls. Tumors were considered successfully ablated if they demonstrated no contrast enhancement at follow-up computed tomography or MR imaging (mean, 14 months; range, 4-30 months). RESULTS: Twenty-four of 26 tumors were successfully ablated, 23 of which required only one treatment session. Two complications occurred in a total of 27 cryoablations: one hemorrhage, which required a blood transfusion, and one abscess, which was treated successfully with percutaneous catheter drainage. CONCLUSION: MR imaging-guided percutaneous cryotherapy of renal tumors shows promise for the treatment of selected small renal tumors, and MR imaging can be used to monitor the treatment intraprocedurally. This technique may prove useful for ablation of renal tumors completely in one session, but long-term follow-up is needed.

Adult↗
PubMed2005

Radiofrequency ablation of liver tumors: a new cause of benign portal venous gas.

PURPOSE: To retrospectively describe and categorize the presence of portal venous gas (PVG) from radiofrequency (RF) ablation of hepatic tumors. MATERIALS AND METHODS: The study was HIPAA compliant, and informed consent was waived. Thirty-four consecutive computed tomography (CT)-guided percutaneous RF ablations of liver tumors in 26 patients (13 men, 13 women; mean age, 69 years) with five hepatocellular carcinomas and 21 metastatic liver tumors (13 colon, five other, and three unknown primary tumors) were performed with an institutional review board-approved protocol. Two treatment modalities were used: RF ablation alone (13 procedures) and combined RF ablation and ethanol injection (21 procedures). Presence of PVG was quantified with three parameters: maximum length of a portal venous branch with gas, number of Couinaud segments in which PVG was seen, and total number of portal venous branch points with gas. Then an overall PVG score from 0 to 5 was determined. Also, when tumoral gas was seen on CT scans, the largest cross-sectional area of gas was measured. The two ablation methods were compared for quantities of PVG and tumoral gas. The role of N(2)O anesthetic in PVG and tumoral gas formation during ablation also was studied. Statistical analyses were performed with Wilcoxon rank sum and Student t tests. RESULTS: In 25 procedures (74%), gas was found in portal vein branches; in 30 procedures (88%), gas was also found in tumoral and peritumoral tissues. There was no significant difference in frequency of PVG between the ablation methods. Combined therapy yielded significantly greater lengths of PVG (P < .002) and more portal venous branch points (P < .001) than did RF ablation alone. Mean PVG score was 2.4 +/- 0.4 (standard error of the mean) for combined therapy and 0.9 +/- 0.2 for RF ablation alone (P < .004). N(2)O anesthetic was associated with greater amounts of tumoral gas (P < .008) and PVG (P < .03). Tumoral gas, peritumoral gas, and PVG dissipated within 20 minutes after ablation in all patients. No morbidity or mortality was associated with PVG. CONCLUSION: RF ablation is a common yet benign cause of transient PVG, tumoral gas, and peritumoral gas. Combined RF and ethanol ablation was associated with more PVG than was RF ablation alone.

Aged↗
PubMed2005

Radiofrequency ablation of thoracic lesions: part 1, experiments in the normal porcine thorax.

OBJECTIVE: Radiofrequency ablation has been used extensively in the liver for the localized thermal coagulation of tumors. It has been applied more recently percutaneously in the lung under CT imaging guidance. In advance of our own clinical application, we performed experimental percutaneous radiofrequency ablation in normal lung tissues in a large animal model using a U.S. Food and Drug Administration-approved device to assess its use. MATERIALS AND METHODS: Radiofrequency ablation of 22 thoracic sites was performed in vivo in three pigs with an array-style electrode. Tissue impedance and ablation duration were measured for each site. The intact lungs were excised for gross inspection and for imaging with CT and MRI. Representative lesions were evaluated histologically. RESULTS: The mean intraprocedural tissue impedance was 93 Ohms (range, 52-184 Ohms). Six of 22 ablations exhibited a marked increase in impedance after 5 min of treatment. On gross inspection, parenchymal lesions were generally round and targetlike in appearance. CT showed sites of ablation to be composed of a heterogeneous inner zone surrounded by a high-density outer zone. On MRI, the inner zone was typically hyperintense on T1-weighted fast spin-echo imaging, and the outer zone was hyperintense on T2-weighted fast spin-echo imaging. At histology, the inner zone was characterized by coagulation necrosis, and the outer zone by hyperemia and edema. No acute lung-specific complications were seen. There was one extensive skin burn and one cardiac-related death. CONCLUSION: These results support current seminal clinical evidence that percutaneous radiofrequency ablation in the lung is feasible and can be applied safely. Radiofrequency-induced lesions in the normal porcine lung can be visualized with both CT and MRI; image appearance is concordant with histologic tissue changes.

Animals↗
PubMed2004

Imaging and percutaneous management of acute complicated pancreatitis.

Acute pancreatitis varies from a mild, self-limited disease to one with significant morbidity and mortality in its most severe forms. While clinical criteria abound, imaging has become indispensable to diagnose the extent of the disease and its complications, as well as to guide and monitor therapy. Percutaneous interventional techniques offer options that can be life-saving, surgery-sparing or important adjuncts to operation. Close cooperation and communication between the surgeon, gastroenterologist and interventional radiologist enhance the likelihood of successful patient care.

Abscess↗
PubMed2004

Evaluation of patients referred for percutaneous ablation of renal tumors: importance of a preprocedural diagnosis.

OBJECTIVE: Percutaneous ablation of renal cell carcinoma has the potential to be as effective as partial nephrectomy. Because the entire tumor cannot be examined at pathology, diagnosis relies solely on imaging and percutaneous biopsy. Diagnoses of cancer have been rendered using imaging alone in some clinical trials of percutaneous ablation. If these trials inadvertently included benign masses, the efficacy of ablation was overestimated. Therefore, we sought to determine the prevalence of benign masses in a population of patients referred for percutaneous tumor ablation of presumed renal cell carcinoma. SUBJECTS AND METHODS: Twenty-seven patients were referred by urologists for MRI-guided cryotherapy of suspected renal cell carcinoma. Renal masses ranged from 1.0 to 4.6 cm (mean, 2.2 cm) in diameter. The CT, MRI, and percutaneous biopsy findings were tabulated and compared with surgical and imaging follow-up. RESULTS: Ten patients (37%) had a benign renal mass, including three angiomyolipomas, that had no evidence of fat on CT or MRI. Three masses were proven benign by biopsy, three by imaging, and four by a combination of biopsy and imaging. The masses in the remaining 17 patients were ablated. Biopsy revealed malignant cells in 10, suspicious cells in four, and atypical cells in two; one was nondiagnostic. CONCLUSION: A substantial percentage of patients referred for percutaneous ablation of renal tumors had benign masses. If CT or MRI alone cannot be used to diagnose a benign entity, patients should undergo a biopsy before the treatment session.

Adult↗
PubMed2004

Three-dimensional assessment of MRI-guided percutaneous cryotherapy of liver metastases.

OBJECTIVE: We report our initial investigation of the use of a 3D method for assessing percutaneous tumor ablations. We hypothesized that these 3D techniques could be used to assess the technical success of ablations and that 3D metrics would be predictive of treatment response. CONCLUSION: Three-dimensional assessment of percutaneous tumor ablations provides a quantitative evaluation of the technical success of the procedure. Three-dimensional computer-based techniques can both quantify coverage of a tumor and create a virtual ablation margin for percutaneous procedures, akin to a surgical margin. Although results are preliminary, 3D metrics were useful in predicting treatment response.

Aged↗
PubMed2004

A modified CT severity index for evaluating acute pancreatitis: improved correlation with patient outcome.

OBJECTIVE: This study was conducted to assess the correlation with patient outcome and interobserver variability of a modified CT severity index in the evaluation of patients with acute pancreatitis compared with the currently accepted CT severity index. MATERIALS AND METHODS: Of 266 consecutive patients diagnosed with acute pancreatitis during a 1-year period, 66 underwent contrast-enhanced MDCT within 1 week of the onset of symptoms. Three radiologists who were blinded to patient outcome independently scored the severity of the pancreatitis using both the currently accepted and modified CT severity indexes. The modified index included a simplified assessment of pancreatic inflammation and necrosis as well as an assessment of extrapancreatic complications. Outcome parameters included the length of hospital stay; the need for surgery or percutaneous intervention; and the occurrences of infection, organ failure, and death. For both the current and modified indexes, correlation between the severity of the pancreatitis and patient outcome was estimated using the Wilcoxon's rank sum test and Fisher's exact test. Interobserver agreement for both indexes was calculated using the kappa statistic. RESULTS: When applying the modified index, the severity of pancreatitis and the following parameters correlated more closely than when the currently accepted index was applied: the length of the hospital stay (0-34 days) (modified index [p = 0.0054-0.0714] vs current index [p = 0.0052-0.3008]); the need for surgical or percutaneous procedures (10/66 patients) (modified index [p = 0.0112] vs current index [p = 0.0324]); and the occurrence of infection (21/66 patients) (modified index [p < 1e(-10)] vs current index [p < 1e(-04)]). Significant correlation between the severity of pancreatitis and the development of organ failure (9/66 patients) was seen only using the modified index (p = 0.0024), not the current index (p = 0.0513). The interobserver agreement was similar with the modified (kappa range, 0.71-0.85) and the current (kappa range, 0.63-0.86) indexes. CONCLUSION: The modified CT severity index correlates more closely with patient outcome measures than the currently accepted CT severity index, with similar interobserver variability.

Acute Disease↗
PubMed2004

Combined radiofrequency and alcohol injection for percutaneous hepatic tumor ablation.

OBJECTIVE: We sought to determine if alcohol potentiates radiofrequency energy by obtaining larger ablative volumes in 30 liver tumors in human patients. SUBJECTS AND METHODS: We compared two groups of patients: one group treated with radiofrequency ablation alone (radiofrequency-alone group), and a second group treated with radiofrequency ablation and immediate prior injection of alcohol (combined group). The radiofrequency-alone group comprised 20 ablations (mean diameter, 8.4 cm; colorectal cancer metastases [n = 15]; other metastases [n = 5]). The combined group consisted of 30 radiofrequency ablations (mean diameter, 8.8 cm; metastatic colorectal cancer [n = 17]; other metastases [n = 8]; and hepatocellular carcinoma [n = 5]) treated with alcohol injection immediately before radiofrequency ablation. The amount of alcohol injected was determined by the size and location of tumors. Preprocedural laboratory tests (complete blood cell count with differential, liver function tests, and coagulation parameters) were performed in all patients, along with pre- and postprocedural CT, MRI, and PET. Measurements of tissue necrosis were obtained on the postprocedural CT scans and MR images. Volumes of necrosis calculated in each group were corrected for the number of radiofrequency applications and were statistically compared using the Student's t test. In addition, tissue impedances obtained during the radiofrequency ablation procedure were compared between the two groups. RESULTS: The mean ablation volumes for the radiofrequency-alone group were 32.3 cm(2) (median, 28.6 cm(2); range, 14.4-61.8 cm(2)) and for the combined group, 84.6 cm(2) (median, 78.3 cm(2); range, 34.6-149 cm(2)). The difference in the necrosis volumes was significantly larger (p < 0.0001) in the combined group. Overall, the combined treatment group underwent fewer radiofrequency applications per session. Tissue impedance during radiofrequency ablation was higher in the combined group (mean, 62.7 vs 57.3 Omega in the radiofrequency alone group; p = 0.0005) at comparable times during the ablations. No major complications were seen in either group. CONCLUSION: Percutaneous radiofrequency ablation appears to be potentiated by immediate prior alcohol injection into the tumor. Consistently larger lesions are obtainable in fewer sessions, without any increase of complications, using the combined method.

Aged↗
PubMed2003

Image-guided 25-gauge needle biopsy for thoracic lesions: diagnostic feasibility and safety.

PURPOSE: To report our experience regarding the feasibility and safety of 25-gauge needles for biopsy of thoracic lesions. MATERIALS AND METHODS: Twenty-six patients with thoracic lesions, predominately pulmonary nodules, measuring 0.7-5.2 cm (mean, 1.6 cm) underwent biopsy with computed tomographic (n = 24), ultrasonographic (n = 1), or fluoroscopic (n = 1) guidance. Nineteen patients had severe chronic obstructive pulmonary disease (COPD), one had severe restrictive lung disease, and one had a coagulopathy; the other five patients had nonpulmonary primary tumors. Biopsy with an inner 25-gauge needle traversing an outer extrapleural coaxial cannula was performed in all patients. Cytologic quick staining was performed routinely to determine specimen adequacy and to establish a preliminary diagnosis. Complications, specimen adequacy, and need for larger specimens were evaluated. RESULTS: Adequate specimens (as determined by cytopathologists) were obtained in 24 (92%) of 26 patients, with a definitive diagnosis achieved in 23 (88%) patients during initial quick staining (17 malignant and six benign diagnoses). Two cases initially considered suspicious for malignancy were reclassified as benign (thymoma and histoplasmosis). At the request of cytopathologists, a larger needle was used to supplement the 25-gauge needle in six patients: In one patient, it provided further diagnostic information; in four, it did not; and in one, it confirmed non-Hodgkin lymphoma. Five patients developed a small pneumothorax (<10%) with use of the 25-gauge needle alone; one other patient, in whom larger needles were placed, received a radiologic chest catheter to evacuate the pneumothorax, thereby allowing the biopsy to continue. CONCLUSION: Image-guided 25-gauge needle biopsy is both feasible and safe.

Adult↗
PubMed2003

Percutaneous biopsy of renal masses: sensitivity and negative predictive value stratified by clinical setting and size of masses.

OBJECTIVE: The purpose of our retrospective study was to evaluate the sensitivity and negative predictive value of percutaneous biopsy of renal masses stratified by clinical setting and the size of the mass. MATERIALS AND METHODS: We categorized 115 consecutive percutaneous biopsies of renal masses in 113 patients into four clinical settings and three groups of mass sizes. The sensitivity and negative predictive value were computed (with 95% confidence intervals [CI]) for each clinical setting and for each size group. RESULTS: For all procedures (n = 115), the sensitivity and negative predictive value were 90% (95% CI, 81-95%) and 64% (95% CI, 44-81%), respectively. For patients with a known malignancy who presented with a renal mass (n = 55), the sensitivity and negative predictive value were 90% (95% CI, 78-96%) and 38% (95% CI, 10-74%), respectively. For patients with no known malignancy and suspected unresectable tumor (n = 36), the sensitivity and negative predictive value were 92% (95% CI, 76-98%) and 0%, respectively. For patients with no known malignancy who presented with a cystic mass (n = 16), the sensitivity and negative predictive value were 33% (95% CI, 2-87%) and 87% (95% CI, 58-98%), respectively. For patients who were not surgical candidates with a renal cell carcinoma (n = 8) that was thought to be resectable, both the sensitivity and negative predictive value were 100%. For masses 3 cm and less (n = 31), the sensitivity and negative predictive value were 84% (95% CI, 63-95%) and 60% (95% CI, 27-86%), respectively. For masses between 4 and 6 cm (n = 42), the sensitivity and negative predictive value were 97% (95% CI, 83-100%) and 89% (95% CI, 51-99%), respectively. For masses greater than 6 cm (n = 42), the sensitivity and negative predictive value were 87% (95% CI, 71-95%) and 44% (95% CI, 15-77%), respectively. CONCLUSION: Percutaneous renal mass biopsy has a high sensitivity in three clinical settings: patients with a known malignancy, patients with no known malignancy and suspected unresectable tumor, and nonsurgical patients with a mass suspected to be a resectable renal cell carcinoma. Negative results in small (< or = 3 cm) and large (> 6 cm) masses should be viewed with caution.

Aged↗
PubMed2002

Salinoma window technique for mediastinal lymph node biopsy.

Computed tomographic-guided transthoracic needle biopsy can access virtually all mediastinal lymph node stations, but is limited by the potential for pneumothorax and bleeding. To avoid these possible complications, the extrapleural "salinoma" technique was used for computed tomographic-guided mediastinal biopsies in 15 patients. Sampling methods were coaxial (8), tandem (5), and single pass (2). Diagnostic yield was 93% with no significant bleeding or pneumothorax. The salinoma technique permits biopsy of deep mediastinal lesions to stage pulmonary malignancies, while providing a technique that limits complications.

Biopsy, Needle↗