Case records of the Massachusetts General Hospital. Case 28-2006. A 59-year-old man with masses in both kidneys.
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Carcinoma, Renal Cell↗
Biomedical subjects
Peter R Mueller
Publications and source records attributed to Peter R Mueller.
Effect of obesity on image quality: fifteen-year longitudinal study for evaluation of dictated radiology reports.
PURPOSE: To retrospectively assess the effect of obesity on image quality, as determined from dictated radiology reports filed between 1989 and 2003. MATERIALS AND METHODS: Institutional review board approval was obtained for this HIPAA-compliant study; informed consent was not required. Electronic records were searched for radiology reports with the phrase "limited due to body habitus" (hereafter, "habitus limited") filed between 1989 and 2003; reports were retrospectively reviewed. Habitus limited was qualified as the search phrase by auditing radiologic images and patient weights. Trends in the number of habitus-limited reports were calculated for each year, and linear regression analysis was performed. The number of habitus-limited reports was also compared between modalities within a year and within each modality across 15 years. The trend was correlated with the prevalence of obesity in Massachusetts by using the Pearson correlation coefficient. RESULTS: There was a significant difference (P < .001) between the weight of patients with habitus-limited reports and the weight of patients with reports that were not habitus limited. Overall, 7778 (0.15%) of 5 253 014 reports were habitus limited. Between 1989 and 2003, there was a linear increase of 0.010% per year (95% confidence interval: 0.007%, 0.013%; P < .001). There was a positive correlation between the increased number of habitus-limited reports and the increased prevalence of obese individuals in Massachusetts between 1991 and 2001. The modality most commonly associated with habitus-limited reports was abdominal ultrasonography. CONCLUSION: There was a small but progressive increase in the number of habitus-limited radiology reports between 1989 and 2003.
Adolescent↗
Evaluation of living renal donors: accuracy of three-dimensional 16-section CT.
PURPOSE: To retrospectively assess the sensitivity and specificity of three-dimensional (3D) 16-section computed tomography (CT) in the evaluation of vessels, pelvicalyceal system, and ureters in living renal donors, with surgical findings as the reference standard. MATERIALS AND METHODS: This was a HIPAA-compliant study. Institutional review board approval was obtained for the review of subjects' medical records and data analysis, with waiver of informed consent. Forty-six renal donors (18 men, 28 women; mean age, 42 years) were examined with 16-section CT. Two blinded reviewers independently studied renal vascular and urographic anatomy of each donor CT scans by fist using 3D images alone, then transverse images alone, and finally transverse and 3D data set. Image quality, degree of diagnostic confidence, and time used for review were recorded. Sensitivity and specificity were calculated. RESULTS: For 3D images, transverse images, and transverse in conjunction with 3D data sets, the respective sensitivity and specificity of CT in evaluation of accessory arteries by reviewer 1 were 100% and 100%, 89% and 100%, and 100% and 100%, and those by reviewer 2 were 89% and 97%, 89% and 100%, and 89% and 100%; the respective sensitivity and specificity in evaluation of venous anomalies by reviewer 1 were 100% and 98%, 100% and 98%, and 100% and 98%, and those by reviewer 2 were 100% and 98%, 100% and 95%, and 100% and 98%. For focused comprehensive assessment of renal donors with 3D scans alone, a reviewer on average (average of reviewers 1 and 2) used 2.4 minutes per scan, demonstrated full confidence in 93%, and rated the quality as excellent in 76%. CONCLUSION: For focused assessment of renal vascular and urographic anatomy, review of 3D data set alone provides high sensitivity and specificity with regard to findings seen at surgery.
Adult↗
Adrenal lesions: characterization with fused PET/CT image in patients with proved or suspected malignancy--initial experience.
PURPOSE: To retrospectively evaluate the accuracy of the fused positron emission tomographic (PET)/computed tomographic (CT) image for characterization of adrenal lesions in patients who have proved malignancy or are suspected of having malignancy. MATERIALS AND METHODS: Institutional review board approval was received for this retrospective HIPAA-compliant study, and informed consent was waived. Forty-one adrenal lesions in 38 patients (21 men, 17 women; mean age, 66 years; range, 37-86 years) were evaluated with PET/CT. Of the 41 lesions, nine were assumed to be malignant with documentation of enlargement (n = 8) or reduction in size in response to treatment (n = 1), and 32 were assumed to be benign with documentation of stability for 6 months (n = 31) or with confirmation with biopsy results (n = 1). The PET examination findings were positive when adrenal lesion maximum standardized uptake values (SUVs) exceeded hepatic maximum SUVs. CT contrast medium washout analysis was used to further characterize two lesions with PET findings positive for malignancy. The t test was used to assess significant (P < .05) differences between fluorine 18 fluorodeoxyglucose (FDG) uptake of benign lesions and that of malignant lesions. RESULTS: At PET/CT, findings for all malignant lesions were positive (mean adrenal lesion-liver activity ratio, 4.04; range, 1.53-17.08). Of the 32 benign lesions, most (30 of 32) had activity less than that of the liver (mean ratio, 0.66; range, 0.22-0.94). PET/CT demonstrated sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 93.8%, 81.8%, 100%, and 95.1%, respectively. Incorporating contrast material-enhanced CT with delayed imaging increased specificity to 100% because two lesions with PET findings positive for malignancy were characterized as benign. There was a significant difference between maximum SUV (P < .05) and the ratio of adrenal lesion-liver FDG activity (P < .001) in benign versus malignant adrenal lesions. CONCLUSION: PET/CT provides a powerful combination of functional and attenuation information for adrenal lesion characterization. All malignant lesions were detected at PET/CT, with no false-negative results.
Adrenal Gland Neoplasms↗
Adrenocortical carcinoma: contrast washout characteristics on CT.
OBJECTIVE: The purpose of this study was to characterize pathologically proven adrenocortical carcinoma by examination of washout attenuation characteristics on contrast-enhanced CT images. CONCLUSION: Adrenocortical carcinoma has relative contrast retention on delayed contrast-enhanced CT. All tumors in this series had a relative percentage washout less than 40%, a finding consistent with malignant disease.
Adrenal Cortex Neoplasms↗
Imaging-guided catheter drainage of abdominal collections with fistulous pancreaticobiliary communication.
OBJECTIVE: Our aim was to study the success of percutaneous imaging-guided catheter drainage of abdominal collections with documented fistulous pancreaticobiliary communication. MATERIALS AND METHODS: Fifty-seven patients (age range, 23-88 years) with abdominal collections who underwent imaging-guided catheter drainage were included in this retrospective study. These collections showed communication with either the pancreatic duct (n = 15) or the biliary duct (n = 42) on imaging. The imaging guidance included CT (n = 40), sonography (n = 17), and fluoroscopy (n = 4), either alone or in combination. The success of catheter drainage was described as resolution of the collection on follow-up imaging and clinical improvement. Other treatments directed toward management of leaks or collections were also recorded. RESULTS: The success rates of catheter drainage for abdominal collections with biliary and pancreatic ductal communication were 93% (39/42) and 67% (10/15), respectively. The difference was statistically significant (p = 0.01). The three complications seen in this study were pneumothorax in one patient, bowel perforation in one, and death in one. The drainage catheter was upsized in five patients and an additional catheter was needed in nine patients. CONCLUSION: Imaging-guided catheter drainage is a clinically useful option for drainage of abdominal collections that have pancreaticobiliary communications. The success rate is significantly better for collections with biliary communication than for those with pancreatic communication.
Adult↗
Renal oncocytoma displaying intense activity on 18F-FDG PET.
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Adenoma, Oxyphilic↗
Percutaneous radiofrequency ablation of ovarian cancer metastasis to the liver: indications, outcomes, and role in patient management.
OBJECTIVE: Stages III and IV ovarian cancer are treated with a combination of chemotherapy and resection, in some cases including second and third surgical procedures, to achieve cytoreduction. Percutaneous radiofrequency ablation has proved effective in local control of hepatic tumors. We report early experience with percutaneous radiofrequency ablation in the management of isolated foci of metastatic ovarian cancer and assess the efficacy of the technique in achieving and maintaining local control by percutaneous cytoreduction. CONCLUSION: Percutaneous radiofrequency ablation is effective in achieving local control in selected patients with metastasis from ovarian cancer. In patients with limited macroscopic disease, cytoreduction can be achieved without surgery.
Adult↗
Distinguishing benign from malignant adrenal masses: multi-detector row CT protocol with 10-minute delay.
PURPOSE: To retrospectively evaluate the accuracy of precontrast attenuation, relative percentage washout (RPW), and absolute percentage washout (APW) in distinguishing benign from malignant adrenal masses at multi-detector row computed tomography (CT). MATERIALS AND METHODS: This HIPAA-compliant retrospective study had institutional review board approval; the need for informed consent was waived. One hundred twenty-two adrenal masses were evaluated in 99 patients (51 men, 48 women; age range, 37-86 years) who had undergone CT performed according to the study protocol and who either were given a pathologic diagnosis or underwent follow-up imaging. Unenhanced images were obtained before administration of 120 mL of an intravenous contrast agent with a 75-second scan delay. Delayed images were obtained after 10 minutes. RPW and APW were computed. Receiver operating characteristic (ROC) analysis was performed to compare mean attenuation and both RPW and APW. Analysis was first performed with the exclusion of pheochromocytomas, myelolipomas, and cysts. Precontrast attenuation criteria specific for benignity or malignancy were determined, and ROC analysis of results for the entire nonpheochromocytoma group was then performed. RESULTS: By using an RPW of 37.5% and excluding cysts and myelolipomas, all malignant lesions were detected with a sensitivity of 100% (17 of 17 lesions) and a specificity of 95% (90 of 95 lesions). Area under the binomial ROC curve (A(z)) values were 0.912, 0.985, and 0.892 for precontrast attenuation, RPW, and APW, respectively. Precontrast attenuation of less than 0 or more than 43 HU indicated benign and malignant entities, respectively. Incorporation of these criteria into the APW analysis yielded a sensitivity of 100% (17 of 17 lesions) and a specificity of 98% (93 of 95 lesions) for a threshold washout value of 52.0%. This attenuation-corrected APW generated the greatest A(z) value (ie, 0.988). Combining all the information available from the protocol yielded a sensitivity of 100% (17 of 17 lesions) and a specificity of 98% (98 of 100 lesions) for differentiating benign from malignant masses. CONCLUSION: Precontrast attenuation of less than 0 HU supercedes the washout profile in the evaluation of an individual adrenal mass. Noncalcified, nonhemorrhagic adrenal lesions with precontrast attenuation of more than 43 HU should be considered suspicious for malignancy.
Adrenal Gland Diseases↗
Case records of the Massachusetts General Hospital. Case 29-2005. A 68-year-old man with periorbital swelling, rash, and weakness.
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Aged↗
Multi-detector row CT in evaluation of 94 living renal donors by readers with varied experience.
PURPOSE: To retrospectively assess the accuracy of four-section multi-detector row computed tomography (CT) in the evaluation of renal transplant donors when scans are read by one of multiple readers with varied levels of expertise, by using surgery as the reference standard. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board and complied with the Health Insurance Portability and Accountability Act. Informed consent was waived. Between October 1999 and March 2003, 94 renal donors (42 men, 52 women; mean age, 44 years) underwent four-section multi-detector row CT. Unenhanced scanning of the abdomen was performed with 5-mm section thickness and table speed of 15 mm per rotation. Next, 135-150 mL of nonionic iodinated (300 mg/mL) contrast material was injected intravenously at a rate of 4-5 mL/sec. Contrast material-enhanced CT was initiated 20-25 seconds, 65-70 seconds, and 10 minutes after start of injection. Arterial phase scanning was performed with 1.25-mm section thickness and 7.5-mm table speed. Venous and excretory phase scanning was performed with 2.5-mm section thickness and 15-mm table speed. Each scan was evaluated independently by one of 11 readers for renal vascular and ureteral anatomic variants. Findings at CT were compared with those at surgery. Sensitivity and specificity (with 95% confidence intervals) and accuracy of CT were calculated on the basis of presence or absence of variant anatomy at surgery. RESULTS: CT depicted 107 of 114 renal arteries confirmed at surgery; seven accessory arteries were missed in six donor kidneys. CT depicted 95 of 98 renal veins confirmed at surgery. Sensitivity and specificity of CT were 66% and 100%, 75% and 100%, and 50% and 100%, and overall accuracy was 94%, 97%, and 99%, for identification of variant anatomy of renal arteries, veins, and ureters, respectively. CONCLUSION: Multi-detector row CT as the sole imaging technique in the preoperative evaluation of living renal donors is accurate even when images are read by multiple readers with varied levels of expertise.
Adult↗
Percutaneous radiofrequency ablation of renal cell carcinoma.
Conventional curative therapy for renal cell carcinoma has been open nephrectomy. However, several less invasive and/or nephron-sparing procedures have been developed as alternatives in selected patients. The newest of these therapeutic modalities involves percutaneous image-guided ablation with straight or expandable needle applicators that deposit energy. Radiofrequency ablation is the modality for which there is the largest reported experience with percutaneous application, and involves the use of electrical current to generate frictional heating of tissue. Animal studies confirm the ability of radiofrequency ablation to cause regions of necrosis within normal kidney and in VX2 tumors. Clinically, radiofrequency ablation of small renal cell carcinoma is increasingly being performed in selected patients who are not ideal surgical candidates. Results are excellent for small exophytic tumors, but successful treatment is less likely as tumor size increases or the location becomes more central. Complete treatment of most tumors requires one or more overlapping ablations with the needle electrodes positioned so as to cause necrosis in the entire volume of tumor. The number of overlapping ablations and the position of the needle electrodes vary based on tumor size and geometry. For very large tumors, pre-ablation catheter embolization may enhance the results of ablation by decreasing blood flow and perfusion mediated cooling. Following ablation, imaging with CT or MR is performed to assess the result and to diagnose any residual tumor so that it can be treated. Because the tumor remains in situ, imaging follow-up continues indefinitely. The complication rate of radiofrequency ablation is favorable when compared to surgical techniques. Long-term survival data are not yet available.
Animals↗
Imaging of acute mesenteric ischemia using multidetector CT and CT angiography in a porcine model.
Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols. After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findings--compared with pathologic diagnoses-- predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia.
Acute Disease↗
Long-term followup of patients with renal cell carcinoma treated with radio frequency ablation with curative intent.
PURPOSE: We defined the role of radio frequency ablation in the treatment of renal cell carcinoma. MATERIALS AND METHODS: A total of 16 patients with biopsy proven renal cell carcinoma were treated with radio frequency ablation in an outpatient setting and followed for a minimum of 4 years. RESULTS: Of the 16 patients 5 died before 4 years of followup of unrelated causes. All except 1 tumor was successfully treated. All patients with exophytic tumors were successfully treated. CONCLUSIONS: Radio frequency ablation of exophytic renal cell carcinomas less than 5 cm in diameter is effective in eradicating the tumor and comparable to surgical extirpation at 4 years.
Adult↗
CT and fluoroscopically guided percutaneous embolization treatment of a pseudoaneurysm associated with pancreatitis.
A novel approach to embolization treatment with a cyanoacrylate solution for a bleeding pseudoaneurysm associated with pancreatitis is described in the setting of a critically ill patient. Computed tomography and a C-arm fluoroscopic unit were used to guide percutaneous placement of a needle and injection of the embolic material. This technique represents an alternative form of embolization when traditional angiographic techniques are not possible.
Aneurysm, False↗
Radiofrequency ablation of a central renal tumor: protection of the collecting system with a retrograde cold dextrose pyeloperfusion technique.
Renal radiofrequency (RF) ablation therapy is a safe and effective therapy for small renal cell carcinoma. Although the risk of complications is low, the potential for ureteral or calyceal injury does increase in the case of a centrally located lesion. A retrograde cold dextrose pyeloperfusion technique was designed to protect the collecting system in a patient who underwent percutaneous RF ablation of a central tumor of the left kidney.
Carcinoma, Renal Cell↗
Assessing tumor perfusion and treatment response in rectal cancer with multisection CT: initial observations.
PURPOSE: To use first-pass perfusion computed tomography (CT) to prospectively investigate tumor vascularity in rectal cancer and to determine whether any of the perfusion parameters would predict tumor response to chemotherapy and radiation therapy. MATERIALS AND METHODS: The institutional review board approved this study, and informed prior consent was obtained from participants. Perfusion CT of rectal cancer was performed with four-section multi-detector row CT in 15 patients (13 men, two women; mean age, 62.1 years; age range, 46-84 years). Five patients with prostate cancer served as controls. All patients with rectal cancer underwent 6-8 weeks of chemotherapy and radiation therapy followed by surgery. In nine patients, perfusion CT was repeated after completion of chemotherapy and radiation therapy. Contrast medium-enhanced dynamic CT was performed with a static table position for 45 seconds, and the data were analyzed by using commercial software to calculate tissue blood flow (BF), blood volume, mean transit time (MTT), and vascular permeability-surface area product. Perfusion parameters of normal rectum and tumor were compared. Perfusion parameters before and after chemotherapy and radiation therapy were compared. A tumor was considered to have responded if its stage at pathologic analysis indicated regression compared with the preoperative stage. Baseline perfusion values were compared between responders and nonresponders. Statistical analysis was performed with the Student t test. RESULTS: Rectal cancer showed higher BF and shorter MTT compared with those of normal rectum (P < or =.05). After chemotherapy and radiation therapy, tumors showed significant reduction in BF and increase in MTT (P < or =.05). There was a significant difference in baseline BF and MTT values between responders and nonresponders (P < or =.05). Tumors in three patients with high initial BF and short MTT showed poor response. CONCLUSION: Perfusion CT of rectal cancer can enable assessment of tumor vascularity and perfusion changes that result from chemotherapy and radiation therapy. In this small patient sample, tumors with initial high BF and short MTT values tended to respond poorly to chemotherapy and radiation therapy.
Aged↗
Fungus-infected fluid collections in thorax or abdomen: effectiveness of percutaneous catheter drainage.
PURPOSE: To retrospectively evaluate the effectiveness of percutaneous catheter drainage in the treatment of fungus-infected fluid collections in the thorax or abdomen and to identify any factor that may be predictive of a poor clinical outcome. MATERIALS AND METHODS: Approval for this study was obtained from the hospital ethics subcommittee on human studies. Because the study was retrospective, patient informed consent was not required. This study was compliant with the Health Insurance Portability and Accountability Act. Retrospective analysis was performed of cases of fungus-infected fluid collections in the thorax or abdomen treated by using percutaneous catheter drainage in 60 patients (36 male and 24 female patients; mean age, 57 years; range, 2 months to 91 years) during 5 years. The patient medical records were reviewed to identify recognized factors for predisposition to fungal infection. The details of percutaneous catheter drainage and microbiologic findings were recorded. The technical success (ability of catheters placed to drain collections treated) and the clinical success (ability of patients to recover fully without surgery) of percutaneous catheter drainage were determined. A multifactor logistic regression analysis was performed to identify any clinical or microbiologic factor predictive of a poor clinical outcome. RESULTS: Seventy-three fungus-infected fluid collections were drained in 60 patients. The collections originated from the pleura (n = 6), mediastinum (n = 2), liver (n = 3), pancreas (n = 5), obstructed biliary or urinary tract (n = 9), gallbladder (n = 1), and abdominopelvic area (n = 47). The technical success rate for catheter drainage was 79% (41 of 52 patients); the clinical success rate, 57% (34 of 60 patients). Twenty (33%) patients died from all causes during hospital admission. Multifactor logistic regression analysis was used to identify predictors of a poor clinical outcome; complexity of collection, history of malignancy, and admission to intensive care unit were significant (P < .03) and independent predictors. CONCLUSION: Despite a moderately high technical success rate with percutaneous catheter drainage of fungus-infected fluid collections, clinical success rate was much lower. Both imaging appearance (complexity of collection) and clinical factors (history of malignancy, admission to intensive care unit) influenced prognosis.
Abdomen↗