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Image-guided percutaneous biopsy of the adrenal gland: Review of indications, technique, and complications
Image-guided Percutaneous Biopsy of the Adrenal Gland: Review of Indications, Technique, and Complications Ronald S. Arellano, MD, Mukesh G. Harisinghani, MD, Debra A. Gervais, MD, Peter F. Hahn, MD, and Peter R. Mueller, MD
Approximately 5% of computed tomographic (CT) scans of the abdomen obtained for reasons other than specific adrenal disease demonstrate an unsuspected adrenal lesion.1 The detection of an unsuspected adrenal lesion raises 2 important clinical questions: Can the lesion be characterized as benign or malignant on the basis of CT imaging characteristics alone? If not, is percutaneous biopsy of the adrenal lesion indicated? The purpose of this article is to review the indications, techniques, and complications of image-guided percutaneous biopsy of the adrenal gland.
Indications Over the last 10 years, several investigators have used CT enhancement properties and image analysis of adrenal tumors to characterize adrenal lesions. Previous studies2,3 have shown high sensitivity and specificity for benign adrenal tumors when the CT attenuation of an adrenal lesion is 10 Hounsfield units (HU) or less on unenhanced images (Figs 1 and 2). Unfortunately, a small number of benign adenomas are lipid poor and therefore show attenuation values greater than 10 HU on unenhanced images. In such cases, or when unenhanced images are unavailable, delayed contrast-enhanced evaluation may be helpful as an aid to further characterization. Recently, investigators have recommended From the Department of Radiology, Division of Abdominal Imaging and Intervention, Massachusetts General Hospital, Boston, MA Reprint requests: Ronald S. Arellano, MD, Division of Abdominal Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114 E-mail: [email protected]. Curr Probl Diagn Radiol 2003;32:3-10. © 2003 Mosby, Inc. All rights reserved. 0363-0188/2003/$35.00 ⫹ 0 55/1/120002 doi:10.1067/cdr.2003.120002
Curr Probl Diagn Radiol, January 2003
determining the CT enhancement washout of adrenal lesions as an aid to lesion characterization.4 This value is calculated as follows:
Enhanced Attenuation (60 Seconds)— Delayed Enhanced Attenuation (15 Minutes) When the enhancement washout is greater than 50%, then the lesion likely represents a benign lipid-poor adenoma, and further imaging work-up can stop (Fig 3). This is especially true when initial delayed enhancement values are less than 35 HU and the patient has no history of extraadrenal malignancy. Malignant lesions, on the other hand, are believed to have a disrupted capillary network that results in delayed clearance of contrast material. Hence, the enhancement washout of malignant lesions are often less than 50% (Fig 4). When such a lesion is encountered, further evaluation therefore depends on whether the patient has an extraadrenal primary malignancy. When an extraadrenal malignancy is present, percutaneous biopsy is indicated to confirm a diagnosis and to plan treatment options. Alternatively, institutional preferences may require magnetic resonance imaging or positron emission tomographic evaluation before biopsy. When an extraadrenal malignancy is absent or unknown, then the adrenal lesion can be monitored with CT, nuclear scintigraphy, or surgery.1 A CT-based imaging algorithm for the above discussion is given in Fig 5.4,5
Preparation Preliminary Steps After the indication for adrenal biopsy has been established, a thorough review of all pertinent imaging
3
FIG 1. Unenhanced CT image of the abdomen, which demonstrates a left adrenal lesion (arrow). Region of interest analysis of the left adrenal lesion demonstrated attenuation values of – 8 HU, consistent with a benign adenoma.
FIG 2. Contrast-enhanced CT scan of the abdomen demonstrates low attenuation lesion of the right adrenal gland (arrow). Region of interest analysis demonstrates attenuation values of – 80 HU, consistent with a benign lesion.
FIG 3. A, Contrast-enhanced CT image of the abdomen obtained for nonspecific abdominal pain demonstrated bilateral adrenal masses (arrows). Region of interest analysis of the lesions revealed attenuation values of approximately 50 HU. B, Fifteen-minute delayed enhanced images of bilateral adrenal glands (arrows). The region of interest analysis revealed attenuation values of approximately 16 HU for the lesions. The delayed enhanced washout of the lesions was greater than 50%, and therefore the lesions were classified as adenomas.
studies (CT, ultrasonography, and magnetic resonance imaging) is necessary. This serves to establish the image guidance for the biopsy and to plan the safest approach to the lesion. A review of the medical history serves to highlight patients at particular risk for procedure related complications, (ie, chronic obstructive pulmonary disease or coagulopathy).
Laboratory Review Correctable prolonged prothrombin times require intravenous transfusion of fresh frozen plasma or
4
intramuscular injection of vitamin K (Fig 6). At our institution, fresh frozen plasma is given for prothrombin times greater than 14.5 seconds and is administered immediately before and during the procedure. Ideally, vitamin K injections (25 to 50 mg administered intramuscularly) have optimal effect when given daily for 3 days before the biopsy. Platelets are administered for counts less than 50,000/mm3. Intravenous heparin is discontinued 1 hour before the procedure. Preprocedure antibiotics are not indicated.
Curr Probl Diagn Radiol, January 2003
FIG 4. A, Unenhanced CT image of the abdomen in a patient with a history of breast carcinoma. A right adrenal lesion was detected (arrow). Region of interest analysis of the lesion revealed attenuation values of 25 HU. B, Contrast-enhanced CT images of the same lesion (arrow) during portal venous phase. Region of interest analysis revealed enhancement to approximately 46 HU. C, Fifteen-minute delayed contrast enhanced image of the right adrenal gland (arrow). Region of interest analysis revealed delayed enhanced attenuation of 18 HU. The delayed washout of the lesion was less than 50%. In this patient with a history of breast carcinoma, percutaneous biopsy of the adrenal gland was requested to determine metastatic disease. D, CT-guided percutaneous biopsy of the adrenal gland demonstrating needle within the right adrenal gland (arrow). Biopsy results confirmed metastatic disease.
Curr Probl Diagn Radiol, January 2003
5
accurate position of the biopsy needle. Additionally, any procedure related complications (ie, bleeding, pneumothorax) could be quickly assessed with CT scanning.
Patient Positioning
FIG 5. Suggested algorithmic approach for the work-up of incidentally detected adrenal masses by computed tomography.4,5
Technique Image Guidance Unless the lesion is very large and easily targeted with ultrasound guidance (Fig 7), all adrenal gland biopsies are performed with computed tomographic guidance. CT guidance allows clear anatomic detail of the adrenal gland and adjacent structures and shows
Most image-guided percutaneous adrenal biopsies are performed with the patient in the lateral decubitus position, with the gland of interest down. This position displaces the ipsilateral lung away from the posterior costophrenic sulcus, thus minimizing traversal of lung parenchyma en route to the adrenal gland (Fig 8). Alternate approaches have also been described. For example, the right adrenal gland can be targeted via a transhepatic approach (Fig 9).6 When coagulation parameters are normal, the hepatic parenchyma acts to tamponade the needle path, thus minimizing the risk of bleeding. Alternatively, access to either adrenal gland can be obtained by a transrenal approach (Fig 10). Similarly, transgastric and transpancreatic routes to target the left adrenal gland have been described (Fig 11).7 Posterior approaches to the adrenal gland with the patient in the prone position can be achieved with or without gantry angulation (Fig 12). Use of the tilt capabilities of the CT gantry can often minimize the limitations imposed by the overlying lung.8,9 This results in a needle trajectory through minimal pleural space, thereby minimizing the risk of pneumothorax. Additionally, artificial widening of the paravertebral space with percutaneous injection of normal saline has been described as technique to improve access to the gland.10
FIG 6. Coagulation parameters for percutaneous adrenal biopsy.
6
Curr Probl Diagn Radiol, January 2003
FIG 7. A, Ultrasound image of a large adrenal tumor (arrows). B, Ultrasound-guided adrenal biopsy demonstrates needle tip in the adrenal gland (arrow).
FIG 8. A, Axial image of the left adrenal gland with patient in prone position demonstrating lung in the posterior costophrenic sulcus (arrows). B, Axial image of the left adrenal gland with patient in the left lateral decubitus position. Note how the lung has been displaced out of the posterior costophrenic sulcus.
All image-guided percutaneous adrenal gland biopsies are performed with a 17-gauge coaxial needle system (Fig 13). Once the tip of the 17-gauge coaxial needle is placed in the gland, the inner stylette is exchanged for a 22-gauge needle for cytology speci-
Curr Probl Diagn Radiol, January 2003
mens or an 18-gauge needle for core biopsy specimens. The combination of an experienced radiologist and on-site review of the biopsy specimens by a pathologist can be expected to yield a high success rate.11,12
7
FIG 9. CT-guided right adrenal gland biopsy via a transhepatic approach. FIG 10. CT-guided adrenal gland biopsy with a transrenal approach (arrow indicates left kidney).
FIG 11. Transgastric approach to the adrenal gland (arrows indicate stomach).
Complications
FIG 12. Angled gantry approach to the adrenal gland.
8
Image-guided percutaneous biopsy is a relatively safe procedure that carries with it few risks. Uncorrectable coagulopathy, poor patient compliance, and lesion inaccessibility are conditions that preclude adrenal gland biopsy. Otherwise, the potential complications of percutaneous adrenal gland biopsy include bleeding, infection, pneumothorax, organ injury, and adverse reaction to intravenous conscious sedation. The bleeding risk can be minimized by optimizing the coagulation status of the patient, by limiting the number of needle passes, and by choosing the safest path to the lesion. Hemorrhagic complications are rare and usually self-limited and resolve over time. Transfusions are rarely indicated. Infections are minimized
Curr Probl Diagn Radiol, January 2003
FIG 13. A, Coaxial needle system used for image-guided percutaneous adrenal biopsy. B, Coaxial needle system for image-guided percutaneous biopsy with inner stylette removed from 17-gauge needle and replaced for 22-gauge CHIBA needle. C, Coaxial needle system used for image-guided percutaneous biopsy with inner stylette removed from 17-gauge needle and replaced with 18-gauge core biopsy needle.
FIG 14. A, Axial image of a CT-guided left adrenal gland biopsy demonstrates transpleural approach. Patient is in the prone position. Note needle trajectory through lung. B, Post biopsy axial image demonstrates a pneumothorax.
by careful attention to sterile technique. Most procedure-related pneumothoraxes are inconsequential and resolve without the need for intervention (Fig 14). However, even small pneumothoraxes can result in significant respiratory distress for patients with severe underlying lung disease. Symptomatic pneumothoraces require treatment with chest tube drainage.
Curr Probl Diagn Radiol, January 2003
Conclusion Image-guided percutaneous biopsy of the adrenal gland is an important tool for the evaluation of indeterminate adrenal lesions. This is especially true for patients with an oncology history who require tissue characterization to establish a diagnosis and
9
treatment options. When used in conjunction with specific CT imaging analysis, percutaneous biopsy of the adrenal gland offers high sensitivity and specificity in the work-up of patients with adrenal gland masses.
REFERENCES 1. Kloos RT, Gross MD, Francis IR, Korobkin M, Shapiro B. Incidentally discovered adrenal masses. Endocr Rev 1995;16: 460-84. 2. Boland GW, Lee MJ, Gazelle GS, Halpern EF, McNichols MM, Mueller PR. Characterization of adrenal masses using unenhanced CT: an analysis of the CT literature. AJR Am J Roentgenol 1998;171:201-4. 3. Korobkin M, Brodeur FJ, Yutzy GG, Francis IR, Quint LE, Dunnick NR, et al. Differentiation of adrenal adenomas from nonadenomas using CT attenuation values. AJR Am J Roentgenol 1996;166:531-6. 4. Pena CS, Boland GWL, Hahn PF, Lee MJ, Mueller PR. Characterization of indeterminate (lipid-poor) adrenal masses: use of washout characteristics at contrast-enhanced CT. Radiology 2000; 217:798 – 802.
10
5. Korobkin M. CT characterization of adrenal masses: the time has come. Radiology 2000;217:629-32. 6. Price RB, Bernardino ME, Berkman WA, Sones PJ Jr, Torres WE. Biopsy of the right adrenal gland by the transhepatic approach. Radiology 1983;2:566. 7. Kane NM, Korobkin M, Francis IR, Quint LE, Cascade PN. Percutaneous biopsy of left adrenal masses: prevalence of pancreatitis after anterior approach. AJR Am J Roentgenol 1991;157:777-80. 8. Yueh N, Halvorsen A Jr, Letourneau JG, Grass JR. Gantry tilt technique for CT-guided biopsy and drainage. J Comput Assist Tomogr 1989;13:182-4. 9. Hussain S. Gantry angulation in CT-guided percutaneous adrenal biopsy. AJR Am J Roentgenol 19;157:777-80. 10. Karampekios S, Hatjidakis AA, Drositis J, Goutsoyiannis N. Artificial paravertebral widening for percutaneous CT-guided adrenal biopsy. J Comput Assist Tomogr 1998;22;2:308 –10. 11. Silverman SG, Mueller PR, Pinkney LP, Koenker RM, Seltzer SE. Predictive value of image-guided adrenal biopsy: analysis of results of 101 biopsies. Radiology 1993;187:715-8. 12. Phillips MD, Silverman SG, Cibas ES, Seltzer SE. Negative predictive value of imaging-guided abdominal biopsy results. AJR Am J Roentgenol 1998;171:693-6.
Curr Probl Diagn Radiol, January 2003
Approximately 5% of computed tomographic (CT) scans of the abdomen obtained for reasons other than specific adrenal disease demonstrate an unsuspected adrenal lesion.1 The detection of an unsuspected adrenal lesion raises 2 important clinical questions: Can the lesion be characterized as benign or malignant on the basis of CT imaging characteristics alone? If not, is percutaneous biopsy of the adrenal lesion indicated? The purpose of this article is to review the indications, techniques, and complications of image-guided percutaneous biopsy of the adrenal gland.
Indications Over the last 10 years, several investigators have used CT enhancement properties and image analysis of adrenal tumors to characterize adrenal lesions. Previous studies2,3 have shown high sensitivity and specificity for benign adrenal tumors when the CT attenuation of an adrenal lesion is 10 Hounsfield units (HU) or less on unenhanced images (Figs 1 and 2). Unfortunately, a small number of benign adenomas are lipid poor and therefore show attenuation values greater than 10 HU on unenhanced images. In such cases, or when unenhanced images are unavailable, delayed contrast-enhanced evaluation may be helpful as an aid to further characterization. Recently, investigators have recommended From the Department of Radiology, Division of Abdominal Imaging and Intervention, Massachusetts General Hospital, Boston, MA Reprint requests: Ronald S. Arellano, MD, Division of Abdominal Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114 E-mail: [email protected]. Curr Probl Diagn Radiol 2003;32:3-10. © 2003 Mosby, Inc. All rights reserved. 0363-0188/2003/$35.00 ⫹ 0 55/1/120002 doi:10.1067/cdr.2003.120002
Curr Probl Diagn Radiol, January 2003
determining the CT enhancement washout of adrenal lesions as an aid to lesion characterization.4 This value is calculated as follows:
Enhanced Attenuation (60 Seconds)— Delayed Enhanced Attenuation (15 Minutes) When the enhancement washout is greater than 50%, then the lesion likely represents a benign lipid-poor adenoma, and further imaging work-up can stop (Fig 3). This is especially true when initial delayed enhancement values are less than 35 HU and the patient has no history of extraadrenal malignancy. Malignant lesions, on the other hand, are believed to have a disrupted capillary network that results in delayed clearance of contrast material. Hence, the enhancement washout of malignant lesions are often less than 50% (Fig 4). When such a lesion is encountered, further evaluation therefore depends on whether the patient has an extraadrenal primary malignancy. When an extraadrenal malignancy is present, percutaneous biopsy is indicated to confirm a diagnosis and to plan treatment options. Alternatively, institutional preferences may require magnetic resonance imaging or positron emission tomographic evaluation before biopsy. When an extraadrenal malignancy is absent or unknown, then the adrenal lesion can be monitored with CT, nuclear scintigraphy, or surgery.1 A CT-based imaging algorithm for the above discussion is given in Fig 5.4,5
Preparation Preliminary Steps After the indication for adrenal biopsy has been established, a thorough review of all pertinent imaging
3
FIG 1. Unenhanced CT image of the abdomen, which demonstrates a left adrenal lesion (arrow). Region of interest analysis of the left adrenal lesion demonstrated attenuation values of – 8 HU, consistent with a benign adenoma.
FIG 2. Contrast-enhanced CT scan of the abdomen demonstrates low attenuation lesion of the right adrenal gland (arrow). Region of interest analysis demonstrates attenuation values of – 80 HU, consistent with a benign lesion.
FIG 3. A, Contrast-enhanced CT image of the abdomen obtained for nonspecific abdominal pain demonstrated bilateral adrenal masses (arrows). Region of interest analysis of the lesions revealed attenuation values of approximately 50 HU. B, Fifteen-minute delayed enhanced images of bilateral adrenal glands (arrows). The region of interest analysis revealed attenuation values of approximately 16 HU for the lesions. The delayed enhanced washout of the lesions was greater than 50%, and therefore the lesions were classified as adenomas.
studies (CT, ultrasonography, and magnetic resonance imaging) is necessary. This serves to establish the image guidance for the biopsy and to plan the safest approach to the lesion. A review of the medical history serves to highlight patients at particular risk for procedure related complications, (ie, chronic obstructive pulmonary disease or coagulopathy).
Laboratory Review Correctable prolonged prothrombin times require intravenous transfusion of fresh frozen plasma or
4
intramuscular injection of vitamin K (Fig 6). At our institution, fresh frozen plasma is given for prothrombin times greater than 14.5 seconds and is administered immediately before and during the procedure. Ideally, vitamin K injections (25 to 50 mg administered intramuscularly) have optimal effect when given daily for 3 days before the biopsy. Platelets are administered for counts less than 50,000/mm3. Intravenous heparin is discontinued 1 hour before the procedure. Preprocedure antibiotics are not indicated.
Curr Probl Diagn Radiol, January 2003
FIG 4. A, Unenhanced CT image of the abdomen in a patient with a history of breast carcinoma. A right adrenal lesion was detected (arrow). Region of interest analysis of the lesion revealed attenuation values of 25 HU. B, Contrast-enhanced CT images of the same lesion (arrow) during portal venous phase. Region of interest analysis revealed enhancement to approximately 46 HU. C, Fifteen-minute delayed contrast enhanced image of the right adrenal gland (arrow). Region of interest analysis revealed delayed enhanced attenuation of 18 HU. The delayed washout of the lesion was less than 50%. In this patient with a history of breast carcinoma, percutaneous biopsy of the adrenal gland was requested to determine metastatic disease. D, CT-guided percutaneous biopsy of the adrenal gland demonstrating needle within the right adrenal gland (arrow). Biopsy results confirmed metastatic disease.
Curr Probl Diagn Radiol, January 2003
5
accurate position of the biopsy needle. Additionally, any procedure related complications (ie, bleeding, pneumothorax) could be quickly assessed with CT scanning.
Patient Positioning
FIG 5. Suggested algorithmic approach for the work-up of incidentally detected adrenal masses by computed tomography.4,5
Technique Image Guidance Unless the lesion is very large and easily targeted with ultrasound guidance (Fig 7), all adrenal gland biopsies are performed with computed tomographic guidance. CT guidance allows clear anatomic detail of the adrenal gland and adjacent structures and shows
Most image-guided percutaneous adrenal biopsies are performed with the patient in the lateral decubitus position, with the gland of interest down. This position displaces the ipsilateral lung away from the posterior costophrenic sulcus, thus minimizing traversal of lung parenchyma en route to the adrenal gland (Fig 8). Alternate approaches have also been described. For example, the right adrenal gland can be targeted via a transhepatic approach (Fig 9).6 When coagulation parameters are normal, the hepatic parenchyma acts to tamponade the needle path, thus minimizing the risk of bleeding. Alternatively, access to either adrenal gland can be obtained by a transrenal approach (Fig 10). Similarly, transgastric and transpancreatic routes to target the left adrenal gland have been described (Fig 11).7 Posterior approaches to the adrenal gland with the patient in the prone position can be achieved with or without gantry angulation (Fig 12). Use of the tilt capabilities of the CT gantry can often minimize the limitations imposed by the overlying lung.8,9 This results in a needle trajectory through minimal pleural space, thereby minimizing the risk of pneumothorax. Additionally, artificial widening of the paravertebral space with percutaneous injection of normal saline has been described as technique to improve access to the gland.10
FIG 6. Coagulation parameters for percutaneous adrenal biopsy.
6
Curr Probl Diagn Radiol, January 2003
FIG 7. A, Ultrasound image of a large adrenal tumor (arrows). B, Ultrasound-guided adrenal biopsy demonstrates needle tip in the adrenal gland (arrow).
FIG 8. A, Axial image of the left adrenal gland with patient in prone position demonstrating lung in the posterior costophrenic sulcus (arrows). B, Axial image of the left adrenal gland with patient in the left lateral decubitus position. Note how the lung has been displaced out of the posterior costophrenic sulcus.
All image-guided percutaneous adrenal gland biopsies are performed with a 17-gauge coaxial needle system (Fig 13). Once the tip of the 17-gauge coaxial needle is placed in the gland, the inner stylette is exchanged for a 22-gauge needle for cytology speci-
Curr Probl Diagn Radiol, January 2003
mens or an 18-gauge needle for core biopsy specimens. The combination of an experienced radiologist and on-site review of the biopsy specimens by a pathologist can be expected to yield a high success rate.11,12
7
FIG 9. CT-guided right adrenal gland biopsy via a transhepatic approach. FIG 10. CT-guided adrenal gland biopsy with a transrenal approach (arrow indicates left kidney).
FIG 11. Transgastric approach to the adrenal gland (arrows indicate stomach).
Complications
FIG 12. Angled gantry approach to the adrenal gland.
8
Image-guided percutaneous biopsy is a relatively safe procedure that carries with it few risks. Uncorrectable coagulopathy, poor patient compliance, and lesion inaccessibility are conditions that preclude adrenal gland biopsy. Otherwise, the potential complications of percutaneous adrenal gland biopsy include bleeding, infection, pneumothorax, organ injury, and adverse reaction to intravenous conscious sedation. The bleeding risk can be minimized by optimizing the coagulation status of the patient, by limiting the number of needle passes, and by choosing the safest path to the lesion. Hemorrhagic complications are rare and usually self-limited and resolve over time. Transfusions are rarely indicated. Infections are minimized
Curr Probl Diagn Radiol, January 2003
FIG 13. A, Coaxial needle system used for image-guided percutaneous adrenal biopsy. B, Coaxial needle system for image-guided percutaneous biopsy with inner stylette removed from 17-gauge needle and replaced for 22-gauge CHIBA needle. C, Coaxial needle system used for image-guided percutaneous biopsy with inner stylette removed from 17-gauge needle and replaced with 18-gauge core biopsy needle.
FIG 14. A, Axial image of a CT-guided left adrenal gland biopsy demonstrates transpleural approach. Patient is in the prone position. Note needle trajectory through lung. B, Post biopsy axial image demonstrates a pneumothorax.
by careful attention to sterile technique. Most procedure-related pneumothoraxes are inconsequential and resolve without the need for intervention (Fig 14). However, even small pneumothoraxes can result in significant respiratory distress for patients with severe underlying lung disease. Symptomatic pneumothoraces require treatment with chest tube drainage.
Curr Probl Diagn Radiol, January 2003
Conclusion Image-guided percutaneous biopsy of the adrenal gland is an important tool for the evaluation of indeterminate adrenal lesions. This is especially true for patients with an oncology history who require tissue characterization to establish a diagnosis and
9
treatment options. When used in conjunction with specific CT imaging analysis, percutaneous biopsy of the adrenal gland offers high sensitivity and specificity in the work-up of patients with adrenal gland masses.
REFERENCES 1. Kloos RT, Gross MD, Francis IR, Korobkin M, Shapiro B. Incidentally discovered adrenal masses. Endocr Rev 1995;16: 460-84. 2. Boland GW, Lee MJ, Gazelle GS, Halpern EF, McNichols MM, Mueller PR. Characterization of adrenal masses using unenhanced CT: an analysis of the CT literature. AJR Am J Roentgenol 1998;171:201-4. 3. Korobkin M, Brodeur FJ, Yutzy GG, Francis IR, Quint LE, Dunnick NR, et al. Differentiation of adrenal adenomas from nonadenomas using CT attenuation values. AJR Am J Roentgenol 1996;166:531-6. 4. Pena CS, Boland GWL, Hahn PF, Lee MJ, Mueller PR. Characterization of indeterminate (lipid-poor) adrenal masses: use of washout characteristics at contrast-enhanced CT. Radiology 2000; 217:798 – 802.
10
5. Korobkin M. CT characterization of adrenal masses: the time has come. Radiology 2000;217:629-32. 6. Price RB, Bernardino ME, Berkman WA, Sones PJ Jr, Torres WE. Biopsy of the right adrenal gland by the transhepatic approach. Radiology 1983;2:566. 7. Kane NM, Korobkin M, Francis IR, Quint LE, Cascade PN. Percutaneous biopsy of left adrenal masses: prevalence of pancreatitis after anterior approach. AJR Am J Roentgenol 1991;157:777-80. 8. Yueh N, Halvorsen A Jr, Letourneau JG, Grass JR. Gantry tilt technique for CT-guided biopsy and drainage. J Comput Assist Tomogr 1989;13:182-4. 9. Hussain S. Gantry angulation in CT-guided percutaneous adrenal biopsy. AJR Am J Roentgenol 19;157:777-80. 10. Karampekios S, Hatjidakis AA, Drositis J, Goutsoyiannis N. Artificial paravertebral widening for percutaneous CT-guided adrenal biopsy. J Comput Assist Tomogr 1998;22;2:308 –10. 11. Silverman SG, Mueller PR, Pinkney LP, Koenker RM, Seltzer SE. Predictive value of image-guided adrenal biopsy: analysis of results of 101 biopsies. Radiology 1993;187:715-8. 12. Phillips MD, Silverman SG, Cibas ES, Seltzer SE. Negative predictive value of imaging-guided abdominal biopsy results. AJR Am J Roentgenol 1998;171:693-6.
Curr Probl Diagn Radiol, January 2003