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CT and angiographic correlates: Surgical image of renal mass lesions
CT AND ANGIOGRAPHIC SURGICAL GEORGE
PILLARI,
WON J. LEE, SHEILA
IMAGE
MICHAEL
OF RENAL MASS LESIONS
M.D.
M.D.
KUMARI, CHEN,
CORRELATES:
HENRY J. ABRAMS, MITCHELL
M.D.
ALBERT
M.D.
BUCHBINDER,
P. SUTTON,
M.D.
M.D.
M.D.
From the Departments of Radiology and Urology, Long Island Jewish-Hillside Medical Center, New Hyde Park, and the School of Medicine, The Health Sciences Center, The State University of New York at Stony Brook, New York
ABSTRACT - Twenty-three consecutive patients with surgically proved renal mass lesions were examined preoperatively by means of computerized tomography (CT) and renal angiography. Histopathology of the 23 renal masses included the following: hypernephroma (17), transitional cell carcinoma (3), oncocytoma (2), benign cyst (1). Computed tomography was correct in the preoperative diagnosis of 21 of 23 masses (91 per cent); angiographic diagnosis was correct in 18 of 23 consecutive masses (78 per cent). Correlation of the findings on CT and angiography resulted in correct diagnosis in 22 of the 23 lesions (96 per cent). Independently, CT and angiography each contribute essential information for diagnosis and preoperative planning. CT discloses anatomic detail, tissue consistency, organ system relationships, and relatively precise estimates of tumor bulk. Angiography remains a necessary complement providing a surgical image of tumor vascularity and vessel origins.
Material and Methods
Correlation of findings on angiography and computed tomography (CT) directs an ordered and confident surgical plan for the management of renal mass lesions. Summary evaluation of these studies indexes the essential diagnostic criteria of malignant and benign lesions of the kidney; additionally, these studies combine to provide an understandable, surgical view of the primary renal lesion and its anatomic relationship to contiguous structures and other organ systems. This report examines the results of CT and angiographic preoperative imaging of renal mass lesions in 23 consecutive patients. Emphasis is given to the complementary nature of these studies noting that integration’ and summation of results will provide a more comprehensive preoperative image of surgical anatomy.
Over an eighteen-month period, 23 consecutive patients with surgically proved renal mass lesions were examined preoperatively by means of CT and renal angiography. Lesions were presumed to be solid in character on the basis of screening by means of nephrotomography and sonography. CT scanning was performed with intravenous contrast enhancement (300 cc. infusion of 30 per cent meglumine diatrizoate [Renografin]) on an E. M.I. 5005 scanner with an eighteensecond scan time and a 320 x 320 matrix display. Sections through the kidneys were obtained at 10 or 15-mm. intervals. In 3 cases contrast was infused through a lower extremity vein to obtain opacification of the inferior vena
2%
UROLOGY
/ MARCH 1981 I
VOLUME
XVII, NUMBER
3
cava.2 Aortography and selective angiography were performed in 20 cases; in 3 cases aortography was satisfactory for diagnosis and selective study was not performed. Inferior venacavogram was performed in those cases in which the renal vein and inferior vena cava were not visualized following selective renal artery injecwere described as tion (16 cases). Tumors vascular or hypovascular based on the number and size of vessels, presence or absence of tumor stain, or arteriovenous shunting. 3,4 Staging of renal tumors5 was performed but will be the subject of a separate report. Results
FIGURE 1. Selective renal arteriograph y. Wellcontained, richly vascular renal cell carcinoma in lower pole of left kidney; lesion is small with only minimal distortion of normal renal contour; mass was not imaged on CT.
Histopathology of the 23 renal masses included the following: hypernephroma (17), transitional cell carcinoma (3), oncocytoma (2), benign cyst (1). Computed tomography was correct in the preoperative diagnosis of 21 of 23 masses. A 3.5cm. hypernephroma, symmetrical, encapsulated and within the normal renal contour was not imaged on CT (Fig. 1). Additionally, a transitional cell tumor of the renal pelvis measuring 3 cm. in size failed to be imaged on CT; this lesion was seen only on retrograde pyelography. Angiographic diagnosis was correct in 18 of 23 consecutive masses. Of the 18 diagnostic studies, lesions were classified as vascular in
FIGURE 2. (A) Renal arteriography discloses some irregularity of cortical margin in lower pole of left kidney; study is inconclusive and non&agnostic fbr mass lesion. (B) Cross-sectional images of the same lesion clearly demonstrate large irregularly marginated mass extending posteriorly from lawyer pole of left kidney; areas of diminished attenuation (i.e., necrosis) are seen on CT scan.
UROLOGY
I MARCH1981
i VOLUMEXVII,NUMBER3
297
FIGURE 3. (A) Angiography is equivocal, describing some cortical irregularity over lateral margin of left kidney. (B) Large mass assuming posterior disposition in retroperitoneum is delineated clearly on CT scan. TABLE
Results of imaging renal muss lesions I , I
I.
POSITIVE
10 and hypovascular in 8. In the 5 cases in which angiography was nondiagnostic, the neoplasms were demonstrated to be avascular or hypovascular at surgery; included in this group of arteriographically “missed” lesions were transitional cell carcinoma (2), avascular hypernephromas (2) measuring 5 by 8 cm. and 6 by 8 cm., respectively (Figs. 2 and 3), and a benign renal cyst incorrectly interpreted as a malignant hypovascular lesion, described as cystic with malignant marginal vascularity. Results of findings on CT and angiography are summarized in Table I. Other significant contributory findings demonstrated exclusively on angiography included the following: duplication of the renal artery (3 cases); inferior vena cava thrombosis (2 cases); parasitic tumor blood supply from the mesentery or lumbar vessels (2 cases) (Fig. 4); periureteric or other venous collateral channels (3 cases); a neoplasm in a solitary kidney demonstrated on angiography. Size and volume of tumor-s
I
NEC~i’DIAGNOSTIC VE ACCURACY EOUIVOCAL
ANCIOCRAPHY C-TCOMBINED
apart) through the vertical plane of the tumor provides the third dimension for volume calculation. Volume studies on angiography are much less accurate and frequently are precluded due to the absence of opacification in avascular masses and incomplete opacification in those masses with associated necrosis or hemorrhage. In the present series of 22 diagnostic CT studies, description of size, contour, and volume on CT correlated accurately with surgical specimens, Comparison of CT and angiography indicates that arteriography renders a poor estimate of tumor size, particularly in avascular or hypovascular masses. Among the avascular or hypovascular neoplasms (14 of 23 cases in the present series), it is interesting to note that the CT-angio ratio of two dimensional size is at least two to one in every case.
Invariably CT measurements were more precise and in most cases revealed the masses to be larger in size than anticipated on angiography. The third dimension of CT study allows an accurate estimate of tumor volume. For example, the CT images in Figures 2B and 3B permit measurement of the anterior-posterior and horizontal tumor planes; assembly and addition of contiguous sections (10 mm. or 15 mm.
Clearly, the most noteworthy findings in this analysis are the following: 1. Selective renal angiography proved to be inadequate for diagnosis in 5 of 23 solid renal
298
UROLOGY
Comment
/ MARCH 1981 / VOLUME
XVII, NUMBER
3
(A} Hyperwascular mass with nonhomogeneous FIGURE 4. stain defined on selective renal arteriography (oncocytoma). (B) Tumor volume and disposition within retroperitoneum seen to greater advantage on CT sections.
masses. Fo~rr of these lesions were described and confid~~iitly interpreted on CT, i.e., transitional cell carcinoma (1); hypovascular hypernephroma (21, benign cyst (1). 2. CT w,ir insufficient for diagnosis in 2 of 23 cases; thcsse include a vascular 3.5-cm. hypernephroma (Fig. 1) demonstrated on angiography and a transitional cell carcinoma seen only on retrograde i)yelography. 3. Combined or summary evaluation of both angiographv and CT proscribed a confident accurate preoperative surgical plan in 22 of 23 consecutive, surgically proved renal mass lesions. The only lesion which qualifies as totally “missed” by. angiography and CT was a transitional cell carcinoma of the renal pelvis (3 by 2 cm.) which was visualized on retrograde pyelography. Independently, CT and angiography each contribute information essential for diagnosis and preoperativ.e planning (Fig. 4). CT defines (‘1) mass disposition within the retroperitoneum; (2) mass volume and extension; (3) tissue characterization (i.e., calcification, cyst, fat. necrosis and/or hemorrhage etc.); (4) contralateral kidney evaluation; (5) lymph node and other organ system involvement (staging). Angiography describes: (1) tumor vascularity; arteriovenous shunting, tumor circulation time, malignant versus benign vessel characteristics; (2) vascular anatomy including the number of renal arteries, lumbar or mesenteric artery collaterals; (3) the renal vein, inferior vena cava, and venous collaterals; (4) the tumor margin (i.e., encapsulated, contained mass versus an invasive poorly defined tumor edge). 3,4
Cross sectional images (CT)and angiography combine to describe and characterize renal mass lesions. Together these studies reveal a more dynamic and understandable image of normal and abnormal surgical anatomy. CT discloses anatomic detail, tissue consistency, organ system relationships, and relatively precise estimates of tumor bulke5 These determinations are made noninvasively and relatively independent of tumor hemodynamics. The sensitivity of CT is evident in this series of 23 patients, however, angiography remains a necessary complement providing fundamental presurgical delineation of tumor vascularity in those neoand vessel origins. Additionally, plasms less than 3 to 4 cm. in size (Fig. 1) which fail to distort the renal cortical margin significantly, vascular study presents a level of sensitivity greater than the resolution capability of an eighteen-second CT scanner.
VOLUME XVII, NUMBER 3
299
UROLOGY
!
MARCH 1981
/
New Hyde Park, New York 11042 (DR. PILLARI) ACKNOWLEDGMENT. To Richard Ma&as and Fred Liebman, Department of Audiovisual Resources, Long Island Jewish-Hillside Medical Center, for their assistance. References 1. J&e CC: Integrated medical imaging, Invest. Radiol. 14: 1 (1979). 2. Pillari G: Computed tomographic cave-orography: lower extremity contrast infusion simultaneous with computed tomography of the retroperitoneum, Radiology 130: 797 (1979). 3. Abrams HL: Renal tumor versus renal cyst I, Cardiovasc. Radio]. 1: 59 (1978). 4. IDEM: Renal tumor versus renal cyst II, ibid. 1: 125 (1978). 5. Love L, ef al: Computed tomography staging in renal carcinoma, Ural. Radiol. 1: 3 (1979).
PILLARI,
WON J. LEE, SHEILA
IMAGE
MICHAEL
OF RENAL MASS LESIONS
M.D.
M.D.
KUMARI, CHEN,
CORRELATES:
HENRY J. ABRAMS, MITCHELL
M.D.
ALBERT
M.D.
BUCHBINDER,
P. SUTTON,
M.D.
M.D.
M.D.
From the Departments of Radiology and Urology, Long Island Jewish-Hillside Medical Center, New Hyde Park, and the School of Medicine, The Health Sciences Center, The State University of New York at Stony Brook, New York
ABSTRACT - Twenty-three consecutive patients with surgically proved renal mass lesions were examined preoperatively by means of computerized tomography (CT) and renal angiography. Histopathology of the 23 renal masses included the following: hypernephroma (17), transitional cell carcinoma (3), oncocytoma (2), benign cyst (1). Computed tomography was correct in the preoperative diagnosis of 21 of 23 masses (91 per cent); angiographic diagnosis was correct in 18 of 23 consecutive masses (78 per cent). Correlation of the findings on CT and angiography resulted in correct diagnosis in 22 of the 23 lesions (96 per cent). Independently, CT and angiography each contribute essential information for diagnosis and preoperative planning. CT discloses anatomic detail, tissue consistency, organ system relationships, and relatively precise estimates of tumor bulk. Angiography remains a necessary complement providing a surgical image of tumor vascularity and vessel origins.
Material and Methods
Correlation of findings on angiography and computed tomography (CT) directs an ordered and confident surgical plan for the management of renal mass lesions. Summary evaluation of these studies indexes the essential diagnostic criteria of malignant and benign lesions of the kidney; additionally, these studies combine to provide an understandable, surgical view of the primary renal lesion and its anatomic relationship to contiguous structures and other organ systems. This report examines the results of CT and angiographic preoperative imaging of renal mass lesions in 23 consecutive patients. Emphasis is given to the complementary nature of these studies noting that integration’ and summation of results will provide a more comprehensive preoperative image of surgical anatomy.
Over an eighteen-month period, 23 consecutive patients with surgically proved renal mass lesions were examined preoperatively by means of CT and renal angiography. Lesions were presumed to be solid in character on the basis of screening by means of nephrotomography and sonography. CT scanning was performed with intravenous contrast enhancement (300 cc. infusion of 30 per cent meglumine diatrizoate [Renografin]) on an E. M.I. 5005 scanner with an eighteensecond scan time and a 320 x 320 matrix display. Sections through the kidneys were obtained at 10 or 15-mm. intervals. In 3 cases contrast was infused through a lower extremity vein to obtain opacification of the inferior vena
2%
UROLOGY
/ MARCH 1981 I
VOLUME
XVII, NUMBER
3
cava.2 Aortography and selective angiography were performed in 20 cases; in 3 cases aortography was satisfactory for diagnosis and selective study was not performed. Inferior venacavogram was performed in those cases in which the renal vein and inferior vena cava were not visualized following selective renal artery injecwere described as tion (16 cases). Tumors vascular or hypovascular based on the number and size of vessels, presence or absence of tumor stain, or arteriovenous shunting. 3,4 Staging of renal tumors5 was performed but will be the subject of a separate report. Results
FIGURE 1. Selective renal arteriograph y. Wellcontained, richly vascular renal cell carcinoma in lower pole of left kidney; lesion is small with only minimal distortion of normal renal contour; mass was not imaged on CT.
Histopathology of the 23 renal masses included the following: hypernephroma (17), transitional cell carcinoma (3), oncocytoma (2), benign cyst (1). Computed tomography was correct in the preoperative diagnosis of 21 of 23 masses. A 3.5cm. hypernephroma, symmetrical, encapsulated and within the normal renal contour was not imaged on CT (Fig. 1). Additionally, a transitional cell tumor of the renal pelvis measuring 3 cm. in size failed to be imaged on CT; this lesion was seen only on retrograde pyelography. Angiographic diagnosis was correct in 18 of 23 consecutive masses. Of the 18 diagnostic studies, lesions were classified as vascular in
FIGURE 2. (A) Renal arteriography discloses some irregularity of cortical margin in lower pole of left kidney; study is inconclusive and non&agnostic fbr mass lesion. (B) Cross-sectional images of the same lesion clearly demonstrate large irregularly marginated mass extending posteriorly from lawyer pole of left kidney; areas of diminished attenuation (i.e., necrosis) are seen on CT scan.
UROLOGY
I MARCH1981
i VOLUMEXVII,NUMBER3
297
FIGURE 3. (A) Angiography is equivocal, describing some cortical irregularity over lateral margin of left kidney. (B) Large mass assuming posterior disposition in retroperitoneum is delineated clearly on CT scan. TABLE
Results of imaging renal muss lesions I , I
I.
POSITIVE
10 and hypovascular in 8. In the 5 cases in which angiography was nondiagnostic, the neoplasms were demonstrated to be avascular or hypovascular at surgery; included in this group of arteriographically “missed” lesions were transitional cell carcinoma (2), avascular hypernephromas (2) measuring 5 by 8 cm. and 6 by 8 cm., respectively (Figs. 2 and 3), and a benign renal cyst incorrectly interpreted as a malignant hypovascular lesion, described as cystic with malignant marginal vascularity. Results of findings on CT and angiography are summarized in Table I. Other significant contributory findings demonstrated exclusively on angiography included the following: duplication of the renal artery (3 cases); inferior vena cava thrombosis (2 cases); parasitic tumor blood supply from the mesentery or lumbar vessels (2 cases) (Fig. 4); periureteric or other venous collateral channels (3 cases); a neoplasm in a solitary kidney demonstrated on angiography. Size and volume of tumor-s
I
NEC~i’DIAGNOSTIC VE ACCURACY EOUIVOCAL
ANCIOCRAPHY C-TCOMBINED
apart) through the vertical plane of the tumor provides the third dimension for volume calculation. Volume studies on angiography are much less accurate and frequently are precluded due to the absence of opacification in avascular masses and incomplete opacification in those masses with associated necrosis or hemorrhage. In the present series of 22 diagnostic CT studies, description of size, contour, and volume on CT correlated accurately with surgical specimens, Comparison of CT and angiography indicates that arteriography renders a poor estimate of tumor size, particularly in avascular or hypovascular masses. Among the avascular or hypovascular neoplasms (14 of 23 cases in the present series), it is interesting to note that the CT-angio ratio of two dimensional size is at least two to one in every case.
Invariably CT measurements were more precise and in most cases revealed the masses to be larger in size than anticipated on angiography. The third dimension of CT study allows an accurate estimate of tumor volume. For example, the CT images in Figures 2B and 3B permit measurement of the anterior-posterior and horizontal tumor planes; assembly and addition of contiguous sections (10 mm. or 15 mm.
Clearly, the most noteworthy findings in this analysis are the following: 1. Selective renal angiography proved to be inadequate for diagnosis in 5 of 23 solid renal
298
UROLOGY
Comment
/ MARCH 1981 / VOLUME
XVII, NUMBER
3
(A} Hyperwascular mass with nonhomogeneous FIGURE 4. stain defined on selective renal arteriography (oncocytoma). (B) Tumor volume and disposition within retroperitoneum seen to greater advantage on CT sections.
masses. Fo~rr of these lesions were described and confid~~iitly interpreted on CT, i.e., transitional cell carcinoma (1); hypovascular hypernephroma (21, benign cyst (1). 2. CT w,ir insufficient for diagnosis in 2 of 23 cases; thcsse include a vascular 3.5-cm. hypernephroma (Fig. 1) demonstrated on angiography and a transitional cell carcinoma seen only on retrograde i)yelography. 3. Combined or summary evaluation of both angiographv and CT proscribed a confident accurate preoperative surgical plan in 22 of 23 consecutive, surgically proved renal mass lesions. The only lesion which qualifies as totally “missed” by. angiography and CT was a transitional cell carcinoma of the renal pelvis (3 by 2 cm.) which was visualized on retrograde pyelography. Independently, CT and angiography each contribute information essential for diagnosis and preoperativ.e planning (Fig. 4). CT defines (‘1) mass disposition within the retroperitoneum; (2) mass volume and extension; (3) tissue characterization (i.e., calcification, cyst, fat. necrosis and/or hemorrhage etc.); (4) contralateral kidney evaluation; (5) lymph node and other organ system involvement (staging). Angiography describes: (1) tumor vascularity; arteriovenous shunting, tumor circulation time, malignant versus benign vessel characteristics; (2) vascular anatomy including the number of renal arteries, lumbar or mesenteric artery collaterals; (3) the renal vein, inferior vena cava, and venous collaterals; (4) the tumor margin (i.e., encapsulated, contained mass versus an invasive poorly defined tumor edge). 3,4
Cross sectional images (CT)and angiography combine to describe and characterize renal mass lesions. Together these studies reveal a more dynamic and understandable image of normal and abnormal surgical anatomy. CT discloses anatomic detail, tissue consistency, organ system relationships, and relatively precise estimates of tumor bulke5 These determinations are made noninvasively and relatively independent of tumor hemodynamics. The sensitivity of CT is evident in this series of 23 patients, however, angiography remains a necessary complement providing fundamental presurgical delineation of tumor vascularity in those neoand vessel origins. Additionally, plasms less than 3 to 4 cm. in size (Fig. 1) which fail to distort the renal cortical margin significantly, vascular study presents a level of sensitivity greater than the resolution capability of an eighteen-second CT scanner.
VOLUME XVII, NUMBER 3
299
UROLOGY
!
MARCH 1981
/
New Hyde Park, New York 11042 (DR. PILLARI) ACKNOWLEDGMENT. To Richard Ma&as and Fred Liebman, Department of Audiovisual Resources, Long Island Jewish-Hillside Medical Center, for their assistance. References 1. J&e CC: Integrated medical imaging, Invest. Radiol. 14: 1 (1979). 2. Pillari G: Computed tomographic cave-orography: lower extremity contrast infusion simultaneous with computed tomography of the retroperitoneum, Radiology 130: 797 (1979). 3. Abrams HL: Renal tumor versus renal cyst I, Cardiovasc. Radio]. 1: 59 (1978). 4. IDEM: Renal tumor versus renal cyst II, ibid. 1: 125 (1978). 5. Love L, ef al: Computed tomography staging in renal carcinoma, Ural. Radiol. 1: 3 (1979).