Correspondence LABIN, I. N., TENZER, M. L., BOOKER, M. & BRUNDAGE, B. H.,
1987. Measurement of myocardial blood flow by ultrafast computed tomography. Circulation, 76(6): 1262-1273. Yours etc., S. REES
National Heart & Lung Hospital, Sydney Street, London SW3 6NP (Received 6 January 1992, accepted 10 April 1992) Reference MILES, K. A., 1991. Measurement of tissue perfusion by dynamic computed tomography. British Journal ofRadiology, 64,409412.
colon was evident on an abdominal computed tomography (CT) study. A new surgical biopsy revealed IRF. The patient was treated with bilateral percutaneous nephrostomy and steroids. Repeat CT after 4 months revealed almost complete resolution of the fibrotic process. 1 year later, abdominal CT disclosed again a soft tissue homogeneous para-aortic mass and mesenteric lymph adenopathy (Fig. la). To rule out malignancy CT-guided percutaneous biopsy of the adenopathy was performed and histology showed nonspecific inflammatory changes. No organisms were identified from the specimen. CT at 6 and 12 months, after steroid treatment revealed reduction of the retroperitoneal mass and almost complete resolution of the adenopathy (Fig. lb). IRF is considered an autoimmune periaortitis resulting from leakage of ceroid from atheromatous plaques in the aortic wall (Mitchinson, 1984). CT and magnetic resonance are the imaging modalities of election in the diagnosis of IRF (Brooks et al, 1987;
Author's relpy THE EDITOR—SIR,
I am most grateful for the references S. Rees has supplied on the measurement of blood flow using computed tomography (CT) in response to my paper (Miles, 1991). My comment in the discussion should have stated that absolute values for tissue perfusion from CT have not been reported previously in man. All of the papers listed by S. Rees describe work performed only in animals and I remain unaware of any reports of human studies. The method for calculating tissue perfusion that I have described also benefits from being applicable to a wide range of different tissues. This is not so for the renal work of Jaschke et al (1987) whose technique requires data from the renal vein. I am grateful for the opportunity to correspond on this topic as the ability of CT to provide functional information is poorly recognized. Yours etc., K.A.
MILES
Departments of Radiology and Nuclear Medicine, Addenbrookes Hospital, Hills Road, Cambridge CB2 2QQ (Received 2 March 1992, accepted 10 April 1992) Reference JASCHKE, W., COGAN, M. G., SIEVERS, R.,
GOULD, R. & LIPTON, M.
J., 1987. Measurement of renal blood flow by cine computed tomography. Kidney International, 31(4), 1038-1042. MILES, K. A., 1991. Measurement of tissue perfusion by dynamic computed tomography. British Journal ofRadiology, 64,409412.
Mesenteric lymphadenopathy in idiopathic retroperitoneal fibrosis THE EDITOR—SIR,
Bilateral ureteral obstruction in a 54-year-old man was diagnosed as idiopathic retroperitoneal fibrosis (IRF) on the basis of surgical biopsy and treated with bilateral ureterolysis 8 years ago. 5 years later, the patient presented with symptoms of colonic partial obstruction and mild renal failure. Relapse involving the peri vascular retroperitoneum and the pelvis extending to the mesosigmoid
Vol. 65, No. 774
Figure 1. (a) Contrast-enhanced abdominal CT shows multiple homogeneous enlarged mesenteric lymph nodes (arrows) measuring 1-1.5 cm. There is a soft tissue mass (representing the IRF) surrounding the aorta and inferior vena cava. Note the hydronephrotic right kidney and nephrostomy catheters in both renal plevis. (b) Contrast-enhanced abdominal CT 1 year later demonstrated nearly complete resolution of mesenteric lymphadenopathy and marked reduction of the retroperitoneal mass. Note the persistent bilateral hydronephrosis.
555
1987. Measurement of myocardial blood flow by ultrafast computed tomography. Circulation, 76(6): 1262-1273. Yours etc., S. REES
National Heart & Lung Hospital, Sydney Street, London SW3 6NP (Received 6 January 1992, accepted 10 April 1992) Reference MILES, K. A., 1991. Measurement of tissue perfusion by dynamic computed tomography. British Journal ofRadiology, 64,409412.
colon was evident on an abdominal computed tomography (CT) study. A new surgical biopsy revealed IRF. The patient was treated with bilateral percutaneous nephrostomy and steroids. Repeat CT after 4 months revealed almost complete resolution of the fibrotic process. 1 year later, abdominal CT disclosed again a soft tissue homogeneous para-aortic mass and mesenteric lymph adenopathy (Fig. la). To rule out malignancy CT-guided percutaneous biopsy of the adenopathy was performed and histology showed nonspecific inflammatory changes. No organisms were identified from the specimen. CT at 6 and 12 months, after steroid treatment revealed reduction of the retroperitoneal mass and almost complete resolution of the adenopathy (Fig. lb). IRF is considered an autoimmune periaortitis resulting from leakage of ceroid from atheromatous plaques in the aortic wall (Mitchinson, 1984). CT and magnetic resonance are the imaging modalities of election in the diagnosis of IRF (Brooks et al, 1987;
Author's relpy THE EDITOR—SIR,
I am most grateful for the references S. Rees has supplied on the measurement of blood flow using computed tomography (CT) in response to my paper (Miles, 1991). My comment in the discussion should have stated that absolute values for tissue perfusion from CT have not been reported previously in man. All of the papers listed by S. Rees describe work performed only in animals and I remain unaware of any reports of human studies. The method for calculating tissue perfusion that I have described also benefits from being applicable to a wide range of different tissues. This is not so for the renal work of Jaschke et al (1987) whose technique requires data from the renal vein. I am grateful for the opportunity to correspond on this topic as the ability of CT to provide functional information is poorly recognized. Yours etc., K.A.
MILES
Departments of Radiology and Nuclear Medicine, Addenbrookes Hospital, Hills Road, Cambridge CB2 2QQ (Received 2 March 1992, accepted 10 April 1992) Reference JASCHKE, W., COGAN, M. G., SIEVERS, R.,
GOULD, R. & LIPTON, M.
J., 1987. Measurement of renal blood flow by cine computed tomography. Kidney International, 31(4), 1038-1042. MILES, K. A., 1991. Measurement of tissue perfusion by dynamic computed tomography. British Journal ofRadiology, 64,409412.
Mesenteric lymphadenopathy in idiopathic retroperitoneal fibrosis THE EDITOR—SIR,
Bilateral ureteral obstruction in a 54-year-old man was diagnosed as idiopathic retroperitoneal fibrosis (IRF) on the basis of surgical biopsy and treated with bilateral ureterolysis 8 years ago. 5 years later, the patient presented with symptoms of colonic partial obstruction and mild renal failure. Relapse involving the peri vascular retroperitoneum and the pelvis extending to the mesosigmoid
Vol. 65, No. 774
Figure 1. (a) Contrast-enhanced abdominal CT shows multiple homogeneous enlarged mesenteric lymph nodes (arrows) measuring 1-1.5 cm. There is a soft tissue mass (representing the IRF) surrounding the aorta and inferior vena cava. Note the hydronephrotic right kidney and nephrostomy catheters in both renal plevis. (b) Contrast-enhanced abdominal CT 1 year later demonstrated nearly complete resolution of mesenteric lymphadenopathy and marked reduction of the retroperitoneal mass. Note the persistent bilateral hydronephrosis.
555
