1979, The British Journal of Radiology, 52, 761
SEPTEMBER 1979
Correspondence ventional radiography. Ultrasound showed a dilated left ureter and a very large right ureter (Fig. 1). A right antegrade pyelogram was performed. This showed a megaureter. The second patient was referred for investigation of "pancreatic calcification". Ultrasound showed bilateral hydronephrosis, and left renal calculi. Both ureters were well seen in transverse and longitudinal section (Figs. 2 and
much lower down. It is unlikely that an ectopic ureter would enter the bladder in the position shown and in the absence of surgical and autopsy confirmation I would question the interpretation of the ultrasonogram. Yours, etc., PATRICIA MORLEY.
Department of Diagnostic Radiology, Ultrasonic Unit, Western Infirmary, Glasgow G11 6NT. (Received December 1978)
The third patient, a young girl, had falling renal function following a recent transplant. Ultrasound demonstrated a normal transplant ureter thus excluding obstructive uropathy (Fig. 4). The features of acute rejection were noted in the transplanted kidney. In all three cases the ureters can be seen to enter the bladder from behind in the region of the bladder base. It is therefore hard to accept that the structure labelled "ureterocele" in Dr. Nikapota's article is anything other than a collection of bowel shadows. Indeed, even allowing for some loss of detail in the reproduction, careful scrutiny of Fig. 2 shows that a similar appearance is present immediately above the "ureterocele". Simple ureteroceles arise at the normal ureteric orifice a site that corresponds to the top of the structure labelled "diverticulum". Furthermore the ultrasound appearances of ureteroceles have already been described. Typically a "cyst within a cyst" is seen (Pollack and Goldberg, 1977). Yours, etc.,
REFERENCE NIKAPOTA, V. L. B. and WRAY, M. I., 1978. Grey-scale
ultrasound demonstration of ureterocele and hydroureter. British Journal of Radiology, 51, 1016-1018.
T h e Z 2 94 " r u l e " THE EDITOR—SIR,
The recent letter of reply by Jones (1979) will, I hope, "nail the coffin shut" on the Z 2 ' 94 "rule" for determination of the effective atomic number of compounds and mixtures. Numerous authors {e.g. McCullough, 1975; White, 1977; Rutherford et al., 1975) have developed a Z m dependence for the electronic cross-section of_the photoelectric effect in "soft tissue" materials (i.e. 6 ^ Z ^ 8 ) , where m is usually and 3.8, not 2.94 as widely used. The tenacity between2 3.5 of the Z 9 4 rule is illustrated by the fact that it has appeared within the last month in three manuscripts I have reviewed and, in all cases, the "disagreements" that the authors went to great pains to explain away mwere easily clarified when a more appropriate variation of Z was assumed. Yours, etc.,
L. A. BERGER.
Royal Free Hospital, Pond Street, London NW3 2QG. {Received January 1979) REFERENCES NIKAPOTA, V. L. B. and WRAY, M. I., 1978. Grey-scale
ultrasound demonstration of ureterocele and hydroureter, British Journal of Radiology, 51, 1016-1018.
E. C. MCCULLOUGH.
POLLACK, H. M. and GOLDBERG, B. B., 1977. Ed. B. B.
Mayo Clinic/Foundation, Goldberg In Abdominal Grey-scale Ultrasonography, 324. Rochester, MN 55901, USA. (John Wiley and Sons, New York.) (Received June 1979)
Grey-scale ultrasound demonstration of ureterocele and hydroureter
REFERENCES JONES, D. E. A., 1979. The calculation of effective atomic number, Z. British Journal of Radiology, 52, 330-331. MCCULLOUGH, E. C , 1975. Photon attenuation in computed tomography. Medical Physics, 2, 307-320.
THE EDITOR—SIR,
RUTHERFORD, R. A., PULLAN, B., ISHERWOOD, I. and
In the case report demonstrating a ureterocele and hydroureter in your December, 1978 issue (Nikapota and Wray, 1978), the authors have shown the ureter entering the bladder close to the summit. We have examined a significant number of patients with dilated ureters and these are usually identified in a more posterior position entering the bladder
GODDARD, J., 1975. Quantitative aspects of computer assisted tomography. British Journal if Radiology, 48, 605. WHITE, D. R., 1977. An analysis of the Z-dependence of photon and electron interactions. Physics in Medicine and Biology, 22,219-22$.
761
SEPTEMBER 1979
Correspondence ventional radiography. Ultrasound showed a dilated left ureter and a very large right ureter (Fig. 1). A right antegrade pyelogram was performed. This showed a megaureter. The second patient was referred for investigation of "pancreatic calcification". Ultrasound showed bilateral hydronephrosis, and left renal calculi. Both ureters were well seen in transverse and longitudinal section (Figs. 2 and
much lower down. It is unlikely that an ectopic ureter would enter the bladder in the position shown and in the absence of surgical and autopsy confirmation I would question the interpretation of the ultrasonogram. Yours, etc., PATRICIA MORLEY.
Department of Diagnostic Radiology, Ultrasonic Unit, Western Infirmary, Glasgow G11 6NT. (Received December 1978)
The third patient, a young girl, had falling renal function following a recent transplant. Ultrasound demonstrated a normal transplant ureter thus excluding obstructive uropathy (Fig. 4). The features of acute rejection were noted in the transplanted kidney. In all three cases the ureters can be seen to enter the bladder from behind in the region of the bladder base. It is therefore hard to accept that the structure labelled "ureterocele" in Dr. Nikapota's article is anything other than a collection of bowel shadows. Indeed, even allowing for some loss of detail in the reproduction, careful scrutiny of Fig. 2 shows that a similar appearance is present immediately above the "ureterocele". Simple ureteroceles arise at the normal ureteric orifice a site that corresponds to the top of the structure labelled "diverticulum". Furthermore the ultrasound appearances of ureteroceles have already been described. Typically a "cyst within a cyst" is seen (Pollack and Goldberg, 1977). Yours, etc.,
REFERENCE NIKAPOTA, V. L. B. and WRAY, M. I., 1978. Grey-scale
ultrasound demonstration of ureterocele and hydroureter. British Journal of Radiology, 51, 1016-1018.
T h e Z 2 94 " r u l e " THE EDITOR—SIR,
The recent letter of reply by Jones (1979) will, I hope, "nail the coffin shut" on the Z 2 ' 94 "rule" for determination of the effective atomic number of compounds and mixtures. Numerous authors {e.g. McCullough, 1975; White, 1977; Rutherford et al., 1975) have developed a Z m dependence for the electronic cross-section of_the photoelectric effect in "soft tissue" materials (i.e. 6 ^ Z ^ 8 ) , where m is usually and 3.8, not 2.94 as widely used. The tenacity between2 3.5 of the Z 9 4 rule is illustrated by the fact that it has appeared within the last month in three manuscripts I have reviewed and, in all cases, the "disagreements" that the authors went to great pains to explain away mwere easily clarified when a more appropriate variation of Z was assumed. Yours, etc.,
L. A. BERGER.
Royal Free Hospital, Pond Street, London NW3 2QG. {Received January 1979) REFERENCES NIKAPOTA, V. L. B. and WRAY, M. I., 1978. Grey-scale
ultrasound demonstration of ureterocele and hydroureter, British Journal of Radiology, 51, 1016-1018.
E. C. MCCULLOUGH.
POLLACK, H. M. and GOLDBERG, B. B., 1977. Ed. B. B.
Mayo Clinic/Foundation, Goldberg In Abdominal Grey-scale Ultrasonography, 324. Rochester, MN 55901, USA. (John Wiley and Sons, New York.) (Received June 1979)
Grey-scale ultrasound demonstration of ureterocele and hydroureter
REFERENCES JONES, D. E. A., 1979. The calculation of effective atomic number, Z. British Journal of Radiology, 52, 330-331. MCCULLOUGH, E. C , 1975. Photon attenuation in computed tomography. Medical Physics, 2, 307-320.
THE EDITOR—SIR,
RUTHERFORD, R. A., PULLAN, B., ISHERWOOD, I. and
In the case report demonstrating a ureterocele and hydroureter in your December, 1978 issue (Nikapota and Wray, 1978), the authors have shown the ureter entering the bladder close to the summit. We have examined a significant number of patients with dilated ureters and these are usually identified in a more posterior position entering the bladder
GODDARD, J., 1975. Quantitative aspects of computer assisted tomography. British Journal if Radiology, 48, 605. WHITE, D. R., 1977. An analysis of the Z-dependence of photon and electron interactions. Physics in Medicine and Biology, 22,219-22$.
761
