Postgrad Med J: first published as 10.1136/pgmj.5.59.193 on 1 August 1930. Downloaded from X-RAY EXAMINATION OF THE URINARY TRACT 193 X-RAY EXAMINATION OF peak, double screens, and the Bucky grid are essential points in the production of radio- THE URINARY TRACT. grams of the necessary quality. By S. COCHRANE SHANKS, URINARY CALCULUS. M.B., C .B. The presence or absence of a urinary Radiologist to the Prince of Wales' General Hospital; stone of any considerable size can be Assistant Radiologist to Charing Cross Hospital. determined radiographically with as great WITH the gradual improvement in radio- certainty as in almost any diagnostic proce- the dure in medicine or surgery. The occur- logical technique during past twenty rence of a stone so as to cast no years, X-ray examination has assumed a transparent greater importance in the diagnosis of shadow in a radiogram is sufficiently rare to disease of the urinary tract than almost any excite comment when it does occur. The other ancillary method. Indeed, no investi- shadow cast by a calculus depends on its gation of the urinary tract from the surgical radiopacity compared with that of the sott can be as without tissues (the latter being equal approximately aspect regarded complete to that of water), and depends on three X-ray examination. In many cases the and its chemical diagnosis is settled by that means, and in factors: its size, its structure, others the field of narrowed composition. possibilities by The effect of the first two is obvious; the exclusion, say, of calculus, hydronephrosis, and &c. larger the stone the denser the shadow, Preparation of the Patient.-This is of the more porous the stone the less dense. ofcopyright. some importance. It is desirable that the Chemical Cormtposition.-The radiopacity canal be as as an element, i.e., its capacity for arresting patient's alimentary empty X-rays varies directly with its atomic number. possible; both fluid, faecal and gaseous the contents may obscure the radiographic The higher the atomic number, greater picture. With modern technique, in which is this capacity. contrast is the Below is appended a table of atomic great desideratum, any numbers of importance in radiology. considerable collection of gas in the colon http://pmj.bmj.com/ might literally " black out" the renal areas H. i. Na. 1. K. I9. Ba. 56. in the negative. The routine preparation is He. 2. Mg. 12. Ca. 20. Pb. 82. as follows : C. 6. Al. I3. Br. 35. Bi. 83. (I) An aperient on the day before. Salines N. 7 P. I5. Ag. 47. should not be used, because of their compo- 0. 8. S. I6. I. 53. sition and tendency to cause gaseous disten- An atom of any element is composed of sion. Castor oil is probably the most an equal number of protons and electrons. on September 25, 2021 by guest. Protected satisfactory. Hydrogen contains one of each. In all the (2) On the day of the examination an other atoms the arrangement is in the form enema may be given, if the result of the of a nucleus containing all the protons and aperient has not been satisfactory. As little half the electrons, the remaining, or plane- food as possible should be taken, the quality tary, electrons being arranged planet-wise in being unimportant. shells round the nucleus. The atomic (3) The bladder should be emptied number corresponds with the number of immediately before the examination. planetary electrons. It is supposed that Technique.-Ingeneral, screen examination the rays are arrested by striking the electrons, is of no value. As a routine, radiograms and that the more there are of them the should be taken to include the whole tract. more radiopaque the substance is. A low kilovoltage, in the region of 70 kv. The soft tissues are composed in the main Postgrad Med J: first published as 10.1136/pgmj.5.59.193 on 1 August 1930. Downloaded from 194 X-RAY EXAMINATION OF THE URINARY TRACT of C, H, O and N, all of them elements with they can be displaced from side to side by a low atomic number. Any calculus con- moving the patient. If the stone be in a taining in quantity elements of a higher vesical diverticulum no displacement takes atomic number will cast a shadow in a place. Their shape is usually round, oval radiogram. or ovoid, and a common and typical Types of calculi with reference to their appearance is lamination of their shadow. opacity :- Pure Uric Acid Stone.-No shadow. DIFFERENTIAL DIAGNOSIS OF URINARY Ammonium Urate Stone.-A faint CALCULI. shadow. Phosphatic Stone. - A moderate The following may simulate urinary shadow. calculi :- Oxalate Stone.-A dense shadow, Renal. because of a large percentage of Intestinal Contents, Enteroliths, Shot from calcium. Game.-Re-examination after further pre- Cystine and xanthine stones, if pure, paration will distinguish between these. cast no shadow, but usually they Calcified Abdominal Glands.-These typi- contain some calcium. cally show an irregular density and outline, Virtually the opacity of a stone which distinguishes them. depends on its calcium and Calcified Gall-stones.-These are com- phosphorus content, as do the monly ringed, and, if multiple, facetted. A bones. lateral radiogram shows them in the anterior part of the abdomen, while renal stones liecopyright. POINTS IN THE RADIOGRAPHIC DIAGNOSIS posteriorly. OF CALCULI. Calcified Tuberculous Kidney.--Here the Kidney.-The shape is usually angular if shadows are mottled and diffuse. small, in which case they are commonly Papilloma of Skin on Back.-Inspection multiple. If large, they are branching, and will exclude this. tend to form a " cast" of the renal pelvis http://pmj.bmj.com/ and calyces. They are typically uniform in Ureteric. texture. A satisfactory radiogram will show Calcified Abdominal Glands. the outline of the kidney, and the shadow Tip of Lumbar Transverse Process.-This must be within this area. may be very dense compared with the rest Ureter.-As these are formed in the kidnev of the transverse process, and if, as it not the shape is that of a small renal stone. infrequently is, in the form of an acces- They are in the line of the ureter. This sory epiphysis, may closely simulate a on September 25, 2021 by guest. Protected passes down across the tips of the transverse stone. processes of the lumbar vertebrae, over the Calcareous Iliac Artery : Calcified Sacro- line of the sacro-iliac joint, and finally sciatic Ligament.-These give irregular sweeps round medial to tlhe shadow of the striated shadows. brim of the true pelvis to reach the bladder. Phleboliths.-These are the commonest If the stone is oval the long axis should be source of confusion. They occur very fre- in that of the ureter. Passage of an opaque quently in the iliac veins in the pelvis. If ureteric catheter will indicate the site of the single and in the ureteric line they cannot opacity relative to the ureter. be distinguished from ureteric stones with- Bladder.-Vesical calculi cast their shadow out the use of an opaque catheter. As a a little above the symphysis pubis, and in rule they are multiple, and their irregular or near the mid-line. If the bladder be full distribution gives the clue to their nature. Postgrad Med J: first published as 10.1136/pgmj.5.59.193 on 1 August 1930. Downloaded from X-RAY EXAMINATION OF THE URINARY TRACT 195 Bladder. the administration should be stopped when Prostatic Calculi and Calcification. The lumbar pain occurs, or when Io c.c. has shadows are rather low for the vesical area, been given. In some cases of hydrone- lying as they do behind the symphysis, and if phrosis renal pain does not occur with the calculi are multiple, or the calcification distension, and it is therefore unwise to extensive, the prostate is outlined. inject more than IO c.c. unless an appreciable Fcecal mass in rectum, particularly if quantity of urine has been previously drawn opaque medicines, such as bismuth, have off from the renal pelvis. been taken. A purge, followed by re- After a satisfactory outline of the renal examination, will settle the matter. pelvis has been obtained, the ureter can be Calcified Fibroid.-The irregular striation outlined fully by withdrawing the catheter will usually distinguish this rather rare almost out of the ureter, and then, while condition. the exposure is being made, keeping the Pelvic Dermoid.-If this contains teeth or ureter distended by pressure from the bone, a shadow will be cast. The recogni- syringe. tion of a tooth crown decides the nature in The pyelogram is of value in demonstrat- these cases. ing the following conditions. Calcareous Seminal Vesicles.-A rare con- Hydronephrosis.-A pyelogram will give dition, giving an irregular shadow. clear and unequivocal evidence of hydrone- Phlebolith. phrosis in all but the very earliest cases. Foreign body, introduced by a hysterical The earliest change is clubbing of the patient. This may form the nucleus of a calyces, broadening and shortening of the stone. calycal necks, and gradual distension of the renal pelvis. The junction of ureter and OTHER RADIOGRAPHIC AIDS IN DOUBTFUL pelvis becomes demarcated, and the uretercopyright. CASES OF CALCULUS. and lower margin of the pelvis form an Opaque Catheter.-The tip of an opaque increasingly acute angle. Finally the whole catheter may not coincide with the shadow becomes converted into a more or less of a renal calculus, but should at least be loculated sac. near it. The shadow of the catheter must Calculous Pyonephrosis.-A pyelogram will coincide with that of a ureteric stone, and show the latter element, and so will indicate moreover, must coincide in radiograms the operation of choice.