B SCAN DETECTION OF PELVIC MASSES: ACCURACY COMPARED TO THE BARIUM ENEMA

INTRAVENOUS PYELOGRAM

by Michael Hogan, MD and Aree Srichomkuan, MD

ABSTRACT One hundred fifty nine pelvic ultrasonic examinations were performed; 54 were verified. The relative diagnostic accuracy of ultrasound, intravenous pyelograms, and barium enemas in detecting pelvic masses is discussed. Ultrasound is highly accurate except in ascites. While barium enema and intravenous pyelogram are both inaccurate. Ultrasound should be the initial examination for the evaluation of patients with a possible pelvic mass.

Indexing Words Pelvic Mass Ultrasound Intravenous Pyelogram Barium Enema

Ultrasound continues to be more and more frequently used. This is particularly true in obstetrics, while in the field of gynecology its usefulness has not been as widely accepted. Other diagnostic procedures such as the barium enema and intravenous pyelogram continue to be ordered during the workup of a pelvic mass. Some of these procedures admittedly are or- dered to evaluate the extent of the disease pro- cess, but others are ordered to determine whether a pelvic mass is or is not present. Be- cause of this, we decided to review the accuracy of ultrasound and correlate its accuracy with that of the barium enema and intravenous pyelogram in detecting pelvic masses. This paper deals with 54 consecutive patients who were referred to the ultrasound laboratory at West Virginia University Hospital for evaluation of a possible pelvic mass and who subsequently had operative verification. One hundred fifty nine pelvic ultrasonic examinations were performed during this time period, but only 54 diagnoses were verified. No examination performed when a known pregnancy was present was included.

RESULTS

Of the 54 patients referred to the ultrasound laboratory for possible pelvic mass, three were pregnant. Two other patients had inc’onclusive

From the Department of Radiology. West Virginia University

Received May 11. 1977; revision accepted February 2. 1978. For reprints contact: Michael Hogan, M.D., Associate Profes-

sor. Department of Radiology, West Virginia University School of Medicine, Morgantown, West Virginia 26506.

JCU. Vol. 6 , 73-142 ( 1 9 7 8 ) . 0 1 9 7 8 , John Wiley and Sons. 0091-2751/78/0006-0103 $01.00.

School of Medicine, Morgantown. West Virginia.

studies, Incidentally, both of these patients had negative surgical explorations. The remaining 49 were included in this retrospective analysis. Although not necessarily in the same patients, 26 had a barium enema and 27 had an intra- venous pyelogram.

Of 49 patients who had ultrasonic examina- tions, pelvic masses were confirmed in 45. Of these 45 patients, 40 had a positive ultrasound procedure. Four of the five patients in whom no mass was detected by ultrasound had gross ascites. Why the ascites interferred with the accuracy of ultrasound in detecting pelvic masses is unknown. However, Hanke (1) stated that, for unknown reasons, large amounts of ascites also made scanning of the pancreas difficult. In the four cases with negative explor- ations, the ultrasound examinations were also negative. These findings indicate that ultra- sound is highly accurate in the detection of pelvic masses, except in the presence of ascites.

Of the 26 patients who had barium enema examinations, 22 had pelvic masses. Only 11 of these had positive barium enemas while 11 had negative barium enemas. The other four had both negative explorations and negative barium enemas. The barium enema is thus inaccurate in the detection of pelvic masses.

Of 27 patients who had intravenous pyelo- grams, 23 had a pelvic mass. Only 12 of these had a positive intravenoue pyelogram while 11 had negative intravenous pyelograms. The other four had both negative explorations and nega-

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tive intravenous pyelograms. The intravenous pyelogram, like the barium enema, is also inaccurate in the detection of pelvic masses.

DISCUSSION

Although several authors (2-5) have demon- strated the value of ultrasound in diagnosing pelvic masses, its role in the workup of such pelvic masses does not seem to be fully appre- ciated. Adequate pelvic and abdominal exami- nations cannot always adequately be per- formed in obese patients, patients who have had prior surgery or irradiation, some children, or patients who have guarding because of tender- ness or other reasons. These conditions are indi- cations for an ultrasound examination of the pelvis.

The above comparative results are not sur- prising and could have been anticipated. Yet physicians still commonly request barium enemas and intravenous pyelograms as the first procedure in clinical situations in which the diagnosis of a pelvic mass is a possibility. Both of these procedures are inaccurate in such situ- ations and are helpful only when positive. Ultrasound is much more accurate and should be the first procedure ordered in such a situa- tion. Instead of relying upon indirect evidence or pressure upon the rectum, bladder, or ureters, ultrasound provides a two-dimensional image of

the pelvic structures. The discovery of small masses still presents a problem, because the resolution of present ultrasound equipment is approximately 2.5 cm.

Ultrasound also avoids radiation to a potenti- ally pregnant person. Three of these fifty four patients referred to the ultrasound laboratory for possible pelvic mass were indeed pregnant.

Ultrasound studies are also readily available. Ultrasound equipment and trained personnel are sufficiently abundant so that information formerly sought with radiographic procedures can be obtained by ultrasound. The allegiance to older and more familiar but less accurate studies should be relinquished. Ultrasound should be the initial study in the diagnostic workup of a possible pelvic mass.cd

REFERENCES

1. Hancke S: Ultrasonic scanning of the pancreas. J Clin Ultrasound 4:233, 1976.

2. Cochrane WJ; Thomas MA: Ultrasound in obstetrics and gynecology. Br J Radiol 110:649,1974.

3. Donald I, Abdulla U: Ultrasonics in obstetrics and gynecology. Br J Radiol 10:604, 1967.

4. Thompson H E : The clinical use OP pulsed echo ultrasound in obstetrics and gynecology. Obstet Gynec Surv 23:903, 1968.

5. Morley P, Barnett E: The use of ultrasound in the diagnosis of pelvic masses. Br J Radiol 43:602, 1970.

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