SONOGRAPHIC DEMONSTRATION OF INTRAUTERINE CONTRACEPTIVE DEVICES by I. Watt, MRCP, FRCR: E. Watt, MB, D.Obst RCOG; M. Halliwell, BSc; and F.G.M. Ross, FRCR, DMRD
ABSTRACT Ultrasonic examination of the uterus is the investigation of choice in the initial localization of an IUCD within the uterine cavity. The use of compound B scanning in conjunction with A scans has been completely reliable to date. Radiography should be reserved for those patients in whom an expected device is not shown within the uterine cavity, and for those in whom the determination of the type of device is important and the scan is equivocal.
Indexing Words Ultrasound
Intrauterine Cavity
Intrauterine Contraceptive Devices
INTRODUCTION
MATERIAL
Nearly half a million intrauterine contraceptive devices (IUCD) are being worn in the United Kingdom and the number is rapidly increasing. The efficacy of the device depends upon its continued presence within the uterine cavity; clinical confirmation of this is usually possible by locating the threads provided on the device within the vagina. However, in up t o 10 per cent of Lippes loops, the threads become withdrawn into the uterine cavity (1). An average of 7.2 per cent of all devices are spontaneously expelled (2), and a small but important proportion are extrauterine in position. Location of a device when the threads are not visible is therefore an important problem. Probing with a uterine sound may confirm the presence of the device, but i t will not identify the type of device present or confirm that it is wholly intrauterine. Various methods of localization include plain film radiography, with or without a lateral radiograph, a uterine sound in position, hysterosalpingography, fluoroscopy, and hysteroscopy. Reports that ultrasound may be of value (3-6) have prompted the present assessment of ultrasound, both in the localization and identification of such devices (3, 4).
Fifty-five patients referred from Family Planning Clinics thought t o be wearing IUCD’s were examined. Their ages ranged between 1 9 and 50 years (mean 30.9 years). Thirty-six patients were referred for examination in whom the presence of their Loop was not in doubt. These comprised 17 with Lippes loops, 1 2 with Gravigards and seven with Dalkon shields. A further 19 patients were examined specifically because the continued presence of the IUCD was in doubt. There were 1 2 patients with Lippes loops, five with Gravigards, and two with Saf-T-Coils. In none of these 19 patients were the threads visible; the device could not be felt on uterine sounding in 18, and one patient was thought to be pregnant. Twenty-two volunteers aged between 19 and 42 years (mean 23.4 years) without an IUCD were also examined. Nine patients were taking an oral contraceptive preparation and 13 were not; five of the latter were examined immediately after termination of pregnancy in the first trimester.
From Dept. of Radiodiagnosis, Bristol Royal Infirmary, Bristol, England. Received August 5 . 1976; revision accepted April 5, 1977. For reprints contact: Dr. Ross, Consultant Radiologist, Department of Radiodiagnosis, Bristol Royal Infirmary, Bristol, England BS2 8 H W
378
METHOD
All examinations were performed in the Ultrasound Department at the Bristol General Hospital, using a locally made scanner (7) with a 2 MHz transducer and with 2-5 dB of added attenuation. All patients were examined with full bladders. Longitudinal compound B scans were made initially a t 1 cm intervals. A single JOURNAL O F CLINICAL ULTRASOUND
FIGURE 1. Diagrammatic representation of an A scan made o n a longitudinal section of the uterus. T h e ratio of the average height of the echoes reflected from the anterior uterine wall ( A ) and the posterior uterine wall ( P ) t o that from the uterine cavity (C) was recorded.
TABLE I Uterine Wall-to-Cavity Ratios 22 VOLUNTEERS:
55 PATIENTS:
12.5 x 2 9.2 9.1 8.8 8.3 8.0 x 3 7.5 x 3 7.0 6.5 6.0 x 2 5.0 x 2 4.7 4.5 3.5 3.1
10.00 (Expelled) 8.8 (Translocated) 5.3 (Expelled) 3.1 (Expelled) 2.5 2.3 2.0 x 2 1.9x 2 1.8 x 2 1.7 x 2 1.6 x 5 1.53 ~ 1.4 x 2 1.3 x 7 1.2 x 4 1.1 x 2 1.0 x 10 .9x 4 .8 x 2 .7 .6.
Graph I 1 cm intervals, the level being chosen by reference to the longitudinal scans. With experience fewer Polaroid pictures were exposed as information was taken from the monitor. A t most eight pictures were taken. The longitudinal scan upon which the most definite midline uterine echo had been visualized was rescanned and an A scan was made through the anterior and posterior uterine walls. The amplitudes of echoes reflected from the anterior and posterior uterine walls and the echoes from the cavity were recorded (Fig. 1). A ratio was expressed of the average amplitude from the uterine walls to that from the uterine cavity (Table I). A ratio between the anterior and posterior uterine walls was also determined (Table 11). The entire procedure occupied 5 to 15 minutes of scanning and recording time. When an IUCD was thought to be present, a Mean and one standard deviation marked. blind assessment of the type of device was made. E = device expelled. T = device translocated. Scans were made without initial recourse to clinscan was made, if necessary, to demonstrate the ical information. Ten patients in the problem group were also uterine cavity more clearly, at a half centimeter Six were examined early in the radiographed. interval. Several transverse scans were made at 379 VOLUME 5,NUMBER 6
TABLE II Anterior-to-Posterior Uterine Wall Ratios 22 VOLUNTEERS:
55 PATIENTS:
1.ox5 .92
1.6 1.5~2 1.2 1.I 1.0 x 11 .98 .94 .9 x 2
.88x 2 .86 .80 .75 x .67 x .6 x .57 x .46
3 4 2 2
.88 .85 .81 .80 x 3 .75 x 4 .73 .70 .67 x 4 .64 .63 .61 .59 .57 .50 x 4 .46 .44 .40 .34 .33 x 2 .26 .25 .23 .20
Graph II
Of these, 48 were patients in whom an IUCD had been inserted, and one was a volunteer who had a pronounced midline uterine echo, thought t o be a Dalkon shield. In three patients who had a Gravigard, an Antigon, and a Saf-T-Coil, the scan was equivocal. In one patient who had an IUCD in place, a coexisting pregnancy was demonstrated (seven weeks of amenorrhea). The overall accuracy of compound B scanning was 95 per cent.
Mean and one standard deviation marked.
A Scans. In 51 of the 55 patients in whom an IUCD had been inserted and was still present, the uterine wall-to-cavity ratio was 1.32 t SD.41. In the four patients in whom the device was not present, the wall-to-cavity ratio varied b6tween 3.1 and 10. There was no significant difference in the ratio between the various types of IUCDls. The wall-to-cavity ratio in the volunteer patients was 7.19 k SD.2.46. N o difference was found between those groups taking or not taking an oral contraceptive pill, but there was a higher ratio in the small group who had had abortion, implying RESULTS a smaller amplitude uterine cavity signal (t=2.13, Detection p .05). The difference in the wall-to-cavity B Scan. In 25 of the 77 scans the uterus was ratios between the IUCD patients and the volunthought to be empty of an IUCD. Of these, 2 1 teers was significant to the p .001 level were volunteer patients, three were patients who (t=ll.14). Analysis of the anterior-to-posterior had expelled their IUCD’s, and in one the device uterine wall ratios revealed no significant differhad perforated through the uterine wall. In 49 ences among any of the groups. There was no patients, an IUCD was identified by ultrasound. significant difference in ratios in terms of days
series, at a time when xray confirmation was felt to be necessary, in spite of the fact that a device had been clearly shown by ultrasound. A further four patients were examined because an expected device had not been shown by ultrasound. In three of these patients, the radiograph confirmed the absence of a device, but in one a device was shown. However, laparotomy revealed that this device had perforated the uterine wall.
380
J O U R N A L O F CLINICAL ULTRASOUND
2A
3A
28
3B
F)GURE 2. ( A ) Longitudinal scan 1 crn to the left of the midline with 10 dB of added attenuation. (B) Line drawing, The normal uterine outline and faint cavity echo i s shown in a volunteer without an IUCD i6 position.
FIGURE 3. ( A ) Longitudinal scan 1 cm t o the l e f t of t h e rnldline with 4 dB of added attenuation. (B) Line drawing. The normal uterine outline is again shown. There are multiple echoes from the uterine cavity in a patient wearing a Lippes loop.
from the last menstrual period, patient age, or parity. Similarity between the anterior-toposterior wall ratios between the volunteer and IUCD group of patients indicates that the observed difference in uterine wall-to-cavity ratio represents a true alteration in the intensity of the cavitv echo.
per cent). No difference between the types of devices could be found on the A scan ratios. DISCUSSION
Plain film radiography in the anteroposterior and lateral projections will confirm the presence and type of an intrauterine device. It does not, however, demonstrate the relationship between IDENTIFICATION the device and the uterine cavity without the Blind assessment of the type of IUCD present additional use of invasive techniques to outline achieved a 65 per cent overall accuracy. Correct the uterus or its cavity. Ultrasound has become recognized as a valuidentification was highest with a Lippes loop (78 per cent) and lowest with a Dalkon shield (13 able method for localizing an IUCD within the
V O L U M E 5 , NUMBER 6
381
uterine cavity (3-6)when its continued presence is clinically in doubt. Compound B scanning reveals the uterine outline and an echo from the cavity (Fig. 2). The presence of an IUCD within the cavity is shown by high amplitude echoes with an often typical pattern (Fig. 3). Ultrasonic scanning is noninvasive and free from the hazards of exposure to ionizing radiation, and therefore may be employed at any stage of the menstrual cycle and in the possible presence of early pregnancy. The only preparation necessary is a full bladder and discomfort is minimal. The technique is not expensive, and, with experience, can be performed in less than 10 minutes. Previously reported accuracy of compound B scanning in the localization of an intrauterine IUCD has varied between 89 per cent ( 4 ) and 100 per cent (5-6).However, difficulty has been reported with coexisting pregnancy, and local experience has shown that normal but pronounced uterine cavity echoes can be confused with those from a featureless device such as the Dalkon shield. A scanning has been reported only once previously (8),but no quantitation was applied to the results. A scanning has not been hitherto used in routine practice in conjunction with compound B scanning. An accuracy for the localization of an intrauterine device with compound B scanning may be expected in the region of 95 per cent. With the addition of A scans, the method is even more reliable. While the identification of the type of device present by radiography is invariably accurate, identification by compound B scanning is dis-
382
appointing, both in our series and elsewhere ( 4 ) . The A scan has not helped in distinguishing among the types of devices, and radiography was necessary in those few circumstances where it was important to know the type of device present and the scan was equivocal. ACKNOWLEDGEMENTS
The authors wish to thank the many Family Planning Clinic doctors who referred patjents and .volunteers for the study, and Mr. E. J. Turnbull for the illustrations. REFERENCES 1. Ianniruberto A and Mastroberardino A: Ultrasonic localization of the Lippes loop. Am J Obstet Gynecol114:78 (1972). 2. Progress Report, April 1972-June 1974. Family Planning Research Unit, University of Exeter, 14:20, 1974. 3. Barnett E and Morley P: Abdominal Echography. Butterworths, London, 1974. 4. Janssens D, Vrijens M, Thiery M and Van Kets H: Ultrasonic detection, localization and typing of intrauterine contraceptive devices (IUCD’s). Contraception 8:485,1973. 5. Zelnick E, Saary Z and Gershowitz H: Ultrasonic localization of “Missing IUCD’s”. Ultrasound Med Biol 1:233,1975. 6. Piiroinen 0: Ultrasonic localization of intrauterine contraceptive devices. Acta Obstet Gynec Scand 51: 203,1972. 7. McCarthy CF, Read Aea, Ross FGM, and Wells PNT: Ultrasonic scanning of the liver. Quart J Med 35:517,1967. 8. Winters HS: Ultrasound detection of intrauterine contraceptive devices. Am J Obstet Gynecol 95: 880,1966.
JOURNAL O F CLINICAL ULTRASOUND
ABSTRACT Ultrasonic examination of the uterus is the investigation of choice in the initial localization of an IUCD within the uterine cavity. The use of compound B scanning in conjunction with A scans has been completely reliable to date. Radiography should be reserved for those patients in whom an expected device is not shown within the uterine cavity, and for those in whom the determination of the type of device is important and the scan is equivocal.
Indexing Words Ultrasound
Intrauterine Cavity
Intrauterine Contraceptive Devices
INTRODUCTION
MATERIAL
Nearly half a million intrauterine contraceptive devices (IUCD) are being worn in the United Kingdom and the number is rapidly increasing. The efficacy of the device depends upon its continued presence within the uterine cavity; clinical confirmation of this is usually possible by locating the threads provided on the device within the vagina. However, in up t o 10 per cent of Lippes loops, the threads become withdrawn into the uterine cavity (1). An average of 7.2 per cent of all devices are spontaneously expelled (2), and a small but important proportion are extrauterine in position. Location of a device when the threads are not visible is therefore an important problem. Probing with a uterine sound may confirm the presence of the device, but i t will not identify the type of device present or confirm that it is wholly intrauterine. Various methods of localization include plain film radiography, with or without a lateral radiograph, a uterine sound in position, hysterosalpingography, fluoroscopy, and hysteroscopy. Reports that ultrasound may be of value (3-6) have prompted the present assessment of ultrasound, both in the localization and identification of such devices (3, 4).
Fifty-five patients referred from Family Planning Clinics thought t o be wearing IUCD’s were examined. Their ages ranged between 1 9 and 50 years (mean 30.9 years). Thirty-six patients were referred for examination in whom the presence of their Loop was not in doubt. These comprised 17 with Lippes loops, 1 2 with Gravigards and seven with Dalkon shields. A further 19 patients were examined specifically because the continued presence of the IUCD was in doubt. There were 1 2 patients with Lippes loops, five with Gravigards, and two with Saf-T-Coils. In none of these 19 patients were the threads visible; the device could not be felt on uterine sounding in 18, and one patient was thought to be pregnant. Twenty-two volunteers aged between 19 and 42 years (mean 23.4 years) without an IUCD were also examined. Nine patients were taking an oral contraceptive preparation and 13 were not; five of the latter were examined immediately after termination of pregnancy in the first trimester.
From Dept. of Radiodiagnosis, Bristol Royal Infirmary, Bristol, England. Received August 5 . 1976; revision accepted April 5, 1977. For reprints contact: Dr. Ross, Consultant Radiologist, Department of Radiodiagnosis, Bristol Royal Infirmary, Bristol, England BS2 8 H W
378
METHOD
All examinations were performed in the Ultrasound Department at the Bristol General Hospital, using a locally made scanner (7) with a 2 MHz transducer and with 2-5 dB of added attenuation. All patients were examined with full bladders. Longitudinal compound B scans were made initially a t 1 cm intervals. A single JOURNAL O F CLINICAL ULTRASOUND
FIGURE 1. Diagrammatic representation of an A scan made o n a longitudinal section of the uterus. T h e ratio of the average height of the echoes reflected from the anterior uterine wall ( A ) and the posterior uterine wall ( P ) t o that from the uterine cavity (C) was recorded.
TABLE I Uterine Wall-to-Cavity Ratios 22 VOLUNTEERS:
55 PATIENTS:
12.5 x 2 9.2 9.1 8.8 8.3 8.0 x 3 7.5 x 3 7.0 6.5 6.0 x 2 5.0 x 2 4.7 4.5 3.5 3.1
10.00 (Expelled) 8.8 (Translocated) 5.3 (Expelled) 3.1 (Expelled) 2.5 2.3 2.0 x 2 1.9x 2 1.8 x 2 1.7 x 2 1.6 x 5 1.53 ~ 1.4 x 2 1.3 x 7 1.2 x 4 1.1 x 2 1.0 x 10 .9x 4 .8 x 2 .7 .6.
Graph I 1 cm intervals, the level being chosen by reference to the longitudinal scans. With experience fewer Polaroid pictures were exposed as information was taken from the monitor. A t most eight pictures were taken. The longitudinal scan upon which the most definite midline uterine echo had been visualized was rescanned and an A scan was made through the anterior and posterior uterine walls. The amplitudes of echoes reflected from the anterior and posterior uterine walls and the echoes from the cavity were recorded (Fig. 1). A ratio was expressed of the average amplitude from the uterine walls to that from the uterine cavity (Table I). A ratio between the anterior and posterior uterine walls was also determined (Table 11). The entire procedure occupied 5 to 15 minutes of scanning and recording time. When an IUCD was thought to be present, a Mean and one standard deviation marked. blind assessment of the type of device was made. E = device expelled. T = device translocated. Scans were made without initial recourse to clinscan was made, if necessary, to demonstrate the ical information. Ten patients in the problem group were also uterine cavity more clearly, at a half centimeter Six were examined early in the radiographed. interval. Several transverse scans were made at 379 VOLUME 5,NUMBER 6
TABLE II Anterior-to-Posterior Uterine Wall Ratios 22 VOLUNTEERS:
55 PATIENTS:
1.ox5 .92
1.6 1.5~2 1.2 1.I 1.0 x 11 .98 .94 .9 x 2
.88x 2 .86 .80 .75 x .67 x .6 x .57 x .46
3 4 2 2
.88 .85 .81 .80 x 3 .75 x 4 .73 .70 .67 x 4 .64 .63 .61 .59 .57 .50 x 4 .46 .44 .40 .34 .33 x 2 .26 .25 .23 .20
Graph II
Of these, 48 were patients in whom an IUCD had been inserted, and one was a volunteer who had a pronounced midline uterine echo, thought t o be a Dalkon shield. In three patients who had a Gravigard, an Antigon, and a Saf-T-Coil, the scan was equivocal. In one patient who had an IUCD in place, a coexisting pregnancy was demonstrated (seven weeks of amenorrhea). The overall accuracy of compound B scanning was 95 per cent.
Mean and one standard deviation marked.
A Scans. In 51 of the 55 patients in whom an IUCD had been inserted and was still present, the uterine wall-to-cavity ratio was 1.32 t SD.41. In the four patients in whom the device was not present, the wall-to-cavity ratio varied b6tween 3.1 and 10. There was no significant difference in the ratio between the various types of IUCDls. The wall-to-cavity ratio in the volunteer patients was 7.19 k SD.2.46. N o difference was found between those groups taking or not taking an oral contraceptive pill, but there was a higher ratio in the small group who had had abortion, implying RESULTS a smaller amplitude uterine cavity signal (t=2.13, Detection p .05). The difference in the wall-to-cavity B Scan. In 25 of the 77 scans the uterus was ratios between the IUCD patients and the volunthought to be empty of an IUCD. Of these, 2 1 teers was significant to the p .001 level were volunteer patients, three were patients who (t=ll.14). Analysis of the anterior-to-posterior had expelled their IUCD’s, and in one the device uterine wall ratios revealed no significant differhad perforated through the uterine wall. In 49 ences among any of the groups. There was no patients, an IUCD was identified by ultrasound. significant difference in ratios in terms of days
series, at a time when xray confirmation was felt to be necessary, in spite of the fact that a device had been clearly shown by ultrasound. A further four patients were examined because an expected device had not been shown by ultrasound. In three of these patients, the radiograph confirmed the absence of a device, but in one a device was shown. However, laparotomy revealed that this device had perforated the uterine wall.
380
J O U R N A L O F CLINICAL ULTRASOUND
2A
3A
28
3B
F)GURE 2. ( A ) Longitudinal scan 1 crn to the left of the midline with 10 dB of added attenuation. (B) Line drawing, The normal uterine outline and faint cavity echo i s shown in a volunteer without an IUCD i6 position.
FIGURE 3. ( A ) Longitudinal scan 1 cm t o the l e f t of t h e rnldline with 4 dB of added attenuation. (B) Line drawing. The normal uterine outline is again shown. There are multiple echoes from the uterine cavity in a patient wearing a Lippes loop.
from the last menstrual period, patient age, or parity. Similarity between the anterior-toposterior wall ratios between the volunteer and IUCD group of patients indicates that the observed difference in uterine wall-to-cavity ratio represents a true alteration in the intensity of the cavitv echo.
per cent). No difference between the types of devices could be found on the A scan ratios. DISCUSSION
Plain film radiography in the anteroposterior and lateral projections will confirm the presence and type of an intrauterine device. It does not, however, demonstrate the relationship between IDENTIFICATION the device and the uterine cavity without the Blind assessment of the type of IUCD present additional use of invasive techniques to outline achieved a 65 per cent overall accuracy. Correct the uterus or its cavity. Ultrasound has become recognized as a valuidentification was highest with a Lippes loop (78 per cent) and lowest with a Dalkon shield (13 able method for localizing an IUCD within the
V O L U M E 5 , NUMBER 6
381
uterine cavity (3-6)when its continued presence is clinically in doubt. Compound B scanning reveals the uterine outline and an echo from the cavity (Fig. 2). The presence of an IUCD within the cavity is shown by high amplitude echoes with an often typical pattern (Fig. 3). Ultrasonic scanning is noninvasive and free from the hazards of exposure to ionizing radiation, and therefore may be employed at any stage of the menstrual cycle and in the possible presence of early pregnancy. The only preparation necessary is a full bladder and discomfort is minimal. The technique is not expensive, and, with experience, can be performed in less than 10 minutes. Previously reported accuracy of compound B scanning in the localization of an intrauterine IUCD has varied between 89 per cent ( 4 ) and 100 per cent (5-6).However, difficulty has been reported with coexisting pregnancy, and local experience has shown that normal but pronounced uterine cavity echoes can be confused with those from a featureless device such as the Dalkon shield. A scanning has been reported only once previously (8),but no quantitation was applied to the results. A scanning has not been hitherto used in routine practice in conjunction with compound B scanning. An accuracy for the localization of an intrauterine device with compound B scanning may be expected in the region of 95 per cent. With the addition of A scans, the method is even more reliable. While the identification of the type of device present by radiography is invariably accurate, identification by compound B scanning is dis-
382
appointing, both in our series and elsewhere ( 4 ) . The A scan has not helped in distinguishing among the types of devices, and radiography was necessary in those few circumstances where it was important to know the type of device present and the scan was equivocal. ACKNOWLEDGEMENTS
The authors wish to thank the many Family Planning Clinic doctors who referred patjents and .volunteers for the study, and Mr. E. J. Turnbull for the illustrations. REFERENCES 1. Ianniruberto A and Mastroberardino A: Ultrasonic localization of the Lippes loop. Am J Obstet Gynecol114:78 (1972). 2. Progress Report, April 1972-June 1974. Family Planning Research Unit, University of Exeter, 14:20, 1974. 3. Barnett E and Morley P: Abdominal Echography. Butterworths, London, 1974. 4. Janssens D, Vrijens M, Thiery M and Van Kets H: Ultrasonic detection, localization and typing of intrauterine contraceptive devices (IUCD’s). Contraception 8:485,1973. 5. Zelnick E, Saary Z and Gershowitz H: Ultrasonic localization of “Missing IUCD’s”. Ultrasound Med Biol 1:233,1975. 6. Piiroinen 0: Ultrasonic localization of intrauterine contraceptive devices. Acta Obstet Gynec Scand 51: 203,1972. 7. McCarthy CF, Read Aea, Ross FGM, and Wells PNT: Ultrasonic scanning of the liver. Quart J Med 35:517,1967. 8. Winters HS: Ultrasound detection of intrauterine contraceptive devices. Am J Obstet Gynecol 95: 880,1966.
JOURNAL O F CLINICAL ULTRASOUND
