- Email: [email protected]
Magnetic resonance imaging findings in ovarian torsion
Magnetic
Pergamon
Resonance Imaging, Vol. 13, No. 1, pp. 111-113, 1995 Copyright 0 1994 Elsevier Science Ltd Printed in the USA. All rights reserved 0730-725x/95 $9.50 + .oa
0730-725X(94)00099-9
l CaseReport MAGNETIC
RESONANCE
IMAGING KIRAN
FINDINGS
IN OVARIAN
TORSION
A. JAIN
Department of Radiology, University of California Davis Medical Center, Sacramento, CA 95817, USA
INTRODUCTION
cle on Tr- and T2-weighted images (Figs. 1B and 1C). On T&weighted images the ovarian parenchyma was interspersed with round and curvilinear areas of high signal intensity (Fig. 1C). The cyst within the enlarged ovary showed marked low signal intensity (similar to urine) on T, -weighted (300/ 15) images and high signal intensity (similar to urine) on T2-weighted (2500/70) images (Figs. 1B and 1C). At surgery the right sided mass was actually found to be the left ovary on a long mesovarium which had flipped over to the right side. The right ovary was normal. Left salpingo-oophorectomy was performed. The left ovary measured 11.5 x 9.0 x 3.0 cm and the gross appearance was dark, reddish-purple mass. The specimen was markedly hemorrhagic and dilated and engorged blood vessels were found in the specimen. The cyst was filled with blood tinged yellowish watery material. Permanent sections of the left ovary confirmed the diagnosis of hemorrhagic infarction. Portions of the fallopian tube also showed hemorrhagic infarction.
Hemorrhagic infarction of the ovary is a known complication of ovarian torsion. However, the imaging findings on magnetic resonance imaging (MRI) are not well known. One case report is available.’ Edema of the ovary is primarily due to obstruction of venous and lymphatic flow with continued arterial perfusion, which leads to diffuse enlargement and edema of the ovarian parenchyma and distension of the follicles due to transudation of fluid within them. The degree of torsion at this time is insufficient to cause ischemic necrosis, but is sufficient to elevate capillary hydrostatic pressure and to interfere with lymphatic drainage. With further progression of time, venous occlusion occurs, which is followed by arterial thrombosis.’ At this time, hemorrhagic infarction of the ovary results. MRI findings are reported in a case of a massively enlarged ovary with surgically and pathologically proven hemorrhagic infarction secondary to ovarian torsion. The findings differ from those previously reported.’
DISCUSSION
CASE REPORT A 13-yr-old premenarcheal girl was admitted to the hospital because of right lower quadrant abdominal pain and a palpable mass. She had no significant past medical history. Pelvic sonography, using the transabdominal approach, revealed a 11.5 x 9.0 x 3 .O cm predominantly solid mass with a 2.5 x 2.0 x 2.0 cm cyst within it. This mass was located to the right of the uterus and extended up to midline (Fig. 1A). The uterus was normal. MR images showed diffuse enlargement of the ovarian parenchyma which had low signal intensity similar to mus-
Mechanical torsion of the vascular pedicle of the ovary (ovarian torsion) is an unusual, though not rare, condition occurring in females in the first two decades of life; it has its highest incidence before puberty and during pregnancy. By a 3:2 ratio, the right side is more often involved; a predominance thought to be related to the diminished space in the left side of the pelvis due to presence of sigmoid colon and differences in venous drainage.3 In 70% of cases, torsion of the ovary occurs in patients with abnormal ovaries. A normal ovary may also undergo torsion, but this finding is more com-
j/13/94; ACCEPTED 7/13/94. Address correspondence to Kiran A. Jain, MD, Depart-
ment of Radiology, UC Davis Medical Center, Ticon II, 2516
RECEIVED
Stockton Blvd., Sacramento, CA 95817, USA. 111
112
Magnetic ResonanceImaging 0 Volume 13, Number 1, 1995
Fig. 1A. Transverse sonogram showed enlarged ovary (0) with a cyst (cursors).
mon in prepubertal females in whom a mobile ovary due to a long mesovarium may allow torsion at the mesosalpinx to occur.4 Ovarian torsion is most often precipitated by hemorrhage into the ovary or the presence of a mass. It may also occur as a result of processes that increase the weight of the ovary, as happens in superovulation with multiple follicles or vascular engorgement secondary to incompetent ovarian vein valves5
Fig. IB. Torsive left ovary in a 1%yr-old patient. Coronal T,-weighted (3OW15) MR image showslow-intensity ovarian parenchyma (arrows) surrounding a central cyst (C). B = urinary bladder.
Fig. 1C. Sagittal T2-weighted (2500/70) MR image shows high-intensity round and serpentine areas (arrows). C = cyst, B = urinary bladder, R = fluid-filled rectosigmoid.
The clinical presentation of patients with ovarian torsion is nonspecific. Onset of pelvic or lower abdominal pain is acute and accompanied by nausea and vomiting. The acuteness of onset and tenderness suggest a process other than inflammation. Approximately 50% of patients have a history of similar episodes, presumably corresponding to twisting and untwisting of the ovary.6 The findings described on MRI examination can be helpful in recognizing the diagnosis of ovarian torsion with hemorrhagic infarction. The low intensity of the enlarged ovarian parenchyma on both T, and T2 images with high intensity rounded and curvilinear areas were the distinctive MRI findings in this case. The low signal intensity of the ovarian parenchyma on T, - and T,-weighted images may be attributed to infarction as the intensity of normal ovarian parenchyma is reported to be that of striated muscle on T, and approaches that of fat on T2-weighted images.’ The intensity of edematous ovarian parenchyma would show low intensity on T, -weighted images and high intensity on T2weighted images.8 The serpiginous curvilinear high signal intensity structures within the enlarged ovarian parenchyma have not been described. These most likely represented dilated veins and were noted at pathologic examination. The cyst did not demonstrate evidence of hemorrhage on MRI possibly because, although the ovarian parenchyma showed hemorrhagic infarction at pathology, the cyst was filled with blood tinged serous
MRI
for ovarian torsion 0
fluid and did not contain frank blood. In a sporadic case report on MRI of hemorrhagic infarction Kawakami et al.’ described a finding of a high intensify rim at the periphery of an ovarian tumor on T,-weighted image as an MRI sign of hemorrhagic infarction. Findings in this case were different from their observation. Ovarian masses with hemorrhagic infarction can rupture and lead to peritonitis and even death and emergency surgery may be necessary in selected cases. Early identification of hemorrhagic infarction of the ovary is essential for appropriate management of the patients with ovarian torsion. However, there appears to be a spectrum of imaging findings with ovarian infarction. This might be related to the degree and duration of torsion and the concurrent variable histological changes. REFERENCES 1. Kawakami, K.; Murata, K.; Kawaguchi, N.; et al. Hemorrhagic infarction of the diseased ovary: A common MR
2. 3. 4.
5.
6.
7. 8.
K.A.
JAIN
113
finding in two cases. Magn. Reson. Imaging 11:595-597; 1993. Kapadia, R.; Sternhill, V.; Schwartz, E. Massive edema of the ovary. J. Clin. Ultrasound 10:469-471; 1982. Kanbout, A.I.; Salazar, H.; Tobon, H. Massive ovarian edema. Arch. Pathol. Lab. Med. 103:42-45; 1979. Graif, M.; Itzchak, Y. Sonographic evaluation of ovarian torsion in childhood and adolescence. AJR 150:647649; 1988. Fleischer, A.C.; Williams, L.L.; Jones, H.W., III. Transabdominal and transvaginal color Doppler sonography of ovarian masses. In: A.C. Fleischer, H.W. Jones, III, (Eds.). Early Detection of Ovarian Carcinoma with Transvaginal Sonography Potentials and Limitations, 1st ed. New York: Raven Press; 1993:~~. 85-144. Schultz, L.R.; Newton, W.A.; Clatworthy, H.W. Torsion of previously normal tube and ovary in children. N. Eng. J. Med. 278:343-346; 1963. Doom, G.C.; Hricak, H.; Tscholakoff, D. Adnexal structures: MR imaging. Radiology 158:639-646; 1986. Lee, A.; Kim, K.H.; Lee, B.H.; Chin, S.Y. Massiveedema of the ovary: Imaging findings. AJR 161:343-344; 1993.
Pergamon
Resonance Imaging, Vol. 13, No. 1, pp. 111-113, 1995 Copyright 0 1994 Elsevier Science Ltd Printed in the USA. All rights reserved 0730-725x/95 $9.50 + .oa
0730-725X(94)00099-9
l CaseReport MAGNETIC
RESONANCE
IMAGING KIRAN
FINDINGS
IN OVARIAN
TORSION
A. JAIN
Department of Radiology, University of California Davis Medical Center, Sacramento, CA 95817, USA
INTRODUCTION
cle on Tr- and T2-weighted images (Figs. 1B and 1C). On T&weighted images the ovarian parenchyma was interspersed with round and curvilinear areas of high signal intensity (Fig. 1C). The cyst within the enlarged ovary showed marked low signal intensity (similar to urine) on T, -weighted (300/ 15) images and high signal intensity (similar to urine) on T2-weighted (2500/70) images (Figs. 1B and 1C). At surgery the right sided mass was actually found to be the left ovary on a long mesovarium which had flipped over to the right side. The right ovary was normal. Left salpingo-oophorectomy was performed. The left ovary measured 11.5 x 9.0 x 3.0 cm and the gross appearance was dark, reddish-purple mass. The specimen was markedly hemorrhagic and dilated and engorged blood vessels were found in the specimen. The cyst was filled with blood tinged yellowish watery material. Permanent sections of the left ovary confirmed the diagnosis of hemorrhagic infarction. Portions of the fallopian tube also showed hemorrhagic infarction.
Hemorrhagic infarction of the ovary is a known complication of ovarian torsion. However, the imaging findings on magnetic resonance imaging (MRI) are not well known. One case report is available.’ Edema of the ovary is primarily due to obstruction of venous and lymphatic flow with continued arterial perfusion, which leads to diffuse enlargement and edema of the ovarian parenchyma and distension of the follicles due to transudation of fluid within them. The degree of torsion at this time is insufficient to cause ischemic necrosis, but is sufficient to elevate capillary hydrostatic pressure and to interfere with lymphatic drainage. With further progression of time, venous occlusion occurs, which is followed by arterial thrombosis.’ At this time, hemorrhagic infarction of the ovary results. MRI findings are reported in a case of a massively enlarged ovary with surgically and pathologically proven hemorrhagic infarction secondary to ovarian torsion. The findings differ from those previously reported.’
DISCUSSION
CASE REPORT A 13-yr-old premenarcheal girl was admitted to the hospital because of right lower quadrant abdominal pain and a palpable mass. She had no significant past medical history. Pelvic sonography, using the transabdominal approach, revealed a 11.5 x 9.0 x 3 .O cm predominantly solid mass with a 2.5 x 2.0 x 2.0 cm cyst within it. This mass was located to the right of the uterus and extended up to midline (Fig. 1A). The uterus was normal. MR images showed diffuse enlargement of the ovarian parenchyma which had low signal intensity similar to mus-
Mechanical torsion of the vascular pedicle of the ovary (ovarian torsion) is an unusual, though not rare, condition occurring in females in the first two decades of life; it has its highest incidence before puberty and during pregnancy. By a 3:2 ratio, the right side is more often involved; a predominance thought to be related to the diminished space in the left side of the pelvis due to presence of sigmoid colon and differences in venous drainage.3 In 70% of cases, torsion of the ovary occurs in patients with abnormal ovaries. A normal ovary may also undergo torsion, but this finding is more com-
j/13/94; ACCEPTED 7/13/94. Address correspondence to Kiran A. Jain, MD, Depart-
ment of Radiology, UC Davis Medical Center, Ticon II, 2516
RECEIVED
Stockton Blvd., Sacramento, CA 95817, USA. 111
112
Magnetic ResonanceImaging 0 Volume 13, Number 1, 1995
Fig. 1A. Transverse sonogram showed enlarged ovary (0) with a cyst (cursors).
mon in prepubertal females in whom a mobile ovary due to a long mesovarium may allow torsion at the mesosalpinx to occur.4 Ovarian torsion is most often precipitated by hemorrhage into the ovary or the presence of a mass. It may also occur as a result of processes that increase the weight of the ovary, as happens in superovulation with multiple follicles or vascular engorgement secondary to incompetent ovarian vein valves5
Fig. IB. Torsive left ovary in a 1%yr-old patient. Coronal T,-weighted (3OW15) MR image showslow-intensity ovarian parenchyma (arrows) surrounding a central cyst (C). B = urinary bladder.
Fig. 1C. Sagittal T2-weighted (2500/70) MR image shows high-intensity round and serpentine areas (arrows). C = cyst, B = urinary bladder, R = fluid-filled rectosigmoid.
The clinical presentation of patients with ovarian torsion is nonspecific. Onset of pelvic or lower abdominal pain is acute and accompanied by nausea and vomiting. The acuteness of onset and tenderness suggest a process other than inflammation. Approximately 50% of patients have a history of similar episodes, presumably corresponding to twisting and untwisting of the ovary.6 The findings described on MRI examination can be helpful in recognizing the diagnosis of ovarian torsion with hemorrhagic infarction. The low intensity of the enlarged ovarian parenchyma on both T, and T2 images with high intensity rounded and curvilinear areas were the distinctive MRI findings in this case. The low signal intensity of the ovarian parenchyma on T, - and T,-weighted images may be attributed to infarction as the intensity of normal ovarian parenchyma is reported to be that of striated muscle on T, and approaches that of fat on T2-weighted images.’ The intensity of edematous ovarian parenchyma would show low intensity on T, -weighted images and high intensity on T2weighted images.8 The serpiginous curvilinear high signal intensity structures within the enlarged ovarian parenchyma have not been described. These most likely represented dilated veins and were noted at pathologic examination. The cyst did not demonstrate evidence of hemorrhage on MRI possibly because, although the ovarian parenchyma showed hemorrhagic infarction at pathology, the cyst was filled with blood tinged serous
MRI
for ovarian torsion 0
fluid and did not contain frank blood. In a sporadic case report on MRI of hemorrhagic infarction Kawakami et al.’ described a finding of a high intensify rim at the periphery of an ovarian tumor on T,-weighted image as an MRI sign of hemorrhagic infarction. Findings in this case were different from their observation. Ovarian masses with hemorrhagic infarction can rupture and lead to peritonitis and even death and emergency surgery may be necessary in selected cases. Early identification of hemorrhagic infarction of the ovary is essential for appropriate management of the patients with ovarian torsion. However, there appears to be a spectrum of imaging findings with ovarian infarction. This might be related to the degree and duration of torsion and the concurrent variable histological changes. REFERENCES 1. Kawakami, K.; Murata, K.; Kawaguchi, N.; et al. Hemorrhagic infarction of the diseased ovary: A common MR
2. 3. 4.
5.
6.
7. 8.
K.A.
JAIN
113
finding in two cases. Magn. Reson. Imaging 11:595-597; 1993. Kapadia, R.; Sternhill, V.; Schwartz, E. Massive edema of the ovary. J. Clin. Ultrasound 10:469-471; 1982. Kanbout, A.I.; Salazar, H.; Tobon, H. Massive ovarian edema. Arch. Pathol. Lab. Med. 103:42-45; 1979. Graif, M.; Itzchak, Y. Sonographic evaluation of ovarian torsion in childhood and adolescence. AJR 150:647649; 1988. Fleischer, A.C.; Williams, L.L.; Jones, H.W., III. Transabdominal and transvaginal color Doppler sonography of ovarian masses. In: A.C. Fleischer, H.W. Jones, III, (Eds.). Early Detection of Ovarian Carcinoma with Transvaginal Sonography Potentials and Limitations, 1st ed. New York: Raven Press; 1993:~~. 85-144. Schultz, L.R.; Newton, W.A.; Clatworthy, H.W. Torsion of previously normal tube and ovary in children. N. Eng. J. Med. 278:343-346; 1963. Doom, G.C.; Hricak, H.; Tscholakoff, D. Adnexal structures: MR imaging. Radiology 158:639-646; 1986. Lee, A.; Kim, K.H.; Lee, B.H.; Chin, S.Y. Massiveedema of the ovary: Imaging findings. AJR 161:343-344; 1993.