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This is an MRI of the abdomen and

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pelvis in a patient presenting in the

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early second trimester of pregnancy

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with acute left lower quadrant pain.

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We can see that there is significant respiratory

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motion artifact evident on this exam, which

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is another indicator that the patient is

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likely uncomfortable during this examination.

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These are T2-weighted images of the

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abdomen and pelvis, and before the gravid

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uterus comes into view, we begin to see an

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enlarged, predominantly T2 hyperintense

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mass that is in the left hemiabdomen.

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We can trace it down toward the left

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adnexa, and we can see that it communicates

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with the vascular pedicle, which

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arises from the lateral left uterus.

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So the vascular pedicle goes on to communicate

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with this lesion, which we can determine both

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because of the connection, but also because

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of the peripheral T2 hyperintense follicles

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that this is indeed of ovarian origin.

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A few other characteristics that

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we can use to describe this lesion

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in addition to being predominantly T2

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hyperintense, there are some septated

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or loculated components of this lesion.

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We see multiple T2 hyperintense

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locules, as well as the suggestion

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of some more independent or separate

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areas of nodularity within the lesion.

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This is the gravid uterus.

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We can see that this patient has multiple

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T2 hypointense uterine fibroids.

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In addition to a normal-appearing

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early placenta, we see the fetus

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suboptimally in these images.

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Posterior to the uterus, in the

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right hemipelvis, is a bilobed, mixed

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cystic and complex mass, which is

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in the region of the right ovary.

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We don't see the right ovary on these

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images, and so not seeing the organ of

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interest, but identifying a mass in its

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expected location is called the phantom

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organ sign, which you can use to imply that

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this lesion is of right ovarian origin.

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We can further evaluate these lesions by

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comparing their appearance on T1 non-fat

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saturated and T1 fat-saturated images.

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We can see that the subcutaneous fat is

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bright in the non-fat-saturated image and

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dark in the fat-saturated image.

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Let's start with the left ovarian lesion.

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This lesion is predominantly bright

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on the non-fat-saturated image and

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becomes dark on the fat-saturated image.

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Those areas of nodularity also become

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more apparent on the T1-weighted images

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than they were on the T2-weighted images.

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So we see a predominantly fat-containing

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mass with multiple areas of internal

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nodularity arising from the left ovary.

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When we evaluate the characteristics of

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the right ovarian mass, we can see that on

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the T1 pre-contrast image, there is almost

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a fat debris level within the lesion.

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There's a very clear demarcation between

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two types of material which are contained

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within this one component of the mass.

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In addition to a relatively T1 hypointense

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component of this overall

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lesion arising from the right ovary.

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On the fat-saturated images, we can see

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that what was bright in the anterior

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and dependent portion of this loculated

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component of the lesion saturates

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out and is indeed fat-containing.

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There is some drop in signal on the fat

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saturated images here, as well as here, and

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so this may be hemorrhage or proteinaceous

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debris within these other components.

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And so this is a patient

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who is coming in with bilateral adnexal masses,

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both of which exhibit characteristics of

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ovarian teratomas, mature ovarian teratomas.

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It's important to point out that the

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left ovarian lesion is quite large and

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in addition to connecting to the vascular

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pedicle that extends toward the left lateral

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aspect of the uterus, we do see a small

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amount of swirling in this region as well.

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And so it would be important in this patient

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who's having left lower quadrant pain to

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also do a pelvic ultrasound to evaluate

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the patency of the ovarian vasculature

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on the left and be sure that this patient

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is not experiencing ovarian torsion in

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the context of this large adnexal mass.