Monday, September 24, 2018
Case 7
Nice case of renal vein thrombosis (RVT). Whenever you look at the kidneys, and notice that one side is asymmetrically enlarged, make sure to look at the parenchyma to evaluate its enhancement. Remember - you have a control side (the other kidney), which will often be normal. In this case, the left kidney has delayed enhancement with perinephric stranding. Unfortunately, one of our guys missed the renal vein thrombosis and called this pyelonephritis.
Honestly, I think vascular structures outside of the Aorta are blind spots on CT for most radiologists, especially if it's not a CTA or CTV. Start including the other vascular structures (portal vein, mesenteric and renal vessels, and iliac veins) in your search pattern now so that you can buzz through them on every case looking for hidden abnormalities.
RVT is, much like portal vein thrombosis, related to either bland or tumor thrombus. In this case, there was no renal tumor present (other than some simple cysts), so this was a bland thrombus. According to radiopedia, the majority of bland thrombi are related to hypercoaguability from nephrotic syndrome (something I didn't know!), but I have most commonly seen thrombus in renal cell carcinoma and post trauma. The thrombus can break off and result in pulmonary embolism, so keep that complication in your back pocket. If you aren't sure if the vein is thrombosed, a renal doppler ultrasound would be a quick and helpful exam.
Nice case of renal vein thrombosis (RVT). Whenever you look at the kidneys, and notice that one side is asymmetrically enlarged, make sure to look at the parenchyma to evaluate its enhancement. Remember - you have a control side (the other kidney), which will often be normal. In this case, the left kidney has delayed enhancement with perinephric stranding. Unfortunately, one of our guys missed the renal vein thrombosis and called this pyelonephritis.
Honestly, I think vascular structures outside of the Aorta are blind spots on CT for most radiologists, especially if it's not a CTA or CTV. Start including the other vascular structures (portal vein, mesenteric and renal vessels, and iliac veins) in your search pattern now so that you can buzz through them on every case looking for hidden abnormalities.
RVT is, much like portal vein thrombosis, related to either bland or tumor thrombus. In this case, there was no renal tumor present (other than some simple cysts), so this was a bland thrombus. According to radiopedia, the majority of bland thrombi are related to hypercoaguability from nephrotic syndrome (something I didn't know!), but I have most commonly seen thrombus in renal cell carcinoma and post trauma. The thrombus can break off and result in pulmonary embolism, so keep that complication in your back pocket. If you aren't sure if the vein is thrombosed, a renal doppler ultrasound would be a quick and helpful exam.
Monday, September 17, 2018
Case 6
The sonographer called this a lesion, and from the answers I got this week, most knew it wasn't a real lesion, but weren't sure what to call it. This is an example of a renal junctional parenchymal defect, which is a normal variant. They will be triangular, echogenic foci in the renal cortex, sometimes with an echogenic tract from the cortex into the renal sinus fat. Generally, they are located between the upper pole and interpolar region of the kidney, but can be seen in the lower pole as well, as they are formed from incomplete embryologic fusion of the renal poles. Oftentimes, it is confused for a renal cortical scar or an angiomyolipoma.
The sonographer called this a lesion, and from the answers I got this week, most knew it wasn't a real lesion, but weren't sure what to call it. This is an example of a renal junctional parenchymal defect, which is a normal variant. They will be triangular, echogenic foci in the renal cortex, sometimes with an echogenic tract from the cortex into the renal sinus fat. Generally, they are located between the upper pole and interpolar region of the kidney, but can be seen in the lower pole as well, as they are formed from incomplete embryologic fusion of the renal poles. Oftentimes, it is confused for a renal cortical scar or an angiomyolipoma.
Tuesday, September 11, 2018
Monday, September 10, 2018
Case 5 - This is a nice case of an intraperitoneal focal fat infarction. I didn't show you the appendix in the selected images, but it was normal. When I initially dictated this case, I think I called it an epiploic appendagitis, but now, I think is more likely to be a small omental infarction. These are often mimics of an acute appendicitis. Classically, a primary omental infarction occurs in the right lower quadrant as the blood supply to the right side of the greater omentum is not very robust. Secondary omental infarctions will most often occur in a post-surgical abdomen. Rarely, they can occur in trauma.
On CT, you want to look for encapsulated fat with surrounding inflammatory stranding. If it is in the right lower quadrant, you want to think of an omental infarction. On the other hand, epiploic appendagitis is generally left sided, most commonly in the region of the rectosigmoid colon. However, the second most common location is in the region of the cecum. So, in order to differentiate the two, an omental infarction is larger, often over 5 cm. Regardless, it probably doesn't matter clinically as they are both treated conservatively with NSAIDS.
On CT, you want to look for encapsulated fat with surrounding inflammatory stranding. If it is in the right lower quadrant, you want to think of an omental infarction. On the other hand, epiploic appendagitis is generally left sided, most commonly in the region of the rectosigmoid colon. However, the second most common location is in the region of the cecum. So, in order to differentiate the two, an omental infarction is larger, often over 5 cm. Regardless, it probably doesn't matter clinically as they are both treated conservatively with NSAIDS.
Tuesday, September 4, 2018
There are multiple fractures involving the base of the fifth metatarsal. Today's case is a Pseudo-Jones fracture, which otherwise represents an avulsion fracture, often related to a forcible inversion of the foot in plantar flexion, resulting in the peroneus brevis ripping of the bony protuberance at the base of the 5th metatarsal. In my younger days, I had one of these after a sweet, fade-away jump shot during a charity basketball tournament. Those were the days, but I digress. When progressing more distally along the 5th metatarsal, approximately 2 cm in the region of the metadiaphyseal junction, you'll have the traditional Jones fracture. This represents an extra-articular, transverse fracture of the metatarsal shaft. Here is the same patient's ankle radiographs, which also demonstrate the fracture.
Here is a subtle, but real Jones fracture in another patient, who initially only received ankle radiographs. On how many views can you see the fracture?
Radiopedia has a great write up about these fractures and the proximal 5th metatarsal apophysis (remember: it will be longitudinal and parallel to the 5th metatarsal shaft).
Case courtesy of Dr Andrew Dixon, Radiopaedia.org. From the case rID: 7644
Here is a subtle, but real Jones fracture in another patient, who initially only received ankle radiographs. On how many views can you see the fracture?
Radiopedia has a great write up about these fractures and the proximal 5th metatarsal apophysis (remember: it will be longitudinal and parallel to the 5th metatarsal shaft).
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