* With flank pain
* Increased inflammatory parameters
* Decreased kidney function
Why is the right kidney less dense than the left?
Click here to see the answer
Obstructive kidney stone in the right proximal ureter (arrow) with secondary hydronephrosis
The increased pressure in the collecting system slows the ultrafiltration of urine and causes a slower enhancement of the right kidney in comparison with the left kidney, reflecting the impaired kidney function
A 47-year-old female presented to the Emergency Room with bilateral upper extremity paresthesia, redness and edema. Her symptoms were not position-dependent. The patient was otherwise healthy, and did not take any medication. There is no pertinent surgical history.
An MR angiogram was ordered. The following images were obtained during bolus tracking:
Click here to see the images
T1-weighted images with fat saturation, following contrast administration
Click here to see the diagnosis
Superior vena cava (SVC) syndrome from right apical lung mass
In this patient with bilateral neurological deficits and edema, the suspicion of SVC syndrome must be addressed. This can be done using either an MRI or a CT protocol. In this case, the MRI scout bolus images (Image 1 & 2) revealed a pathognomonic sign for SVC occlusion:
Please note the marked collateral circulation following contrast administration to the right upper extremity with dilation of multiple intercostal and lateral thoracic veins. These collateral vessels then pool into the liver’s quadrate (segment 4 of the liver), giving the characteristic “hot spot sign”. This name originates from terminology in nuclear medicine, where it was occasionally seen in the case of SVC syndrome. Nowadays, it is more likely to be noticed on a CT or MR. This image also reveals the complete occlusion of the SVC.
Following fat-saturated T1-weighted axial image acquisition with contrast, the cause of the obstruction is evident. There is an infiltrative right apical mass which obstructs the SVC, as well as bilateral pleural effusions. Additionally, there is tumor thrombus noted in the left innominate vein, likely secondary to stasis.
Please review the following video and identify all these pertinent findings:
* Macroscopic hematuria and blood at urine meatus
What is the most likely diagnosis? What should we do next?
Click here to see the answer
X-ray: Bilateral pelvis fractures discontinuity iliopectineal line most clearly left-sided
CT: Bilateral ramus superior/anterior iliac bone and ramus inferior pubic bone
Avulsion fracture symphysis pubis
Fracture sacrum on the right
Look also in soft-tissue setting!
Large hematoma posterior of symphysis pubis around urethra and perineum, lateral around the pelvic floor obturator internus muscles and cranially in the retroperitoneal Retzius space anterior of the bladder
Do a RUG: Retrograde Urethrogram. If intact, followed by CT Cystography
RUG shows contrast extravasation and complete rupture of anterior bulbous part of urethra, grade V isolated anterior injury. However, the rupture might be at the anatomic weak point, the bulbomembranous junction, meaning avulsion of the puboprostatic ligament and stretching of the membranous urethra. There is no contrast above the urogenital diaphragm (level of symphysis pubis). Contrast in the bladder is a residue from the IV contrast given for earlier total body CT.
Goldman classification urethral injury
Anterior urethra = Penile and bulbous part
Posterior urethra = Membranous and prostatic part
Type I: stretching the posterior urethra due to disruption of puboprostatic ligaments and hematoma, but urethra is intact
The bulk of the tumour is within the ethmoid sinuses extending inferiorly into the nasal cavity and superiorly into the intracranial cavity through the cribriform plates
What is the lesion like?
Enhancing soft-tissue tumor expanding the ethmoid sinuses and nasal cavity
What are the MRI signal characteristics?
Mixed signal intensity on T2, low signal on T1, and intense enhancement on post-contrast images
What is the differential diagnosis of paranasal sinus tumour?
* Olfactory neuroblastoma: involves the ethmoid sinuses and extends through the cribriform plate into the anterior cranial fossa. Usually, shows intense enhancement and may show calcifications. They are slow growing with sinus expansion
* Juvenile angiofibroma: benign locally aggressive vascular tumor that affects adolescents. It is usually lobulated and expands the sphenopalatine foramen. Intense enhancement on post-contrast images
* Sinonasal carcinoma: heterogeneously enhancing mass that erodes the bone and may extend into the orbits or intracranially
* Lymphoma: low T2 signal with intense contrast enhancement and usually expands the bone