Radiology short cases

🚩Duplication of the pituitary gland (DPG-plus) syndrome



Complete duplication of the pituitary gland with two posterior pituitary bright spots and paired infundibula, located in two separated infundibular recesses

♦️Duplication of the pituitary gland (DPG) is a rare developmental anomaly that may occur in an isolated fashion or in combination with other congenital craniofacial anomalies, hence, the term DPG-plus syndrome.

🚩Ventricular CSF pulsation artifact:

Bilateral rounded signal alteration at the body of both lateral ventricles adjacent to septum pellucidum, in the region of foramina of Monro. They appear of high FLAIR and low T2 signals.

❇️This artifact is not seen on T1 W sequence.

✳️It shouldn't be confused with intraventricular pathology.

❇️This artifact, common in low-field MRI systems, mainly affects FLAIR sequence and occurs more common in young patients with small ventricular sizes

🚩Takayasu arteritis


3D CE-MRA (MIP) shows stenoses of the supra-aortic arteries, especially the brachiocephalic trunk and the left subclavian artery. Near-occlusion of the left vertebral artery.

Probably a case of Takayasu arteritis leading to aortic arch syndrome.

🚩Ulnar Nerve Entrapment:


MR neurography images of a healthy ulnar nerve (top row) and an entrapped ulnar nerve in cubital tunnel syndrome (bottom row).
The abnormal signal hyperintensity (brightness) of the nerve indicates neuropathy, with the nerve enlarged as it courses through the cubital tunnel at the elbow due to prescence of Anconeus epitrochlearis muscle in this case .

♦️Ulnar nerve compression usually occurs around the elbow joint, a condition called cubital tunnel syndrome. Much less often, compression can occur at the wrist, a condition sometimes known as Guyon canal syndrome.

🚩Osteitis pubis:

Axial MRI pelvis STIR sequence in young football player show:

Bone marrow edema around the symphysis pubis (osteitis pubis) with high signal intensity in the adductor attachments on the right side of the symphysis suggestive of adductor tendinopathy (athletic pubalgia).

🚩Perineal dermoid cyst in a young male:

Right perineal cystic lesion located posterior and lateral to the urethra

The main differential diagnosis includes:

perineal abscess
tailgut cyst
pilonidal cyst
anal duct/gland cysts
Epidermoid cyst
benign teratomas

🚩Plantar fibromatosis:

Elongated lesion with irregular margins, measuring approx. 15x10mm is seen along plantar aspect of mid plantar aponeurosis at the level of base of 2nd metatarsal with mild surrounding soft tissue edema

🚩Benign enlargement of the subarachnoid space in infancy BESSI:

MRI brain of 9 month male Axial T2 image demonstrates prominence of the bilateral frontal parietal/temporal extra-axial CSF spaces, without effacement of the involved gyri.
Also of note, is that the cortical veins are adjacent to the inner table of the calvarium. These finding are in keeping with benign enlargement of the subarachnoid space in infancy (BESSI)

🚩Insall-Salvati ratio

The Insall-Salvati ratio or index is the ratio of the patella tendon length to the length of the patella and is used to determine patellar height


♦️Distance lines are used to calculate Insall-Salvati ratio:

A: patellar tendon length (TL): length of the posterior surface of the tendon from the lower pole of the patella to its insertion on the tibia

B: patellar length (PL): greatest pole-to-pole length


🕯Interpretation
On plain radiographs:

patella baja: <0.8

normal: 0.8-1.2

patella alta: >1.2

Insall-Salvati ratio = A/B (or TL/PL)


♦️The modified Insall-Salvati ratio or index is another technique to assess patellar height

Measurement

A: distance from the inferior margin of the patellar articular surface (as opposed to the lower pole of the patella itself) to the patellar tendon insertion
B: length of the patellar articular surface
Modified Insall-Salvati ratio = A/B

🕯Interpretation

normal: 1.25 (range 1.2-2.1)
patella alta: >2

at this cut-off, 3% of normal knees will be classified as patella alta

🚩Horseshoe adrenal gland

The adrenal glands are fused and lie in the midline posterior to the aorta

A horseshoe adrenal gland is a very rare congenital anomaly. It is also sometimes referred to as a butterfly, fused or midline adrenal gland

🚩Reversal sign:

Inversion of the attenuation between white and grey matter, the latter showing lower attenuation compared to the white matter (normally its attenuation is higher).

The reversal sign is seen on non-enhanced brain CT scan due to diffuse anoxic brain injury. Its pathogenesis is complex and not fully understood with multiple factors being implicated

🚩Eosinophilic fasciitis:
MRI demonstrates muscular fascial plane thickening without any myositis. Changes are generally symmetrical.

Bilateral and symmetric thickening with enhancement of the fascia throughout both legs which is most pronounced in the calves.

Eosinophilic fasciitis tends to respond to corticosteroids with excellent response.

🚩Subcoracoid impingement:

Decreased coracohumeral distance is seen, with impingement of subscapularis muscle, by a hypointense spur in coracoid process.
Altered signal is seen at medial aspect of subscapularis tendon, with fluid along the tendon

🚩Quadrilateral space syndrome:

Axial T1 MRI shoulder show

Isolated denervation fatty atrophy of the deltoid muscle

♦️Quadrilateral space syndrome is a rare neurovascular compression syndrome that may manifest with deltoid muscle atrophy due to compression of the axillary nerve within the quadrilateral space.

The compression may be due to fibrous bands, trauma, or hypertrophy of the muscular borders

🚩Methanol poisoning:

Axial contrast-enhanced brain CT shows diffuse cerebral edema with sulcal effacement.

Bilateral and symmetric putaminal hypodensity, that probably reflects acute putaminal necrosis.

8 hours before, a non-contrast brain CT was performed, which didn't show putaminal damage.

🚩Anterior suprapatellar fat pad impingement syndrome:



Increased signal intensity of the suprapatellar fat pad, with a convex posterior border and mass effect over the suprapatellar joint recess.

There is no significant joint effusion.

🚩Parameningeal head and neck rhabdomyosarcoma:


Large heterogeneously enhancing mass occupying the nasopharynx with extension toward the left cavernous sinus.


Parameningeal rhabdomyosarcomas (PM RMS) are tumors arising from sites adjacent to the meninges (nasopharynx, middle ear, paranasal sinuses, infratemporal and pterygopalatine fossa) and constitute half of all head and neck RMS cases

🚩Bizarre parosteal osteochondromatous proliferation (BPOP), also known as (Nora's lesion )


There is an irregularly shaped, predominately well-defined osseous excrescence at the radial aspect of the distal metaphysis of the second metacarpal.
This lesion shows underlying cortical irregularity and no evidence of medullary continuity.
No periosteal reaction is identified, and there is no associated soft-tissue mass

🚩Posterior ankle impingement:

Elongated lateral tubercle of the talus (Stieda process) as well as mild posterior lateral capsular thickening and synovitis with mild focal tenosynovitis involving the flexor hallucis longus.

🚩Parosteal lipoma

A bony protrusion is seen at the medial aspect of the femur with surrounding large low-densityJuxta-cortical fatty mass with variable septations

♦️Parosteal lipomas are rare. They are composed of fat and have a close relation to bone with hyperostosis of cortex but no medullary invasion. The most common sites are the femoral, radial and humeral shafts

🚩Superior mesenteric artery syndrome:


Acute angulation of SMA compresses the third part of the duodenum between the aorta and SMA

🚩Closed loop obstruction - internal hernia into nephrectomy bed:


Right nephrectomy.
Cluster of abnormal loops of small bowel within the nephrectomy bed which are fluid-filled, have thickened walls with slightly diminished enhancement, and are associated with mesenteric edema

🚩Proximal iliotibial band syndrome


The fluid sensitive sequences demonstrate slight thickening of the left iliotibial band enthesis near its attachment to the iliac tubercle which lies postero-inferior to the anterior superior iliac spine. The fluid sensitive sequences show abnormal surrounding high signal change due to partial tear and edema.(i.e. enthesitis). No underling bony abnormality.

🚩Trochanteric bursitis


Thickened wall and fluid collection in the left trochanteric (subgluteal) bursa

🚩Huntington’s disease:

Asymmetric enlargement of frontal horns with loss of medial convexity of caudate- selective caudate atrophy

🚩Pontine Cavernoma with Hemorrhage

Findings:

Multiple MR images demonstrate a parenchymal hematoma in the left pons. There is no significant abnormal enhancement associated with this lesion. A small amount of surrounding edema is present with partial effacement of the fourth ventricle. The hemorrhage within this lesion is of mixed age. There is slight exophytic extend into the prepontine cistern

🚩Septic arthritis of the median atlantoaxial and bilateral atlantooccipital joints:

Sagittal T2(1) showing thickening of the synovial lining of the median atlantoaxial that is well depicted in the axial T2(2). Reduced joint space with articular surface erosions and subarticular edema is also noted involving the bilateral atlantooccipital joints(3).

Post contrast sagittal (4) and axial post contrast(5) images show enhancement of the synovial lining of the median atlantoaxial joint. Enhancement with synovial effusion also noted involving the bilateral atlantooccipital joints(6).

🚩Malposition of central line into azygos vein:

Abrupt bend at the tip of the left central venous catheter.
It was in the azygos vein

🚩Misplaced endotracheal tube:

Esophageal intubation

🚩Reversible Splenial Lesion:

♦️Findings:

Axial FLAIR, axial T1 post contrast, sagittal T2, and axial diffusion weighted imaging demonstrates a well defined, symmetric, non-expansile, nonenhancing signal abnormality at midline involving the corpus callosum splenium. The splenium lesion demonstrates restricted diffusion.

♦️Discussion/Differential Diagnosis:

The reversible splenial lesion is also known as MERS (mild encephalitis/encephalopathy with a reversible isolated SCC lesion), and is typically asymptomatic in isolation as opposed to other causes of corpus callosum lesions that will cause symptoms of hermispheric disconnection.
These are classically associated with stopping or changing antiepileptic drugs, after a single seizure, after focal status epilepticus, but may also be seen with electrolyte imbalance, hypoglycemia, and uremia.

The reversible splenial lesion is nearly always perfectly symmetric involving the central fibers, nonenhancing, and with DWI restriction.

If the lesion does not fulfill these criteria, the wide range of other processes that may affect the corpus callosum should be considered such as MS/ADEM, PRES, DAI, Marchiafave Bignami disease, and neoplasm.

The MERS lesion resolves within 1 month, most by 1 week.

🚩Straight sinus/Vein of galen thrombosis with bilateral thalamic infarction:

Findings:

Axial T1 and T2 weighted images show extensive abnormal signal with mass effect in the thalami, right internal capsule, and right basal ganglia.
The sagittal images show abnormal signal in the straight sinus/vein of galen region consistent with thrombosis.
Lack of flow signal in these areas is confirmed by phase contrast MIP image.

♦️Differential diagnosis:
Bilateral signal abnormalities should raise the possibility of dural sinus/deep venous thrombosis. Other etiologies of bilateral abnormal thalamic signal abnormalities include "top of the basilar" syndrome (occlusion of a large thalamoperforator that supplies both thalami), glioma, metastatic disease, and less likely encephalitis.

🚩Intracranial neurenteric cyst:

A well-defined round mass with smooth margins, located anterior to the brainstem is the characteristic presentation of intracranial neurenteric cysts.

Wide range of signal intensity on T1 and T2 weighted images is attributed to its variable protein content

🚩Right inferior lumbar hernia (Petit hernia):

There is a bowel protruding as content, defect measuring 4.8 cm.

🚩Superior lumbar hernia:

Herniation of abdominal and perinephric fat through a defect in superior lumbar triangle

♦️A Grynfeltt-Lesshaft hernia (or superior lumbar hernia) is a type of lumbar hernia, with herniation occurring through the superior lumbar triangle (of Grynfeltt-Lesshaft.

🚩Stroke

🚩Fredericson MRI classification of medial stress syndrome:

The Fredericson MTSS classification follows a progression related to the extent of injury. This begins with periosteal edema (grade 1), followed by progressive marrow involvement (grades 2 and 3), and eventually cortical stress fracture (grades 4a and 4b).

🚩Medial tibial stress syndrome:

Selected MRI images demonstrate periosteal and subjacent marrow edema along the anteromedial border of the tibial diaphysis, in keeping with medial tibial stress syndrome (shin splints)