Radiology

Incidental finding of a superior lumbar hernia (Grynfeltt-Lesshaft hernia). In this case, only a lobule of retroperitoneal fat is herniating through the defect, but organs can also herniate through.

Continuing the theme of things extending into spaces they don't belong in, this is an incidental finding of an inguinal hernia that contains a small portion of the bladder. The patient got the CT for other reasons.

Bowel into inguinal hernia causing bowel obstruction.

Appendix into inguinal hernia, incidental finding.

Ventriculoperitoneal shunt into inguinal hernia, incidental finding.

[LEFT]: This patient had one of the longer cerebellar tonsillar herniations I've seen. The tonsil is peg-like in shape and extends quite far below the foramen magnum to the level of the C2 posterior arch. As a result, there is crowding at the foramen magnum that is enough to impede CSF flow, resulting in hydrocephalus with dilated ventricles. Partly seen in the cervical cord from C2 and below is a syrinx, an associated finding. Chiari I is thought to be due to not enough space provided for the cerebellum by the calvarium or skull base shape, causing it to herniate into the spinal canal and cause trouble.

[RIGHT]: A comparison normal from online for you to compare the cerebellar tonsils.

[LEFT]: The midbrain has a deep interpeduncular cistern, and the superior cerebellar peduncles are very prominent and elongated, making the brainstem at this level look like a molar tooth. This is a classic finding in Joubert syndrome.

[RIGHT]: A comparison "normal" midbrain. However, this patient's brain is not normal at all. Can you find the abnormalities?

Female in her 30s with painful left shoulder.

[Left]: X-ray shows a mass arising from the left proximal humerus and extending into the adjacent shoulder soft tissues with really aggressive periosteal reaction ("hair on end"). The proximal humerus itself is also heterogeneous with lucent areas. The lateral surface of the upper humerus shows "saucerization," where the cortex is thinned out and looks like a saucer seen on edge.

[Middle]: MRI IR sequence shows a hyperintense bony mass with large soft tissue component.

[Right]: MRI postcontrast T1 IDEAL shows that the mass is enhancing.

This turned out to be high-grade surface osteosarcoma.

33 year old female with abdominal pain, abdominal distention, nausea/vomiting, early satiety, and weight loss.

Bottom right: Ultrasound done in a panorama shows how distended the abdomen is by a large multi-cystic mass.

Top right: Non-panoramic ultrasound image shows how limited the imaging modality is in being able to cover such a large mass. This image also shows a more solid area within the mass.

Left: CT images approximately where the ultrasound was done.

The patient underwent laparotomy with removal of the ovarian, fallopian tube, and appendix. There was a large ovarian cyst that was draining serous fluid (watery), mucinous fuid (mucus-like), and blood. The final path was as titled.

Postcontrast imaging of 2 patients with glioblastoma. These tumors are notorious for spreading along the white matter tracts - in this case the transverse fibers of the corpus callosum, given them a classic "butterfly" appearance.

Two different patients with genetic disorders resulting in overgrowth of the brain.

These represent mutations in cell cycle and cell metabolism genes that lead to larger cells and/or more cells. These types of disorders tend to have mosaicism of some form, which is to say some cells have the mutation active while others don't. The distribution of these cells can be very geographic/regional - in these two cases, one hemisphere of the brain is involved.

Compare this against a previous case with hemispheric atrophy.

Hello everyone!

I am amazed at how quickly this rather specialized community has grown. It gives me perverse pleasure to see that C/Radiology has somehow exceeded C/Medicine in subscriber numbers! So thanks for visiting and allowing me to share my interest in this field with you!

As the community has expanded, we have, of course, come across typical growing pains, and since this is a medical community, some additional factors must also be considered, such as respect for any patient discussions and medical privacy. We have the potential for a lot more growth, but we must be vigilant in respecting medical laws as well. To that end, I have made additional changes to the Community Rules to better clarify the situation for everyone. Additionally, I have conversed with the Lemmy.World admins, who are supportive of this community and now aware of its unique characteristics and requirements.

One major change that has come out of that discussion is that we worry about how inadvertent posts that breach patient confidentiality would behave with federation. It's not like Reddit, where the post is centralized, and there's only one copy to remove. As a consequence, for now, I have changed this community to only allow moderators to post. My hope is that, in the not-too-distant future, Lemmy itself will implement a way for users to post pending moderator approval. Visitors may still comment upon any posts in this Community, and so as a workaround, I've started this megathread for any general questions or discussions you might have regarding radiology. (Please follow the rules still!) If you would like to share a case as a post - please DM me, and I will post on your behalf.

Now onto future updates: For the next few weeks, I will have reduced posting - because I'm going to be away from steady internet. I will continue to post interesting cases I come across thereafter. Eventually, I also plan to have a sticked general guidance on how to look at radiologic images so that you can have a better understanding and capability of looking at these images yourself!

While we're at it, I'm also looking for additional mods to help. I would prefer that you have some medical imaging background, medical background in general, or moderator experience if possible!

Quick one today. Take a look at Patient A and Patient B.

Patient A has a smooth focal indentation of the posterior cervical esophagus.

Patient B has a broader indentation that is also irregular and nodular along its contour.

Patient A has a cricopharyngeal bar, which is a prominence caused by the cricopharyngeus muscle that can cause dysphagia if it gets really prominent. Patient B has esophageal squamous cell carcinoma.

Patient was a young adult working in finance at a major tech company found to be mute and diaphoretic.

Physical exam notable for fever, tachycardiac, hypertension, awake but not following commands, aphasic, and with hyperreflexia and muscle ridigity. CK peaked to 11,344.

MRI shows multiple ovoid to splotchy confluent lesions in the white matter with diffusion restriction. Lesions also enhanced with hyperperfusion (not shown).

Urine drug test positive for cocaine. Infectious work-up was negative. Steroids were started with good recovery.

Patient denied knowingly taking cocaine but did say weekly use of what they thought was MDMA with friends...

Final diagnosis: Levamisole-induced leukoencephalopathy. Levamisole is an antiparasite medication that is no longer used in the US but still in some other countries. It is a common cutting agent in cocaine. It's neurotoxic effects primarily come from causing demyelination.

I remember this episode quite well because it happened around the time I decided to get into the medical field. In the episode, a young teacher had a first-time seizure while in the middle of teaching. House and team attempted to get a brain MRI, but she got an allergic reaction from the IV contrast. Thereafter, some drama happens, and at some point, they break into her house, find out she's been eating raw pork (wtf?), and diagnose her with the tapeworm infection associated with eating raw pork, cysticercosis (and neurocysticercosis, since it also involved her brain). They took an x-ray of her leg to show all the parasites in the muscles, and then House scolds her for being stupid. I remember thinking that was such as crazy medical story.

The reality is - they could have just repeated the brain MRI minus the contrast part, and the radiologist would have been able to identify neurocysticercosis without issue. House would have complained to Cuddy that she really was wasting his time with these basic cases, and the episode would have lasted 15 minutes tops...

Anyhow, this is a 25 year old Hispanic from jail. Just like the House episode, he presented with first time seizure and headaches.

CT of the head [top] shows a cystic lesion in the left frontal lobe. If one pays attention, one can see a small dot (blue arrow) within the cyst representing the scolex of the tapeworm parasite. Just from the CT appearance, history of seizure, and risk factors of jail (the parasite thrives in areas of low sanitation) and Hispanic (the parasite is endemic to South America), neurocysticercosis is the top possibility. A differential diagnosis of cystic brain tumor is provided to complete the picture.

MR [middle and bottom] shows a cystic lesion again. After giving IV contrast [middle right], one can see the cyst has a thin wall of enhancement (teal arrows). On T2 [bottom left] and especially FLAIR [bottom right], one can see a rim of swollen brain (green arrows) from the inflammation going on around the parasite.

This was diagnosed as neurocysticercosis in the colloidal vesicular stage and antiparasite medication was started.

[Top]: X-ray shows a lucent, bubbly, lesion of the distal femur at the metaphysis. On the frontal view [top right], there is breakage through the medial femoral cortex into the adjacent soft tissues, not a good sign.

[Bottom]: MRI shows a multicystic lesion filling the distal femur containing multiple locules, many with fluid-fluid, fluid-debris, and fluid-hemorrhage levels. The most common lesions with this striking appearance are aneurysmal bone cyst, giant cell tumor, or telangiectatic osteosarcoma. Unfortunately, there is clearly extension of the bone tumor beyond the bone (yellow arrows), which favors a more aggressive neoplasm from that differential diagnosis - this turned out to be telangiectatic osteosarcoma.

5 year old who fell off a slide.

Initial imaging shows a comminuted fracture through the distal humerus, compatible with a supracondylar fracture. Nothing else appreciable here, except maybe in retrospect some lucency of the distal humerus where the fracture is.

4- and 7-month follow-up radiographs shows a growing lucent lesion of the distal humerus, expanding the bone there. It has a multicystic appearance. A diagnosis of large simple bone cyst versus aneurysmal bone cyst was proposed.

12 month follow-up was done after the cyst was opened surgically, its contents scraped off, and the resulting cavity was packed with allograft bone chips. At surgery, this turned out to be an aneurysmal bone cyst.

5 year follow-up shows involution of the cyst cavity with some residual heterogeneity and a bone spur at the anterior aspect of the distal humerus.

[Left]: Head CT shows left hemispheric volume loss. The injury happened early enough that even the skull is smaller on that side.

[Right]: Brain MRI shows the severe left hemispheric atrophy. Some of the brain gyri have bulbous ends and a thin neck, resembling mushrooms, a shape called ulegyria and consequence of the brain atrophy. The left lateral ventricle is mildly enlarged due to the atrophied brain.

Red arrows point to 2 big gallstones, top one in the gallbladder and bottom one obstructing a small bowel loop, and a small gallstone in the cystic duct.

Red lines point to hernia entry. Red arrow points to where the bowel tapers and becomes obstructed as it enters the hernia sac.

[Left]: Fetal MRI (FIESTA sequence) shows twins joined from their lower chest to the pelvis, but truly fused and sharing a single abnormal pelvic region. Not shown, but there are 3 lower limbs - one of the twins only had a single lower extremity.

[Right]: Postnatal small bowel follow-through (SBFT). It was unclear initially whether the twins shared a single rectum or had their own rectum. Therefore, contrast was administered via nasogastric tube for the twin with the suspected nonfunctional rectum, and serial imaging was performed until it passed into what turned out to be a separate, functional, but small rectum/anus.

I do not know too much about conjoined twins - not my area of expertise, but the general forms to consider are the side of fusion: ventral (front to front), lateral (side to side), dorsal (back to back), or caudal (tail end to tail end). Within these first 3, there are subtypes depending on how far up the fusion goes (head, chest, abdomen/pelvis); by definition, the caudal version obviously is only a lower body fusion. Once this is derived, an additional classification is the number of upper and lower limbs.

No clinical history saved on this one - sorry.

[Right] Small bowel follow-through (SBFT), where the patient drinks barium, and then we wait a bit until that barium is in the small bowel, then we take some pictures. This study is showing a long segment of terminal ileum that is strictured and severely narrowed in fibrostenotic Crohn's (red bracket). This is called the "string sign."

[Left] Coronal CT performed sometime after the SBFT. You can still see some residual barium in the small and large bowels (blue arrows). Red bracket shows the CT appearance of the terminal ileum stricture. On the CT, you can also see that the strictured segment has submucosal fat deposition, the "fat halo sign."

I didn't save any clinical history for these - sorry.

[Top] Patient 1 - Gigantic mass along the lesser curvature of the stomach. Look down at your belly - this mass is about 1/3rd the width from left to right.

[Mid] Patient 2 - CTs showing gently lobulated and undulating wall thickening of the gastric cardiac and fundus. Notice the transition from the normal gastric rugae to the smoother wall thickening where it is infiltrated by lymphoma. There is also mild (aneurysmal) dilation of the stomach where the wall thickening is located.

[Bottom] Patient 2 - PET-CT. The wall thickening is ridiculously hypermetabolic with a max SUV of 21.3. For comparison, the liver is normally in the range of 2-4 mean SUV.

Tuberculosis, sarcoidosis, lymphoma, and metastatic disease - these 4 can look like almost anything.

57 year old with left flank pain for 12 hours. Urine sample 2+ for blood. White count at 14.

[Top]: Coronal CT shows the left kidney is enlarged, with angry-looking, inflamed, surrounding fat. The renal pelvis is dilated (hydronephrosis).

[Bottom]: Axial CT shows a small stone at the very end of the ureter (ureterovesicular junction).

Pretty straightforward case. For the nonmedical visitors, this is what we look for if your doc wants to get a CT for flank pain / kidney stone suspicion. See the other case for an ultrasound version.

25 year old with right flank and pelvic pain for 2 days. No fevers, chills, nausea, vomiting, or other urinary symptoms however.

[Top]: Ultrasound shows right kidney with distended pelvis (hydronephrosis).

[Mid & Bottom]: Ultrasound transverse and sagittal images shows a 4.5 mm stone at the very end of the ureter (ureterovesicular junction).

Pretty straightforward case. For the nonmedical visitors, this is what we look for if your doc wants to get an US for flank pain / kidney stone suspicion. See the other case for a CT version.

Mom was a 36 year old with active meth abuse, homelessness, and scant prenatal care.

Prenatal ultrasound at 36 weeks shows a highly deformed fetal brain with large fluid-filled spaces that might represent cysts or hydrocephalus. The brain contours are lobulated and irregular due to absence of an overlying skull.

She was recommended for pregnancy termination but no-showed to that procedure. She then presented 3 weeks later, at 39 weeks, in labor. The baby was delivered spontaneously. The baby had absent skull above the level of the ears. The brain was large and could be seen through a membranous sac. The baby passed away one day later.

Acrania is the absence of a skull. Exencephaly is the condition where a brain (which may have otherwise been normal) is not covered by the skull in the prenatal setting. Due to the exposure of brain tissue to amniotic fluid, which is toxic to brain, exencephaly will invariably lead to anencephaly, which is the absence of all/most of the brain.

31 year old doing some doing roof work when he fell. Seen in the ED with right ear bleeding and right-sided decreased hearing.

The normal left side is depicted in the right images (standard convention). Coronal view [top right] shows the middle ear ossicles (arrow) in the middle ear cavity, and axial view [bottom right] shows the normal "ice cream cone" appearance (arrow).

By comparison, the right middle ear ossicles are missing in the middle ear cavity [top left] (arrow with ?) and found in the external auditory canal (arrow with !!) instead. Axial view [bottom left] shows a distinct lack of the ice cream cone appearance. The middle ear and external ear canals are also filled with fluid/blood. The tympanic membrane is clearly ruptured since the middle ear ossicles are outside.

54 year old female with a history of uterine fibroids with persistent abdominal distention despite being told her fibroids shrunk after menopause - presumably via some pelvic ultrasound, which we didn't have.

Abdominal X-ray [top left] was possibly was called normal, which is not completely unreasonable. However, with the help of the follow-up coronal CT [top right], one can see that there is a vague area lacking any bowel gas that looks like it could be a mass. Axial [middle] and sagittal [bottom] CTs show a nonspecific, solid mass, well-circumscribed, with no calcifications, cysts, hemorrhage, or fat inside. The left kidney is pushed up by the mass, but the fat plane between the two is preserved with no evidence of renal invasion.

The patient underwent surgical resection.

Final diagnosis: Retroperitoneal dedifferentiated liposarcoma.

20 year old with a history of trisomy 21 and recent travel to Vietnam. Was seen there for nausea, vomiting, and abdominal pain with diagnosis of acute pancreatitis and what looked like lymphoma (but negative biopsy).

Coronal CT [left]: Big retroperitoneal lymph nodes with central cystic change/necrosis (red arrows).

Axial CT [right]: Done at the level of the green line shows a sausage-shaped pancreas compatible with ongoing versus resolving pancreatitis (red arrows).

Repeat EGD/EUS with celiac lymph node biopsy shows caseating granulomatous inflammation with positive culture and PCR for tuberculosis.

Not the best quality, but this is the only image I saved of this fetal MRI, with a random internet picture of what it would look like after birth.

This is an absolutely insane case that made the NEJM rounds a couple years ago now. I wish this was mine. I don't think there's been another case report like it since.

41 year old Colombian male with HIV-AIDS (not adherent to treatment), tapeworm infection, with several months of fever, cough, fatigue, and weight loss.

Top left: Chest x-ray shows multiple round lung masses.

Top right: Chest CT shows those round lung masses. Look like metastases.

Bottom left: The tumors taken out.

Bottom right: Pathology of the tumors.

The patient underwent empiric treatment for tapeworm and HIV with progression of masses. The CDC was contacted for help when treatment wasn't working.

The tumor cells clearly looked like cancer but were too small to be human cells. Genetic sequencing ultimately showed tapeworm DNA, with mutations and genetic rearrangements compatible with cancer.

Final diagnosis: Metastatic tapeworm cancer, likely developed because the patient had no immune system from the HIV-AIDS.

The patient passed away a few days after the diagnosis was finally made.

52 year old with a remote history of a rare skin cancer, dermatofibrosarcoma protuberans (DFSP) now presenting with recurrent pneumothoraces and difficulty breathing.

Top: Frontal and lateral chest radiographs shows the lungs filled by numerous cysts of varying sizes. Some cysts have layering fluid in them forming fluid levels.

Bottom: Axial CT through the mid lungs shows the numerous cysts, some with layering fluid, some with wall thickening.

Differential diagnosis for cystic lung disease: airway disease (emphysema, bronchiectasis from various causes), infectious/inflammatory (abscesses, vasculitis), cellular proliferation (cystic metastases, papillomatosis, mesenchymal cystic hamartomas, eosinophilic granulomas, lymphangioleiomyomatosis), injury (traumatic cysts, old lung infarcts).

Final diagnosis: The history of a histiocytic skin cancer suggested an extremely rare entity for cystic lung disease called pulmonary cystic fibrohistiocytic tumor.

It is sort of unclear if the lung cysts represent metastases from the fibrous histiocytic skin cancer or a separate primary neoplasm. The disease has an indolent progressive course. There is no good treatment for this as far as I am aware. These patients also get pulmonary arteriovenous malformations that might need embolization - you can see this patient does have a few embo coils on the chest radiographs at the left lung base.

59 year old with no past medical history, now with new dyspnea on exertion.

Top: Chest radiographs show development of cardiomegaly since 6 years prior. The pulmonary vascular markings are also more prominent than before, suggesting pulmonary congestion.

Bottom: MRI Cine FIESTA sequences in the 4- and 2-chamber views at end-diastole. There are prominent trabeculations towards the cardiac apex at both the left and right ventricles. In particular, there is an outer layer of dense myocardium and a thicker inner layer of trabeculated myocardium.

Final Diagnosis: Cardiac noncompaction.

Comparison Case: Meth-Induced Cardiomyopathy.

Cardiac noncompaction is a genetic disorder leading to failure of the myocardium to form "compact" walls. It is extremely rare. The presentation depends on how bad the noncompaction is, so can be asymptomatic to heart failure, arrhythmias, and thromboembolism.

20 year old with HIV-AIDS and tuberculosis with intracranial involvement (TB meningitis), not on treatment for these things.

Appropriate treatment was started, including TB medications and anti-retrovirals for HIV. 2 weeks later, the patient had decreased levels of consciousness.

Top images [A] show the brain at 3 different levels on postcontrast MRI prior to treatment. Bottom images [B] show the follow-up MRI at the time of worsening neurologic status. There is a clear progression of nodular leptomeningeal enhancement throughout the brain.

Taking the above findings into context with the time of treatment, this was felt to be consistent with immune reconstitution inflammatory syndrome, an exaggerated immune response to a co-infection (TB) when a person's immune deficiency (HIV-AIDS) is corrected. High-dose steroids were started with significant improvement. One month later, a steroid taper was attempted, but the TB-IRIS relapsed. Ultimately, it took a year of slow taper to get the patient off the steroids while continuing to treat the HIV and TB.

66 year old with progressive cognitive and neurological decline, becoming catatonic within 2 months.

MRI DWI [1, 2, 3] shows cortical ribboning (cortex diffusion restriction [1]), and diffusion restriction in the deep gray nuclei and insula [2, 3] in a symmetric fashion.

MRI FLAIR [4] shows abnormal bright signal at the sites of diffusion restriction.

MRI postcontrast T1 [5] and SWI [6] are normal.

Based on the above findings, there was a strong suspicion this was something bad. A lumbar puncture was performed under appropriate infection control guidelines. Results showed positive CSF results for 14-3-3, T-tau protein, and RT-QuIC. The patient had already been discharged to a nursing facility when these results came back, so the nursing facility was notified as well as the public health department. The patient was placed on comfort care.

Final diagnosis: sporadic Creutzfeldt-Jakob disease (CJD).

41 year old female who was stabbed through her right inframammary fold (aka under her right breast).

CT through 3 sequential phases shows a linear laceration through the right lobe of the liver. There is a small focus of contrast extravasation that enlarges over time, eventually spilling out of the liver into the peritoneal cavity. These findings are consistent with an AAST grade IV liver injury.

Oh, the knife also apparently went through the liver and diaphragm, into the chest cavity, because she also had a hemopneumothorax.

Her blood counts were trended and were stable, so she didn't need surgery for the liver laceration. She did have a chest tube placed for the pneumothorax.

Photo: 8 year old with a mass at the top of his head since birth.

Top left: Sagittal T1 shows a pedunculated mass protruding through the midline calvarium.

Top & bottom mid: Sagittal postcontrast T1 SPGR shows the relation of the hairpin-shaped vessel and the superior sagittal sinus to the scalp mass. There is a fenestration (hole) in the superior sagittal sinus through which the fibrous stalk courses.

Top right: Sagittal T2 shows a hairpin-shaped vessel directed towards the lesion.

Bottom right: 3D MR venogram shows the hairpin-shaped vessel pointing towards the lesion.

Atretic parietal cephalocele is a congenital abnormal herniation of the brain covering +/- brain through a midline defect of the parietal bones. It is atretic because this herniation then atrophies until only a fibrous stalk connects it to the rest of the intracranial compartment. It is associated with a persistent falcine sinus, an embryonic vertical positioning of the straight sinus.

Radiopaedia article on it.

A companion case to this one. Bilateral groins with fat-containing hernias. The right-sided hernia also has a small air-filled tubular structure consistent with an appendix. There are no inflammatory changes to suggest acute appendicitis, so this is an incidental finding.

A right inguinal hernia containing an appendix is called an Amyand hernia and apparently pretty rare at <1% of inguinal hernias.

45 year old with a ventriculoperitoneal shunt (VPS) for history of toxoplasmosis. Incidental finding - no symptoms.

CT shows bilateral groin fluid collections. The right fluid collection contains the distal loops and tip of the VPS. So, just an incidental bit of cerebrospinal fluid in the groin.

36 year old female with a history of C-section. Then she started feeling a growing mass in her surgical scar.

CT shows a spiculated mass along the C-section scar that invades the right inferior rectus muscle. A differential diagnosis of desmoid tumor, endometriosis, and soft tissue sarcoma was provided.

Surgical resection of the mass was performed, which turned out to be endometriosis.

Top left and right: X-rays showing a BIG right jaw mass. Whispy calcifications likely represent spiculated periosteal reaction, a very aggressive bony reaction.

Bottom left: CT in the bone/calcification window shows the periosteal reaction better.

Bottom right: MR in the T2 sequence shows the full extent of the jaw mass and how it extends far beyond the mandible's margins, both outward and inward into the floor of mouth.

While this mass is very large, in general, jaw osteosarcoma has a better prognosis than conventional osteosarcomas.