I ve been loggin in some radiology cases on this blog. click https://rad-log.blogspot.in/
I ll try to post more post this year 2018 on this blog. It is a useful blog.
SPLENOSIS
Splenosis is defined as the autotransplantation of splenic tissue resulting from the spillage of cells from the pulp of the spleen after splenic injury or splenectomy. Splenic implants are generally numerous, can be located anywhere in the peritoneal cavity, are supplied by arteries from the surrounding tissue rather than a hilar artery, have no particular shape, and have neither a hilus nor a normal capsule. Splenic implants located in the peritoneal cavity may be confused with renal neoplasms , abdominal lymphomas ,and endometriosis . If splenic rupture is associated with a diaphragmatic tear, the implants may seed the pleural cavity or pericardium , which causes intrathoracic splenosis.
Radiology:
CT – non enhanced shows round ,oval or irregular shaped multiple masses .
CECT – Homogenous enhancement of all these masses
Ferumoxides-enhanced MRI as a novel technique for diagnosing splenosis
Radionuclide Imaging: Scintigraphy using Technetium-99m heat-damaged erythrocytes (RBC) or Indium 111-labeled platelets is more sensitive and specific for splenic uptake, making these tests the current diagnostic tools of choice.
Gastric Ca vs Gastric Lymphoma
CHARACTER CARCINOMA LYMPHOMA
A. WALL THICKNESS <1 cm > 4 cm
B.MURAL THICKENING LESS HOMOGENOUS MORE HOMOGENOUS
C.PERIGASTRIC FAT AFFECTED PRESERVED
D.ADENOPATHY EXTENT ABOVE RENAL VEIN BELOW RENAL VEIN
E.LN SIZE MEDIUM LARGE
CARCINOMA LYMPHOMA
GI duplication cysts
- Gastrointestinal duplication cysts are relatively common congenital anomalies which are composed of fluid-filled sacs lined by a layer of epithelium and smooth muscle from the alimentary tract.
- They frequently share a common blood supply and muscular wall from the adjacent portion of the intestine. The most common locations are: Distal ileum (34%), esophagus (19%), stomach (9%), jejunum (9%), and appendix (6%), duodenum (5%).
- The most common type of duplication cyst is spherical in shape, and almost never communicates with the alimentary tract. The more rare tubular type commonly communicates with the GI tract, frequently resulting in superinfection.
- The distal 1/3 of the esophagus is the most common location for esophageal duplications. These duplications commonly contain gastric or pancreatic tissue. Gastric-mucosa containing intestinal duplications can ulcerate, causing hemorrhage and even perforation.
- Narrowing mediastinal lesions to a particular region of the mediastinum greatly refines the differential. For middle mediastinal masses: Bronchogenic cyst, esophageal duplication, neurenteric cyst, lymphangioma, mature cystic teratoma (dermoid).
SLIDES SHOW ESOPHAGEAL DUPLICATION CYST
Radiologic Findings:
- CXR or KUB: May appear as a mediastinal or abdominal mass. Look for displacement of trachea, bronchi, esophagus, other structures. May contain air-fluid levels if communication with GI tract (very rare, tubular type).
- CT: Thin walled, non-enhancing, density anywhere from fluid to soft tissue. Mass located adjacent to alimentary tract.. Oral contrast very helpful in delineating margins of duplication.
- Nuclear medicine: Tc-99m Pertechnetate scintigraphy will demonstrate intestinal duplications containing gastric mucosa.
References:
- Kirks et al, Practical Pediatric Imaging.
- Brandt, Helms et al. Fundamentals of Diagnostic Radiology. 2006, 3rd Ed.
EYE OF THE TIGER SIGN
EYE OF THE TIGER sign is the MRI changes seen in Globus Pallidus in Pantothenate kinase associated neurodegenration. .The Globus Pallidus in T2W MRI shows medial high signal and lateral low signal.
Pantothenate kinase associated neurodegenration
- Most common form of neurodegeneration with iron accumulation in the brain.
- Mutation of pantothenate kinase 2 gene is the etiology
- Best imaging manifestation is the “eye of the tiger sign” owing to the symmetric bilateral T2 hypo intensity adjacent to medial foci of increased T2 signal.
- T2 hypo intensity is secondary to iron deposition within the brain
- Clinical manifestations are rapid onset dystonia, dysarthria, rigidity and choreoathetosis.
- Classically presents with a young child with postural deficits and gait problems.
Renal Artery Stenosis
Left intrarenal doppler spectrum with dampened tardus/parvus waveform
Right intrarenal doppler spectrum normal
Left renal artery occlusion
Patent right renal artery
Volume-rendered image (posterior view) shows bilateral focal narrowing of the proximal main renal artery (arrows) with poststenotic dilatation.
Digital subtraction angiogram shows an approximately 30% stenosis of the right main renal artery (arrow)
Coronal maximum-intensity projection image shows two calcified plaques (arrows) projecting over the proximal right main renal artery
MRA showing right renal artery stenosis
ARTERIOGRAM
RENAL VEIN THROMBOSIS
Normal color doppler ,Renal vasculature
USG shows diffusely hyperechoic kidney with loss of cortico-medullary differentiation
Color Doppler shows absent renal vein doppler signal
CT Scan axial section shows hypoattenuating thrombus in the left renal vein
CT scan Excretory phase shows enhancement of collaterals around ureter
MRA showing low signal thrombus partially obstructing the tumour
Most common cause is membranous nephropathy , Nephrotic synrome
Tumour Thrombus
M – Mass , Arrow – Thrombus
Most common cause of tumour thrombus is Renal Cell Carcinoma
Reference :
a.Radiographics
b.Dr.Manjunath’s blog
c.Image consult
d.Medscape
Renal Papillary Necrosis – Differential Diagnosis
D/D
A.In early ischaemic stage :During the early ischemic stage of renal papillary necrosis, corticomedullary or parenchymal phase multi–detector row CT shows a poorly marginated area of decreased enhancement at the tip of the medullary pyramid.
.1. Pyelonephritis also may be visible as a circumscribed area of reduced enhancement at CT during the corticomedullary and parenchymal phases, but the lesions in pyelonephritis are typified by lobar or segmental involvement instead of being limited to the medullary pyramid.
2.Moreover, during the late parenchymal phase, the margins of the lesions show the intense venous hyperemia that characterizes inflammatory disease.
3.Attenuation coefficients and locations may help differentiate ischemic lesions from cysts, abscesses, and hematomas.
B.In cases of advanced disease: causes of cystic lesions in the areas of renal medullae or sinuses should be considered in the differential diagnosis. Other possible causes include
1.hydronephrosis,
2. congenital megacalices
3. parapelvic cyst
4.caliceal diverticula.
In particular, the location of the arcuate artery relative to cystic lesions may be helpful for differentiation
Cavities produced by renal papillary necrosis can be differentiated from those in hydronephrosis by an irregular cavity contour and by extension of the cavity to arcuate arteries. Moreover, in hydronephrosis all calices are blunt tipped, whereas in papillary necrosis one or more calices may extend beyond the levels of others
Arrowheads indicating arcuate arteries
Like the cavities in renal papillary necrosis, pelvocaliceal diverticula may manifest as contrast material–filled fluid collections adjacent to calices. However, these two entities can usually be distinguished on the basis of location: Pelvocaliceal diverticula are not found in papillae but, rather, adjacent to the caliceal fornices or, less commonly, to an infundibulum or the renal pelvis
Renal Papillary Necrosis – Stages and Imaging findings
Normal kidney showing vasculature on color doppler USG
Longitudinal color Doppler US image shows blunting of the upper polar calices (arrows), which are bordered by arcuate vessels (arrowheads)
Early Ischemic Change in the Medullary Pyramid
Renal papillary necrosis is the consequence of an ischemic process in the renal papillae. Infection that causes inflammation of the interstitium also may lead to compression of the medullary vasculature and thus predispose the vessels to ischemic change. Perfusion compromise as a consequence of vasculitis in diabetes mellitus, tuberculosis, or the curtailment of flow observed in hemoglobinopathy, analgesic nephropathy, or acute urinary obstruction, also sets the stage for ischemic changes in the medullary pyramid (1)
Urographic findings during this period of early ischemic change are usually normal. Ischemic changes of the medulla are identified more often and localized more accurately with multi–detector row CT than with IV urography or ultrasonography (US)
Reversible stage ischaemic changes . Contrast-enhanced parenchymal phase CT image shows multiple poorly marginated, hypoattenuated lesions (arrowheads) in the papillary regions and the excretion of contrast material into the renal pelvis (arrow)
EARLY STAGE PAPILLARY NECROSIS
Necrotising papillitis resulting in papillary necrosis as shown by hypoattenuating medullary lesions indicating papillary necrosis and swollen kidney
ADVANCED PAPILLARY NECROSIS
In the advanced stage of necrosis, clefts originate from the fornices and extend into and dissect the medullary pyramids and papillae, ultimately causing the papillae to slough. Caliceal deformities in renal papillary necrosis occur in three forms: medullary, papillary, and in situ
a.normal, b.papillary , c.medullary d.sloughed papillae
PAPILLARY FORM
IVU showing Papillary form 
CECT showing papillary form in excretory phase imaging
MEDULLARY FORM
IVU showing medullary form
CT showing medullary form cleft arising from fornix and forms medullary pattern
SLOUGING PHASE
Can result in blunted cavity if 1.slough passed out or 2. scarring & calcification if slough retained. The The calcification of necrotic papillae is common in patients with analgesic nephropathy.
Medullary cavity communicating with calyces after sloughing off
Calcification due analgesic nephropathy
HEALING PHASE
During the healing phase, the papilla may epithelialize, and its tip may take on a blunted appearance. In addition, shrinkage of the kidney may occur with reduction of parenchymal thickness. This common sequela of renal papillary necrosis has been attributed to the secondary atrophy of nephrons caused by necrosis of the loops of Henle, which pass deeply into the medulla. Moreover, the loss of renal cortex and associated hypertrophy of the Bertin columns result in a typical irregular wavy renal outline
BLUNT CALYCES
BLUNT CALYCES IN EXCRETORY PHASE
SHRUNKEN KIDNEY ,THIN CORTEX AND HYPOATTENUATING AREA IN PARENCHYMAL PHASE
Hydrosalphinx vs Cystadenoma. How to differentiate on MRI?
On MR images, the hydrosalpinx appears as a fluid-filled tubular structure that arises from the upper lateral margin of the uterine fundus and is separate from the ipsilateral ovary. A dilated fallopian tube folds upon itself to form a sausagelike C- or S-shaped cystic mass as seen below
Sagittal T2-weighted MR image shows an S-shaped cystic mass (arrow) and partially effaced plicae (arrowhead), findings that help differentiate the hydrosalpinx from an ovarian cystadenoma.
Axial T2-weighted MR image shows an elongated cystic lesion with internal septa (arrows) in the left adnexa, a finding that mimics hydrosalpinx.
Sagittal T2-weighted MR image of the same patient clearly demonstrates the round mass (arrows) and complete intracystic septa, findings suggestive of an ovarian cystadenoma rather than hydrosalpinx.
REFERENCE:
dxradiologia 