CASES

1. CASES Dr Prashanth. G R2-Radiology SSGH Baroda 18/12/07

2. Case 1 • A 17-year-old boy presented to the emergency department with a 6-hour history of right flank pain and hematuria. • Recently he had had a diagnosis of bilateral hydronephrosis and a right orchiectomy for an undescended testis. • Laboratory results showed leukocytosis and urine analysis, 2+ white blood cells and 50 red blood cells/high-power field. The serum creatinine was 1.1 mg/dL. • The clinicians suspected pyelonephritis, and a noncontrast computed tomography (CT) scan of the abdomen and pelvis was performed. An IVP & MCUG were also obtained.

3. IMAGING FINDINGSNoncontrast CT scan of the abdomen shows massive hydronephrosis, with the right kidney worse than the left , marked bilateral redundant hydroureter, a thick-walled bladder, and absent abdominal wall musculature.

4. IVU showed a poorly functioning right kidney with a massive renal pelvis and marked left hydronephrosis and redundant hydroureter.

5. A large diverticulum is seen off the dome of the bladder s/o a urachal diverticulum in cystogram.

6. On MCUG dilatation of the posterior urethra is seen without urethral obstruction.

7. Diagnosis • Eagle-Barrett Syndrome aka Prune-Belly Syndrome is defined as a triad of deficiency of the abdominal wall musculature, dilated urinary tract, and undescended testicles.  • The term “prune belly” reflects the characteristic wrinkled appearance of the abdominal wall in the newborn due to the complete or partially complete absence of abdominal wall muscles • Newer hypotheses ascribe the syndrome to a gestational insult disrupting mesodermal development. Embryogenesis of the abdominal wall musculature and lining of the genitourinary tract are consequently damaged.  • An X-linked defect is suggested by the predominance of affected males. However, females can be affected in 5% cases, casting doubt upon this observation.

8. There is B/L hydroureteronephrosis. • The distal ureter is more affected than the proximal ureter. • Often, the bladder is enlarged and nontrabeculated because of the replacement of smooth muscle by collagen. It can be elongated and attached to a patent urachus or urachal diverticulum superiorly. • The dilated bladder may prevent the testicles from descending.  • The prostate is markedly hypoplastic, leading to dilation of the prostatic urethra. The anterior urethra is abnormal in 70% of cases, often in the form of a scaphoid megalourethra.

9. Females can have urethral atresia. • Virtually all males have bilateral undescended testes. Females usually have normal ovaries, but abnormalities of the uterus and vagina. • Often vesico-ureteral reflux is seen .  • Other findings of PBS include malrotation, cardiac anomalies, dimpling of the lateral aspect of the knees and elbows, talipes equinovarus, and hip dysplasias.  The orthopaedic findings are thought to be due to oligohydramnios.  • Pulmonary findings are also related to the oligohydramnios and can include pulmonary hypoplasia with pneumothorax and pneumomediastinum.

10. Morbidity relates to the degree of dilation of the urinary tract, in which poor ureteral peristalsis and weak forward propulsion of urine in the ureters results in stasis, infection, and stone formation. • Renal failure results from underlying renal dysplasia and the aforementioned complications of urinary stasis. • Twenty percent of patients are stillborn, 30% die of renal failure or urosepsis within the first 2 years of life, and the remaining 50% have varying degrees of urinary pathology.

11. DD • The diagnosis is suspected in the fetus when US imaging reveals an enlarged bladder, dilated ureters, and an abnormal abdominal wall. However, the same constellation of US findings can be caused by posterior urethral valves (PUV) with severe hydroureteronephrosis. • Radiologic findings in PBS that distinguish it from PUV include greater dilation and redundancy of the distal thirds of the ureters and anterior urethral abnormalities. In some rare cases, urethroscopy may be necessary to differentiate these entities.

12. POSTERIOR URETHRAL VALVE • PUV are the most common congenital obstructive lesion of the urethra, occurring only in phenotypic boys. • PUVs result from the formation of a thick, valvelike membrane that courses obliquely from the verumontanum to the most distal portion of the prostatic urethra. • An orifice of variable size is typically located centrally. • VCUG is the best imaging technique for the diagnosisof posterior urethral valves.

13. VCUG findings include • Dilatation and elongation of the posterior urethra, • Occasionally, a linear radiolucent band corresponding to the valve is noted. • Hypertrophic bladder neck which appears narrow in relation to the dilated posterior urethra. • Bladder trabeculation, hypertrophy and diverticula • Associated VUR with gross HN .

14.  VCUG image shows distention of the posterior urethra and abrupt change in caliber at the junction of the posterior and anterior urethra. Bladder wall trabeculations are also noted - PUV

15. Transverse US image of the bladder in a male infant demonstrates bladder wall thickening and dilatation of the posterior urethra, resulting in a keyhole appearance (arrow). Dilated ureters are noted posterior to the bladder . ‘Keyhole sign’

16. TREATMENT AND PROGNOSIS • The prognosis depends on the severity of the abnormalities. • The presentation can range from stillborn fetuses to older children with recurrent infections and renal insufficiency. • Orchiopexy is required due to the increased risk of malignancy in undescended testes. • Repair of the abdominal wall musculature is not simply cosmetic, as it plays an important role in pulmonary, bladder, and intestinal function and is crucial in the surgical management of these patients.

17. Case 2 An 86yr old pt underwent chest X-ray examination as a part of routine geriatric work up.

18. A 3-4cm sized lt.upper lobe mass with areas of lucencies & surrounding arcuate parenchymal distortion and a healed posterior rib fracture are noted.

19. Axial CT images show the irregular lt.upper lobe mass with peripheral attachment to the thickened pleura. Parenchymal distortion is noted at the inferomedial aspect of the lesion.

20. Differentials include • Primary bronchogenic carcinoma. • Round atelectasis On CT guided FNAC, the lesion did not show any evidence of malignancy & on further investigation, pt revealed h/o a car accident 4yrs back. So the diagnosis of round atelectasis is kept. The valuable clue to diagnosis in this case is the healed rib fracture.

21. Discussion • Round atelectasis is a pseudotumor that often mimics a bronchogenic carcinoma. • It most often associated with prior asbestos exposure but caused by other insults including trauma. • In theory any process that results in dvpt of pleural effusion a/w atelectasis results in round atelectasis. • Specifically if an effusion results in fibrinous adhesions to the atelectatic lung, subsequent lung trapping results in a “rolling up” of this portion the lung.

22. As the effusion clears the remaining lung in the region reexpands leaving only the rolled-up trapped lung as an evidence of prior effusion. • Thus round atelectasis is a peripheral process requiring adhesions with the pleura. • The arcuate parenchymal distortion a/w the mass seen in Xray & CT images represent the bronchovascular structures trapped in the rolled-up lung. • This parenchymal distortion in inferomedial portion of the mass with relation to its hilus has been termed the “comet sign”

23. Case 3 A 21yr old female pt presented at 26wks gestational age with discordant monochorionic diamniotic twins.

24. The smaller fetus had no measurable amniotic fluid & the larger twin had polyhydramnios. Fetal anatomy was normal. After reduction amniocentesis of 2250 ml from the amniotic cavity of the larger twin, the intertwin membrane becomes visible & fluid is noted around the smaller fetus.

25. Umbilical artery velocimetry of the smaller fetus shows an abnormal A/B (systolc-diastolic) ratio of 6.2 & venous pulsation. Umbilical artery velocimetry of the larger fetus demonstrates a normal A/B ratio of 2.2.

26. Dx : Twin – twin transfusion syndrome (TTTS) • TTTS occurs as a result of shunting of blood btw the circulatory systems of monochorionic twins ( 5 – 30% cases) • The intraplacental anastomosis is usually deep seated in a single shared cotyledon commonly arteriovenous but can be arterioarterial. • The clinical features depend on the volume of blood shunted from one fetus to the other. Severe cases result in miscarriage or stillbirth. • Traditionally the diagnosis of TTTS is made retrospectively on the basis of intertwin difference in birth wt of 20% or more & Hb of 5% or more.

27. The classic findings are that of a small, hypotensive, hypovolemic, anemic donor with oligohydramnios & a fluid overloaded, polycythemic, hypertensive recipient with polyhydramnios.

28. Sonographic diagnosis depend on the following: • Presence of a MC twin pregnancy. • Discordant growth – predictors are differences in AC of greater than or equal to18-20mm, EFW of 15% or a second trimister BPD of 5mm. • Disparity in AF volume - The pathognomonic features include the presence of a large bladder in the recipient in the polyhydramniotic sac & absent bladder in the anuric donor which is stuck immobile at the edge of the placenta or the uterine wall, held fixed by the collapsed membranes of the anhydramniotic sac.

29. Other findings include a 1.Hypertrophied dilated heart in the recipient with absence or reversal of flow in ductus venosus during atrial contraction & echogenic bowel, absence of ED flow in the umbilical artery and a dilated heart in the donor. 2.Hydrops in one fetus. 3.Disparity in the size or no: of vessels in the umbilical cord. 4.UA A/B ratio difference of >0.4%. 5.The superficial communicating vessel can be demonstrated at the placental insertion of intertwin membrane using color doppler.

30. USG images of one fetus of a MCDA twin at 12wks of GA showing increased NT & an enlarged bladder. Early changes of TTTS can be identified as early as 11-14wks & manifest as incresed nuchal translucency in one or both the fetuses.

31. Case 4 An 18yr old pt presented with abdominal pain, nausea & wt loss of a few months duration.

32. CT scout film shows that there is a large soft tissue opacity in upper abdomen displacing the bowel loops to pelvis.

33. Axial CECT images of abdomen shows there is marked dilatation of stomach & proximal duodinum. Transition to normal caliber is seen from 3rd part of duodinum where it passes btw SMA & aorta. The distance btw SMA & aorta is 5mm ( normal is 10-20mm )

34. On upper GI series there is a sharp cut off at the level of 3rd part of duodinum. In fluoroscopy, delayed duodinal transit & to&fro movement in prox: duodinum was seen. Mucosal folds were normal

35. In prone oblique position the obstruction is relieved & the barium passes into the distal normal small bowel.

36. Sagittal MRA image - The angle formed by the SMA & aorta ( aortomesenteric angle ) is approximately 23 degrees. Normal aortomesenteric angle is 45 wt a range of 35 – 60 degrees.

37. Dx: SMA syndrome • Aka Wilkie’s syndrome, the Cast syndrome, c/c duodinal ileus. • Usually affects young females. • Presentats with c/c postprandial abd.pain, belching, bloating, nausea & vomiting. • Symptoms may occur after an episode of rapid & dramatic wt loss – anorexia nervosa, cancer, burns & severe injuries. • Also occurs in pts with body cast for tt of spinal fractures.

38. SMA syndrome is most often the result of narrowing of the aortomesenteric angle ( Normal 35 – 60 degrees ) which causes compression of the 3rd part of duodinum as it passes btw SMA & aorta. • The aortomesenteric distance also becomes reduced ( Normal is btw 10 -20 mm ). • Rare causes include an abnormally high & fixed attachment of Ligament of Trietz with puling up of duodinum, abnormally low origin of SMA , compression of the duodinum secondary to peritoneal adhesions, traumatic aneurysm of the SMA & the familial SMA syndrome.

39. CT is the best way to assess the pt. It provides information about the duodinum, aortomesenteric distance along with retreperitoneal & mesenteric fat. • USG & arteriography ( conventional, CTA & MRA ) can be used to measure the AM angle & distance. • Manometric study helps in d/d SMA syndrome & neuroathic/myopathic forms of c/c pseudoobstructions. • Intitial tt is by conservative measures, on failing which surgery is resort to – duodinojejunostomy & lysis of lig: of Trietz & mobilisation of duodinum.

40. Case 5 A 66yr old female pt presented with delirium following sx for ca bladder. There is no significant medical history.

41. CT reveals scatterd areas of white matter hypointensities. Grey matter & basal ganglia are spared.

42. MR images reveal multiple cystic appearing white matter lesions of varying sizes mainly in the periventricular region. The lesions show CSF signal on all sequences & do not enhance. There is no restricted diffusion/blooming

43. On FLAIR images focal hyperintensities are seen around some of the lesions. No mass effect is seen.

44. Dx: Giant Tumefactive Virchow-Robin Spaces • PVSs ( perivascular spaces) aka Virchow-Robin spaces are pia lined interstitial fluid filled structures that accompany the penetrating arteries. • When enlarged they may be mistaken for a pathologic process & may cause mass effect. • They appear as clusters of varying size cystic spaces that are isointense relative to CSF & do not enhance. • They are most commonly seen in the mesencephalothalamic region & may cause hydrocephalus. • Although, may have striking mass effect, giant PVS,s should not be mistaken for neoplasm or other diseases

45. Patients usually present with nonspecific findings that are not attributable to the giant PVSs. • Giant PVS,s that occur in white matter may have surrounding signal intensity abnormality on T2 wieghted or FLAIR images. • One theory is that this associated signal intensity alteration may represent advanced chronic ischaemic change related to mass effect of PVSs. • In younger patients signal abnormality is more diffuse & is thought to be due to gliosis or spongiosis.

46. Case 6 • A 23yrs old male presented with complaints of heaviness in chest & easy fatigability. • No other significant history.

47. Chest X-ray showing a soft tissue opacity mass lesion with lobulated margins in the anterior mediastinum.

49. DIAGNOSIS • TERATOMA

50. ANTERIOR MEDIASTINAL MASSES Terrible Lymphoma, Leukemia Thyroid Thymoma Teratoma