CASES

1. CASES BHUMIKA SUTHAR 3rd Yr RESIDENT DEPT. OF RADIODAIGNOSIS BARODA MEDICAL COLLEGE,SSGH 25/06/08

2. Case 1 History: • 11 yrs old Child with HT not responding to antiHT. • US abdomen: normal. • Doppler US: revealed a focal zone of stenosis with peak velocity of 225cm/sec in proximal right renal artery with distally decreased waveforms. • Aortography revealed a normal aorta. • This was followed by selective renal arteriogram.

3. PROXIMAL RIGHT RENA ARTERY • Doppler spectrum from the proximal Right renal artery shows flow acceleration of close to 225cm/sec inside the stent. Intrarenal Doppler spectrum shows a waveform with a pulsus tardus configuration, which indicates severe hemodynamic repercussions INTRARENAL SPECTRUM

4. Selective Rt. renal arteriogram shows focal area of stenosis in proximal third main renal artery with minimal post-stenotic dilatation.SO OUR CASE IS OF RENOVASCULAR HT

5. Discussion • Systemic HT is less common in children.(1-5%). • 80% of HT in children is due to secondary HT. • Renovascular etiology in 5-25% of children with secondary HT.

6. RENAL HYPERTENSION Vascular causes Parenchymal causes Atherosclerosis Fibromuscular dysplasia Thrombosis/ embolism Arteritis-takayasu arteritis buerger’s disease, polyarteritis nodosa Neurofibromatosis Vascular trauma Arterial dissection Aneurysm of aorta Extrinsic compression Chronic Bilateral Parenchymal Disease Unilateral Parenchymal Disease Reflux nephropathy HN Chronic GN PCKD Radiotherapy (much less common)Reflux nephropathyHN TumorsTB

7. How to investigate a case of renovascular HT? • Clinical suspicion: • Findings highly s/o renovacular disease: • Severe or sudden onset HT in younger patients, • Associated vascular disease • Difficulty in treating HT despite of multidrug therapy • Presence of abdominal bruits • Rule out causes other than renovascular one 3. Appropriate investigations to confirm the renovasular etiology & then to come to a final diagnosis.

8. Radiological investigations • Ultrasound: • to rule out renal parenchymal causes of HT like HN, polycystic kidney disease, tumors. • In the absence of such causes with significant difference in the size of two kidneys should suggest renovascular etiology. Though a normal appearance of kidneys doesn't rule out same. • Duplex ultrasound • Diagnosis of RAS is based on findings as: • A peak systolic velocity of >100cm/s in the renal artery. • Renal artery to aorta velocity ratio-significant stenosis if the ratio is >3.5. • Parvus tardus waveform in the intrarenal vessels. • Turbulent flow in the post stenotic artery.

9. Plasma renin activity: • Baseline plasma renin activity - elevated in 50-80% pt. • Renal vein renin measurements: • compare renin release from each kidney and are used to predict the success of surgical revascularization. • Increased renin secretion in the ischemic kidney as compared to the contralateral kidney, ie, a renal vein renin difference of 1.5, constitutes a positive test result and suggests that revascularization will treat elevated blood pressure successfully.

10. Radionuclide study (captopril challenge test): • Accurate method of identifying functionally significant renovascular HT. It has a sensitivity & specificity of >90% in pts with normal renal function & a normal baseline renogram. • A baseline dynamic renal scan is done using 99m Tc-DTPA. • A repeat study after giving of 25mg of captopril. • ACE positive study: • Fall in total & relative function of affected kidney(>10%) • Delayed time to peak maximum activity (>2min or 40%) • Prolonged intrarenal transit time (>2 min)

11. CAPTOPRIL CHALANGE RADIONUCLITIDE TEST

12. CT angio / MR angio • high sensitivity & specificity in detection of main RAS of > 50%. • The resolution of CTA & MRA are sufficient for main RA. • Disadvantages: • Not useful in the assessment of intrarenal & segmenatal arteries. • Accessory arteries <3mm cann’t be visualised. • Pressure measurements can’t be done. • Limited use of CT angio in patients with high creatinine. • cost and technique availability. • Gado. enhanced MRA scores slightly above CTA as it is superior in identification of accessory arteries, no radiation or nephrotoxicity & also multiple projection and temporal processing can be done.

13. Renal Digital Subtracion Arteriography • its use is limited prior to angioplasty or stenting. • Flush aortography is usually adequate for the purpose. • the stenotic renal artery is catheterized & a selective arteriogram is obtained. • Next the catheter is passed beyond the stenosis to measure the intraarterial pressure to know whether there is a gradient across the lesion.

14. Pressure gradient <15mm of Hg across the stenosis Pressure gradient >15mm of Hg Or 10% of systolic pressure Significant stenosis Insignificant stenosis Angioplasty is done

15. In our case…Selective Rt. renal arteriogram shows focal area of stenosis in proximal third main renal artery with minimal post-stenotic dilatation.

16. There is a long list of renovascular causes… • Atherosclerosis • Fibromuscular dysplasia • Thrombosis/ embolism • Arteritis- takayasu arteritis, buerger’s disease, polyarteritis nodosa, postradiation • Neurofibromatosis • Vascular trauma • Arterial dissection • Aneurysm of aorta

17. Atherosclerosis: produces stenosis of proximal RA similar as in our case but it can be safely excluded considering the age of patient who is a child.

18. Medial fibroplasia subtype of FMD • bilateral affection is common, • there is sparing of proximal third main RA, • The string of bead appearance is hallmark.

19. Thrombosis/ • emblism • gives a smooth cutoff sign on angio rather than a focal stricture.

20. Takayasu’s arteritis typically involves ostial part of renal artery, involvement of aorta is always present.

21. So considering the age & the location of stenosis the following remaining differentials can be kept: • Fibromuscular dysplasia (intimal fibroplasia subtype) • Neurofibromatosis

22. Fibromuscular dysplasia: (intimal fibroplasia subtype) charcteristic unilateral involvement of proximal renal artery which shows smooth symmetrical stenosis with no aortic involvement. • Neurofibromatosis: • is a rare cause of renal artery stenosis. • There is typically a smooth stenosis at the orifice of the renal artery with significant post stenotic dilation. This may be associated with abdominal aortic coarctation or rarely iliac artery stenoses.

23. RAS in Neurofibromatosis: (a) Mid stream aortography shows delayed filling of right intrarenal vessels and a high grade proximal stenosis of the main (upper) right renal artery (arrow). The left renal arteries are unremarkable. (b) Delayed aortography confirms markedly delayed opacification of right intrarenal vasculature (c) Selective renal arteriography shows poststenotic dilatation and mild proximal narrowing of the segmental renal artery.

24. Diagnosis: • Fibromuscular dysplasia (intimal fibroplasia subtype) • Is it important to differentiate between the medial fibroplasia & intimal fibroplasia subtype? • by the view of treatment as medial fibroplasia is non progressive & the beaded appearance dialtes easily at low pressure with excellent long term results. • While intimal fibroplasiaare progressive & have smooth stenosis which may not dilate satisfactorily so that stenting is necessary.

25. CASE 2 • 25 yrs old male patient presented with h/o headache. • MRI has been done…..

26. A round mass is seen in the midline of the posterior nasopharynx that is of low SI on • T1-weighted images and high signal intensity on T2-weighted images.

27. Thornwaldt Cyst • = Thornwaldt cyst, or nasopharyngeal cyst. • A midline pouch within the posterior roof of nasopharnx. • Due to an adherence of the notochord to the pharyngeal ectoderm during development, resulting in the outpouching of ectoderm into the pharyngobasilar fascia. • When this epithelial lined cyst secretes mucus, either spontaneously or secondary to inflammation, a cyst is formed. Adenoidectomy has been implicated as etiologic factor, due to injury to the pharyngeal duct orifice, with resulting inflammation,infection and subsequent cyst development. • The peak age between 15 and 30 years.

28. asymptomatic unless an infection develops. • Infected TC may cause occipital headaches, persistent purulent drainage with a foul taste and odor, postnasal drip,sore throat. • CT: • A low density lesion in the midline in the posterior roof of the nasopharynx is highly suggestive of a Thornwaldt's cyst. MRI: • Investigation of choice to delineate & characterise TC.

29. Round & well circumscribed lesion with sharp contours. • A lesion situated between the longus capitus muscles, that is at least 7 mm or larger in diameter, without associated inflammatory changes in the surrounding soft tissues or concurrent bone involvement. • T1W- Hypointense lesion • T2WI-Intensity is similar to CSF • may reveal peripheral enhancement on post contrast. • The presence of protein and/or associated hemorrhage within the cyst leads to high SI on both T1 and T2 weighted images.

31. CASE 3 • 70 YRS OLD MALE PRESENTED WITH C/O COUGH & DYSPNEA…..

32. Saber sheath trachea Narrowing of the coronal diameter of the intrathoracic portion of the trachea on AP film.

34. DIAGNOSIS: Saber Sheath Trachea.

35. Xray: 25 mm in male 23mm female NORMAL ANATOMY CT: 19.8 mm in female 21.4 mm in male • Roughly rounded tube • Anterior-lateral cartilaginous rings give the trachea a C-shape • Smooth appearance as it enters the thorax • Coronal and sagittal diameters are 1:1

36. Saber-Sheath Trachea • Saber-sheath trachea is common and almost always associated with chronic obstructive pulmonary disease. • characterized by a marked decrease in coronal diameter of intrathoracic trachea associated with an increase in its sagittal diameter as a result of cartilage weakness. • The extrathoracic trachea is normal. • CT: • Inward bowing or displacement of the lateral tracheal walls • CT during forced expiration may show further inward bowing of the tracheal walls (tracheomalacia).

37. Drawing shows typical appearance of saber-sheath trachea compared with normal trachea. Cartilage is shown as dark gray.Narrowing of trachea is caused by deformity of tracheal cartilage. Mucosa and submucosa are normal.

38. Saber-sheath trachea in 64-year-old man with chronic obstructive pulmonary disease. Posteroanterior chest radiograph reveals diffuse narrowing of coronal diameter of intrathoracic trachea (straight arrows). Note that extrathoracic trachea is normal in diameter (curved arrow). Lateral chest radiograph shows increased tracheal diameter throughout its intrathoracic course (arrows).

39. Saber-sheath trachea in 64-year-old man with chronic obstructive pulmonary disease. CT scan (10-mm collimation) obtained at thoracic inlet reveals that sagittal diameter—coronal diameter ratio of intrathoracic trachea exceeds 2:1. Tracheal walls are mildly thickened with ossification of tracheal rings.

40. Tracheal Stenosis: • Acquired stenosis caused by intubation or tracheostomy induced Inflammation & pressure necrosis of the tracheal mucosa. • CT: as eccentric or concentric soft-tissue thickening internal to normal-appearing tracheal cartilage. • The outer tracheal wall has a normal appearance without evidence of deformity or narrowing. • Expiratory CT shows little change in tracheal diameter.

41. Drawing shows appearance of tracheal stenosis caused by granulation tissue compared with normal trachea. Soft tissue internal to tracheal cartilage is thickened.

42. 80-yr-old man with acute tracheal stenosis representing granulation tissue after intubation. collimated CT scan shows narrowing of tracheal lumen by increased thickness of soft tissue internal to tracheal cartilage and thickening of posterior tracheal membrane. Tracheal cartilage is faintly calcified and appears normal in shape. Outer tracheal wall has normal configuration and trachea has normal oval shape. On parasagittal reconstruction from 3-mm collimated CT scans, narrowing appears focal and hour-glass-shaped. Granulation tissue is visible internal to calcified cartilage of anterior tracheal wall.

43. Tracheobronchopathia Osteochondroplastia • characterized by development of osseous or cartilaginous nodules or both in the submucosa of the trachea and bronchial walls & tracheal cartilage. • CT: thickened tracheal cartilage with small 3- to 8-mm calcific nodules along its inner aspect, protruding into the tracheal lumen. • The appearance is much more irregular than that seen with normal cartilage calcification.

44. 64-year-old man with tracheobronchopathia osteochondroplastica. Drawing shows typical appearance of tracheobronchopathia osteochondroplastica. Submucosal nodules of calcified cartilage involve anterior and lateral tracheal walls. These nodules result in irregular inner tracheal wall. CT scan shows typical findings of this entity: irregular nodular areas of calcification involving anterior and lateral (cartilaginous) portions of tracheal wall. Calcifications are much more irregular and result in irregular narrowing of tracheal lumen.

45. Tracheal Diverticulum: • commonly associated with COPD. • along Rt posterolateral tracheal wall near the thoracic inlet between cartilaginous & muscular portions of tracheal wall. • As isolated paratracheal air cysts or may be seen communicating with the tracheal lumen. • 88 yr-old man with tracheal diverticulum,CT scan shows it to arise fromposterolateral rt tracheal wall near thoracic inlet, posterior to tracheal cartilage. • Communication with tracheal lumen is seen.

46. Mounier-Kuhn Syndrome(Tracheobronchomegaly) • C/b marked dilatation of the trachea and mainstem bronchi. • associated with atrophy of cartilaginous,muscular,elastic components of tracheal wall. • seen in connective tissue abnormalities. • CT: thinning of the tracheal wall and a tracheal diameter of more than 3 cm. • The trachea tends to collapse with forced expiration (tracheomalacia). 57-yr-old man wittracheobronchomegaly. CT scan shows tracheal wall to be thin, measuring 3.7 cm in diameter.

47. Wegener's Granulomatosis: • mucosal and submucosal inflammation and ulceration. • Subglottic involvement is most typical with variable involvement of the distal trachea & proximal mainstem bronchi. • CT: circumferential wall thickening and narrowing of the tracheal lumen.

48. 55-year woman with Wegener's granulomatosis, Drawing shows typical appearance of Wegener's granulomatosis. Mucosal and submucosal inflammation results in concentric thickening of tracheal wall and mucosal ulceration, with involvement of both cartilaginous (anterior and lateral) and membranous (posterior) portions.. Irregularity of mucosal surface suggests ulceration.

49. Amyloidosis • Deposits are submucosal and most commonly involve the entire trachea. • On CT: concentric, smooth, or nodular thickening of the submucosal tracheal wall. • Cartilage is normal but concentric calcification or ossification may occur without malacia. • 47-yr man with tracheobronchial amyloidosis. Submucosal deposits of amyloid result in concentric, smooth, or nodular thickening of tracheal wall. Calcification is common and may also be concentric.

50. 47-year-old man with tracheobronchial amyloidosis. CT scan shows smooth concentric tracheal wall thickening that involves posterior wall to lesser degree. Concentric submucosal calcification is seen along inner tracheal wall. CT scan shows concentric thickening and calcification of both main bronchi, typical of tracheobronchial amyloidosis