Neonatal abdominal real-time sonography

Transcription

1 Neonatal abdominal real-time sonography Thomas E. Sumner, M.D. Charles Phelps, II, M.D. J ames E. Crowe, M.D. James F. Martin, M.D. Because it makes rapid, reliable imagingpossible at the cribside, real-time ultrasonography is rapidly gaining in popularity for the diagnostic evaluation ofpediatric patients. Real-time ultrasonography is rapidly gaining popularity over conven- Introduction tional static B-scanning in pediatrics. In a B-scanner, the transducer is attached to an articulated arm that confines its motion to a single plane. Real-time imaging employs single or multiple specialized transducers capable of rapidly scanning in various planes. As a result, a set of B-scans is so quickly performed that the dynamics of the echo sources can be traced. It is especially valuable in the evaluation of moving structures, such as the heart. Instead of static B-scan images, real-time sonography provides dynamic images similar to fluoroscopy. Real-time sonographic imaging can be used to survey all portions of the abdomen rapidly and thoroughly, to follow a vessel to its origin and visualize its movement, to localize an organ, and to identify a mass quickly. Its versatility and speed are particularly applicable to neonatal abdominal examination. An additional major advantage of some real-time scanning devices is that they are portable. This permits cribside examination, making it unnecessary to remove an infant from his isolette. Recent advances in the resolution and documentation of real-time images tend to offset the disadvantage of their small size. In general, real-time systems provide a fast and effective imaging modality for screening neonates with suspected abdominal masses. Furthermore, real-time sonography is often diagnostic and may obviate the need for other more complex, more costly or invasive studies. From the Department of Radiology, Wake Forest University, Bowman Gray School of Medicine, Winston-Salem, N. C. Address reprint requests to Dr. Thomas Sumner, 300 South Hawthorne Road, Winston-Salem, N. C Volume 1, Number S November 1981 RadioGraphics 29

2 Sumner, et al. Diffuse Hepatic Hemangiomata Case 1 Case 1 is an 18-day-old male infant with congestive heart failure, hepatomegaly and skin hemangiomas. The abdominal radiograph (Figure 1A) demonstrates hepatomegaly; the chest radiograph (Figure 1B) demonstrates cardiomegaly with vascular congestion. The supine longitudinal B- scan (Figure 1C) demonstrates an enlarged liver with a dilated hepatic vein draining into the inferior vena cava. Real-time sonography (Figure 1D) demonstrates an enlarged liver with multiple areas of decreased echogenicity. These relatively anechoic areas do contain internal echoes in contrast to the enlarged vascular structures which are echo free. Notice the enlarged hepatic vein draining into the inferior vena cava. In this clinical context, this patient was thought most likely to have hepatic hemangiomas resulting in hepatomegaly with high output cardiac failure. Hepatic CT scan (Figure 1E) demonstrated areas of decreased density on the unenhanced study. Subsequent aortography (Figure if) demonstrated venous pooling indicative of diffuse hepatic hemangiomata. The clinical triad consists of hepatomegaly, congestive heart failure, and cutaneous hemangiomas in one-third of patients with hepatic hemangioendotheliomatosis. Bruits may be heard over the liver and there may be liver calcifications. Complications include congestive heart failure, hyperconsumptive coagulopathy, and hepatic rupture (1). Treatment usually consists of steroids when there is diffuse involvement; radiation or surgery may be used with local involvement. These lesions regress in approximately 6-12 months. r -#{149}#{149}#{149} - ;T#{149}= #{149} A F J= * -=.- -SI Figure 1A Hepatomegaly. Figure lb Cardiomegaly, vascular congestion. 30 RadioGraphics November 1981 Volume 1, Number 3

3 Sumner, et al. Case 1 #{149} : :;ii:t#{149}#{149}- * _#{149},,4 4..-#{149}= #{149} #{149} : i...l I V #{149}#{149}J #{149},,.- ;T -,-. i;-.,j :..#{149} 1C Figure Longitudinal supine hepatic B-scan: varying sized, relatively anechoic areas. IVC: inferior vena cava, HV: large hepatic vein. Figure ld Longitudinal supine hepatic real-time sonogram showing multiple relatively anechoic areas (arrowheads), enlarged hepatic vein [V] drains into inferior vena cava [IVC]. H heart. _,...eir Liver CT (uninfused): hepatomegaly with multiple areas of Figure if decreased density. Aortogram: diffuse hepatic venous pooling. Volume 1, Number 3 November 1981 RadioGraphics 31

4 Sumner, et al. Calcified Thrombus Inferior Vena Cava in Case 2 Case 2 is a 1,600-gram premature infant delivered by cesarean section because of fetal distress. Initial abdominal radiographs (Figures 2A & B) demonstrated a right upper quadrant calcification. The ovoid or bulletshaped calcification is in the region of the inferior vena cava. This radiological appearance is typical of calcified thrombus within the inferior vena cava. Transverse supine B-scan of the liver (Figure 2C) demonstrates a highly echogenic focus in the region of the inferior vena cava; the longitudinal supine B-scan (Figure 2D) demonstrates the dense echo collection to be within the inferior vena cava. Real-time abdominal sonography (Figures 2E & F) localized the calcification within the inferior vena cava and established the patency of the inferior vena cava and the renal veins. Further invasive angiographic studies were precluded, real-time sonography having established the diagnosis. Calcification of a thrombus within the inferior vena cava has been reported in 20 case reports since 1961 (2). The age at which the lesion is detected ranges from the first day of life to late adulthood, and the typical radiographic appearance is that of a bullet-shaped or ovoid calcification to the right of T11-12 in the region of the inferior vena cava. The patients are usually asymptomatic, but there may be extension of the inferior vena cava thrombus into the renal veins. Therefore, it is important to establish the patency of the renal veins. Diagnosis previously depended on inferior vena cavagraphy and radionuclide venography. We now advocate real-time sonography not only to establish this diagnosis, but also to exclude intrahepatic calcification or calcification in a right upper quadrant mass such as a neuroblastoma. #{149}#{149}t#{149} I. 5. *4 : %#{149}#{149} I A : _.a_ B..... Figures 2A & B Bullet-shaped right upper quadrant calcification (arrowheads). 32 RadioGraphics November 1981 Volume 1, Number 3

5 Sumner, et at. Case 2 I r#{149}-; Sb. #{149}.#{149}.,( q. =. _ hka :b. t - p C D Figures 2C & D Transverse supine (C) and longitudinal supine (D) hepatic B-scan: dense echo collection (arrowheads) within inferior vena cava (IVC) with posterior acoustic shadowing (open arrows). Figures 2E & F Transverse supine (E) and longitudinal supine (F) hepatic real-time sonogram: dense echo collection 1+] representing calcification within inferior vena cava [IVC] with posterior acoustic shadowing (open arrows). L liver. Volume 1, Number S November 1981 RadioGraphics 33

6 Sumner, et at. Multicystic Kidney- Potter Type II Case 3 Case 3 is a 2-day-old infant with a right-sided abdominal mass. Intravenous urography (Figure 3A) demonstrated non-visualization of the right kidney. The differential diagnosis included multicystic kidney and a severely hydronephrotic right kidney, possibly due to ureteropelvic junction obstruction. B-scan sonography in the region of the right kidney (Figures SB & C) demonstrated multiple echo-free areas separated by linear echo collections having the appearance of septa. Real-time sonography (Figure 3D) demonstrated a similar appearance. In differentiating multicystic kidney from severe hydronephrosis, one looks for a dilated pelvis located medially (3). In this case a medial hydropelvis was not identified. Neither ureteral dilatation nor a bladder abnormality such as a ureterocele was detected. Further evaluation with technetium glucoheptonate (Figures SE & F) demonstrated a photopenic (photon deficient) region in the area of the right kidney on the early scan. The 31/2 hour delayed scan had a similar appearance. This finding suggested a multicystic kidney rather than a hydronephrotic kidney secondary to ureteropelvic junction obstruction. (A hydronephrotic kidney would not be expected to remain photopenic on an isotope study if renal function existed.) At surgery, a multicystic right kidney with no vascular supply and no ureteral drainage was identified (Figure 3G). Histologic diagnosis was multicystic kidney, Potter Type II. Figure 3A - Non-opacified right kidney, normal cystogram. 34 RadioGraphics November 1981 Volume 1, Number 3

7 Sumner, et at. Neonatal abdominal.real-time sonography Case 3 Figures 3B, C & D Supine transverse (B) and longitudinal (C) B-scans: right kidney replaced by multiple anechoic compartments separated by echogenic septations. Transverse supine real-time sonogram (D): right kidney replaced by multiple anechoic compartments [C] separated by echogenic septations. -.. #{149} $#{149} ;.,-#{149} - - #{149} ) #{149} -#{149}... Figures 3E, F & G Early (E) and delayed (F) technetium glucoheptonate scans showing non-function on right [R], POST = posterior. Surgical specimen (G): multicystic kidney without vascular supply or ureter. Volume 1, Number 3 November 1981 RadioGraphics 35

8 Sumner, et at. Polycystic Kidneys- Potter Type I Case 4 Case 4 is a one-day-old male infant with bilateral flank masses. Intravenous urography (Figure 4A) demonstrated the typical appearance of infantile polycystic kidney disease with contrast material radiating perpendicularly and extending to the peripheral cortex within ectatic tubules. Contact B-scan in the prone longitudinal position (Figure 4B) demonstrated enlarged highly echogenic kidneys. Real-time sonography in the longitudinal supine position using the liver as an acoustic window (Figure 4C) demonstrated an enlarged highly echogenic right kidney. Its echogenicity is greater than that of the adjacent liver parenchyma which is the reverse of normal. This appearance has been described in various types of polycystic disease of the kidneys (4). The typical appearance of this patient s intravenous urogram as well as the sonographic appearance is consistent with the infantile form of polycystic disease or Potter Type I. This patient s liver sonogram was normal. I, *. #{149} - =#{149}#{149} - #{149},- 4 - f #{149}#{149}#{149} * \#{149}) :- #{149}:#{149} Figure 4A Classical urographic appearance of renal tubular ectasia. 36 RadioGraphics November 1981 Volume 1, Number 3

9 Sumner, et al. Case 4 Figure 4B Prone longitudinal renal B-scan: increased echogenicity of kidney parenchyma with loss of central pelvocalyceal echoes. Normal liver [L} ultrasonograrn. Figure 4C Supine longitudinal real-time sonogram: enlarged kidney (arrowheads) with kidney echogenicity exceeding liver echogenicity. K kidney; L liver. Volume 1, Number 3 November 1981 RadioGraphics 37

10 Sumner, et at. Polycystic Case 5 Kidneys- Potter Type III Case 5 is a one-day-old female infant with suspected bilateral nephromegaly. Intravenous urography (Figure 5A) demonstrated enlarged kidneys bilaterally with slight calyceal spreading and without marked infundibular narrowing. B-scan renal sonography in the longitudinal supine position on the right (Figure SB) demonstrated an enlarged, highly echogenic kidney whose echogenicity exceeded that of adjacent normal liver parenchyma. Real-time sonography (Figure 5C) demonstrated similar findings. This sonographic appearance is highly suggestive of cystic disease of the kidney, and we believe the radiographic appearance combined with the sonographic appearance in this patient indicates the adult form of polycystic kidney disease, Potter Type III. Liver and pancreatic sonography were normal. Bilateral flank masses (Cases 4 & 5), may result from polycystic disease of the kidney. Adult and infantile varieties, inherited as autosomal dominant and recessive traits, respectively, cannot be easily distinguished during infancy by ultrasonography alone (5). Neonatal ultrasonography reveals enlarged kidneys with diffusely increased echogenicity, poor definition and/or distortion of renal outlines and loss of definition of the central pelvocalyceal echo complex (6). Patients with infantile polycystic disease may have increased liver echogenicity because of hepatic fibrosis (7,8); whereas, hepatic and pancreatic cysts may be detected in older patients with adult polycystic disease. Intravenous urography and a detailed family history help to establish the correct diagnosis in these two conditions. Figure 5A Enlarged kidneys with slight calyceal spreading. 38 RadioGraphics November 1981 Volume 1, Number 3

11 Sumner, et al. Case 5 Figure 5B Supine longitudinal renal B-scan: enlarged highly echogenic kidney [K], renal echogenicity exceeds liver [LI. Figure SC Supine longitudinal real-time sonogram: enlarged highly echogenic right kidney [K] with normal liver [L]. Volume 1, Number S November 1981 RadioGraphics 39

12 Sumner, et al. Conclusion This exhibit urges application of real-time sonography in the evaluation of the neonatal abdomen. Normal vascular anatomy is easily delineated; vascular patency is established by the dynamic aspects of real-time scanning. Size, configuration and tissue characteristics of abdominal viscera are similarly rapidly determined. The advantages of diagnostic utility, speed of examination and portability of equipment make real-time sonography particularly suited for the detection of neonatal abdominal masses. Detection of renal pathology is especially important because renal or perirenal abnormalities account for most neonatal abdominal or flank masses. If hydronephrosis is detected, the course of the ureter should be scanned to identify ureterectasis. Ureterectasis indicates obstruction distal to the ureteropelvic junction and/or vesicoureteral reflux. Possible obstructive etiologies include ureteroceles (simple and ectopic) and posterior urethral valves. The bladder should be examined for a ureterocele that sonographically simulates an intravesical cystic mass (9). If no ureterocele is identified, cystography is warranted to exclude a refluxing megaureter or posterior urethral valves in the male infant. If renal sonography indicates cystic disease of the kidney, intravenous urography and detailed family history may confirm congenital cystic renal disease. Additional confirmatory findings may be supplied by liver and pancreatic scanning. References 1. Slovis TL, Berdon WE, Halter JO, et al Hemangiomas of the liver in infants. Am J Roentgenol 123: , Apr Kassner EG, Baumstark A, Kinkhabwala MN, et at: Calcified thrombus in the inferior vena cava in infants and children. Pediatr Radiol 4: , Apr Ralls PW, Esensten ML, Boger D, et al: Severe hydronephrosis and severe renal cystic disease: ultrasonic differentiation. Am J Roentgenol 134: , Mar Boal DK, Teele RL: Sonography of infantile polycystic kidney disease. Am J Roentgenol 135: , Sept Kendall AR, Pollack HM, Karafin L: Congenital cystic disease of kidney. Urology 4: , Dec Kelsey JA, Bowie JD: Gray-scale ultrasonography in the diagnosis of polycystic kidney disease. Radiology 122: , Mar Rosenfield AT, Siegel NJ, Kappelman NB, et al: Gray scale ultrasonography in medullary cystic disease of the kidney and congenital hepatic fibrosis with tubular ectasia: new observations. Am J Roentgenol 129: , Aug Thomas JL, Sumner TE, Crowe JE: Neonatal detection and evaluation of infantile polycystic disease by gray scale echography. J Clin Ultrasound 6: , Oct Sumner TE, Crowe JE, Resnick MI: Diagnosis of ectopic ureterocele using ultrasound. Urology 15:82-85, Jan RadioGraphics November 1981 Volume 1, Number 3