Section III – Genitourinary Radiology

Figure 1

45. Which of the following conditions could cause the finding shown on this CT scan (Figure 1)?

A. Acute cortical necrosis B. Hyperparathyroidism C. Chronic glomerulonephritis D. Xanthogranulomatous pyelonephritis

Findings: Dense, bilateral medullary nephrocalcinosis

Rationale: A: Acute cortical necrosis can cause cortical nephrocalcinosis, not medullary nephrocalcinosis. B: Hyperparathyroidism with associated hypercalciuria is one of the common causes of medullary

nephrocalcinosis. Other common etiologies include other causes of hypercalciuria/hypercalcemia states, medullary sponge kidney and renal tubular acidosis type I. Hyperparathyroidism and renal tubular acidosis type I tend to cause denser nephrocalcinoisis than medullary sponge kidney.

C: Chronic glomerulonephritis is a cause of cortical nephrocalcinosis, not medullary nephrocalcinosis. D: Xanthogranulomatous pyelonephritis (XGP) is characterized by staghorn calculi located in the renal

pelvis and infundibula, not calcifications in the renal medulla. Additionally, the calyces are typically dilated and filled with low density debris in Xanthogranulomatous pyelonephritis.

Noncontrast CT Noncontrast CT Figure 2 Figure 3

Contrast-enhanced CT st-enhanced CT Contra

Figure 4 Figure 5

46. You are shown CT images (Figures 2-5) from a 29-year-old patient with hematuria. What is the MOST LIKELY diagnosis?

A. Pyelonephritis B. Suburothelial hemorrhage C. Lymphoma D. Transitional cell carcinoma

Findings: There is hyperdense thickening of the collecting systems bilaterally compatible with suburothelial hemorrhage. Rationale: A: The presence of hyperdense thickening of the urothelium makes this diagnosis unlikely. B: There is diffuse high attenuation thickening of the urothelium bilaterally, indicative of suburothelial hemorrhage. C: While lymphoma can infiltrate into the collecting system, it would not be expected to be hyperdense on noncontrast CT. D: For the same reasons explained in choices A and C, this choice would be unlikely.

Figure 6

47. You are shown a hysterosalpingogram image (Figure 6) from a patient with a history of right

salpingectomy. What is the MOST LIKELY diagnosis?

A. Salpingitis isthmica nodosa B. Endometriosis C. Tuberculosis D. Left tubal obstruction

Findings: The isthmus of the left fallopian tube is irregular with small, periluminal diverticular collections of contrast, most compatible with salpingitis isthmica nodosa. Rationale: A: There are multiple diverticular outpouchings involving an irregular isthmus of the left fallopian tube,

compatible with this diagnosis. B: Endometriosis can be the cause of tubal abnormalities detected on hysterosalpingogram, such as

obstruction and hydrosalpinx, however the constellation of findings in this study would not be typical for endometriosis.

C: Tuberculsosis can give rise to isthmic diverticula identical to those seen with SIN, however contraction of the ampulla and adnexal calcifications are frequent associated findings with tuberculosis and are not present in the test patient.

D: There is contrast spillage into the peritoneal cavity.

Axial T2W image Axial T1W postgadolinium axial image Figure 7 Figure 8

T1W postgadolinium coronal image

Figure 9

48. Based on Figures 7-9, what is the MOST LIKELY diagnosis?

A. Müllerian duct cyst B. Cystic prostate carcinoma C. Seminal vesicle cyst D. Prostatic abscess

Findings: There is a cystic mass in the midline of the prostate gland which demonstrates uniform T2 signal and no enhancement. Out of the choices given, the most likely etiology of a cyst in this location is a Mullerian duct cyst.

Rationale: A: Of the given choices, this is the most likely cause of a cystic lesion in the midline of the prostate gland.

Utricular cysts also occur in the midline but are usually smaller and do not extend above the base of the prostate.

B: Cystic prostate carcinoma is rare and would not appear as a simple cyst. Heterogenous signal, irregular shape and solid nodules would be expected in a cystic prostate cancer.

C: Seminal vesicle cysts are located some distance from the midline. D: A prostatic abscess can result in a cystic lesion at any location in the prostate, however peripheral

enhancement would be expected in the case of an abscess.

Axial T2W image Axial T1W image Postcontrast T1W fat-saturated image

Figure 10 Figure 11 Figure 12

49. Based on Figures 10-12, what is the MOST LIKELY diagnosis?

A. Hemorrhagic ovarian cyst B. Endometrioma C. Hydrosalpinx D. Mature teratoma

Findings: There is a right ovarian mass which is hyperintense on both T1 and T2 weighted sequences, however loses signal on frequency-selective fat saturated sequences. This is compatible with a fat containing lesion. A mature cystic teratoma is by far the most common fat containing ovarian tumor.

Rationale: A: Hemorrhagic masses would be expected to be bright on T1-weighted sequences, but would not lose

signal on fat-saturated sequences. B: Endometriomas are usually bright on T1-weighted sequences, however frequently are lower in signal on

T2-weighted images and will not lose signal with fat saturation. C: Hydrosalpinx appears as a folded tube-shaped structure adjacent to but not within the ovary. It is bright

on T2 weighted sequences and can have varying signal on T1-weighted sequences depending on its contents.

D: Mature teratomas contain fat, which will follow the signal of visceral fat on all imaging sequences, including fat-saturated sequences.

Figure 13 Figure 14

50. You are shown CT images (Figures 13 and 14) of a patient who is 3 weeks status post renal transplant. What is the MOST LIKELY diagnosis?

A. Renal abscess B. Urinoma C. Posttransplant lymphoproliferative disease D. Segmental ischemia

Findings: The post-contrast CT demonstrates a striated enhancement pattern of the parenchyma of the renal transplant in the right pelvis, with wedge-like areas of decreased perfusion. There is a low density lesion which does not fill in with contrast in the upper pole, and mild infiltration of the fat adjacent to the kidney.

Rationale: A: The finding of wedge-like/striated areas of hypoperfusion of the kidney, with mild infiltration of the

adjacent fat, is characteristic of pyelonephritis. The non-enhancing lesion of the upper pole is consistent with a renal abscess.

B: This upper pole low density lesion does not fill with contrast as would be expected in an urinoma, and the abnormal enhancement pattern is characteristic of pyelonephritis.

C: Post transplant lymphoproliferative disease tends to occur approximately 12 months post transplant, and would not be associated with this striated abnormal enhancement of the kidney seen here.

D: The entire transplant is abnormal. Also, infarction with liquifaction would be atypical, especially in the presence of a striated nephrogram.

Figure 15 Figure 16

51. You are shown images from a scrotal ultrasound (Figures 15 and 16) on a 65-year-old man. What

is the MOST LIKELY diagnosis?

A. Renal cell metastases B. Multifocal orchitis C. Lymphoma D. Leukemia

Findings: Multiple hypoechoic masses of the testicle, which demonstrate arterial flow within them, consistent with solid masses within the testis. Rationale: A: Possible, although less common than lymphoma involving the testicle. B: Not typically this relatively well defined and multifocal, with background normal testicular parenchyma. C: Most common etiology for multiple hypoechoic masses of the testicle in patient of this age. Lymphoma

accounts fro about 25% of testicular tumors in patients older than 50 years of age. May appear as one or more focal hypoechoic regions or as a diffusely enlarged hypoechoic testis.

D: May appear similar to lymphoma, but less common.

Figure 17 Figure 18

52. You are shown CT images in soft tissue (Figure 17) and bone (Figure 18) windows in a 58-year-

old man. What is the MOST LIKELY diagnosis?

A. Ureteral calculus B. Transitional cell carcinoma C. Blood clot D. Sloughed papilla

Findings: Filling defect is seen in the proximal right ureter, in a non-dependent location.

Rationale: A: A ureteral calculus would typically be more dense, and would typically be dependent. B: Findings are most consistent with a small focus of transitional cell cancer in the proximal ureter. C: Would typically be dependent. D: Would typically be dependent.

Figure 19

53. You are shown an image from a scrotal ultrasound (Figure 19) of a patient after a motorcycle

accident. What is the MOST LIKELY diagnosis?

A. Testicular neoplasm B. Testicular rupture C. Testicular torsion D. Testicular injury with intact capsule

Findings: There are regions of heterogeneous echotexture within the testis, compatible with hematomas. There is a small crescentic fluid collection, compatible with blood, visible at the margin of the testis. There is a loss of continuity of the capsule. Findings are consistent with capsular disruption/testicular fracture, which is an indication for emergent surgery. Approximately 90% of ruptured testes can be salvaged if surgery is performed within 72 hours of testicular injury, whereas later surgery is associated with a salvage rate of only 55%.

Rationale: A: While a focal region of testicular injury may not be distinguishable from a focal neoplasm on ultrasound

alone, this appearance of multiple heterogeneous regions and capsular trauma favors testicular fracture, particularly in the clinical setting of trauma.

B: The combination of loss of definition of the normal well-defined margin of the testicular capsule is a reliable sign of tunica disruption and testicular rupture. Findings of a heterogeneous echotexture within the testis, testicular contour abnormality, and disruption of the tunica albuginea are considered very sensitive and specific for the diagnosis of testicular rupture.

C: Scrotal trauma may result in testicular torsion, usually due to underlying bell-clapper deformity, with sonographic appearance similar to that of non-trauma-related testicular torsion. In testicular torsion without testicular rupture, one would not expect the heterogeneity and interruption in the tunica seen here.

D: There is capsular disruption, as seen by discontinuity of tunica.

Figure 20 Figure 21 Figure 22

54. You are shown a pelvic ultrasound (Figure 20) and CT images (Figures 21 and 22) of a 38-year-old woman. What is the MOST LIKELY diagnosis?

A. Urachal diverticulum B. Pyosalpinx C. Endometrioma D. Ectopic pregnancy

Findings: Fluid filled tubular structure anterior to the uterus on the left, with adjacent inflammatory change.

Rationale: A: A urachal diverticulum would be midline and anterior to the bladder. B: The above findings are most consistent with pyosalpinx. C: Although the low level echoes within the structure could certainly be seen with an endometrioma, the

tubular configuration and degree of surrounding inflammation would be unusual. D: The abnormality is tubular and clearly involving a tube. An ectopic pregnancy would typically cause

more rounded or amorphous lesions with surrounding fluid.

Figure 23

55. What is the MOST LIKELY cause of the stripes that appear in the CR image (Figure 23)?

A. Patient’s clothing pattern B. Patient motion C. Malfunction of automatic exposure control system D. Aliasing from a stationary antiscatter grid

Rationale: A. Clothing patterns generally do not appear in radiographs. B. Motion result in loss of sharpness, not a periodic pattern such as this. C. AEC malfunction would produce over- or under-exposure. This image appears to be properly exposed. D. Individual grid lines are rarely visible on digital radiographs, but an interference pattern (“moiré”

pattern) is formed when the CR pixel matrix under samples the gridline frequency. This is a classic example of a violation of the Nyquist Sampling theorem. The net effect of such under sampling is known as aliasing.

56. Concerning prostate cancer, which of the following statements is TRUE?

A. Stage C disease is characterized by extension of the tumor through the prostatic capsule. B. Extension of prostate cancer through the prostatic capsule on ultrasound or MRI is suspected

when the tumor touches the capsule. C. The majority of prostate carcinomas occur in the central zone of the prostate. D. Most prostate carcinomas present as hyperintense nodules on T2-weighted images.

Rationale: A: Stage B disease is tumor confined by the capsule. Stage C disease is extension of neoplasm through the

capsule. B: Tumor transgression is suspected when the capsule is bulging or tumor extends through the capsule.

Abutment of tumor to the capsule without bulging is more consistent with Stage B disease. C: 80-90% of prostate cancers occur in the peripheral zone of the prostate gland. D: Prostate cancers typically are hypointense relative to the normally hyperintense peripheral zone tissue

on T2 weighted images.

57. Concerning the MOST common form of extravesical ectopic ureteral insertion of the upper pole moiety, which of the following statements is MOST CORRECT?

A. The ectopic ureteral insertion is almost always associated with the upper-pole moiety. B. In males, the ureteral insertion is below the external sphincter, and they are incontinent. C. In females, the majority of ectopic ureteral insertions are inside of sphincter control, and they

are continent. D. Most cases are associated with partial duplication.

Rationale: A: This is a correct statement. B: In males, the ectopic ureter insertion is always above the sphincter, and they are continent. A common

clinical presentation for males is chronic or recurrent epididymitis due to ectopic insertion into the ipsilateral vas deferens or seminal vesicle.

C: In females, the ectopic ureteral insertion is usually outside of sphincter control and they are incontinent. D: Most (> 2/3) of cases of extravesical ectopic ureteral insertions are associated with COMPLETE

duplication.

58. Concerning an adnexal mass, which of the following statements is TRUE?

A. A high signal on T1-weighted images is diagnostic of a teratoma. B. A low signal on T2-weighted images is diagnostic of an endometrioma. C. Extraovarian masses are most likely benign. D. Mucinous neoplasms are typically less complex morphologically than serous neoplasms.

Rationale: A: High T1 signal is indicative of hemorrhage, fluid with high protein content, or fat. It is not diagnostic of

a teratoma. Drop in signal on fat saturation images is needed to confirm fat within the lesion, and would then be diagnostic of a teratoma.

B: Low T2 signal can be seen in an endometrioma secondary to blood products. However, low signal can also be seen in fibrous lesions such as fibroma. Thecomas and Brenner tumors can also have low signal on T2 images.

C: Most extra-ovarian masses are benign. This is a key imaging feature to determine on any pelvic imaging exam.

D: The opposite is true. Mucinous ovarian neoplasms are typically larger and more complex than serous neoplasms. A serous cystadenoma can present as a unilocular, simple cyst.

59. The risk of prenatal death from radiation exposure is highest at which of the following stages of embryo/fetus development?

A. Preimplantation (0-2 wks) B. Major organogenesis (2-8 wks) C. Fetal growth (8-40 wks) D. All stages (0-40 wks)

Rationale: A: The effect of radiation at this stage is “all-or-nothing.” If the conceptus survives, it is thought to develop

fully, with no radiation damage. B: Risk of prenatal death decreases during this stage, but risk of major organ malformations and growth

retardation increase. C: All risks decrease during this phase, except for cancer risk which is approximately the same throughout

gestation. D: Risk of prenatal death is highest in preimplantation phase and decreases after that.

60. Regarding renal neoplasms, which of the following statements is TRUE?

A. Papillary renal cell carcinoma typically appears as a hypervascular mass on CT or MRI. B. Renal medullary carcinoma is an aggressive tumor that carries a poor prognosis. C. Renal cell carcinoma with invasion of the IVC and retroperitoneal lymphadenopathy but no

distant metastases is considered stage IIIB. D. Oncocytomas are easily distinguished from renal cell carcinoma on imaging studies.

Rationale: A: Papillary renal cell carcinomas typically appear as hypovascular, often minimally enhancing lesions. B: Renal medullary carcinoma is an aggressive neoplasm which arises almost exclusively in patients with

sickle cell trait. C: According to the Robson system, renal cell carcinoma with both venous involvement and nodal

metastases is staged as 3C disease. D: While up to 33% of oncocytomas have a characteristic central stellate scar, this is not a pathognomonic

feature and these benign solid tumors are indistinguishable from renal cell carcinoma on imaging studies.

61. Concerning pheochromocytomas, which of the following statements is TRUE?

A. Greater than 90% are “light-bulb” bright on T2-weighted MR images. B. They are associated with multiple endocrine neoplasia (MEN) II and neurofibromatosis. C. Histologic analysis is used to determine the presence of malignancy. D. Cystic degeneration or necrosis is uncommon.

Rationale: A: Only about 65% of pheochromocytomas have high signal on T2 weighted images. B: Pheochromocytomas are associated with multiple syndromes, including MEN II and III,

neurofibromatosis, von Hippel Lindau disease, Carney triad and Sturge Weber syndrome. C: The only reliable indicator of malignancy in a pheochromocytoma is the presence of metastases. Tumor

characteristics such as mitotic rate, capsular invasion and size are not accurate predictors of malignancy.

D: Pheochromocytomas have a variable appearance on imaging studies and can demonstrate hemorrhagic, cystic or fatty change, necrosis and calcification.

62. Regarding development of nephrogenic systemic fibrosis (NSF) after administration of gadolinium-based contrast agents, which of the following statements is TRUE?

A. In patients on hemodialysis, current recommendations are for a dialysis session within 2 days of gadolinium administration.

B. Lowering the dose of gadolinium has no effect on the risk of developing NSF. C. There is minimal risk that a patient on peritoneal dialysis will develop NSF after gadolinium

administration. D. Patients with renal insufficiency who have had recent major surgery or major infection

are at increased risk. E. This is a self-limiting disease that responds well to corticosteroids.

Rationale: A: Although the effectiveness of hemodialysis in preventing NSF is unknown, aggressive dialysis is

recommended to clear gadolinium from the bloodstream. Current recommendations are for 2 dialysis sessions within 24 hours of gadolinium administration.

B: Lowering dose most likely has a protective effect against NSF as studies have shown that renal failure patients receiving a double dose of gadolinium are much more at risk than in patients receiving a single dose.

C: Peritoneal dialysis (PD) is ineffective at clearing gadolinium (5ml/min) versus hemodialysis (64ml/min.) Gadolinium administration in patients on PD should be avoided.

D: Most patients with NSF have had some form of endothelial or vascular injury (such as surgery, thromboembolic event, vascular rejection, malignant hypertension), and up to 90% of patients have undergone some form of surgery (e.g. transplantation, fistula repair, other reconstructive vascular procedures), in addition to compromised renal function and exposure to gadolinium-based contrast agents.

E: NSF is a progressive, often severely debilitating disease that has been shown to involve visceral organs as well as the skin.

63. Regarding female urethral diverticula, which of the following statements is TRUE?

A. Twenty percent of patients have urinary incontinence. B. Most cases are congenital in origin. C. They often have a “saddle-bag” configuration. D. The most sensitive test is a voiding cystourethrography.

Rationale: A: 60% of patients have urinary incontinence. B: Most diverticula are the result of repeated infection of the periurethral glands. This results in abscess

formation and rupture into the urethra, thereby creating the diverticulum. 30-50% of patients have a history of recurrent urinary tract infections.

C: Urethral diverticula frequently have a characteristic "saddle-bag" shape, which can help identify it as originating from the urethra on imaging studies.

D: Voiding cystourethrography is not the most sensitive test for diverticula. MRI and voiding CT urethrography have much better sensitivity.

64. Regarding vesicoureteral reflux (VUR), which of the following statements is TRUE?

A. Of children who have a UTI, 25-50% have vesicoureteral reflux. B. For either radiographic or radionuclide cystography, a voiding study is unnecessary. C. Reflux nephropathy is characterized by calyceal blunting with normal thickness of overlying

renal cortex. D. Asymptomatic siblings of children with VUR are at 5% to 10% increased risk for VUR.

Rationale: A: Correct.

B: For either radiographic or radionuclide cystography, it is important to do a voiding study, to increase sensitivity for detection of vesicoureteral reflux.

C: Focal calyceal blunting or calyceal clubbing, with adjacent parenchymal thinning is the characteristic appearance of reflux nephropathy, or chronic atrophic pyelonephritis.

D: 26-51% of siblings will have VUR.

65. Regarding urinary diversions, which of the following statements is TRUE?

A. Small bowel obstruction is the most common early postoperative complication (within the first 30 days).

B. Urinary obstruction commonly occurs within the first 30 days. C. Parastomal hernias are a common late complication, with 10% requiring surgical repair. D. Ureteral strictures occur more commonly at the right ureteral anastomosis than at the left. E. Local tumor recurrence occurs fairly commonly (in approximately 50% of cases).

Rationale: A: Ileus is the most common post operative complication, affecting 18-23% of patients. B: Urinary obstruction is a late complication, not an early complication. C: Correct.

D: Stricture occurs on the left more than the right because of the angulation of the ureter. E: Tumor recurrence occurs locally in 3-16% of cases.

66. Which of the following findings is associated with in utero diethylstilbestrol (DES) exposure?

A. T-shaped uterine cavity B. Uterine didelphys C. Bicornuate uterus D. Renal agenesis

Rationale: A: Diethylstilbestrol was given to pregnant patients in the 1950's and 60's to prevent miscarriage. In

addition to the characteristic T-shaped uterine cavity seen on HSG and MRI, these patients can have generalized uterine hypoplasia, short strictures of the uterine corpus, vaginal and cervical carcinomas (esp. clear cell adenocarcinoma), and increased spontaneous abortion and premature birth.

B: This is not associated with in utero DES exposure. C: This is not associated with in utero DES exposure. D: DES exposure in utero is not associated with urinary tract abnormalities.