Adult renal cystic disease: a genetic, biological, and developmental primer.

Renal cystic diseases in adults are a heterogeneous group of disorders characterized by the presence of multiple cysts in the kidneys. These diseases may be categorized as hereditary, acquired, or developmental on the basis of their pathogenesis. Hereditary conditions include autosomal dominant polycystic kidney disease, medullary cystic kidney disease, von Hippel-Lindau disease, and tuberous sclerosis. Acquired conditions include cystic kidney disease, which develops in patients with end-stage renal disease. Developmental cystic diseases of the adult kidney include localized renal cystic disease, multicystic dysplastic kidney, and medullary sponge kidney. In recent years, many molecular and cellular mechanisms involved in the pathogenesis of renal cystic diseases have been identified. Hereditary renal cystic diseases are characterized by genetic mutations that lead to defects in the structure and function of the primary cilia of renal tubular epithelial cells, abnormal proliferation of tubular epithelium, and increased fluid secretion, all of which ultimately result in the development of renal cysts. A better understanding of these pathophysiologic mechanisms is now providing the basis for the development of more targeted therapeutic drugs for some of these disorders. Cross-sectional imaging provides useful information for diagnosis, surveillance, prognostication, and evaluation of treatment response in renal cystic diseases.

Direct intrahepatic cavo-portal shunts in Budd-Chiari syndrome: Role of simultaneous fluoroscopy and trans-abdominal ultrasonography.

BACKGROUND: Transjugular intrahepatic porto-systemic shunt (TIPS) for Budd-Chiari syndrome (BCS) can be inserted from inferior vena cava or hepatic vein to portal vein. The former is performed when hepatic veins are not suitable and is technically more challenging. METHODS: In this retrospective study, 7 patients with chronic BCS needed cavo-portal shunt as hepatic veins were neither amenable to plasty nor provided access for TIPS placement. Simultaneous fluoroscopic and trans-abdominal ultrasound guidance was used at the time of portal vein puncture. RESULTS: Technical success and clinical improvement were obtained in all patients. Median 3 (range 1-4) attempts were needed to puncture the portal vein. There were no significant complications. Uncovered stents were used in six patients and stent occlusion was common, but could be managed by re-intervention. CONCLUSION: Cavo-portal shunt is an effective technique for patients with BCS uncontrolled by medical therapy. Additional trans-abdominal ultrasound in oblique parasagittal plane keeps the procedure safe.

PET/CT illustration of metastatic breast cancer to the left mandibular foramen.

Mental nerve neuropathy (numb chin/lip syndrome) is a sensory neuropathy presenting with numbness in the distribution of the inferior alveolar nerve/mental nerve (chin and lower lip). This is typically unilateral and can be secondary to dental disease or malignancy. When caused by malignancy, these symptoms can be either an initial presentation of an unsuspected tumor or progressive metastatic disease, both of which would indicate poor prognosis. We describe a 48-year-old female patient with a history of breast cancer who presented with left chin numbness and manifested a metastatic lesion involving the left mandibular foramen on PET/CT and subsequent MRI.

The sea anchor technique: a novel method to aid in stent-assisted embolization of giant cerebral aneurysms.

Endovascular navigation past some large or giant intracranial aneurysms for the purpose of stent deployment can be difficult. Some of these lesions have a morphology which compels the operator to navigate through the aneurysm dome in order to gain distal access, a step which requires straightening of the delivery microcatheter before a stent can be deployed. In most patients this can be achieved by simply retracting the microcatheter and reducing the loop within the aneurysm. However, in certain patients the acute angle formed between aneurysm inflow and outflow tracts as well as the dynamics of tension within the microcatheter act together to prevent this from happening. Instead of retracting and straightening across the aneurysm neck, the microcatheter withdraws leaving the intra-aneurysm loop intact. This challenge can thwart attempts at stent placement and subsequent embolization. The authors describe a simple and safe technique to circumvent this problem, a way of stabilizing the distal tip of the microcatheter which they term the 'sea anchor'.

Somatostatin receptor molecular imaging for metastatic intracranial hemangiopericytoma.

Intracranial hemangiopericytomas (HPCs) are rare tumors that closely mimic meningiomas. However, in contrast to meningiomas, HPCs have a relatively high incidence of local recurrence and distant metastases, manifesting the need for sensitive noninvasive methods of detection that efficiently image the entire body. We present a rare case of a right optic nerve sheath HPC in which we identified a previously unknown distant metastasis in the thoracic spine on an 111In-pentetreotide scan. We detail the radiologic characteristics seen with somatostatin receptor imaging, FDG PET, and MRI and discuss how to exploit these findings to detect recurrence and metastatic disease in HPC.

Renal function outcomes for multifocal renal neoplasms managed by radiofrequency ablation.

PURPOSE: To evaluate renal function changes related to radiofrequency ablation (RFA) for the treatment of multifocal renal neoplasms. METHODS: This is an institutional review board-approved, Health Insurance Portability and Accountability Act compliant retrospective study of all patients treated with computed tomography guided RFA for multifocal renal neoplasms at one institution. Fifty-seven subjects, mean age 70 (range 37-88) years, underwent RFA of 169 renal neoplasms (average size 2.0 cm). Subjects had between 2 and 8 (mean 2.96) neoplasms ablated. Estimated glomerular filtration rate (eGFR) was measured before and after RFA. Complications related to RFA were recorded. RESULTS: eGFR decreased on average of 4.4 % per tumor treated and 6.7 % per ablation session (average 1.76 tumors treated per session). For subjects with the largest neoplasm measuring >3 cm, eGFR decreased an average of 14.5 % during the course of their treatment. If the largest neoplasm measured 2-3 cm, eGFR decreased an average of 7.7 %, and if the largest neoplasm measured <2 cm, eGFR decreased an average of 3.8 %. Subjects with reduced baseline renal function were more likely to have a greater decline in eGFR after RFA. There was a minor complication rate of 6.3 % (6 of 96 sessions), none of which required treatment, and a major complication rate of 4.2 % (4 of 96 sessions). CONCLUSION: RFA for the treatment of multifocal renal neoplasms results in mild decline of renal function.

Evolution of a ureteric stone from the renal pelvis to the ureter on skeletal scintigraphy with CT correlation.

Because bone-seeking radiopharmaceuticals are excreted into the urine by the kidneys, normal kidneys and bladder are well visualized on skeletal scintigrams leading to incidental detection of urinary tract abnormalities in up to 15% of bone scans. Although the findings pertaining to the urinary tract on skeletal scintigraphy are seldom suggestive of a definitive diagnosis, they are highly specific for renal disease, with fewer than 2% false-positive studies reported. In the presented case, we demonstrate the evolution of a ureteric stone from the renal pelvis into the ureter on sequential skeletal scintigraphy with CT correlation.