Utilization and cost effectiveness review of shunt series to rule out ventriculoperitoneal shunt malfunction

Purpose: To evaluate the usefulness of the conventional radiographic shunt series in the initial work-up of patients suspected of having ventriculoperitoneal shunt malfunction, and to describe an imaging work-up algorithm. Methods: Charts of 33 patients with shunt series were retrieved from medical records and reviewed. Twelve patients were excluded either because there was no head CT scan done at the time of the shunt series or because the studies were done immediately postoperatively. The remaining 21 patients had a total of 67 shunt series and head CT scans performed to rule out shunt malfunction. Patients' age range was 8 months to 81 years. There were 9 female and 12 male patients. Only three patients were more than 17 years old. Results: In 12/67 cases (18 %) the CT demonstrated normal-size ventricles. In none of these cases did the patients undergo shunt revision. Of the cases where there was an abnormal CT result, 22/67 (33 %) showed increasing hydrocephalus, 5 (7 %) showed enlarged ventricles with no comparison study, and 28 (42 %) showed stable enlarged ventricles. The shunt was revised in 22/67 (33 %) cases. No shunt series was interpreted as demonstrating abnormality of the shunt. Conclusion: Routine shunt series should not be the initial imaging study in the work-up of patients who present to rule out shunt malfunction. They may be helpful following CT and neurosurgical evaluation of those patients who are scheduled to undergo operative shunt revision.     

Transjugular Intrahepatic Portosystemic Shunt Placement in Patients with Cirrhosis and Concomitant Portal Vein Thrombosis

Purpose To determine the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) creation in patients with liver cirrhosis complicated by thrombosed portal vein. Methods This study reviewed 15 cases of TIPS creation in 15 cirrhotic patients with portal vein thrombosis at our institution over an 8-year period. There were 2 women and 13 men with a mean age of 53 years. Indications were refractory ascites, variceal hemorrhage, and refractory pleural effusion. Clinical follow-up was performed in all patients. Results The technical success rate was 75% (3/4) in patients with chronic portal vein thrombosis associated with cavernomatous transformation and 91% (10/11) in patients with acute thrombosis or partial thrombosis, giving an overall success rate of 87%. Complications included postprocedural encephalopathy and localized hematoma at the access site. In patients with successful shunt placement, the total follow-up time was 223 months. The 30-day mortality rate was 13%. Two patients underwent liver transplantation at 35 days and 7 months, respectively, after TIPS insertion. One patient had an occluded shunt at 4 months with an unsuccessful revision. The remaining patients had functioning shunts at follow-up. Conclusion TIPS creation in thrombosed portal vein is possible and might be a treatment option in certain patients.     

Periventricular leukomalacia in combination with intraventricular hemorrhage: sonographic features and sequelae

Periventricular leukomalacia (PVL) is well recognized as a relatively uncommon yet particularly serious complication of prematurity. Although the sonographic features of PVL have been described, its association with intraventricular hemorrhage (IVH) has not been emphasized. Reviewing 26 consecutive cases of PVL in neonates of 34 weeks or less gestational age, significant associated hemorrhage was found in six (23%). Small quantities of blood were also noted in most of the other 20 infants. Of the six infants with both significant IVH and PVL, five required ventricular shunt and all had particularly poor clinical outcomes. In the neonates who required surgical intervention, rapid ventricular enlargement was accompanied by extensive periventricular cyst formation. Eventually, the septations within the cysts and frequently even the ependyma of superior/posterior lateral ventricles degenerated. Cysts merged imperceptibly with the ventricles giving an appearance that mimicked severe hydrocephalus. This was termed "pseudoventricle formation," as the large intracerebral cerebrospinal fluid spaces are primarily porencephaly and not enlarged ventricles. Response to shunting was minimal by sonography in all five cases and multiple shunt revisions were required in four. Clinical follow-up in children with significant IVH in combination with PVL has shown severe mental retardation and tetraplegia in all cases.     

18F-FDG PET与99Tcm-MDP骨扫描诊断肿瘤骨转移的比较分析

目的:探讨18F-FDG PET显像对于肿瘤骨转移的诊断价值,并与99Tcm-MDP骨显像进行对比分析。方法:97例肿瘤及疑诊为肿瘤的患者在30天内先后行18F-FDG PET-CT及99Tcm-MDP骨扫描,对比分析两者的显像结果。结果:97例中经临床和病理确诊基于病例分析,为骨转移63例,62例18F-FDG PET显像阳性,1例假阴性;99Tcm-MDP骨显像阳性49例,假阴性14例,两者敏感度分别为98.4%和77.8%,差异有显著性意义(P<0.05);34例为阴性患者,其中PET显像阴性29例、假阳性5例,骨显像阴性21例、假阳性13例,两者的特异度为85.3%和61.8%(P>0.05),符合率为93.8%和72.2%(P<0.05)。基于病灶分析,97例中共分析1261个骨骼区,骨转移存在于226个骨骼区,剔除不能定性的14个区,18F-FDG PET显像阳性222个区,假阴性4个区;而骨扫描显像阳性154个区,假阴性72个区;两者的敏感度分别为98.7%和68.1%,差异有显著性意义(P<0.05)。1021个阴性区,其中18F-FDGPET显像为阴性1010个区,假阳性11个区;骨扫描显像阴性1001个区,假阳性20个区;两者特异度分别为98.9%和98.0%,差异无统计学意义(P>0.05)。18F-FDG PET的诊断符合率为98.8%,骨显像为92.6%,两者差异有显著性意义(P<0.05)。以CT表现分组,溶骨性病灶和CT上无明显异常改变病灶的FDG PET和骨扫描的检出率分别为99.4%和72.6%及81.5%和40.7%,差异有显著性意义(P<0.05)。结论:18F-FDG PET诊断敏感度及准确性均高于骨扫描对溶骨病灶和CT上无明显改变病灶的检出优于骨扫描。     

Factor analysis of gated cardiac blood-pool data: application to patients with congenital heart disease.

Ventricular emptying was evaluated in patients with congenital heart disease (CHD) with left-to-right (L-R) shunt by factor analysis of gated equilibrium radionuclide angiography. In 36 (95%) of 38 ventricular septal defect patients and 20 (95%) of 21 atrial septal defect patients with small L-R shunt (pulmonary to systemic blood flow, Qp/Qs less than or equal to 2.5), as well as all patent ductus arteriosus patients, two significant cardiac factors corresponding to the ventricles (ventricular factor) and the atria plus large vessels (atrial factor) were extracted. However, in all of nine ventricular septal defect patients with large L-R shunt (Qp/Qs greater than 2.5), two different ventricular factors were determined which corresponded to the right and left ventricles (RV and LV). The RV factor showed a delay of ejection phase compared with the LV factor, and the delay was correlated with the value of Qp/Qs (r = 0.82, P less than 0.01). In eight (80%) of 10 ASD patients with large L-R shunt (Qp/Qs greater than 2.5), RV was described by the two different ventricular factors located in the septal and free-wall regions. The LV was extracted in the same factor as that located in the septal region of RV. This study demonstrates the capability of factor analysis in the pathophysiological investigation of CDH with L-R shunt.     

Cerebrospinal fluid flow in children with normal and dilated ventricles studied by MR imaging

Purpose: To quantify the cerebrospinal fluid (CSF) dynamics in the aqueduct of children with normal and dilated ventricles using MR phase-contrast technique.Material and Methods: Eighteen patients (6 months to 17 years of age) with various neurological symptoms underwent routine brain MR imaging and CSF flow measurement in the aqueduct. Nine patients had normal ventricles, 5 had dilated ventricles and 4 had a ventriculoperitoneal shunt.Results: The CSF velocity and flow rates in the aqueduct in patients with normal and dilated ventricles showed marked inter-individual variation and clear overlap. In a patient with tight aqueductal stenosis and increased ventricular pressure, pronounced CSF flow in the aqueduct was measured. Absence of flow in another patient with aqueductal stenosis was detected. Measurable although low flow in the aqueduct in 4 patients with a ventriculoperitoneal shunt was found.Conclusion: Quantitative phase MR flow measurement in the aqueduct demonstrated aqueductal stenosis; these patients had either pronounced flow or no flow in the aqueduct.     

Common occurrence of benign liver lesions in patients with newly diagnosed breast cancer investigated by MRI for suspected liver metastases.

The purpose of this study was to determine the prevalence of benign liver lesions in patients with breast cancer who are referred to magnetic resonance (MR) imaging for suspected breast cancer metastases at initial presentation. The original MR imaging reports of consecutive patients with breast cancer were reviewed; these patients had undergone MR imaging at our institution to investigate for suspected breast cancer liver metastases, at initial presentation between April 1993 and May 1998. Determination of the presence of benign and malignant liver lesions in each patient was made, as well as their relative frequencies. Diagnostic accuracy of MR imaging was evaluated by correlation with histologic specimens (5 patients) and imaging follow-up (27 patients). Thirty-four patients with newly diagnosed breast carcinoma were evaluated with MR imaging. A total of 11 (32%) of these patients had benign lesions only. Of 21 (62%) total patients who had malignant liver lesions, 19 had breast cancer metastases (2 had coexistent benign lesions), 1 had metastatic carcinoid, and 1 had hepatocellular carcinoma. No liver lesions were detected in two patients (6%). In one patient with biopsy-proven subcentimeter breast metastases, no focal lesions were shown on MR imaging. No other diagnostic errors in classification of liver lesions by MR imaging occurred, as shown by clinical correlation and imaging follow-up in all patients. True positive detection of malignant liver lesion was 20/21, true negative was 13/13, false positive was 0/13, and false negative was 1/21, for a sensitivity of 95% and a specificity of 100% for the detection of malignant liver lesions. Benign liver lesions are common in breast cancer patients suspected clinically of having liver metastases. Benign lesions alone were observed in one-third of our patients. The high diagnostic accuracy of MR imaging in the evaluation of hepatic lesions underscores the value of this technique for baseline investigation of breast cancer patients with clinically suspected liver metastases, particularly patients in whom treatment approaches are dramatically affected by the presence of liver metastases. J. Magn. Reson. Imaging 1999;10:165-169.     

Comparison of Transthoracic Contrast Echocardiography with High-Resolution Chest CT after Embolization of Pulmonary Arteriovenous Malformation

PurposeTo compare postembolotherapy follow-up graded transthoracic contrast echocardiography (TTCE) and high-resolution computed tomography (CT) of the chest and to evaluate the use of graded TTCE in the early postembolic period.Materials and MethodsThirty-five patients (6 men and 29 women; mean age, 56 years; range, 27–78 years) presenting for postembolotherapy follow-up between 2017 and 2021 with concurrent high-resolution CT and graded TTCE were analyzed retrospectively. Untreated pulmonary arteriovenous malformations (PAVMs) with a feeding artery of ≥2 mm were considered treatable.ResultsNinety-four percent of patients (33 of 35) did not have treatable PAVMs on high-resolution CT. TTCE was negative for shunts (Grade 0) in 34% of patients (n = 12). Of patients with a TTCE positive for shunts (23 of 35, 66%), 83% had a Grade 1 shunt, 13% had a Grade 2 shunt, and 4% had a Grade 3 shunt. No patient with a Grade 0 or 1 shunt had a treatable PAVM on high-resolution CT. Of the 2 patients with PAVMs requiring treatment, one had a Grade 2 shunt and one had a Grade 3 shunt. TTCE grade was significantly associated with the presence of a treatable PAVM on high-resolution CT (P < .01).ConclusionsGraded TTCE predicts the need for repeat embolotherapy and does so reliably in the early postembolotherapy period. This suggests that graded TTCE can be utilized in the postembolotherapy period for surveillance, which has the potential to lead to a decrease in cumulative radiation in this patient population.     

Ventriculoperitoneal shunt function: evaluation by sonography

The function of ventriculoperitoneal shunts was evaluated by ultrasonography in 17 patients. In 10 of 15 patients with properly functioning shunts, a small amount of free intraperitoneal fluid was found. However, absence of demonstrable fluid did not reliably indicate shunt malfunction. No asymptomatic patients had large amounts of ascites or loculated fluid collections, both of which were considered pathologic in shunt patients.     

Ultrasound-Guided Fine-Needle Aspiration Biopsy of Thyroid Nodules Smaller Than 5 mm in the Maximum Diameter: Assessment of Efficacy and Pathological Findings

Objective

The aim of this study was to determine the efficacy of the use of an ultrasound-guided fine-needle aspiration biopsy (US-FNAB) to diagnose thyroid nodules smaller than 5 mm in the maximum diameter and to evaluate pathological findings of small thyroid malignancies.

Materials and Methods

From May 2007 to April 2008, we evaluated the findings of US-FNABs of small thyroid nodules less than 5 mm in the maximum diameter. The cytopathological findings were retrospectively reviewed and the diagnostic performance of the use of an US-FNAB was examined in all patients.

Results

Of 201 small thyroid nodules in 180 patients, there were 162 adequate specimens (81%). Among 180 patients, 75 patients underwent thyroid surgery and 50 malignant and 33 benign nodules were identified based on a pathological examination. All small malignant thyroid nodules were identified as papillary thyroid microcarcinomas (PTMCs). There were 34 (55%) true positive, 0 (0%) false positive, 23 (37%) true negative and five (8%) false negative results for malignancy after performing a first US-FNAB in 62 surgically confirmed nodules. The sensitivity (87%), specificity (100%), positive predictive value (100%), negative predictive value (82%), accuracy (92%), false positive rate (0%) and false negative rate (8%) for an US-FNAB were determined. In 23 patients with a primary PTMC, capsular invasion (9%, 2 of 23), a perithyroidal lymph node metastasis (30%, 7 of 23), the rate of multifocality (9%, 2 of 23) and bilaterality (4%, 1 of 23) were also determined.

Conclusion

An US-FNAB of thyroid nodules smaller than 5 mm in the maximum diameter is an effective diagnostic procedure.     

Normal pressure hydrocephalus: vascular white matter changes on MR images must not exclude patients from shunt surgery.

BACKGROUND AND PURPOSE: White matter changes such as periventricular hyperintensity (PVH) and deep white matter hyperintensity (DWMH) are associated with both periventricular edema and ischemic white matter degeneration. Their diagnostic and predictive value in normal pressure hydrocephalus (NPH) is unclear. To identify prognostically important changes, we classified PVH and DWMH at MR imaging in a large series of patients with NPH, before and after ventriculoperitoneal shunt surgery. METHODS: Axial proton density- and T2-weighted turbo spin-echo sequences and coronal T1-weighted sequences were performed on a 0.5-T imager in 34 patients with NPH, before and 3 months after shunt surgery. PVH at the anterior, central, and posterior thirds of the lateral ventricles was assessed on transaxial images with a semiquantitative five-step scale describing the extension (in mm) and shape of the PVH. DWMH was quantified with a four-step scale. The number of cortical and subcortical lacunar infarctions, the flow void sign, and the width of the third and lateral ventricles were registered. Gait ability, need for sleep, urinary incontinence, living conditions, and psychometric test performance were assessed pre- and postoperatively. RESULTS: After shunt surgery, 25 patients improved and nine did not. PVH, DWMH, and other MR imaging variables before shunting did not differ between groups, and no MR imaging variable could predict the clinical effect of shunt surgery. Postoperatively, the width of PVH was reduced in the improved patients, and clinical improvement correlated with reduction in PVH. Only the irregular type of PVH located at the frontal horns was reduced postoperatively. The presence of risk factors or MR imaging changes normally associated with cerebrovascular disease had no negative influence on the outcome of shunt surgery. CONCLUSION: The presence of DWMH or subcortical lacunar infarctions in NPH did not predict a poor outcome from shunt surgery and should not be used as exclusion criteria for shunting. No MR imaging findings could predict outcome of shunt surgery in patients with NPH. Clinical improvement after surgery is associated with reduction in the irregular type of PVH located around the frontal horns.     

Echographic study with high-frequency and high-spatial resolution transducer in the evaluation of renal transplant in pediatric age

PURPOSE: We investigated the role of power Doppler US with a high-frequency and high-resolution transducer (13 MHz) in the visualization of interlobular arterioles in patients with normally functioning renal transplants or with chronic rejection. MATERIAL AND METHODS: We examined 15 patients (mean age 15 years; range 10-18 years) with a General Electric 500 MD unit using 7.5 and 13 MHz linear transducers. In all the patients serum creatinine and diuresis were evaluated; 4 patients underwent US-guided biopsy that resulted in the diagnosis of chronic rejection. RESULTS: Normally functioning renal transplants were found in 11 patients and chronic rejection was seen in 4. In normally functioning renal transplants, interlobular vessels could be depicted as "cortical blush" with the 7.5 MHz transducer; in the same patients power Doppler US with the 13 MHz transducer permitted a correct evaluation of interlobular vessels that were arranged in series like a palisade. In chronic rejection power Doppler US with the 13 MHz transducer better depicted cortical vascularity and showed irregular, narrow arteries. CONCLUSION: Power Doppler US with a 13 MHz transducer is particularly useful in children after renal transplants due to their reduced tissutal thickness. The lateral resolution of 13 MHz transducers (< 0.3 mm) allows to separate interlobular vessels from each other and the high frequency of the probe can depict interlobular vessels in the peripheral cortex. The optimal visualization of cortical vascularity with a 13 MHz transducer allows early detection of chronic rejection.     

CT of functioning tumors of the pancreas

Thirty-three patients suspected of having a functioning tumor of the pancreas were studied with computed tomography (CT); 25 had angiographic studies also. Thirty-one cases were confirmed surgically; the other two were lost at follow-up and were excluded from the series. Of the 31 patients, 21 had insulinomas, five had Zollinger-Ellison syndrome, and five had assorted apudomas. CT was positive in 71% of the cases and negative in 29%; 22.6% of the studies were false negative and 6.4% were true negative. There were no false positives. Of the 21 patients with insulinomas, only one had false-negative CT and angiographic studies, caused by diffuse microadenomatosis. In one patient, two separate lesions of the pancreas were seen and identified correctly on both CT and angiography. All identified lesions smaller than 2 cm were seen only because of a hyperdensity on the enhanced CT scan. Lesions larger than 2 cm were identified either because their size distorted the pancreatic contour or because of their vascularity. The importance of proper CT technique using fast scanners and repeated bolus injections of contrast medium is stressed.     

Association between false negative hepatobiliary scans and initial gallbladder visualization after 30 min

We have reviewed the experience of our institution and the literature concerning the use of hepatobiliary scintigraphy for the diagnosis of acute cholecystitis. The aim of this study was to assess whether the hepatobiliary scintigraphic finding of initial gallbladder visualization within 30 min is a more reliable criterion for excluding acute cholecystitis than gallbladder visualization within 1 h after tracer injection. In our institution's consecutive series, 113 of 211 hepatobiliary studies had gallbladder visualization within 1 h. Gallbladder visualization time in this group had a log normal distribution, with gallbladder visualization occurring within 30 min in 107 of 113 (95%). Gallbladder visualization occurred between 31 and 60 min in only 6 (5%); nevertheless, our one false negative study came from this small subgroup of patient studies (P = 0.05). Review of the literature (1645 patients with iminodiacetic acid [99mTc-IDA] derivative studies) revealed 6 further timed false negative results with gallbladder visualization within 1 h. Of these studies, in 4 (67%) the gallbladder was visualized between 31 and 60 min and in only 2 before 30 min. One of these latter 2 patients had a rare anatomy. Analysis of the pooled institutional and literature data gave an estimated false negative rate of 21% if the gallbladder was visualized between 31 and 60 min. This was significantly higher (P less than 0.001) than the 0.5% false negative rate when the gallbladder was seen prior to 30 min, but similar to the false negative rate of 16% reported by Weissmann et al. for studies with initial visualization after 1 h.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous transluminal renal angioplasty of the solitary kidney]

We report on our experience with percutaneous transluminal angioplasty (PTA) of the renal artery in solitary kidney patients. PTA was performed on 31 subjects (mean age: 52 years): 7 had a solitary kidney because of nephrectomy and 24 had a solitary functioning kidney. Patients were selected with clinical and laboratory examinations first and then with angiography. PTA was employed to treat renal artery stenoses 60%-95% of the whole arterial lumen. The procedure has been considered technically successful in 29 cases, with 77%-33% reduction of the mean amount of stenosis. As to the clinical evaluation of the results, blood pressure and creatinine values variations were considered. Of the 25 patients on follow-up, 13 appeared to be treated (52%), 8 improved (32%) and 4 unchanged (18%). On the whole, we observed 5 complications (2 hematomas at the approach site, 1 intimal dissection and 2 segmental infarcts), with a 23.4% rate comparable with PTA complications in non-solitary kidney patients. The good revascularization, the reduction in blood pressure values, the very small percentage of complications point to PTA of the renal artery as the procedure of choice in solitary kidney patients.     

Percutaneous intervention in portosystemic shunts in Budd-Chiari syndrome.

Budd-Chiari syndrome is a rare, often fatal illness resulting from hepatic venous outflow obstruction. Surgically created portosystemic shunts are frequently necessary in these patients for portal decompression. Over the past 15 years, 30 patients have been surgically treated for this condition at the Johns Hopkins Hospital. Of the 22 long-term survivors (range, 6 months to 13 years), five (23%) have required further surgical intervention and five (23%) have required percutaneous intervention for shunt complications. Percutaneous procedures included angioplasty (n = 10), atherectomy (n = 1), and urokinase therapy (n = 1). Of the five patients treated percutaneously, one has died of complications from her disease. The remaining four have been followed up for a mean of 16.2 months (range, 5-31 months) and all are in stable condition. None of the five treated with percutaneous interventional procedures have required additional surgical procedures or shunt revisions. Although this series is small, the findings indicate that percutaneous intervention may play a strong adjunctive role to surgery in the treatment of selected patients with portosystemic shunt complications.     

Peritoneovenous Shunt Insertion for Intractable Ascites-A District General Hospital Experience

Ascites often contributes to patient morbidity and discomfort. When refractory to medical management, it has been managed with repeated paracentesis, implantable ports for drainage, or diversion to the urinary bladder. Peritoneovenous shunt insertion has been a technique that was traditionally performed only by surgeons but is now within the realm of interventional radiologists. Its advantage is that protein-rich ascitic fluid is returned to the intravascular compartment. This retrospective study elaborates on the successes and problems encountered during shunt insertion in our first 13 patients. Two patients are well with a functioning shunt at 14 and 32 weeks. In 6 the shunt functioned until the patients death from the underlying malignancy. Two required revision with variable success and in 2, shunt function could not be salvaged. There was one procedure-related mortality. Radiological insertion of these shunts is feasible and should be considered for selected patients. Options are available for assessment and salvaging of dysfunctional shunts.     

CT of malignant melanoma: patterns of small bowel and mesenteric involvement

Abdominal CT of 230 patients (310 CT examinations) with a diagnosis of malignant melanoma was retrospectively reviewed for the evaluation of small bowel and mesenteric involvement. Seventeen (7.4%) patients had evidence of small bowel and mesenteric involvement on CT. There were four distinct patterns of disease: (a) intraluminal masses in 3 patients; (b) ulcerating lesions in 2; (c) diffuse infiltration in 6; (d) implants in 10. Four patients had more than two patterns of involvement. Of the 10 patients with tumor implants, carcinomatosis was noted in 2. Two patients had intussusception and 4 had extensive mesenteric nodal involvement. Of the 17 patients, 12 (71%) had at least one symptom referable to the gastrointestinal tract, while 5 (29%) were clinically asymptomatic. Fourteen of the 17 patients (82%) had additional intraabdominal metastases to sites other than small bowel and mesentery.     

Percutaneous transluminal angioplasty of dialysis access shunts]

Sixteen balloon angioplasties were performed in 10 patients with upper-extremity dialysis access shunts. The initial success rate was 80% (12/15). Of the initial successes, 58% (7/12) were patent at six months and 13% (1/8) at one year. In nine cases, repeat PTA was necessary. The mean interval of patency was about four months. The longest interval was two and a half years. The complication of thrombosis of the loop shunt during PTA was successfully treated by fibrinolytic therapy.     

Cerebrospinal fluid flow in patients with dilated ventricles studied with MR imaging

The purpose of this study was to measure the cerebrospinal fluid (CSF) velocity and flow in the aqueduct in patients with wide ventricles with or without signs of normal pressure hydrocephalus (NPH) before and after shunt surgery. We studied 18 patients with wide ventricles with MRI and measured the CSF velocity values in the aqueducts. Twelve patients with the clinical triad of NPH were examined. Six patients were studied only before shunt surgery and 6 patients were studied both before and after shunt surgery. Three patients with wide ventricles without clinical triad of NPH, and 3 patients with hydrocephalus following subarachnoid hemorrhage were also examined. Seven NPH patients with hyperdynamic CSF flow and three NPH patients with normal CSF velocity and flow values showed a positive clinical response to shunt surgery. Two of the three patients with hydrocephalus and hyperdynamic CSF flow values in the aqueduct secondary to subarachnoid bleeding responded to shunt surgery. One patient with same disease and low CSF velocity and flow values did not respond. No change was detected in the CSF flow values of the aqueduct when measurements before and after shunt surgery were compared. Ventriculoperitoneal shunting does not change the CSF dynamics in the aqueduct. Received: 8 March 1999; Revised: 30 November 1999; Accepted: 23 February 2000